| /* |
| * Copyright 1988, 1989 Hans-J. Boehm, Alan J. Demers |
| * Copyright (c) 1991-1995 by Xerox Corporation. All rights reserved. |
| * Copyright (c) 1996-1999 by Silicon Graphics. All rights reserved. |
| * Copyright (c) 1999 by Hewlett-Packard Company. All rights reserved. |
| * |
| * THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED |
| * OR IMPLIED. ANY USE IS AT YOUR OWN RISK. |
| * |
| * Permission is hereby granted to use or copy this program |
| * for any purpose, provided the above notices are retained on all copies. |
| * Permission to modify the code and to distribute modified code is granted, |
| * provided the above notices are retained, and a notice that the code was |
| * modified is included with the above copyright notice. |
| */ |
| |
| # include "private/gc_priv.h" |
| # ifdef THREADS |
| # include "atomic_ops.h" |
| # endif |
| |
| # if defined(LINUX) && !defined(POWERPC) |
| # include <linux/version.h> |
| # if (LINUX_VERSION_CODE <= 0x10400) |
| /* Ugly hack to get struct sigcontext_struct definition. Required */ |
| /* for some early 1.3.X releases. Will hopefully go away soon. */ |
| /* in some later Linux releases, asm/sigcontext.h may have to */ |
| /* be included instead. */ |
| # define __KERNEL__ |
| # include <asm/signal.h> |
| # undef __KERNEL__ |
| # else |
| /* Kernels prior to 2.1.1 defined struct sigcontext_struct instead of */ |
| /* struct sigcontext. libc6 (glibc2) uses "struct sigcontext" in */ |
| /* prototypes, so we have to include the top-level sigcontext.h to */ |
| /* make sure the former gets defined to be the latter if appropriate. */ |
| # include <features.h> |
| # if 2 <= __GLIBC__ |
| # if 2 == __GLIBC__ && 0 == __GLIBC_MINOR__ |
| /* glibc 2.1 no longer has sigcontext.h. But signal.h */ |
| /* has the right declaration for glibc 2.1. */ |
| # include <sigcontext.h> |
| # endif /* 0 == __GLIBC_MINOR__ */ |
| # else /* not 2 <= __GLIBC__ */ |
| /* libc5 doesn't have <sigcontext.h>: go directly with the kernel */ |
| /* one. Check LINUX_VERSION_CODE to see which we should reference. */ |
| # include <asm/sigcontext.h> |
| # endif /* 2 <= __GLIBC__ */ |
| # endif |
| # endif |
| # if !defined(OS2) && !defined(PCR) && !defined(AMIGA) && !defined(MACOS) \ |
| && !defined(MSWINCE) |
| # include <sys/types.h> |
| # if !defined(MSWIN32) |
| # include <unistd.h> |
| # endif |
| # endif |
| |
| # include <stdio.h> |
| # if defined(MSWINCE) |
| # define SIGSEGV 0 /* value is irrelevant */ |
| # else |
| # include <signal.h> |
| # endif |
| |
| #ifdef UNIX_LIKE |
| # include <fcntl.h> |
| #endif |
| |
| #if defined(LINUX) || defined(LINUX_STACKBOTTOM) |
| # include <ctype.h> |
| #endif |
| |
| /* Blatantly OS dependent routines, except for those that are related */ |
| /* to dynamic loading. */ |
| |
| #ifdef AMIGA |
| # define GC_AMIGA_DEF |
| # include "AmigaOS.c" |
| # undef GC_AMIGA_DEF |
| #endif |
| |
| #if defined(MSWIN32) || defined(MSWINCE) || defined(CYGWIN32) |
| # define WIN32_LEAN_AND_MEAN |
| # define NOSERVICE |
| # include <windows.h> |
| /* It's not clear this is completely kosher under Cygwin. But it */ |
| /* allows us to get a working GC_get_stack_base. */ |
| #endif |
| |
| #ifdef MACOS |
| # include <Processes.h> |
| #endif |
| |
| #ifdef IRIX5 |
| # include <sys/uio.h> |
| # include <malloc.h> /* for locking */ |
| #endif |
| |
| #if defined(LINUX) || defined(FREEBSD) || defined(SOLARIS) || defined(IRIX5) \ |
| || defined(USE_MMAP) || defined(USE_MUNMAP) |
| # define MMAP_SUPPORTED |
| #endif |
| |
| #if defined(MMAP_SUPPORTED) || defined(ADD_HEAP_GUARD_PAGES) |
| # if defined(USE_MUNMAP) && !defined(USE_MMAP) |
| --> USE_MUNMAP requires USE_MMAP |
| # endif |
| # include <sys/types.h> |
| # include <sys/mman.h> |
| # include <sys/stat.h> |
| # include <errno.h> |
| #endif |
| |
| #ifdef DARWIN |
| /* for get_etext and friends */ |
| #include <mach-o/getsect.h> |
| #endif |
| |
| #ifdef DJGPP |
| /* Apparently necessary for djgpp 2.01. May cause problems with */ |
| /* other versions. */ |
| typedef long unsigned int caddr_t; |
| #endif |
| |
| #ifdef PCR |
| # include "il/PCR_IL.h" |
| # include "th/PCR_ThCtl.h" |
| # include "mm/PCR_MM.h" |
| #endif |
| |
| #if !defined(NO_EXECUTE_PERMISSION) |
| # define OPT_PROT_EXEC PROT_EXEC |
| #else |
| # define OPT_PROT_EXEC 0 |
| #endif |
| |
| #if defined(LINUX) && \ |
| (defined(USE_PROC_FOR_LIBRARIES) || defined(IA64) || !defined(SMALL_CONFIG)) |
| # define NEED_PROC_MAPS |
| #endif |
| |
| #ifdef NEED_PROC_MAPS |
| /* We need to parse /proc/self/maps, either to find dynamic libraries, */ |
| /* and/or to find the register backing store base (IA64). Do it once */ |
| /* here. */ |
| |
| #define READ read |
| |
| /* Repeatedly perform a read call until the buffer is filled or */ |
| /* we encounter EOF. */ |
| ssize_t GC_repeat_read(int fd, char *buf, size_t count) |
| { |
| ssize_t num_read = 0; |
| ssize_t result; |
| |
| while (num_read < count) { |
| result = READ(fd, buf + num_read, count - num_read); |
| if (result < 0) return result; |
| if (result == 0) break; |
| num_read += result; |
| } |
| return num_read; |
| } |
| |
| /* Determine the length of a file by incrementally reading it into a */ |
| /* This would be sily to use on a file supporting lseek, but Linux */ |
| /* /proc files usually do not. */ |
| size_t GC_get_file_len(int f) |
| { |
| size_t total = 0; |
| ssize_t result; |
| # define GET_FILE_LEN_BUF_SZ 500 |
| char buf[GET_FILE_LEN_BUF_SZ]; |
| |
| do { |
| result = read(f, buf, GET_FILE_LEN_BUF_SZ); |
| if (result == -1) return 0; |
| total += result; |
| } while (result > 0); |
| return total; |
| } |
| |
| size_t GC_get_maps_len(void) |
| { |
| int f = open("/proc/self/maps", O_RDONLY); |
| size_t result = GC_get_file_len(f); |
| close(f); |
| return result; |
| } |
| |
| /* |
| * Copy the contents of /proc/self/maps to a buffer in our address space. |
| * Return the address of the buffer, or zero on failure. |
| * This code could be simplified if we could determine its size |
| * ahead of time. |
| */ |
| char * GC_get_maps(void) |
| { |
| int f; |
| int result; |
| static char init_buf[1]; |
| static char *maps_buf = init_buf; |
| static size_t maps_buf_sz = 1; |
| size_t maps_size, old_maps_size = 0; |
| |
| /* The buffer is essentially static, so there must be a single client. */ |
| GC_ASSERT(I_HOLD_LOCK()); |
| |
| /* Note that in the presence of threads, the maps file can */ |
| /* essentially shrink asynchronously and unexpectedly as */ |
| /* threads that we already think of as dead release their */ |
| /* stacks. And there is no easy way to read the entire */ |
| /* file atomically. This is arguably a misfeature of the */ |
| /* /proc/.../maps interface. */ |
| |
| /* Since we dont believe the file can grow */ |
| /* asynchronously, it should suffice to first determine */ |
| /* the size (using lseek or read), and then to reread the */ |
| /* file. If the size is inconsistent we have to retry. */ |
| /* This only matters with threads enabled, and if we use */ |
| /* this to locate roots (not the default). */ |
| |
| /* Determine the initial size of /proc/self/maps. */ |
| /* Note that lseek doesn't work, at least as of 2.6.15. */ |
| # ifdef THREADS |
| maps_size = GC_get_maps_len(); |
| if (0 == maps_size) return 0; |
| # else |
| maps_size = 4000; /* Guess */ |
| # endif |
| |
| /* Read /proc/self/maps, growing maps_buf as necessary. */ |
| /* Note that we may not allocate conventionally, and */ |
| /* thus can't use stdio. */ |
| do { |
| while (maps_size >= maps_buf_sz) { |
| /* Grow only by powers of 2, since we leak "too small" buffers. */ |
| while (maps_size >= maps_buf_sz) maps_buf_sz *= 2; |
| maps_buf = GC_scratch_alloc(maps_buf_sz); |
| # ifdef THREADS |
| /* Recompute initial length, since we allocated. */ |
| /* This can only happen a few times per program */ |
| /* execution. */ |
| maps_size = GC_get_maps_len(); |
| if (0 == maps_size) return 0; |
| # endif |
| if (maps_buf == 0) return 0; |
| } |
| GC_ASSERT(maps_buf_sz >= maps_size + 1); |
| f = open("/proc/self/maps", O_RDONLY); |
| if (-1 == f) return 0; |
| # ifdef THREADS |
| old_maps_size = maps_size; |
| # endif |
| maps_size = 0; |
| do { |
| result = GC_repeat_read(f, maps_buf, maps_buf_sz-1); |
| if (result <= 0) return 0; |
| maps_size += result; |
| } while (result == maps_buf_sz-1); |
| close(f); |
| # ifdef THREADS |
| if (maps_size > old_maps_size) { |
| GC_err_printf("Old maps size = %d, new maps size = %d\n", |
| old_maps_size, maps_size); |
| ABORT("Unexpected asynchronous /proc/self/maps growth: " |
| "Unregistered thread?"); |
| } |
| # endif |
| } while (maps_size >= maps_buf_sz || maps_size < old_maps_size); |
| /* In the single-threaded case, the second clause is false. */ |
| maps_buf[maps_size] = '\0'; |
| |
| /* Apply fn to result. */ |
| return maps_buf; |
| } |
| |
| // |
| // GC_parse_map_entry parses an entry from /proc/self/maps so we can |
| // locate all writable data segments that belong to shared libraries. |
| // The format of one of these entries and the fields we care about |
| // is as follows: |
| // XXXXXXXX-XXXXXXXX r-xp 00000000 30:05 260537 name of mapping...\n |
| // ^^^^^^^^ ^^^^^^^^ ^^^^ ^^ |
| // start end prot maj_dev |
| // |
| // Note that since about august 2003 kernels, the columns no longer have |
| // fixed offsets on 64-bit kernels. Hence we no longer rely on fixed offsets |
| // anywhere, which is safer anyway. |
| // |
| |
| /* |
| * Assign various fields of the first line in buf_ptr to *start, *end, |
| * *prot, *maj_dev and *mapping_name. Mapping_name may be NULL. |
| * *prot and *mapping_name are assigned pointers into the original |
| * buffer. |
| */ |
| char *GC_parse_map_entry(char *buf_ptr, ptr_t *start, ptr_t *end, |
| char **prot, unsigned int *maj_dev, |
| char **mapping_name) |
| { |
| char *start_start, *end_start, *maj_dev_start; |
| char *p; |
| char *endp; |
| |
| if (buf_ptr == NULL || *buf_ptr == '\0') { |
| return NULL; |
| } |
| |
| p = buf_ptr; |
| while (isspace(*p)) ++p; |
| start_start = p; |
| GC_ASSERT(isxdigit(*start_start)); |
| *start = (ptr_t)strtoul(start_start, &endp, 16); p = endp; |
| GC_ASSERT(*p=='-'); |
| |
| ++p; |
| end_start = p; |
| GC_ASSERT(isxdigit(*end_start)); |
| *end = (ptr_t)strtoul(end_start, &endp, 16); p = endp; |
| GC_ASSERT(isspace(*p)); |
| |
| while (isspace(*p)) ++p; |
| GC_ASSERT(*p == 'r' || *p == '-'); |
| *prot = p; |
| /* Skip past protection field to offset field */ |
| while (!isspace(*p)) ++p; while (isspace(*p)) ++p; |
| GC_ASSERT(isxdigit(*p)); |
| /* Skip past offset field, which we ignore */ |
| while (!isspace(*p)) ++p; while (isspace(*p)) ++p; |
| maj_dev_start = p; |
| GC_ASSERT(isxdigit(*maj_dev_start)); |
| *maj_dev = strtoul(maj_dev_start, NULL, 16); |
| |
| if (mapping_name == 0) { |
| while (*p && *p++ != '\n'); |
| } else { |
| while (*p && *p != '\n' && *p != '/' && *p != '[') p++; |
| *mapping_name = p; |
| while (*p && *p++ != '\n'); |
| } |
| |
| return p; |
| } |
| |
| /* Try to read the backing store base from /proc/self/maps. */ |
| /* Return the bounds of the writable mapping with a 0 major device, */ |
| /* which includes the address passed as data. */ |
| /* Return FALSE if there is no such mapping. */ |
| GC_bool GC_enclosing_mapping(ptr_t addr, ptr_t *startp, ptr_t *endp) |
| { |
| char *prot; |
| ptr_t my_start, my_end; |
| unsigned int maj_dev; |
| char *maps = GC_get_maps(); |
| char *buf_ptr = maps; |
| |
| if (0 == maps) return(FALSE); |
| for (;;) { |
| buf_ptr = GC_parse_map_entry(buf_ptr, &my_start, &my_end, |
| &prot, &maj_dev, 0); |
| |
| if (buf_ptr == NULL) return FALSE; |
| if (prot[1] == 'w' && maj_dev == 0) { |
| if (my_end > addr && my_start <= addr) { |
| *startp = my_start; |
| *endp = my_end; |
| return TRUE; |
| } |
| } |
| } |
| return FALSE; |
| } |
| |
| /* Find the text(code) mapping for the library whose name starts with nm. */ |
| GC_bool GC_text_mapping(char *nm, ptr_t *startp, ptr_t *endp) |
| { |
| size_t nm_len = strlen(nm); |
| char *prot; |
| char *map_path; |
| ptr_t my_start, my_end; |
| unsigned int maj_dev; |
| char *maps = GC_get_maps(); |
| char *buf_ptr = maps; |
| |
| if (0 == maps) return(FALSE); |
| for (;;) { |
| buf_ptr = GC_parse_map_entry(buf_ptr, &my_start, &my_end, |
| &prot, &maj_dev, &map_path); |
| |
| if (buf_ptr == NULL) return FALSE; |
| if (prot[0] == 'r' && prot[1] == '-' && prot[2] == 'x' && |
| strncmp(nm, map_path, nm_len) == 0) { |
| *startp = my_start; |
| *endp = my_end; |
| return TRUE; |
| } |
| } |
| return FALSE; |
| } |
| |
| #ifdef IA64 |
| static ptr_t backing_store_base_from_proc(void) |
| { |
| ptr_t my_start, my_end; |
| if (!GC_enclosing_mapping(GC_save_regs_in_stack(), &my_start, &my_end)) { |
| if (GC_print_stats) { |
| GC_log_printf("Failed to find backing store base from /proc\n"); |
| } |
| return 0; |
| } |
| return my_start; |
| } |
| #endif |
| |
| #endif /* NEED_PROC_MAPS */ |
| |
| #if defined(SEARCH_FOR_DATA_START) |
| /* The I386 case can be handled without a search. The Alpha case */ |
| /* used to be handled differently as well, but the rules changed */ |
| /* for recent Linux versions. This seems to be the easiest way to */ |
| /* cover all versions. */ |
| |
| # if defined(LINUX) || defined(HURD) |
| /* Some Linux distributions arrange to define __data_start. Some */ |
| /* define data_start as a weak symbol. The latter is technically */ |
| /* broken, since the user program may define data_start, in which */ |
| /* case we lose. Nonetheless, we try both, prefering __data_start. */ |
| /* We assume gcc-compatible pragmas. */ |
| # pragma weak __data_start |
| extern int __data_start[]; |
| # pragma weak data_start |
| extern int data_start[]; |
| # endif /* LINUX */ |
| extern int _end[]; |
| |
| ptr_t GC_data_start; |
| |
| void GC_init_linux_data_start() |
| { |
| extern ptr_t GC_find_limit(ptr_t, GC_bool); |
| |
| # if defined(LINUX) || defined(HURD) |
| /* Try the easy approaches first: */ |
| if ((ptr_t)__data_start != 0) { |
| GC_data_start = (ptr_t)(__data_start); |
| return; |
| } |
| if ((ptr_t)data_start != 0) { |
| GC_data_start = (ptr_t)(data_start); |
| return; |
| } |
| # endif /* LINUX */ |
| GC_data_start = GC_find_limit((ptr_t)(_end), FALSE); |
| } |
| #endif |
| |
| # ifdef ECOS |
| |
| # ifndef ECOS_GC_MEMORY_SIZE |
| # define ECOS_GC_MEMORY_SIZE (448 * 1024) |
| # endif /* ECOS_GC_MEMORY_SIZE */ |
| |
| // FIXME: This is a simple way of allocating memory which is |
| // compatible with ECOS early releases. Later releases use a more |
| // sophisticated means of allocating memory than this simple static |
| // allocator, but this method is at least bound to work. |
| static char memory[ECOS_GC_MEMORY_SIZE]; |
| static char *brk = memory; |
| |
| static void *tiny_sbrk(ptrdiff_t increment) |
| { |
| void *p = brk; |
| |
| brk += increment; |
| |
| if (brk > memory + sizeof memory) |
| { |
| brk -= increment; |
| return NULL; |
| } |
| |
| return p; |
| } |
| #define sbrk tiny_sbrk |
| # endif /* ECOS */ |
| |
| #if (defined(NETBSD) || defined(OPENBSD)) && defined(__ELF__) |
| ptr_t GC_data_start; |
| |
| void GC_init_netbsd_elf(void) |
| { |
| extern ptr_t GC_find_limit(ptr_t, GC_bool); |
| extern char **environ; |
| /* This may need to be environ, without the underscore, for */ |
| /* some versions. */ |
| GC_data_start = GC_find_limit((ptr_t)&environ, FALSE); |
| } |
| #endif |
| |
| # ifdef OS2 |
| |
| # include <stddef.h> |
| |
| # if !defined(__IBMC__) && !defined(__WATCOMC__) /* e.g. EMX */ |
| |
| struct exe_hdr { |
| unsigned short magic_number; |
| unsigned short padding[29]; |
| long new_exe_offset; |
| }; |
| |
| #define E_MAGIC(x) (x).magic_number |
| #define EMAGIC 0x5A4D |
| #define E_LFANEW(x) (x).new_exe_offset |
| |
| struct e32_exe { |
| unsigned char magic_number[2]; |
| unsigned char byte_order; |
| unsigned char word_order; |
| unsigned long exe_format_level; |
| unsigned short cpu; |
| unsigned short os; |
| unsigned long padding1[13]; |
| unsigned long object_table_offset; |
| unsigned long object_count; |
| unsigned long padding2[31]; |
| }; |
| |
| #define E32_MAGIC1(x) (x).magic_number[0] |
| #define E32MAGIC1 'L' |
| #define E32_MAGIC2(x) (x).magic_number[1] |
| #define E32MAGIC2 'X' |
| #define E32_BORDER(x) (x).byte_order |
| #define E32LEBO 0 |
| #define E32_WORDER(x) (x).word_order |
| #define E32LEWO 0 |
| #define E32_CPU(x) (x).cpu |
| #define E32CPU286 1 |
| #define E32_OBJTAB(x) (x).object_table_offset |
| #define E32_OBJCNT(x) (x).object_count |
| |
| struct o32_obj { |
| unsigned long size; |
| unsigned long base; |
| unsigned long flags; |
| unsigned long pagemap; |
| unsigned long mapsize; |
| unsigned long reserved; |
| }; |
| |
| #define O32_FLAGS(x) (x).flags |
| #define OBJREAD 0x0001L |
| #define OBJWRITE 0x0002L |
| #define OBJINVALID 0x0080L |
| #define O32_SIZE(x) (x).size |
| #define O32_BASE(x) (x).base |
| |
| # else /* IBM's compiler */ |
| |
| /* A kludge to get around what appears to be a header file bug */ |
| # ifndef WORD |
| # define WORD unsigned short |
| # endif |
| # ifndef DWORD |
| # define DWORD unsigned long |
| # endif |
| |
| # define EXE386 1 |
| # include <newexe.h> |
| # include <exe386.h> |
| |
| # endif /* __IBMC__ */ |
| |
| # define INCL_DOSEXCEPTIONS |
| # define INCL_DOSPROCESS |
| # define INCL_DOSERRORS |
| # define INCL_DOSMODULEMGR |
| # define INCL_DOSMEMMGR |
| # include <os2.h> |
| |
| |
| /* Disable and enable signals during nontrivial allocations */ |
| |
| void GC_disable_signals(void) |
| { |
| ULONG nest; |
| |
| DosEnterMustComplete(&nest); |
| if (nest != 1) ABORT("nested GC_disable_signals"); |
| } |
| |
| void GC_enable_signals(void) |
| { |
| ULONG nest; |
| |
| DosExitMustComplete(&nest); |
| if (nest != 0) ABORT("GC_enable_signals"); |
| } |
| |
| |
| # else |
| |
| # if !defined(PCR) && !defined(AMIGA) && !defined(MSWIN32) \ |
| && !defined(MSWINCE) \ |
| && !defined(MACOS) && !defined(DJGPP) && !defined(DOS4GW) \ |
| && !defined(NOSYS) && !defined(ECOS) |
| |
| # if 0 |
| /* Use the traditional BSD interface */ |
| # define SIGSET_T int |
| # define SIG_DEL(set, signal) (set) &= ~(sigmask(signal)) |
| # define SIG_FILL(set) (set) = 0x7fffffff |
| /* Setting the leading bit appears to provoke a bug in some */ |
| /* longjmp implementations. Most systems appear not to have */ |
| /* a signal 32. */ |
| # define SIGSETMASK(old, new) (old) = sigsetmask(new) |
| # endif |
| |
| /* Use POSIX/SYSV interface */ |
| # define SIGSET_T sigset_t |
| # define SIG_DEL(set, signal) sigdelset(&(set), (signal)) |
| # define SIG_FILL(set) sigfillset(&set) |
| # define SIGSETMASK(old, new) sigprocmask(SIG_SETMASK, &(new), &(old)) |
| |
| |
| static GC_bool mask_initialized = FALSE; |
| |
| static SIGSET_T new_mask; |
| |
| static SIGSET_T old_mask; |
| |
| static SIGSET_T dummy; |
| |
| #if defined(GC_ASSERTIONS) && !defined(THREADS) |
| # define CHECK_SIGNALS |
| int GC_sig_disabled = 0; |
| #endif |
| |
| void GC_disable_signals(void) |
| { |
| if (!mask_initialized) { |
| SIG_FILL(new_mask); |
| |
| SIG_DEL(new_mask, SIGSEGV); |
| SIG_DEL(new_mask, SIGILL); |
| SIG_DEL(new_mask, SIGQUIT); |
| # ifdef SIGBUS |
| SIG_DEL(new_mask, SIGBUS); |
| # endif |
| # ifdef SIGIOT |
| SIG_DEL(new_mask, SIGIOT); |
| # endif |
| # ifdef SIGEMT |
| SIG_DEL(new_mask, SIGEMT); |
| # endif |
| # ifdef SIGTRAP |
| SIG_DEL(new_mask, SIGTRAP); |
| # endif |
| mask_initialized = TRUE; |
| } |
| # ifdef CHECK_SIGNALS |
| if (GC_sig_disabled != 0) ABORT("Nested disables"); |
| GC_sig_disabled++; |
| # endif |
| SIGSETMASK(old_mask,new_mask); |
| } |
| |
| void GC_enable_signals(void) |
| { |
| # ifdef CHECK_SIGNALS |
| if (GC_sig_disabled != 1) ABORT("Unmatched enable"); |
| GC_sig_disabled--; |
| # endif |
| SIGSETMASK(dummy,old_mask); |
| } |
| |
| # endif /* !PCR */ |
| |
| # endif /*!OS/2 */ |
| |
| /* Ivan Demakov: simplest way (to me) */ |
| #if defined (DOS4GW) |
| void GC_disable_signals() { } |
| void GC_enable_signals() { } |
| #endif |
| |
| /* Find the page size */ |
| word GC_page_size; |
| |
| # if defined(MSWIN32) || defined(MSWINCE) |
| void GC_setpagesize(void) |
| { |
| GetSystemInfo(&GC_sysinfo); |
| GC_page_size = GC_sysinfo.dwPageSize; |
| } |
| |
| # else |
| # if defined(MPROTECT_VDB) || defined(PROC_VDB) || defined(USE_MMAP) |
| void GC_setpagesize(void) |
| { |
| GC_page_size = GETPAGESIZE(); |
| } |
| # else |
| /* It's acceptable to fake it. */ |
| void GC_setpagesize(void) |
| { |
| GC_page_size = HBLKSIZE; |
| } |
| # endif |
| # endif |
| |
| /* |
| * Find the base of the stack. |
| * Used only in single-threaded environment. |
| * With threads, GC_mark_roots needs to know how to do this. |
| * Called with allocator lock held. |
| */ |
| # if defined(MSWIN32) || defined(MSWINCE) || defined(CYGWIN32) |
| # define is_writable(prot) ((prot) == PAGE_READWRITE \ |
| || (prot) == PAGE_WRITECOPY \ |
| || (prot) == PAGE_EXECUTE_READWRITE \ |
| || (prot) == PAGE_EXECUTE_WRITECOPY) |
| /* Return the number of bytes that are writable starting at p. */ |
| /* The pointer p is assumed to be page aligned. */ |
| /* If base is not 0, *base becomes the beginning of the */ |
| /* allocation region containing p. */ |
| word GC_get_writable_length(ptr_t p, ptr_t *base) |
| { |
| MEMORY_BASIC_INFORMATION buf; |
| word result; |
| word protect; |
| |
| result = VirtualQuery(p, &buf, sizeof(buf)); |
| if (result != sizeof(buf)) ABORT("Weird VirtualQuery result"); |
| if (base != 0) *base = (ptr_t)(buf.AllocationBase); |
| protect = (buf.Protect & ~(PAGE_GUARD | PAGE_NOCACHE)); |
| if (!is_writable(protect)) { |
| return(0); |
| } |
| if (buf.State != MEM_COMMIT) return(0); |
| return(buf.RegionSize); |
| } |
| |
| int GC_get_stack_base(struct GC_stack_base *sb) |
| { |
| int dummy; |
| ptr_t sp = (ptr_t)(&dummy); |
| ptr_t trunc_sp = (ptr_t)((word)sp & ~(GC_page_size - 1)); |
| word size = GC_get_writable_length(trunc_sp, 0); |
| |
| sb -> mem_base = trunc_sp + size; |
| return GC_SUCCESS; |
| } |
| |
| #define HAVE_GET_STACK_BASE |
| |
| /* This is always called from the main thread. */ |
| ptr_t GC_get_main_stack_base(void) |
| { |
| struct GC_stack_base sb; |
| |
| GC_get_stack_base(&sb); |
| return (ptr_t)sb.mem_base; |
| } |
| |
| # endif /* MS Windows */ |
| |
| # ifdef BEOS |
| # include <kernel/OS.h> |
| ptr_t GC_get_main_stack_base(void){ |
| thread_info th; |
| get_thread_info(find_thread(NULL),&th); |
| return th.stack_end; |
| } |
| # endif /* BEOS */ |
| |
| |
| # ifdef OS2 |
| |
| ptr_t GC_get_main_stack_base(void) |
| { |
| PTIB ptib; |
| PPIB ppib; |
| |
| if (DosGetInfoBlocks(&ptib, &ppib) != NO_ERROR) { |
| GC_err_printf("DosGetInfoBlocks failed\n"); |
| ABORT("DosGetInfoBlocks failed\n"); |
| } |
| return((ptr_t)(ptib -> tib_pstacklimit)); |
| } |
| |
| # endif /* OS2 */ |
| |
| # ifdef AMIGA |
| # define GC_AMIGA_SB |
| # include "AmigaOS.c" |
| # undef GC_AMIGA_SB |
| # endif /* AMIGA */ |
| |
| # if defined(NEED_FIND_LIMIT) || defined(UNIX_LIKE) |
| |
| typedef void (*handler)(int); |
| |
| # if defined(SUNOS5SIGS) || defined(IRIX5) || defined(OSF1) \ |
| || defined(HURD) || defined(NETBSD) |
| static struct sigaction old_segv_act; |
| # if defined(_sigargs) /* !Irix6.x */ || defined(HPUX) \ |
| || defined(HURD) || defined(NETBSD) |
| static struct sigaction old_bus_act; |
| # endif |
| # else |
| static handler old_segv_handler, old_bus_handler; |
| # endif |
| |
| void GC_set_and_save_fault_handler(handler h) |
| { |
| # if defined(SUNOS5SIGS) || defined(IRIX5) \ |
| || defined(OSF1) || defined(HURD) || defined(NETBSD) |
| struct sigaction act; |
| |
| act.sa_handler = h; |
| # if 0 /* Was necessary for Solaris 2.3 and very temporary */ |
| /* NetBSD bugs. */ |
| act.sa_flags = SA_RESTART | SA_NODEFER; |
| # else |
| act.sa_flags = SA_RESTART; |
| # endif |
| |
| (void) sigemptyset(&act.sa_mask); |
| # ifdef GC_IRIX_THREADS |
| /* Older versions have a bug related to retrieving and */ |
| /* and setting a handler at the same time. */ |
| (void) sigaction(SIGSEGV, 0, &old_segv_act); |
| (void) sigaction(SIGSEGV, &act, 0); |
| # else |
| (void) sigaction(SIGSEGV, &act, &old_segv_act); |
| # if defined(IRIX5) && defined(_sigargs) /* Irix 5.x, not 6.x */ \ |
| || defined(HPUX) || defined(HURD) || defined(NETBSD) |
| /* Under Irix 5.x or HP/UX, we may get SIGBUS. */ |
| /* Pthreads doesn't exist under Irix 5.x, so we */ |
| /* don't have to worry in the threads case. */ |
| (void) sigaction(SIGBUS, &act, &old_bus_act); |
| # endif |
| # endif /* GC_IRIX_THREADS */ |
| # else |
| old_segv_handler = signal(SIGSEGV, h); |
| # ifdef SIGBUS |
| old_bus_handler = signal(SIGBUS, h); |
| # endif |
| # endif |
| } |
| # endif /* NEED_FIND_LIMIT || UNIX_LIKE */ |
| |
| # if defined(NEED_FIND_LIMIT) || \ |
| defined(USE_PROC_FOR_LIBRARIES) && defined(THREADS) |
| /* Some tools to implement HEURISTIC2 */ |
| # define MIN_PAGE_SIZE 256 /* Smallest conceivable page size, bytes */ |
| |
| /*ARGSUSED*/ |
| void GC_fault_handler(int sig) |
| { |
| LONGJMP(GC_jmp_buf, 1); |
| } |
| |
| void GC_setup_temporary_fault_handler(void) |
| { |
| /* Handler is process-wide, so this should only happen in */ |
| /* one thread at a time. */ |
| GC_ASSERT(I_HOLD_LOCK()); |
| GC_set_and_save_fault_handler(GC_fault_handler); |
| } |
| |
| void GC_reset_fault_handler(void) |
| { |
| # if defined(SUNOS5SIGS) || defined(IRIX5) \ |
| || defined(OSF1) || defined(HURD) || defined(NETBSD) |
| (void) sigaction(SIGSEGV, &old_segv_act, 0); |
| # if defined(IRIX5) && defined(_sigargs) /* Irix 5.x, not 6.x */ \ |
| || defined(HPUX) || defined(HURD) || defined(NETBSD) |
| (void) sigaction(SIGBUS, &old_bus_act, 0); |
| # endif |
| # else |
| (void) signal(SIGSEGV, old_segv_handler); |
| # ifdef SIGBUS |
| (void) signal(SIGBUS, old_bus_handler); |
| # endif |
| # endif |
| } |
| |
| /* Return the first nonaddressible location > p (up) or */ |
| /* the smallest location q s.t. [q,p) is addressable (!up). */ |
| /* We assume that p (up) or p-1 (!up) is addressable. */ |
| /* Requires allocation lock. */ |
| ptr_t GC_find_limit_with_bound(ptr_t p, GC_bool up, ptr_t bound) |
| { |
| static volatile ptr_t result; |
| /* Safer if static, since otherwise it may not be */ |
| /* preserved across the longjmp. Can safely be */ |
| /* static since it's only called with the */ |
| /* allocation lock held. */ |
| |
| GC_ASSERT(I_HOLD_LOCK()); |
| GC_setup_temporary_fault_handler(); |
| if (SETJMP(GC_jmp_buf) == 0) { |
| result = (ptr_t)(((word)(p)) |
| & ~(MIN_PAGE_SIZE-1)); |
| for (;;) { |
| if (up) { |
| result += MIN_PAGE_SIZE; |
| if (result >= bound) return bound; |
| } else { |
| result -= MIN_PAGE_SIZE; |
| if (result <= bound) return bound; |
| } |
| GC_noop1((word)(*result)); |
| } |
| } |
| GC_reset_fault_handler(); |
| if (!up) { |
| result += MIN_PAGE_SIZE; |
| } |
| return(result); |
| } |
| |
| ptr_t GC_find_limit(ptr_t p, GC_bool up) |
| { |
| if (up) { |
| return GC_find_limit_with_bound(p, up, (ptr_t)(word)(-1)); |
| } else { |
| return GC_find_limit_with_bound(p, up, 0); |
| } |
| } |
| # endif |
| |
| #if defined(ECOS) || defined(NOSYS) |
| ptr_t GC_get_main_stack_base(void) |
| { |
| return STACKBOTTOM; |
| } |
| #endif |
| |
| #ifdef HPUX_STACKBOTTOM |
| |
| #include <sys/param.h> |
| #include <sys/pstat.h> |
| |
| ptr_t GC_get_register_stack_base(void) |
| { |
| struct pst_vm_status vm_status; |
| |
| int i = 0; |
| while (pstat_getprocvm(&vm_status, sizeof(vm_status), 0, i++) == 1) { |
| if (vm_status.pst_type == PS_RSESTACK) { |
| return (ptr_t) vm_status.pst_vaddr; |
| } |
| } |
| |
| /* old way to get the register stackbottom */ |
| return (ptr_t)(((word)GC_stackbottom - BACKING_STORE_DISPLACEMENT - 1) |
| & ~(BACKING_STORE_ALIGNMENT - 1)); |
| } |
| |
| #endif /* HPUX_STACK_BOTTOM */ |
| |
| #ifdef LINUX_STACKBOTTOM |
| |
| #include <sys/types.h> |
| #include <sys/stat.h> |
| |
| # define STAT_SKIP 27 /* Number of fields preceding startstack */ |
| /* field in /proc/self/stat */ |
| |
| #ifdef USE_LIBC_PRIVATES |
| # pragma weak __libc_stack_end |
| extern ptr_t __libc_stack_end; |
| #endif |
| |
| # ifdef IA64 |
| # ifdef USE_LIBC_PRIVATES |
| # pragma weak __libc_ia64_register_backing_store_base |
| extern ptr_t __libc_ia64_register_backing_store_base; |
| # endif |
| |
| ptr_t GC_get_register_stack_base(void) |
| { |
| ptr_t result; |
| |
| # ifdef USE_LIBC_PRIVATES |
| if (0 != &__libc_ia64_register_backing_store_base |
| && 0 != __libc_ia64_register_backing_store_base) { |
| /* Glibc 2.2.4 has a bug such that for dynamically linked */ |
| /* executables __libc_ia64_register_backing_store_base is */ |
| /* defined but uninitialized during constructor calls. */ |
| /* Hence we check for both nonzero address and value. */ |
| return __libc_ia64_register_backing_store_base; |
| } |
| # endif |
| result = backing_store_base_from_proc(); |
| if (0 == result) { |
| result = GC_find_limit(GC_save_regs_in_stack(), FALSE); |
| /* Now seems to work better than constant displacement */ |
| /* heuristic used in 6.X versions. The latter seems to */ |
| /* fail for 2.6 kernels. */ |
| } |
| return result; |
| } |
| # endif |
| |
| ptr_t GC_linux_stack_base(void) |
| { |
| /* We read the stack base value from /proc/self/stat. We do this */ |
| /* using direct I/O system calls in order to avoid calling malloc */ |
| /* in case REDIRECT_MALLOC is defined. */ |
| # define STAT_BUF_SIZE 4096 |
| # define STAT_READ read |
| /* Should probably call the real read, if read is wrapped. */ |
| char stat_buf[STAT_BUF_SIZE]; |
| int f; |
| char c; |
| word result = 0; |
| size_t i, buf_offset = 0; |
| |
| /* First try the easy way. This should work for glibc 2.2 */ |
| /* This fails in a prelinked ("prelink" command) executable */ |
| /* since the correct value of __libc_stack_end never */ |
| /* becomes visible to us. The second test works around */ |
| /* this. */ |
| # ifdef USE_LIBC_PRIVATES |
| if (0 != &__libc_stack_end && 0 != __libc_stack_end ) { |
| # if defined(IA64) |
| /* Some versions of glibc set the address 16 bytes too */ |
| /* low while the initialization code is running. */ |
| if (((word)__libc_stack_end & 0xfff) + 0x10 < 0x1000) { |
| return __libc_stack_end + 0x10; |
| } /* Otherwise it's not safe to add 16 bytes and we fall */ |
| /* back to using /proc. */ |
| # elif defined(SPARC) |
| /* Older versions of glibc for 64-bit Sparc do not set |
| * this variable correctly, it gets set to either zero |
| * or one. |
| */ |
| if (__libc_stack_end != (ptr_t) (unsigned long)0x1) |
| return __libc_stack_end; |
| # else |
| return __libc_stack_end; |
| # endif |
| } |
| # endif |
| f = open("/proc/self/stat", O_RDONLY); |
| if (f < 0 || STAT_READ(f, stat_buf, STAT_BUF_SIZE) < 2 * STAT_SKIP) { |
| ABORT("Couldn't read /proc/self/stat"); |
| } |
| c = stat_buf[buf_offset++]; |
| /* Skip the required number of fields. This number is hopefully */ |
| /* constant across all Linux implementations. */ |
| for (i = 0; i < STAT_SKIP; ++i) { |
| while (isspace(c)) c = stat_buf[buf_offset++]; |
| while (!isspace(c)) c = stat_buf[buf_offset++]; |
| } |
| while (isspace(c)) c = stat_buf[buf_offset++]; |
| while (isdigit(c)) { |
| result *= 10; |
| result += c - '0'; |
| c = stat_buf[buf_offset++]; |
| } |
| close(f); |
| if (result < 0x10000000) ABORT("Absurd stack bottom value"); |
| return (ptr_t)result; |
| } |
| |
| #endif /* LINUX_STACKBOTTOM */ |
| |
| #ifdef FREEBSD_STACKBOTTOM |
| |
| /* This uses an undocumented sysctl call, but at least one expert */ |
| /* believes it will stay. */ |
| |
| #include <unistd.h> |
| #include <sys/types.h> |
| #include <sys/sysctl.h> |
| |
| ptr_t GC_freebsd_stack_base(void) |
| { |
| int nm[2] = {CTL_KERN, KERN_USRSTACK}; |
| ptr_t base; |
| size_t len = sizeof(ptr_t); |
| int r = sysctl(nm, 2, &base, &len, NULL, 0); |
| |
| if (r) ABORT("Error getting stack base"); |
| |
| return base; |
| } |
| |
| #endif /* FREEBSD_STACKBOTTOM */ |
| |
| #if !defined(BEOS) && !defined(AMIGA) && !defined(MSWIN32) \ |
| && !defined(MSWINCE) && !defined(OS2) && !defined(NOSYS) && !defined(ECOS) \ |
| && !defined(CYGWIN32) |
| |
| ptr_t GC_get_main_stack_base(void) |
| { |
| # if defined(HEURISTIC1) || defined(HEURISTIC2) |
| word dummy; |
| # endif |
| ptr_t result; |
| |
| # define STACKBOTTOM_ALIGNMENT_M1 ((word)STACK_GRAN - 1) |
| |
| # ifdef STACKBOTTOM |
| return(STACKBOTTOM); |
| # else |
| # ifdef HEURISTIC1 |
| # ifdef STACK_GROWS_DOWN |
| result = (ptr_t)((((word)(&dummy)) |
| + STACKBOTTOM_ALIGNMENT_M1) |
| & ~STACKBOTTOM_ALIGNMENT_M1); |
| # else |
| result = (ptr_t)(((word)(&dummy)) |
| & ~STACKBOTTOM_ALIGNMENT_M1); |
| # endif |
| # endif /* HEURISTIC1 */ |
| # ifdef LINUX_STACKBOTTOM |
| result = GC_linux_stack_base(); |
| # endif |
| # ifdef FREEBSD_STACKBOTTOM |
| result = GC_freebsd_stack_base(); |
| # endif |
| # ifdef HEURISTIC2 |
| # ifdef STACK_GROWS_DOWN |
| result = GC_find_limit((ptr_t)(&dummy), TRUE); |
| # ifdef HEURISTIC2_LIMIT |
| if (result > HEURISTIC2_LIMIT |
| && (ptr_t)(&dummy) < HEURISTIC2_LIMIT) { |
| result = HEURISTIC2_LIMIT; |
| } |
| # endif |
| # else |
| result = GC_find_limit((ptr_t)(&dummy), FALSE); |
| # ifdef HEURISTIC2_LIMIT |
| if (result < HEURISTIC2_LIMIT |
| && (ptr_t)(&dummy) > HEURISTIC2_LIMIT) { |
| result = HEURISTIC2_LIMIT; |
| } |
| # endif |
| # endif |
| |
| # endif /* HEURISTIC2 */ |
| # ifdef STACK_GROWS_DOWN |
| if (result == 0) result = (ptr_t)(signed_word)(-sizeof(ptr_t)); |
| # endif |
| return(result); |
| # endif /* STACKBOTTOM */ |
| } |
| |
| # endif /* ! AMIGA, !OS 2, ! MS Windows, !BEOS, !NOSYS, !ECOS */ |
| |
| #if defined(GC_LINUX_THREADS) && !defined(HAVE_GET_STACK_BASE) |
| |
| #include <pthread.h> |
| |
| #ifdef IA64 |
| ptr_t GC_greatest_stack_base_below(ptr_t bound); |
| /* From pthread_support.c */ |
| #endif |
| |
| int GC_get_stack_base(struct GC_stack_base *b) |
| { |
| pthread_attr_t attr; |
| size_t size; |
| |
| if (pthread_getattr_np(pthread_self(), &attr) != 0) { |
| WARN("pthread_getattr_np failed\n", 0); |
| return GC_UNIMPLEMENTED; |
| } |
| if (pthread_attr_getstack(&attr, &(b -> mem_base), &size) != 0) { |
| ABORT("pthread_attr_getstack failed"); |
| } |
| # ifdef STACK_GROWS_DOWN |
| b -> mem_base = (char *)(b -> mem_base) + size; |
| # endif |
| # ifdef IA64 |
| /* We could try backing_store_base_from_proc, but that's safe */ |
| /* only if no mappings are being asynchronously created. */ |
| /* Subtracting the size from the stack base doesn't work for at */ |
| /* least the main thread. */ |
| LOCK(); |
| { |
| ptr_t bsp = GC_save_regs_in_stack(); |
| ptr_t next_stack = GC_greatest_stack_base_below(bsp); |
| if (0 == next_stack) { |
| b -> reg_base = GC_find_limit(bsp, FALSE); |
| } else { |
| /* Avoid walking backwards into preceding memory stack and */ |
| /* growing it. */ |
| b -> reg_base = GC_find_limit_with_bound(bsp, FALSE, next_stack); |
| } |
| } |
| UNLOCK(); |
| # endif |
| return GC_SUCCESS; |
| } |
| |
| #define HAVE_GET_STACK_BASE |
| |
| #endif /* GC_LINUX_THREADS */ |
| |
| #ifndef HAVE_GET_STACK_BASE |
| /* Retrieve stack base. */ |
| /* Using the GC_find_limit version is risky. */ |
| /* On IA64, for example, there is no guard page between the */ |
| /* stack of one thread and the register backing store of the */ |
| /* next. Thus this is likely to identify way too large a */ |
| /* "stack" and thus at least result in disastrous performance. */ |
| /* FIXME - Implement better strategies here. */ |
| int GC_get_stack_base(struct GC_stack_base *b) |
| { |
| int dummy; |
| |
| # ifdef NEED_FIND_LIMIT |
| # ifdef STACK_GROWS_DOWN |
| b -> mem_base = GC_find_limit((ptr_t)(&dummy), TRUE); |
| # ifdef IA64 |
| b -> reg_base = GC_find_limit(GC_save_regs_in_stack(), FALSE); |
| # endif |
| # else |
| b -> mem_base = GC_find_limit(&dummy, FALSE); |
| # endif |
| return GC_SUCCESS; |
| # else |
| return GC_UNIMPLEMENTED; |
| # endif |
| } |
| #endif |
| |
| /* |
| * Register static data segment(s) as roots. |
| * If more data segments are added later then they need to be registered |
| * add that point (as we do with SunOS dynamic loading), |
| * or GC_mark_roots needs to check for them (as we do with PCR). |
| * Called with allocator lock held. |
| */ |
| |
| # ifdef OS2 |
| |
| void GC_register_data_segments(void) |
| { |
| PTIB ptib; |
| PPIB ppib; |
| HMODULE module_handle; |
| # define PBUFSIZ 512 |
| UCHAR path[PBUFSIZ]; |
| FILE * myexefile; |
| struct exe_hdr hdrdos; /* MSDOS header. */ |
| struct e32_exe hdr386; /* Real header for my executable */ |
| struct o32_obj seg; /* Currrent segment */ |
| int nsegs; |
| |
| |
| if (DosGetInfoBlocks(&ptib, &ppib) != NO_ERROR) { |
| GC_err_printf("DosGetInfoBlocks failed\n"); |
| ABORT("DosGetInfoBlocks failed\n"); |
| } |
| module_handle = ppib -> pib_hmte; |
| if (DosQueryModuleName(module_handle, PBUFSIZ, path) != NO_ERROR) { |
| GC_err_printf("DosQueryModuleName failed\n"); |
| ABORT("DosGetInfoBlocks failed\n"); |
| } |
| myexefile = fopen(path, "rb"); |
| if (myexefile == 0) { |
| GC_err_puts("Couldn't open executable "); |
| GC_err_puts(path); GC_err_puts("\n"); |
| ABORT("Failed to open executable\n"); |
| } |
| if (fread((char *)(&hdrdos), 1, sizeof hdrdos, myexefile) < sizeof hdrdos) { |
| GC_err_puts("Couldn't read MSDOS header from "); |
| GC_err_puts(path); GC_err_puts("\n"); |
| ABORT("Couldn't read MSDOS header"); |
| } |
| if (E_MAGIC(hdrdos) != EMAGIC) { |
| GC_err_puts("Executable has wrong DOS magic number: "); |
| GC_err_puts(path); GC_err_puts("\n"); |
| ABORT("Bad DOS magic number"); |
| } |
| if (fseek(myexefile, E_LFANEW(hdrdos), SEEK_SET) != 0) { |
| GC_err_puts("Seek to new header failed in "); |
| GC_err_puts(path); GC_err_puts("\n"); |
| ABORT("Bad DOS magic number"); |
| } |
| if (fread((char *)(&hdr386), 1, sizeof hdr386, myexefile) < sizeof hdr386) { |
| GC_err_puts("Couldn't read MSDOS header from "); |
| GC_err_puts(path); GC_err_puts("\n"); |
| ABORT("Couldn't read OS/2 header"); |
| } |
| if (E32_MAGIC1(hdr386) != E32MAGIC1 || E32_MAGIC2(hdr386) != E32MAGIC2) { |
| GC_err_puts("Executable has wrong OS/2 magic number:"); |
| GC_err_puts(path); GC_err_puts("\n"); |
| ABORT("Bad OS/2 magic number"); |
| } |
| if ( E32_BORDER(hdr386) != E32LEBO || E32_WORDER(hdr386) != E32LEWO) { |
| GC_err_puts("Executable %s has wrong byte order: "); |
| GC_err_puts(path); GC_err_puts("\n"); |
| ABORT("Bad byte order"); |
| } |
| if ( E32_CPU(hdr386) == E32CPU286) { |
| GC_err_puts("GC can't handle 80286 executables: "); |
| GC_err_puts(path); GC_err_puts("\n"); |
| EXIT(); |
| } |
| if (fseek(myexefile, E_LFANEW(hdrdos) + E32_OBJTAB(hdr386), |
| SEEK_SET) != 0) { |
| GC_err_puts("Seek to object table failed: "); |
| GC_err_puts(path); GC_err_puts("\n"); |
| ABORT("Seek to object table failed"); |
| } |
| for (nsegs = E32_OBJCNT(hdr386); nsegs > 0; nsegs--) { |
| int flags; |
| if (fread((char *)(&seg), 1, sizeof seg, myexefile) < sizeof seg) { |
| GC_err_puts("Couldn't read obj table entry from "); |
| GC_err_puts(path); GC_err_puts("\n"); |
| ABORT("Couldn't read obj table entry"); |
| } |
| flags = O32_FLAGS(seg); |
| if (!(flags & OBJWRITE)) continue; |
| if (!(flags & OBJREAD)) continue; |
| if (flags & OBJINVALID) { |
| GC_err_printf("Object with invalid pages?\n"); |
| continue; |
| } |
| GC_add_roots_inner(O32_BASE(seg), O32_BASE(seg)+O32_SIZE(seg), FALSE); |
| } |
| } |
| |
| # else /* !OS2 */ |
| |
| # if defined(MSWIN32) || defined(MSWINCE) |
| |
| # ifdef MSWIN32 |
| /* Unfortunately, we have to handle win32s very differently from NT, */ |
| /* Since VirtualQuery has very different semantics. In particular, */ |
| /* under win32s a VirtualQuery call on an unmapped page returns an */ |
| /* invalid result. Under NT, GC_register_data_segments is a noop and */ |
| /* all real work is done by GC_register_dynamic_libraries. Under */ |
| /* win32s, we cannot find the data segments associated with dll's. */ |
| /* We register the main data segment here. */ |
| GC_bool GC_no_win32_dlls = FALSE; |
| /* This used to be set for gcc, to avoid dealing with */ |
| /* the structured exception handling issues. But we now have */ |
| /* assembly code to do that right. */ |
| |
| # if defined(GWW_VDB) |
| |
| # ifndef _BASETSD_H_ |
| typedef ULONG * PULONG_PTR; |
| # endif |
| typedef UINT (WINAPI * GetWriteWatch_type)( |
| DWORD, PVOID, SIZE_T, PVOID*, PULONG_PTR, PULONG); |
| static GetWriteWatch_type GetWriteWatch_func; |
| static DWORD GetWriteWatch_alloc_flag; |
| |
| # define GC_GWW_AVAILABLE() (GetWriteWatch_func != NULL) |
| |
| static void detect_GetWriteWatch(void) |
| { |
| static GC_bool done; |
| if (done) |
| return; |
| |
| GetWriteWatch_func = (GetWriteWatch_type) |
| GetProcAddress(GetModuleHandle("kernel32.dll"), "GetWriteWatch"); |
| if (GetWriteWatch_func != NULL) { |
| /* Also check whether VirtualAlloc accepts MEM_WRITE_WATCH, */ |
| /* as some versions of kernel32.dll have one but not the */ |
| /* other, making the feature completely broken. */ |
| void * page = VirtualAlloc(NULL, GC_page_size, |
| MEM_WRITE_WATCH | MEM_RESERVE, |
| PAGE_READWRITE); |
| if (page != NULL) { |
| PVOID pages[16]; |
| ULONG_PTR count = 16; |
| DWORD page_size; |
| /* Check that it actually works. In spite of some */ |
| /* documentation it actually seems to exist on W2K. */ |
| /* This test may be unnecessary, but ... */ |
| if (GetWriteWatch_func(WRITE_WATCH_FLAG_RESET, |
| page, GC_page_size, |
| pages, |
| &count, |
| &page_size) != 0) { |
| /* GetWriteWatch always fails. */ |
| GetWriteWatch_func = NULL; |
| } else { |
| GetWriteWatch_alloc_flag = MEM_WRITE_WATCH; |
| } |
| VirtualFree(page, GC_page_size, MEM_RELEASE); |
| } else { |
| /* GetWriteWatch will be useless. */ |
| GetWriteWatch_func = NULL; |
| } |
| } |
| if (GC_print_stats) { |
| if (GetWriteWatch_func == NULL) { |
| GC_log_printf("Did not find a usable GetWriteWatch()\n"); |
| } else { |
| GC_log_printf("Using GetWriteWatch()\n"); |
| } |
| } |
| done = TRUE; |
| } |
| |
| # endif /* GWW_VDB */ |
| |
| GC_bool GC_wnt = FALSE; |
| /* This is a Windows NT derivative, i.e. NT, W2K, XP or later. */ |
| |
| void GC_init_win32(void) |
| { |
| /* Set GC_wnt. */ |
| /* If we're running under win32s, assume that no DLLs will be loaded */ |
| /* I doubt anyone still runs win32s, but ... */ |
| DWORD v = GetVersion(); |
| GC_wnt = !(v & 0x80000000); |
| GC_no_win32_dlls |= ((!GC_wnt) && (v & 0xff) <= 3); |
| } |
| |
| /* Return the smallest address a such that VirtualQuery */ |
| /* returns correct results for all addresses between a and start. */ |
| /* Assumes VirtualQuery returns correct information for start. */ |
| ptr_t GC_least_described_address(ptr_t start) |
| { |
| MEMORY_BASIC_INFORMATION buf; |
| size_t result; |
| LPVOID limit; |
| ptr_t p; |
| LPVOID q; |
| |
| limit = GC_sysinfo.lpMinimumApplicationAddress; |
| p = (ptr_t)((word)start & ~(GC_page_size - 1)); |
| for (;;) { |
| q = (LPVOID)(p - GC_page_size); |
| if ((ptr_t)q > (ptr_t)p /* underflow */ || q < limit) break; |
| result = VirtualQuery(q, &buf, sizeof(buf)); |
| if (result != sizeof(buf) || buf.AllocationBase == 0) break; |
| p = (ptr_t)(buf.AllocationBase); |
| } |
| return p; |
| } |
| # endif |
| |
| # ifndef REDIRECT_MALLOC |
| /* We maintain a linked list of AllocationBase values that we know */ |
| /* correspond to malloc heap sections. Currently this is only called */ |
| /* during a GC. But there is some hope that for long running */ |
| /* programs we will eventually see most heap sections. */ |
| |
| /* In the long run, it would be more reliable to occasionally walk */ |
| /* the malloc heap with HeapWalk on the default heap. But that */ |
| /* apparently works only for NT-based Windows. */ |
| |
| /* In the long run, a better data structure would also be nice ... */ |
| struct GC_malloc_heap_list { |
| void * allocation_base; |
| struct GC_malloc_heap_list *next; |
| } *GC_malloc_heap_l = 0; |
| |
| /* Is p the base of one of the malloc heap sections we already know */ |
| /* about? */ |
| GC_bool GC_is_malloc_heap_base(ptr_t p) |
| { |
| struct GC_malloc_heap_list *q = GC_malloc_heap_l; |
| |
| while (0 != q) { |
| if (q -> allocation_base == p) return TRUE; |
| q = q -> next; |
| } |
| return FALSE; |
| } |
| |
| void *GC_get_allocation_base(void *p) |
| { |
| MEMORY_BASIC_INFORMATION buf; |
| size_t result = VirtualQuery(p, &buf, sizeof(buf)); |
| if (result != sizeof(buf)) { |
| ABORT("Weird VirtualQuery result"); |
| } |
| return buf.AllocationBase; |
| } |
| |
| size_t GC_max_root_size = 100000; /* Appr. largest root size. */ |
| |
| void GC_add_current_malloc_heap() |
| { |
| struct GC_malloc_heap_list *new_l = |
| malloc(sizeof(struct GC_malloc_heap_list)); |
| void * candidate = GC_get_allocation_base(new_l); |
| |
| if (new_l == 0) return; |
| if (GC_is_malloc_heap_base(candidate)) { |
| /* Try a little harder to find malloc heap. */ |
| size_t req_size = 10000; |
| do { |
| void *p = malloc(req_size); |
| if (0 == p) { free(new_l); return; } |
| candidate = GC_get_allocation_base(p); |
| free(p); |
| req_size *= 2; |
| } while (GC_is_malloc_heap_base(candidate) |
| && req_size < GC_max_root_size/10 && req_size < 500000); |
| if (GC_is_malloc_heap_base(candidate)) { |
| free(new_l); return; |
| } |
| } |
| if (GC_print_stats) |
| GC_log_printf("Found new system malloc AllocationBase at %p\n", |
| candidate); |
| new_l -> allocation_base = candidate; |
| new_l -> next = GC_malloc_heap_l; |
| GC_malloc_heap_l = new_l; |
| } |
| # endif /* REDIRECT_MALLOC */ |
| |
| /* Is p the start of either the malloc heap, or of one of our */ |
| /* heap sections? */ |
| GC_bool GC_is_heap_base (ptr_t p) |
| { |
| |
| unsigned i; |
| |
| # ifndef REDIRECT_MALLOC |
| static word last_gc_no = (word)(-1); |
| |
| if (last_gc_no != GC_gc_no) { |
| GC_add_current_malloc_heap(); |
| last_gc_no = GC_gc_no; |
| } |
| if (GC_root_size > GC_max_root_size) GC_max_root_size = GC_root_size; |
| if (GC_is_malloc_heap_base(p)) return TRUE; |
| # endif |
| for (i = 0; i < GC_n_heap_bases; i++) { |
| if (GC_heap_bases[i] == p) return TRUE; |
| } |
| return FALSE ; |
| } |
| |
| # ifdef MSWIN32 |
| void GC_register_root_section(ptr_t static_root) |
| { |
| MEMORY_BASIC_INFORMATION buf; |
| size_t result; |
| DWORD protect; |
| LPVOID p; |
| char * base; |
| char * limit, * new_limit; |
| |
| if (!GC_no_win32_dlls) return; |
| p = base = limit = GC_least_described_address(static_root); |
| while (p < GC_sysinfo.lpMaximumApplicationAddress) { |
| result = VirtualQuery(p, &buf, sizeof(buf)); |
| if (result != sizeof(buf) || buf.AllocationBase == 0 |
| || GC_is_heap_base(buf.AllocationBase)) break; |
| new_limit = (char *)p + buf.RegionSize; |
| protect = buf.Protect; |
| if (buf.State == MEM_COMMIT |
| && is_writable(protect)) { |
| if ((char *)p == limit) { |
| limit = new_limit; |
| } else { |
| if (base != limit) GC_add_roots_inner(base, limit, FALSE); |
| base = p; |
| limit = new_limit; |
| } |
| } |
| if (p > (LPVOID)new_limit /* overflow */) break; |
| p = (LPVOID)new_limit; |
| } |
| if (base != limit) GC_add_roots_inner(base, limit, FALSE); |
| } |
| #endif |
| |
| void GC_register_data_segments() |
| { |
| # ifdef MSWIN32 |
| static char dummy; |
| GC_register_root_section((ptr_t)(&dummy)); |
| # endif |
| } |
| |
| # else /* !OS2 && !Windows */ |
| |
| # if (defined(SVR4) || defined(AUX) || defined(DGUX) \ |
| || (defined(LINUX) && defined(SPARC))) && !defined(PCR) |
| ptr_t GC_SysVGetDataStart(size_t max_page_size, ptr_t etext_addr) |
| { |
| word text_end = ((word)(etext_addr) + sizeof(word) - 1) |
| & ~(sizeof(word) - 1); |
| /* etext rounded to word boundary */ |
| word next_page = ((text_end + (word)max_page_size - 1) |
| & ~((word)max_page_size - 1)); |
| word page_offset = (text_end & ((word)max_page_size - 1)); |
| volatile char * result = (char *)(next_page + page_offset); |
| /* Note that this isnt equivalent to just adding */ |
| /* max_page_size to &etext if &etext is at a page boundary */ |
| |
| GC_setup_temporary_fault_handler(); |
| if (SETJMP(GC_jmp_buf) == 0) { |
| /* Try writing to the address. */ |
| *result = *result; |
| GC_reset_fault_handler(); |
| } else { |
| GC_reset_fault_handler(); |
| /* We got here via a longjmp. The address is not readable. */ |
| /* This is known to happen under Solaris 2.4 + gcc, which place */ |
| /* string constants in the text segment, but after etext. */ |
| /* Use plan B. Note that we now know there is a gap between */ |
| /* text and data segments, so plan A bought us something. */ |
| result = (char *)GC_find_limit((ptr_t)(DATAEND), FALSE); |
| } |
| return((ptr_t)result); |
| } |
| # endif |
| |
| # if defined(FREEBSD) && (defined(I386) || defined(X86_64) || defined(powerpc) || defined(__powerpc__)) && !defined(PCR) |
| /* Its unclear whether this should be identical to the above, or */ |
| /* whether it should apply to non-X86 architectures. */ |
| /* For now we don't assume that there is always an empty page after */ |
| /* etext. But in some cases there actually seems to be slightly more. */ |
| /* This also deals with holes between read-only data and writable data. */ |
| ptr_t GC_FreeBSDGetDataStart(size_t max_page_size, ptr_t etext_addr) |
| { |
| word text_end = ((word)(etext_addr) + sizeof(word) - 1) |
| & ~(sizeof(word) - 1); |
| /* etext rounded to word boundary */ |
| volatile word next_page = (text_end + (word)max_page_size - 1) |
| & ~((word)max_page_size - 1); |
| volatile ptr_t result = (ptr_t)text_end; |
| GC_setup_temporary_fault_handler(); |
| if (SETJMP(GC_jmp_buf) == 0) { |
| /* Try reading at the address. */ |
| /* This should happen before there is another thread. */ |
| for (; next_page < (word)(DATAEND); next_page += (word)max_page_size) |
| *(volatile char *)next_page; |
| GC_reset_fault_handler(); |
| } else { |
| GC_reset_fault_handler(); |
| /* As above, we go to plan B */ |
| result = GC_find_limit((ptr_t)(DATAEND), FALSE); |
| } |
| return(result); |
| } |
| |
| # endif |
| |
| |
| #ifdef AMIGA |
| |
| # define GC_AMIGA_DS |
| # include "AmigaOS.c" |
| # undef GC_AMIGA_DS |
| |
| #else /* !OS2 && !Windows && !AMIGA */ |
| |
| void GC_register_data_segments(void) |
| { |
| # if !defined(PCR) && !defined(MACOS) |
| # if defined(REDIRECT_MALLOC) && defined(GC_SOLARIS_THREADS) |
| /* As of Solaris 2.3, the Solaris threads implementation */ |
| /* allocates the data structure for the initial thread with */ |
| /* sbrk at process startup. It needs to be scanned, so that */ |
| /* we don't lose some malloc allocated data structures */ |
| /* hanging from it. We're on thin ice here ... */ |
| extern caddr_t sbrk(); |
| |
| GC_add_roots_inner(DATASTART, (ptr_t)sbrk(0), FALSE); |
| # else |
| GC_add_roots_inner(DATASTART, (ptr_t)(DATAEND), FALSE); |
| # if defined(DATASTART2) |
| GC_add_roots_inner(DATASTART2, (ptr_t)(DATAEND2), FALSE); |
| # endif |
| # endif |
| # endif |
| # if defined(MACOS) |
| { |
| # if defined(THINK_C) |
| extern void* GC_MacGetDataStart(void); |
| /* globals begin above stack and end at a5. */ |
| GC_add_roots_inner((ptr_t)GC_MacGetDataStart(), |
| (ptr_t)LMGetCurrentA5(), FALSE); |
| # else |
| # if defined(__MWERKS__) |
| # if !__POWERPC__ |
| extern void* GC_MacGetDataStart(void); |
| /* MATTHEW: Function to handle Far Globals (CW Pro 3) */ |
| # if __option(far_data) |
| extern void* GC_MacGetDataEnd(void); |
| # endif |
| /* globals begin above stack and end at a5. */ |
| GC_add_roots_inner((ptr_t)GC_MacGetDataStart(), |
| (ptr_t)LMGetCurrentA5(), FALSE); |
| /* MATTHEW: Handle Far Globals */ |
| # if __option(far_data) |
| /* Far globals follow he QD globals: */ |
| GC_add_roots_inner((ptr_t)LMGetCurrentA5(), |
| (ptr_t)GC_MacGetDataEnd(), FALSE); |
| # endif |
| # else |
| extern char __data_start__[], __data_end__[]; |
| GC_add_roots_inner((ptr_t)&__data_start__, |
| (ptr_t)&__data_end__, FALSE); |
| # endif /* __POWERPC__ */ |
| # endif /* __MWERKS__ */ |
| # endif /* !THINK_C */ |
| } |
| # endif /* MACOS */ |
| |
| /* Dynamic libraries are added at every collection, since they may */ |
| /* change. */ |
| } |
| |
| # endif /* ! AMIGA */ |
| # endif /* ! MSWIN32 && ! MSWINCE*/ |
| # endif /* ! OS2 */ |
| |
| /* |
| * Auxiliary routines for obtaining memory from OS. |
| */ |
| |
| # if !defined(OS2) && !defined(PCR) && !defined(AMIGA) \ |
| && !defined(MSWIN32) && !defined(MSWINCE) \ |
| && !defined(MACOS) && !defined(DOS4GW) && !defined(NONSTOP) |
| |
| # define SBRK_ARG_T ptrdiff_t |
| |
| #if defined(MMAP_SUPPORTED) |
| |
| #ifdef USE_MMAP_FIXED |
| # define GC_MMAP_FLAGS MAP_FIXED | MAP_PRIVATE |
| /* Seems to yield better performance on Solaris 2, but can */ |
| /* be unreliable if something is already mapped at the address. */ |
| #else |
| # define GC_MMAP_FLAGS MAP_PRIVATE |
| #endif |
| |
| #ifdef USE_MMAP_ANON |
| # define zero_fd -1 |
| # if defined(MAP_ANONYMOUS) |
| # define OPT_MAP_ANON MAP_ANONYMOUS |
| # else |
| # define OPT_MAP_ANON MAP_ANON |
| # endif |
| #else |
| static int zero_fd; |
| # define OPT_MAP_ANON 0 |
| #endif |
| |
| #ifndef HEAP_START |
| # define HEAP_START 0 |
| #endif |
| |
| ptr_t GC_unix_mmap_get_mem(word bytes) |
| { |
| void *result; |
| static ptr_t last_addr = HEAP_START; |
| |
| # ifndef USE_MMAP_ANON |
| static GC_bool initialized = FALSE; |
| |
| if (!initialized) { |
| zero_fd = open("/dev/zero", O_RDONLY); |
| fcntl(zero_fd, F_SETFD, FD_CLOEXEC); |
| initialized = TRUE; |
| } |
| # endif |
| |
| if (bytes & (GC_page_size -1)) ABORT("Bad GET_MEM arg"); |
| result = mmap(last_addr, bytes, PROT_READ | PROT_WRITE | OPT_PROT_EXEC, |
| GC_MMAP_FLAGS | OPT_MAP_ANON, zero_fd, 0/* offset */); |
| if (result == MAP_FAILED) return(0); |
| last_addr = (ptr_t)result + bytes + GC_page_size - 1; |
| last_addr = (ptr_t)((word)last_addr & ~(GC_page_size - 1)); |
| # if !defined(LINUX) |
| if (last_addr == 0) { |
| /* Oops. We got the end of the address space. This isn't */ |
| /* usable by arbitrary C code, since one-past-end pointers */ |
| /* don't work, so we discard it and try again. */ |
| munmap(result, (size_t)(-GC_page_size) - (size_t)result); |
| /* Leave last page mapped, so we can't repeat. */ |
| return GC_unix_mmap_get_mem(bytes); |
| } |
| # else |
| GC_ASSERT(last_addr != 0); |
| # endif |
| return((ptr_t)result); |
| } |
| |
| # endif /* MMAP_SUPPORTED */ |
| |
| #if defined(USE_MMAP) |
| |
| ptr_t GC_unix_get_mem(word bytes) |
| { |
| return GC_unix_mmap_get_mem(bytes); |
| } |
| |
| #else /* Not USE_MMAP */ |
| |
| ptr_t GC_unix_sbrk_get_mem(word bytes) |
| { |
| ptr_t result; |
| # ifdef IRIX5 |
| /* Bare sbrk isn't thread safe. Play by malloc rules. */ |
| /* The equivalent may be needed on other systems as well. */ |
| __LOCK_MALLOC(); |
| # endif |
| { |
| ptr_t cur_brk = (ptr_t)sbrk(0); |
| SBRK_ARG_T lsbs = (word)cur_brk & (GC_page_size-1); |
| |
| if ((SBRK_ARG_T)bytes < 0) { |
| result = 0; /* too big */ |
| goto out; |
| } |
| if (lsbs != 0) { |
| if((ptr_t)sbrk(GC_page_size - lsbs) == (ptr_t)(-1)) { |
| result = 0; |
| goto out; |
| } |
| } |
| # ifdef ADD_HEAP_GUARD_PAGES |
| /* This is useful for catching severe memory overwrite problems that */ |
| /* span heap sections. It shouldn't otherwise be turned on. */ |
| { |
| ptr_t guard = (ptr_t)sbrk((SBRK_ARG_T)GC_page_size); |
| if (mprotect(guard, GC_page_size, PROT_NONE) != 0) |
| ABORT("ADD_HEAP_GUARD_PAGES: mprotect failed"); |
| } |
| # endif /* ADD_HEAP_GUARD_PAGES */ |
| result = (ptr_t)sbrk((SBRK_ARG_T)bytes); |
| if (result == (ptr_t)(-1)) result = 0; |
| } |
| out: |
| # ifdef IRIX5 |
| __UNLOCK_MALLOC(); |
| # endif |
| return(result); |
| } |
| |
| #if defined(MMAP_SUPPORTED) |
| |
| /* By default, we try both sbrk and mmap, in that order. */ |
| ptr_t GC_unix_get_mem(word bytes) |
| { |
| static GC_bool sbrk_failed = FALSE; |
| ptr_t result = 0; |
| |
| if (!sbrk_failed) result = GC_unix_sbrk_get_mem(bytes); |
| if (0 == result) { |
| sbrk_failed = TRUE; |
| result = GC_unix_mmap_get_mem(bytes); |
| } |
| if (0 == result) { |
| /* Try sbrk again, in case sbrk memory became available. */ |
| result = GC_unix_sbrk_get_mem(bytes); |
| } |
| return result; |
| } |
| |
| #else /* !MMAP_SUPPORTED */ |
| |
| ptr_t GC_unix_get_mem(word bytes) |
| { |
| return GC_unix_sbrk_get_mem(bytes); |
| } |
| |
| #endif |
| |
| #endif /* Not USE_MMAP */ |
| |
| # endif /* UN*X */ |
| |
| # ifdef OS2 |
| |
| void * os2_alloc(size_t bytes) |
| { |
| void * result; |
| |
| if (DosAllocMem(&result, bytes, PAG_EXECUTE | PAG_READ | |
| PAG_WRITE | PAG_COMMIT) |
| != NO_ERROR) { |
| return(0); |
| } |
| if (result == 0) return(os2_alloc(bytes)); |
| return(result); |
| } |
| |
| # endif /* OS2 */ |
| |
| |
| # if defined(MSWIN32) || defined(MSWINCE) |
| SYSTEM_INFO GC_sysinfo; |
| # endif |
| |
| # ifdef MSWIN32 |
| |
| # ifdef USE_GLOBAL_ALLOC |
| # define GLOBAL_ALLOC_TEST 1 |
| # else |
| # define GLOBAL_ALLOC_TEST GC_no_win32_dlls |
| # endif |
| |
| word GC_n_heap_bases = 0; |
| |
| word GC_mem_top_down = 0; /* Change to MEM_TOP_DOWN for better 64-bit */ |
| /* testing. Otherwise all addresses tend to */ |
| /* end up in first 4GB, hiding bugs. */ |
| |
| ptr_t GC_win32_get_mem(word bytes) |
| { |
| ptr_t result; |
| |
| if (GLOBAL_ALLOC_TEST) { |
| /* VirtualAlloc doesn't like PAGE_EXECUTE_READWRITE. */ |
| /* There are also unconfirmed rumors of other */ |
| /* problems, so we dodge the issue. */ |
| result = (ptr_t) GlobalAlloc(0, bytes + HBLKSIZE); |
| result = (ptr_t)(((word)result + HBLKSIZE - 1) & ~(HBLKSIZE-1)); |
| } else { |
| /* VirtualProtect only works on regions returned by a */ |
| /* single VirtualAlloc call. Thus we allocate one */ |
| /* extra page, which will prevent merging of blocks */ |
| /* in separate regions, and eliminate any temptation */ |
| /* to call VirtualProtect on a range spanning regions. */ |
| /* This wastes a small amount of memory, and risks */ |
| /* increased fragmentation. But better alternatives */ |
| /* would require effort. */ |
| /* Pass the MEM_WRITE_WATCH only if GetWriteWatch-based */ |
| /* VDBs are enabled and the GetWriteWatch function is */ |
| /* available. Otherwise we waste resources or possibly */ |
| /* cause VirtualAlloc to fail (observed in Windows 2000 */ |
| /* SP2). */ |
| result = (ptr_t) VirtualAlloc(NULL, bytes + 1, |
| # ifdef GWW_VDB |
| GetWriteWatch_alloc_flag | |
| # endif |
| MEM_COMMIT | MEM_RESERVE |
| | GC_mem_top_down, |
| PAGE_EXECUTE_READWRITE); |
| } |
| if (HBLKDISPL(result) != 0) ABORT("Bad VirtualAlloc result"); |
| /* If I read the documentation correctly, this can */ |
| /* only happen if HBLKSIZE > 64k or not a power of 2. */ |
| if (GC_n_heap_bases >= MAX_HEAP_SECTS) ABORT("Too many heap sections"); |
| GC_heap_bases[GC_n_heap_bases++] = result; |
| return(result); |
| } |
| |
| void GC_win32_free_heap(void) |
| { |
| if (GC_no_win32_dlls) { |
| while (GC_n_heap_bases > 0) { |
| GlobalFree (GC_heap_bases[--GC_n_heap_bases]); |
| GC_heap_bases[GC_n_heap_bases] = 0; |
| } |
| } |
| } |
| # endif |
| |
| #ifdef AMIGA |
| # define GC_AMIGA_AM |
| # include "AmigaOS.c" |
| # undef GC_AMIGA_AM |
| #endif |
| |
| |
| # ifdef MSWINCE |
| word GC_n_heap_bases = 0; |
| |
| ptr_t GC_wince_get_mem(word bytes) |
| { |
| ptr_t result; |
| word i; |
| |
| /* Round up allocation size to multiple of page size */ |
| bytes = (bytes + GC_page_size-1) & ~(GC_page_size-1); |
| |
| /* Try to find reserved, uncommitted pages */ |
| for (i = 0; i < GC_n_heap_bases; i++) { |
| if (((word)(-(signed_word)GC_heap_lengths[i]) |
| & (GC_sysinfo.dwAllocationGranularity-1)) |
| >= bytes) { |
| result = GC_heap_bases[i] + GC_heap_lengths[i]; |
| break; |
| } |
| } |
| |
| if (i == GC_n_heap_bases) { |
| /* Reserve more pages */ |
| word res_bytes = (bytes + GC_sysinfo.dwAllocationGranularity-1) |
| & ~(GC_sysinfo.dwAllocationGranularity-1); |
| /* If we ever support MPROTECT_VDB here, we will probably need to */ |
| /* ensure that res_bytes is strictly > bytes, so that VirtualProtect */ |
| /* never spans regions. It seems to be OK for a VirtualFree */ |
| /* argument to span regions, so we should be OK for now. */ |
| result = (ptr_t) VirtualAlloc(NULL, res_bytes, |
| MEM_RESERVE | MEM_TOP_DOWN, |
| PAGE_EXECUTE_READWRITE); |
| if (HBLKDISPL(result) != 0) ABORT("Bad VirtualAlloc result"); |
| /* If I read the documentation correctly, this can */ |
| /* only happen if HBLKSIZE > 64k or not a power of 2. */ |
| if (GC_n_heap_bases >= MAX_HEAP_SECTS) ABORT("Too many heap sections"); |
| GC_heap_bases[GC_n_heap_bases] = result; |
| GC_heap_lengths[GC_n_heap_bases] = 0; |
| GC_n_heap_bases++; |
| } |
| |
| /* Commit pages */ |
| result = (ptr_t) VirtualAlloc(result, bytes, |
| MEM_COMMIT, |
| PAGE_EXECUTE_READWRITE); |
| if (result != NULL) { |
| if (HBLKDISPL(result) != 0) ABORT("Bad VirtualAlloc result"); |
| GC_heap_lengths[i] += bytes; |
| } |
| |
| return(result); |
| } |
| # endif |
| |
| #ifdef USE_MUNMAP |
| |
| /* For now, this only works on Win32/WinCE and some Unix-like */ |
| /* systems. If you have something else, don't define */ |
| /* USE_MUNMAP. */ |
| /* We assume ANSI C to support this feature. */ |
| |
| #if !defined(MSWIN32) && !defined(MSWINCE) |
| |
| #include <unistd.h> |
| #include <sys/mman.h> |
| #include <sys/stat.h> |
| #include <sys/types.h> |
| |
| #endif |
| |
| /* Compute a page aligned starting address for the unmap */ |
| /* operation on a block of size bytes starting at start. */ |
| /* Return 0 if the block is too small to make this feasible. */ |
| ptr_t GC_unmap_start(ptr_t start, size_t bytes) |
| { |
| ptr_t result = start; |
| /* Round start to next page boundary. */ |
| result += GC_page_size - 1; |
| result = (ptr_t)((word)result & ~(GC_page_size - 1)); |
| if (result + GC_page_size > start + bytes) return 0; |
| return result; |
| } |
| |
| /* Compute end address for an unmap operation on the indicated */ |
| /* block. */ |
| ptr_t GC_unmap_end(ptr_t start, size_t bytes) |
| { |
| ptr_t end_addr = start + bytes; |
| end_addr = (ptr_t)((word)end_addr & ~(GC_page_size - 1)); |
| return end_addr; |
| } |
| |
| /* Under Win32/WinCE we commit (map) and decommit (unmap) */ |
| /* memory using VirtualAlloc and VirtualFree. These functions */ |
| /* work on individual allocations of virtual memory, made */ |
| /* previously using VirtualAlloc with the MEM_RESERVE flag. */ |
| /* The ranges we need to (de)commit may span several of these */ |
| /* allocations; therefore we use VirtualQuery to check */ |
| /* allocation lengths, and split up the range as necessary. */ |
| |
| /* We assume that GC_remap is called on exactly the same range */ |
| /* as a previous call to GC_unmap. It is safe to consistently */ |
| /* round the endpoints in both places. */ |
| void GC_unmap(ptr_t start, size_t bytes) |
| { |
| ptr_t start_addr = GC_unmap_start(start, bytes); |
| ptr_t end_addr = GC_unmap_end(start, bytes); |
| word len = end_addr - start_addr; |
| if (0 == start_addr) return; |
| # if defined(MSWIN32) || defined(MSWINCE) |
| while (len != 0) { |
| MEMORY_BASIC_INFORMATION mem_info; |
| GC_word free_len; |
| if (VirtualQuery(start_addr, &mem_info, sizeof(mem_info)) |
| != sizeof(mem_info)) |
| ABORT("Weird VirtualQuery result"); |
| free_len = (len < mem_info.RegionSize) ? len : mem_info.RegionSize; |
| if (!VirtualFree(start_addr, free_len, MEM_DECOMMIT)) |
| ABORT("VirtualFree failed"); |
| GC_unmapped_bytes += free_len; |
| start_addr += free_len; |
| len -= free_len; |
| } |
| # else |
| /* We immediately remap it to prevent an intervening mmap from */ |
| /* accidentally grabbing the same address space. */ |
| { |
| void * result; |
| result = mmap(start_addr, len, PROT_NONE, |
| MAP_PRIVATE | MAP_FIXED | OPT_MAP_ANON, |
| zero_fd, 0/* offset */); |
| if (result != (void *)start_addr) ABORT("mmap(...PROT_NONE...) failed"); |
| } |
| GC_unmapped_bytes += len; |
| # endif |
| } |
| |
| |
| void GC_remap(ptr_t start, size_t bytes) |
| { |
| ptr_t start_addr = GC_unmap_start(start, bytes); |
| ptr_t end_addr = GC_unmap_end(start, bytes); |
| word len = end_addr - start_addr; |
| |
| # if defined(MSWIN32) || defined(MSWINCE) |
| ptr_t result; |
| |
| if (0 == start_addr) return; |
| while (len != 0) { |
| MEMORY_BASIC_INFORMATION mem_info; |
| GC_word alloc_len; |
| if (VirtualQuery(start_addr, &mem_info, sizeof(mem_info)) |
| != sizeof(mem_info)) |
| ABORT("Weird VirtualQuery result"); |
| alloc_len = (len < mem_info.RegionSize) ? len : mem_info.RegionSize; |
| result = VirtualAlloc(start_addr, alloc_len, |
| MEM_COMMIT, |
| PAGE_EXECUTE_READWRITE); |
| if (result != start_addr) { |
| ABORT("VirtualAlloc remapping failed"); |
| } |
| GC_unmapped_bytes -= alloc_len; |
| start_addr += alloc_len; |
| len -= alloc_len; |
| } |
| # else |
| /* It was already remapped with PROT_NONE. */ |
| int result; |
| |
| if (0 == start_addr) return; |
| result = mprotect(start_addr, len, |
| PROT_READ | PROT_WRITE | OPT_PROT_EXEC); |
| if (result != 0) { |
| GC_err_printf( |
| "Mprotect failed at %p (length %ld) with errno %d\n", |
| start_addr, (unsigned long)len, errno); |
| ABORT("Mprotect remapping failed"); |
| } |
| GC_unmapped_bytes -= len; |
| # endif |
| } |
| |
| /* Two adjacent blocks have already been unmapped and are about to */ |
| /* be merged. Unmap the whole block. This typically requires */ |
| /* that we unmap a small section in the middle that was not previously */ |
| /* unmapped due to alignment constraints. */ |
| void GC_unmap_gap(ptr_t start1, size_t bytes1, ptr_t start2, size_t bytes2) |
| { |
| ptr_t start1_addr = GC_unmap_start(start1, bytes1); |
| ptr_t end1_addr = GC_unmap_end(start1, bytes1); |
| ptr_t start2_addr = GC_unmap_start(start2, bytes2); |
| ptr_t end2_addr = GC_unmap_end(start2, bytes2); |
| ptr_t start_addr = end1_addr; |
| ptr_t end_addr = start2_addr; |
| size_t len; |
| GC_ASSERT(start1 + bytes1 == start2); |
| if (0 == start1_addr) start_addr = GC_unmap_start(start1, bytes1 + bytes2); |
| if (0 == start2_addr) end_addr = GC_unmap_end(start1, bytes1 + bytes2); |
| if (0 == start_addr) return; |
| len = end_addr - start_addr; |
| # if defined(MSWIN32) || defined(MSWINCE) |
| while (len != 0) { |
| MEMORY_BASIC_INFORMATION mem_info; |
| GC_word free_len; |
| if (VirtualQuery(start_addr, &mem_info, sizeof(mem_info)) |
| != sizeof(mem_info)) |
| ABORT("Weird VirtualQuery result"); |
| free_len = (len < mem_info.RegionSize) ? len : mem_info.RegionSize; |
| if (!VirtualFree(start_addr, free_len, MEM_DECOMMIT)) |
| ABORT("VirtualFree failed"); |
| GC_unmapped_bytes += free_len; |
| start_addr += free_len; |
| len -= free_len; |
| } |
| # else |
| if (len != 0 && munmap(start_addr, len) != 0) ABORT("munmap failed"); |
| GC_unmapped_bytes += len; |
| # endif |
| } |
| |
| #endif /* USE_MUNMAP */ |
| |
| /* Routine for pushing any additional roots. In THREADS */ |
| /* environment, this is also responsible for marking from */ |
| /* thread stacks. */ |
| #ifndef THREADS |
| void (*GC_push_other_roots)(void) = 0; |
| #else /* THREADS */ |
| |
| # ifdef PCR |
| PCR_ERes GC_push_thread_stack(PCR_Th_T *t, PCR_Any dummy) |
| { |
| struct PCR_ThCtl_TInfoRep info; |
| PCR_ERes result; |
| |
| info.ti_stkLow = info.ti_stkHi = 0; |
| result = PCR_ThCtl_GetInfo(t, &info); |
| GC_push_all_stack((ptr_t)(info.ti_stkLow), (ptr_t)(info.ti_stkHi)); |
| return(result); |
| } |
| |
| /* Push the contents of an old object. We treat this as stack */ |
| /* data only becasue that makes it robust against mark stack */ |
| /* overflow. */ |
| PCR_ERes GC_push_old_obj(void *p, size_t size, PCR_Any data) |
| { |
| GC_push_all_stack((ptr_t)p, (ptr_t)p + size); |
| return(PCR_ERes_okay); |
| } |
| |
| |
| void GC_default_push_other_roots(void) |
| { |
| /* Traverse data allocated by previous memory managers. */ |
| { |
| extern struct PCR_MM_ProcsRep * GC_old_allocator; |
| |
| if ((*(GC_old_allocator->mmp_enumerate))(PCR_Bool_false, |
| GC_push_old_obj, 0) |
| != PCR_ERes_okay) { |
| ABORT("Old object enumeration failed"); |
| } |
| } |
| /* Traverse all thread stacks. */ |
| if (PCR_ERes_IsErr( |
| PCR_ThCtl_ApplyToAllOtherThreads(GC_push_thread_stack,0)) |
| || PCR_ERes_IsErr(GC_push_thread_stack(PCR_Th_CurrThread(), 0))) { |
| ABORT("Thread stack marking failed\n"); |
| } |
| } |
| |
| # endif /* PCR */ |
| |
| |
| # if defined(GC_PTHREADS) || defined(GC_WIN32_THREADS) |
| |
| extern void GC_push_all_stacks(void); |
| |
| void GC_default_push_other_roots(void) |
| { |
| GC_push_all_stacks(); |
| } |
| |
| # endif /* GC_WIN32_THREADS || GC_PTHREADS */ |
| |
| void (*GC_push_other_roots)(void) = GC_default_push_other_roots; |
| |
| #endif /* THREADS */ |
| |
| /* |
| * Routines for accessing dirty bits on virtual pages. |
| * There are six ways to maintain this information: |
| * DEFAULT_VDB: A simple dummy implementation that treats every page |
| * as possibly dirty. This makes incremental collection |
| * useless, but the implementation is still correct. |
| * MANUAL_VDB: Stacks and static data are always considered dirty. |
| * Heap pages are considered dirty if GC_dirty(p) has been |
| * called on some pointer p pointing to somewhere inside |
| * an object on that page. A GC_dirty() call on a large |
| * object directly dirties only a single page, but for |
| * MANUAL_VDB we are careful to treat an object with a dirty |
| * page as completely dirty. |
| * In order to avoid races, an object must be marked dirty |
| * after it is written, and a reference to the object |
| * must be kept on a stack or in a register in the interim. |
| * With threads enabled, an object directly reachable from the |
| * stack at the time of a collection is treated as dirty. |
| * In single-threaded mode, it suffices to ensure that no |
| * collection can take place between the pointer assignment |
| * and the GC_dirty() call. |
| * PCR_VDB: Use PPCRs virtual dirty bit facility. |
| * PROC_VDB: Use the /proc facility for reading dirty bits. Only |
| * works under some SVR4 variants. Even then, it may be |
| * too slow to be entirely satisfactory. Requires reading |
| * dirty bits for entire address space. Implementations tend |
| * to assume that the client is a (slow) debugger. |
| * MPROTECT_VDB:Protect pages and then catch the faults to keep track of |
| * dirtied pages. The implementation (and implementability) |
| * is highly system dependent. This usually fails when system |
| * calls write to a protected page. We prevent the read system |
| * call from doing so. It is the clients responsibility to |
| * make sure that other system calls are similarly protected |
| * or write only to the stack. |
| * GWW_VDB: Use the Win32 GetWriteWatch functions, if available, to |
| * read dirty bits. In case it is not available (because we |
| * are running on Windows 95, Windows 2000 or earlier), |
| * MPROTECT_VDB may be defined as a fallback strategy. |
| */ |
| GC_bool GC_dirty_maintained = FALSE; |
| |
| #if defined(PROC_VDB) || defined(GWW_VDB) |
| |
| /* Add all pages in pht2 to pht1 */ |
| void GC_or_pages(page_hash_table pht1, page_hash_table pht2) |
| { |
| register int i; |
| |
| for (i = 0; i < PHT_SIZE; i++) pht1[i] |= pht2[i]; |
| } |
| |
| #endif |
| |
| #ifdef GWW_VDB |
| |
| # define GC_GWW_BUF_LEN 1024 |
| static PVOID gww_buf[GC_GWW_BUF_LEN]; |
| |
| # ifdef MPROTECT_VDB |
| GC_bool GC_gww_dirty_init(void) |
| { |
| detect_GetWriteWatch(); |
| return GC_GWW_AVAILABLE(); |
| } |
| # else |
| void GC_dirty_init(void) |
| { |
| detect_GetWriteWatch(); |
| GC_dirty_maintained = GC_GWW_AVAILABLE(); |
| } |
| # endif |
| |
| # ifdef MPROTECT_VDB |
| static void GC_gww_read_dirty(void) |
| # else |
| void GC_read_dirty(void) |
| # endif |
| { |
| word i; |
| |
| BZERO(GC_grungy_pages, sizeof(GC_grungy_pages)); |
| |
| for (i = 0; i != GC_n_heap_sects; ++i) { |
| ULONG_PTR count; |
| |
| do { |
| PVOID * pages, * pages_end; |
| DWORD page_size; |
| |
| pages = gww_buf; |
| count = GC_GWW_BUF_LEN; |
| /* |
| * GetWriteWatch is documented as returning non-zero when it fails, |
| * but the documentation doesn't explicitly say why it would fail or |
| * what its behaviour will be if it fails. |
| * It does appear to fail, at least on recent W2K instances, if |
| * the underlying memory was not allocated with the appropriate |
| * flag. This is common if GC_enable_incremental is called |
| * shortly after GC initialization. To avoid modifying the |
| * interface, we silently work around such a failure, it it only |
| * affects the initial (small) heap allocation. |
| * If there are more dirty |
| * pages than will fit in the buffer, this is not treated as a |
| * failure; we must check the page count in the loop condition. |
| * Since each partial call will reset the status of some |
| * pages, this should eventually terminate even in the overflow |
| * case. |
| */ |
| if (GetWriteWatch_func(WRITE_WATCH_FLAG_RESET, |
| GC_heap_sects[i].hs_start, |
| GC_heap_sects[i].hs_bytes, |
| pages, |
| &count, |
| &page_size) != 0) { |
| static int warn_count = 0; |
| unsigned j; |
| struct hblk * start = (struct hblk *)GC_heap_sects[i].hs_start; |
| static struct hblk *last_warned = 0; |
| size_t nblocks = divHBLKSZ(GC_heap_sects[i].hs_bytes); |
| |
| if ( i != 0 && last_warned != start && warn_count++ < 5) { |
| last_warned = start; |
| WARN( |
| "GC_gww_read_dirty unexpectedly failed at %ld: " |
| "Falling back to marking all pages dirty\n", start); |
| } |
| for (j = 0; j < nblocks; ++j) { |
| word hash = PHT_HASH(start + j); |
| set_pht_entry_from_index(GC_grungy_pages, hash); |
| } |
| count = 1; /* Done with this section. */ |
| } else /* succeeded */{ |
| pages_end = pages + count; |
| while (pages != pages_end) { |
| struct hblk * h = (struct hblk *) *pages++; |
| struct hblk * h_end = (struct hblk *) ((char *) h + page_size); |
| do |
| set_pht_entry_from_index(GC_grungy_pages, PHT_HASH(h)); |
| while (++h < h_end); |
| } |
| } |
| } while (count == GC_GWW_BUF_LEN); |
| } |
| |
| GC_or_pages(GC_written_pages, GC_grungy_pages); |
| } |
| |
| # ifdef MPROTECT_VDB |
| static GC_bool GC_gww_page_was_dirty(struct hblk * h) |
| # else |
| GC_bool GC_page_was_dirty(struct hblk * h) |
| # endif |
| { |
| return HDR(h) == 0 || get_pht_entry_from_index(GC_grungy_pages, PHT_HASH(h)); |
| } |
| |
| # ifdef MPROTECT_VDB |
| static GC_bool GC_gww_page_was_ever_dirty(struct hblk * h) |
| # else |
| GC_bool GC_page_was_ever_dirty(struct hblk * h) |
| # endif |
| { |
| return HDR(h) == 0 || get_pht_entry_from_index(GC_written_pages, PHT_HASH(h)); |
| } |
| |
| # ifndef MPROTECT_VDB |
| void GC_remove_protection(struct hblk *h, word nblocks, GC_bool is_ptrfree) |
| {} |
| # endif |
| |
| # endif /* GWW_VDB */ |
| |
| # ifdef DEFAULT_VDB |
| |
| /* All of the following assume the allocation lock is held, and */ |
| /* signals are disabled. */ |
| |
| /* The client asserts that unallocated pages in the heap are never */ |
| /* written. */ |
| |
| /* Initialize virtual dirty bit implementation. */ |
| void GC_dirty_init(void) |
| { |
| if (GC_print_stats == VERBOSE) |
| GC_log_printf("Initializing DEFAULT_VDB...\n"); |
| GC_dirty_maintained = TRUE; |
| } |
| |
| /* Retrieve system dirty bits for heap to a local buffer. */ |
| /* Restore the systems notion of which pages are dirty. */ |
| void GC_read_dirty(void) |
| {} |
| |
| /* Is the HBLKSIZE sized page at h marked dirty in the local buffer? */ |
| /* If the actual page size is different, this returns TRUE if any */ |
| /* of the pages overlapping h are dirty. This routine may err on the */ |
| /* side of labelling pages as dirty (and this implementation does). */ |
| /*ARGSUSED*/ |
| GC_bool GC_page_was_dirty(struct hblk *h) |
| { |
| return(TRUE); |
| } |
| |
| /* |
| * The following two routines are typically less crucial. They matter |
| * most with large dynamic libraries, or if we can't accurately identify |
| * stacks, e.g. under Solaris 2.X. Otherwise the following default |
| * versions are adequate. |
| */ |
| |
| /* Could any valid GC heap pointer ever have been written to this page? */ |
| /*ARGSUSED*/ |
| GC_bool GC_page_was_ever_dirty(struct hblk *h) |
| { |
| return(TRUE); |
| } |
| |
| /* A call that: */ |
| /* I) hints that [h, h+nblocks) is about to be written. */ |
| /* II) guarantees that protection is removed. */ |
| /* (I) may speed up some dirty bit implementations. */ |
| /* (II) may be essential if we need to ensure that */ |
| /* pointer-free system call buffers in the heap are */ |
| /* not protected. */ |
| /*ARGSUSED*/ |
| void GC_remove_protection(struct hblk *h, word nblocks, GC_bool is_ptrfree) |
| { |
| } |
| |
| # endif /* DEFAULT_VDB */ |
| |
| # ifdef MANUAL_VDB |
| |
| /* Initialize virtual dirty bit implementation. */ |
| void GC_dirty_init(void) |
| { |
| if (GC_print_stats == VERBOSE) |
| GC_log_printf("Initializing MANUAL_VDB...\n"); |
| /* GC_dirty_pages and GC_grungy_pages are already cleared. */ |
| GC_dirty_maintained = TRUE; |
| } |
| |
| /* Retrieve system dirty bits for heap to a local buffer. */ |
| /* Restore the systems notion of which pages are dirty. */ |
| void GC_read_dirty(void) |
| { |
| BCOPY((word *)GC_dirty_pages, GC_grungy_pages, |
| (sizeof GC_dirty_pages)); |
| BZERO((word *)GC_dirty_pages, (sizeof GC_dirty_pages)); |
| } |
| |
| /* Is the HBLKSIZE sized page at h marked dirty in the local buffer? */ |
| /* If the actual page size is different, this returns TRUE if any */ |
| /* of the pages overlapping h are dirty. This routine may err on the */ |
| /* side of labelling pages as dirty (and this implementation does). */ |
| /*ARGSUSED*/ |
| GC_bool GC_page_was_dirty(struct hblk *h) |
| { |
| register word index; |
| |
| index = PHT_HASH(h); |
| return(HDR(h) == 0 || get_pht_entry_from_index(GC_grungy_pages, index)); |
| } |
| |
| /* Could any valid GC heap pointer ever have been written to this page? */ |
| /*ARGSUSED*/ |
| GC_bool GC_page_was_ever_dirty(struct hblk *h) |
| { |
| /* FIXME - implement me. */ |
| return(TRUE); |
| } |
| |
| /* Mark the page containing p as dirty. Logically, this dirties the */ |
| /* entire object. */ |
| void GC_dirty(ptr_t p) |
| { |
| word index = PHT_HASH(p); |
| async_set_pht_entry_from_index(GC_dirty_pages, index); |
| } |
| |
| /*ARGSUSED*/ |
| void GC_remove_protection(struct hblk *h, word nblocks, GC_bool is_ptrfree) |
| { |
| } |
| |
| # endif /* MANUAL_VDB */ |
| |
| |
| # ifdef MPROTECT_VDB |
| |
| /* |
| * See DEFAULT_VDB for interface descriptions. |
| */ |
| |
| /* |
| * This implementation maintains dirty bits itself by catching write |
| * faults and keeping track of them. We assume nobody else catches |
| * SIGBUS or SIGSEGV. We assume no write faults occur in system calls. |
| * This means that clients must ensure that system calls don't write |
| * to the write-protected heap. Probably the best way to do this is to |
| * ensure that system calls write at most to POINTERFREE objects in the |
| * heap, and do even that only if we are on a platform on which those |
| * are not protected. Another alternative is to wrap system calls |
| * (see example for read below), but the current implementation holds |
| * applications. |
| * We assume the page size is a multiple of HBLKSIZE. |
| * We prefer them to be the same. We avoid protecting POINTERFREE |
| * objects only if they are the same. |
| */ |
| |
| # if !defined(MSWIN32) && !defined(MSWINCE) && !defined(DARWIN) |
| |
| # include <sys/mman.h> |
| # include <signal.h> |
| # include <sys/syscall.h> |
| |
| # define PROTECT(addr, len) \ |
| if (mprotect((caddr_t)(addr), (size_t)(len), \ |
| PROT_READ | OPT_PROT_EXEC) < 0) { \ |
| ABORT("mprotect failed"); \ |
| } |
| # define UNPROTECT(addr, len) \ |
| if (mprotect((caddr_t)(addr), (size_t)(len), \ |
| PROT_WRITE | PROT_READ | OPT_PROT_EXEC ) < 0) { \ |
| ABORT("un-mprotect failed"); \ |
| } |
| |
| # else |
| |
| # ifdef DARWIN |
| /* Using vm_protect (mach syscall) over mprotect (BSD syscall) seems to |
| decrease the likelihood of some of the problems described below. */ |
| #include <mach/vm_map.h> |
| static mach_port_t GC_task_self; |
| #define PROTECT(addr,len) \ |
| if(vm_protect(GC_task_self,(vm_address_t)(addr),(vm_size_t)(len), \ |
| FALSE,VM_PROT_READ) != KERN_SUCCESS) { \ |
| ABORT("vm_portect failed"); \ |
| } |
| #define UNPROTECT(addr,len) \ |
| if(vm_protect(GC_task_self,(vm_address_t)(addr),(vm_size_t)(len), \ |
| FALSE,VM_PROT_READ|VM_PROT_WRITE) != KERN_SUCCESS) { \ |
| ABORT("vm_portect failed"); \ |
| } |
| # else |
| |
| # ifndef MSWINCE |
| # include <signal.h> |
| # endif |
| |
| static DWORD protect_junk; |
| # define PROTECT(addr, len) \ |
| if (!VirtualProtect((addr), (len), PAGE_EXECUTE_READ, \ |
| &protect_junk)) { \ |
| DWORD last_error = GetLastError(); \ |
| GC_printf("Last error code: %lx\n", last_error); \ |
| ABORT("VirtualProtect failed"); \ |
| } |
| # define UNPROTECT(addr, len) \ |
| if (!VirtualProtect((addr), (len), PAGE_EXECUTE_READWRITE, \ |
| &protect_junk)) { \ |
| ABORT("un-VirtualProtect failed"); \ |
| } |
| # endif /* !DARWIN */ |
| # endif /* MSWIN32 || MSWINCE || DARWIN */ |
| |
| #if defined(MSWIN32) |
| typedef LPTOP_LEVEL_EXCEPTION_FILTER SIG_HNDLR_PTR; |
| # undef SIG_DFL |
| # define SIG_DFL (LPTOP_LEVEL_EXCEPTION_FILTER) (-1) |
| #elif defined(MSWINCE) |
| typedef LONG (WINAPI *SIG_HNDLR_PTR)(struct _EXCEPTION_POINTERS *); |
| # undef SIG_DFL |
| # define SIG_DFL (SIG_HNDLR_PTR) (-1) |
| #elif defined(DARWIN) |
| typedef void (* SIG_HNDLR_PTR)(); |
| #else |
| typedef void (* SIG_HNDLR_PTR)(int, siginfo_t *, void *); |
| typedef void (* PLAIN_HNDLR_PTR)(int); |
| #endif |
| |
| #if defined(__GLIBC__) |
| # if __GLIBC__ < 2 || __GLIBC__ == 2 && __GLIBC_MINOR__ < 2 |
| # error glibc too old? |
| # endif |
| #endif |
| |
| #ifndef DARWIN |
| SIG_HNDLR_PTR GC_old_bus_handler; |
| GC_bool GC_old_bus_handler_used_si; |
| SIG_HNDLR_PTR GC_old_segv_handler; |
| /* Also old MSWIN32 ACCESS_VIOLATION filter */ |
| GC_bool GC_old_segv_handler_used_si; |
| #endif /* !DARWIN */ |
| |
| #if defined(THREADS) |
| /* We need to lock around the bitmap update in the write fault handler */ |
| /* in order to avoid the risk of losing a bit. We do this with a */ |
| /* test-and-set spin lock if we know how to do that. Otherwise we */ |
| /* check whether we are already in the handler and use the dumb but */ |
| /* safe fallback algorithm of setting all bits in the word. */ |
| /* Contention should be very rare, so we do the minimum to handle it */ |
| /* correctly. */ |
| #ifdef AO_HAVE_test_and_set_acquire |
| static volatile AO_TS_t fault_handler_lock = 0; |
| void async_set_pht_entry_from_index(volatile page_hash_table db, size_t index) { |
| while (AO_test_and_set_acquire(&fault_handler_lock) == AO_TS_SET) {} |
| /* Could also revert to set_pht_entry_from_index_safe if initial */ |
| /* GC_test_and_set fails. */ |
| set_pht_entry_from_index(db, index); |
| AO_CLEAR(&fault_handler_lock); |
| } |
| #else /* !AO_have_test_and_set_acquire */ |
| # error No test_and_set operation: Introduces a race. |
| /* THIS WOULD BE INCORRECT! */ |
| /* The dirty bit vector may be temporarily wrong, */ |
| /* just before we notice the conflict and correct it. We may end up */ |
| /* looking at it while it's wrong. But this requires contention */ |
| /* exactly when a GC is triggered, which seems far less likely to */ |
| /* fail than the old code, which had no reported failures. Thus we */ |
| /* leave it this way while we think of something better, or support */ |
| /* GC_test_and_set on the remaining platforms. */ |
| static volatile word currently_updating = 0; |
| void async_set_pht_entry_from_index(volatile page_hash_table db, size_t index) { |
| unsigned int update_dummy; |
| currently_updating = (word)(&update_dummy); |
| set_pht_entry_from_index(db, index); |
| /* If we get contention in the 10 or so instruction window here, */ |
| /* and we get stopped by a GC between the two updates, we lose! */ |
| if (currently_updating != (word)(&update_dummy)) { |
| set_pht_entry_from_index_safe(db, index); |
| /* We claim that if two threads concurrently try to update the */ |
| /* dirty bit vector, the first one to execute UPDATE_START */ |
| /* will see it changed when UPDATE_END is executed. (Note that */ |
| /* &update_dummy must differ in two distinct threads.) It */ |
| /* will then execute set_pht_entry_from_index_safe, thus */ |
| /* returning us to a safe state, though not soon enough. */ |
| } |
| } |
| #endif /* !AO_HAVE_test_and_set_acquire */ |
| #else /* !THREADS */ |
| # define async_set_pht_entry_from_index(db, index) \ |
| set_pht_entry_from_index(db, index) |
| #endif /* !THREADS */ |
| |
| #if !defined(DARWIN) |
| # include <errno.h> |
| # if defined(FREEBSD) |
| # define SIG_OK TRUE |
| # define CODE_OK (code == BUS_PAGE_FAULT) |
| # elif defined(OSF1) |
| # define SIG_OK (sig == SIGSEGV) |
| # define CODE_OK (code == 2 /* experimentally determined */) |
| # elif defined(IRIX5) |
| # define SIG_OK (sig == SIGSEGV) |
| # define CODE_OK (code == EACCES) |
| # elif defined(HURD) |
| # define SIG_OK (sig == SIGBUS || sig == SIGSEGV) |
| # define CODE_OK TRUE |
| # elif defined(LINUX) |
| # define SIG_OK (sig == SIGSEGV) |
| # define CODE_OK TRUE |
| /* Empirically c.trapno == 14, on IA32, but is that useful? */ |
| /* Should probably consider alignment issues on other */ |
| /* architectures. */ |
| # elif defined(HPUX) |
| # define SIG_OK (sig == SIGSEGV || sig == SIGBUS) |
| # define CODE_OK (si -> si_code == SEGV_ACCERR) \ |
| || (si -> si_code == BUS_ADRERR) \ |
| || (si -> si_code == BUS_UNKNOWN) \ |
| || (si -> si_code == SEGV_UNKNOWN) \ |
| || (si -> si_code == BUS_OBJERR) |
| # elif defined(FREEBSD) |
| # define SIG_OK (sig == SIGBUS) |
| # define CODE_OK (si -> si_code == BUS_PAGE_FAULT) |
| # elif defined(SUNOS5SIGS) |
| # define SIG_OK (sig == SIGSEGV) |
| # define CODE_OK (si -> si_code == SEGV_ACCERR) |
| # elif defined(MSWIN32) || defined(MSWINCE) |
| # define SIG_OK (exc_info -> ExceptionRecord -> ExceptionCode \ |
| == STATUS_ACCESS_VIOLATION) |
| # define CODE_OK (exc_info -> ExceptionRecord -> ExceptionInformation[0] \ |
| == 1) /* Write fault */ |
| # endif |
| |
| # if defined(MSWIN32) || defined(MSWINCE) |
| LONG WINAPI GC_write_fault_handler(struct _EXCEPTION_POINTERS *exc_info) |
| # else |
| # include <ucontext.h> |
| /*ARGSUSED*/ |
| void GC_write_fault_handler(int sig, siginfo_t *si, void *raw_sc) |
| # endif /* MSWIN32 || MSWINCE */ |
| { |
| # if !defined(MSWIN32) && !defined(MSWINCE) |
| int code = si -> si_code; /* Ignore gcc unused var. warning. */ |
| ucontext_t * scp = (ucontext_t *)raw_sc; |
| /* Ignore gcc unused var. warning. */ |
| char *addr = si -> si_addr; |
| # endif |
| # if defined(MSWIN32) || defined(MSWINCE) |
| char * addr = (char *) (exc_info -> ExceptionRecord |
| -> ExceptionInformation[1]); |
| # define sig SIGSEGV |
| # endif |
| unsigned i; |
| |
| if (SIG_OK && CODE_OK) { |
| register struct hblk * h = |
| (struct hblk *)((word)addr & ~(GC_page_size-1)); |
| GC_bool in_allocd_block; |
| |
| # ifdef SUNOS5SIGS |
| /* Address is only within the correct physical page. */ |
| in_allocd_block = FALSE; |
| for (i = 0; i < divHBLKSZ(GC_page_size); i++) { |
| if (HDR(h+i) != 0) { |
| in_allocd_block = TRUE; |
| } |
| } |
| # else |
| in_allocd_block = (HDR(addr) != 0); |
| # endif |
| if (!in_allocd_block) { |
| /* FIXME - We should make sure that we invoke the */ |
| /* old handler with the appropriate calling */ |
| /* sequence, which often depends on SA_SIGINFO. */ |
| |
| /* Heap blocks now begin and end on page boundaries */ |
| SIG_HNDLR_PTR old_handler; |
| GC_bool used_si; |
| |
| if (sig == SIGSEGV) { |
| old_handler = GC_old_segv_handler; |
| used_si = GC_old_segv_handler_used_si; |
| } else { |
| old_handler = GC_old_bus_handler; |
| used_si = GC_old_bus_handler_used_si; |
| } |
| if (old_handler == (SIG_HNDLR_PTR)SIG_DFL) { |
| # if !defined(MSWIN32) && !defined(MSWINCE) |
| GC_err_printf("Segfault at %p\n", addr); |
| ABORT("Unexpected bus error or segmentation fault"); |
| # else |
| return(EXCEPTION_CONTINUE_SEARCH); |
| # endif |
| } else { |
| /* |
| * FIXME: This code should probably check if the |
| * old signal handler used the traditional style and |
| * if so call it using that style. |
| */ |
| # ifdef MSWIN32 |
| return((*old_handler)(exc_info)); |
| # else |
| if (used_si) |
| ((SIG_HNDLR_PTR)old_handler) (sig, si, raw_sc); |
| else |
| /* FIXME: should pass nonstandard args as well. */ |
| ((PLAIN_HNDLR_PTR)old_handler) (sig); |
| return; |
| # endif |
| } |
| } |
| UNPROTECT(h, GC_page_size); |
| /* We need to make sure that no collection occurs between */ |
| /* the UNPROTECT and the setting of the dirty bit. Otherwise */ |
| /* a write by a third thread might go unnoticed. Reversing */ |
| /* the order is just as bad, since we would end up unprotecting */ |
| /* a page in a GC cycle during which it's not marked. */ |
| /* Currently we do this by disabling the thread stopping */ |
| /* signals while this handler is running. An alternative might */ |
| /* be to record the fact that we're about to unprotect, or */ |
| /* have just unprotected a page in the GC's thread structure, */ |
| /* and then to have the thread stopping code set the dirty */ |
| /* flag, if necessary. */ |
| for (i = 0; i < divHBLKSZ(GC_page_size); i++) { |
| size_t index = PHT_HASH(h+i); |
| |
| async_set_pht_entry_from_index(GC_dirty_pages, index); |
| } |
| /* The write may not take place before dirty bits are read. */ |
| /* But then we'll fault again ... */ |
| # if defined(MSWIN32) || defined(MSWINCE) |
| return(EXCEPTION_CONTINUE_EXECUTION); |
| # else |
| return; |
| # endif |
| } |
| #if defined(MSWIN32) || defined(MSWINCE) |
| return EXCEPTION_CONTINUE_SEARCH; |
| #else |
| GC_err_printf("Segfault at %p\n", addr); |
| ABORT("Unexpected bus error or segmentation fault"); |
| #endif |
| } |
| #endif /* !DARWIN */ |
| |
| /* |
| * We hold the allocation lock. We expect block h to be written |
| * shortly. Ensure that all pages containing any part of the n hblks |
| * starting at h are no longer protected. If is_ptrfree is false, |
| * also ensure that they will subsequently appear to be dirty. |
| */ |
| void GC_remove_protection(struct hblk *h, word nblocks, GC_bool is_ptrfree) |
| { |
| struct hblk * h_trunc; /* Truncated to page boundary */ |
| struct hblk * h_end; /* Page boundary following block end */ |
| struct hblk * current; |
| GC_bool found_clean; |
| |
| # if defined(GWW_VDB) |
| if (GC_GWW_AVAILABLE()) return; |
| # endif |
| if (!GC_dirty_maintained) return; |
| h_trunc = (struct hblk *)((word)h & ~(GC_page_size-1)); |
| h_end = (struct hblk *)(((word)(h + nblocks) + GC_page_size-1) |
| & ~(GC_page_size-1)); |
| found_clean = FALSE; |
| for (current = h_trunc; current < h_end; ++current) { |
| size_t index = PHT_HASH(current); |
| |
| if (!is_ptrfree || current < h || current >= h + nblocks) { |
| async_set_pht_entry_from_index(GC_dirty_pages, index); |
| } |
| } |
| UNPROTECT(h_trunc, (ptr_t)h_end - (ptr_t)h_trunc); |
| } |
| |
| #if !defined(DARWIN) |
| void GC_dirty_init(void) |
| { |
| # if !defined(MSWIN32) && !defined(MSWINCE) |
| struct sigaction act, oldact; |
| act.sa_flags = SA_RESTART | SA_SIGINFO; |
| act.sa_sigaction = GC_write_fault_handler; |
| (void)sigemptyset(&act.sa_mask); |
| # ifdef SIG_SUSPEND |
| /* Arrange to postpone SIG_SUSPEND while we're in a write fault */ |
| /* handler. This effectively makes the handler atomic w.r.t. */ |
| /* stopping the world for GC. */ |
| (void)sigaddset(&act.sa_mask, SIG_SUSPEND); |
| # endif /* SIG_SUSPEND */ |
| # endif |
| if (GC_print_stats == VERBOSE) |
| GC_log_printf( |
| "Initializing mprotect virtual dirty bit implementation\n"); |
| GC_dirty_maintained = TRUE; |
| if (GC_page_size % HBLKSIZE != 0) { |
| GC_err_printf("Page size not multiple of HBLKSIZE\n"); |
| ABORT("Page size not multiple of HBLKSIZE"); |
| } |
| # if !defined(MSWIN32) && !defined(MSWINCE) |
| # if defined(GC_IRIX_THREADS) |
| sigaction(SIGSEGV, 0, &oldact); |
| sigaction(SIGSEGV, &act, 0); |
| # else |
| { |
| int res = sigaction(SIGSEGV, &act, &oldact); |
| if (res != 0) ABORT("Sigaction failed"); |
| } |
| # endif |
| if (oldact.sa_flags & SA_SIGINFO) { |
| GC_old_segv_handler = oldact.sa_sigaction; |
| GC_old_segv_handler_used_si = TRUE; |
| } else { |
| GC_old_segv_handler = (SIG_HNDLR_PTR)oldact.sa_handler; |
| GC_old_segv_handler_used_si = FALSE; |
| } |
| if (GC_old_segv_handler == (SIG_HNDLR_PTR)SIG_IGN) { |
| GC_err_printf("Previously ignored segmentation violation!?"); |
| GC_old_segv_handler = (SIG_HNDLR_PTR)SIG_DFL; |
| } |
| if (GC_old_segv_handler != (SIG_HNDLR_PTR)SIG_DFL) { |
| if (GC_print_stats == VERBOSE) |
| GC_log_printf("Replaced other SIGSEGV handler\n"); |
| } |
| # endif /* ! MS windows */ |
| # if defined(HPUX) || defined(LINUX) || defined(HURD) \ |
| || (defined(FREEBSD) && defined(SUNOS5SIGS)) |
| sigaction(SIGBUS, &act, &oldact); |
| if (oldact.sa_flags & SA_SIGINFO) { |
| GC_old_bus_handler = oldact.sa_sigaction; |
| GC_old_bus_handler_used_si = TRUE; |
| } else { |
| GC_old_bus_handler = (SIG_HNDLR_PTR)oldact.sa_handler; |
| GC_old_bus_handler_used_si = FALSE; |
| } |
| if (GC_old_bus_handler == (SIG_HNDLR_PTR)SIG_IGN) { |
| GC_err_printf("Previously ignored bus error!?"); |
| GC_old_bus_handler = (SIG_HNDLR_PTR)SIG_DFL; |
| } |
| if (GC_old_bus_handler != (SIG_HNDLR_PTR)SIG_DFL) { |
| if (GC_print_stats == VERBOSE) |
| GC_log_printf("Replaced other SIGBUS handler\n"); |
| } |
| # endif /* HPUX || LINUX || HURD || (FREEBSD && SUNOS5SIGS) */ |
| # if defined(MSWIN32) |
| # if defined(GWW_VDB) |
| if (GC_gww_dirty_init()) |
| return; |
| # endif |
| GC_old_segv_handler = SetUnhandledExceptionFilter(GC_write_fault_handler); |
| if (GC_old_segv_handler != NULL) { |
| if (GC_print_stats) |
| GC_log_printf("Replaced other UnhandledExceptionFilter\n"); |
| } else { |
| GC_old_segv_handler = SIG_DFL; |
| } |
| # endif |
| } |
| #endif /* !DARWIN */ |
| |
| int GC_incremental_protection_needs(void) |
| { |
| if (GC_page_size == HBLKSIZE) { |
| return GC_PROTECTS_POINTER_HEAP; |
| } else { |
| return GC_PROTECTS_POINTER_HEAP | GC_PROTECTS_PTRFREE_HEAP; |
| } |
| } |
| |
| #define HAVE_INCREMENTAL_PROTECTION_NEEDS |
| |
| #define IS_PTRFREE(hhdr) ((hhdr)->hb_descr == 0) |
| |
| #define PAGE_ALIGNED(x) !((word)(x) & (GC_page_size - 1)) |
| void GC_protect_heap(void) |
| { |
| ptr_t start; |
| size_t len; |
| struct hblk * current; |
| struct hblk * current_start; /* Start of block to be protected. */ |
| struct hblk * limit; |
| unsigned i; |
| GC_bool protect_all = |
| (0 != (GC_incremental_protection_needs() & GC_PROTECTS_PTRFREE_HEAP)); |
| for (i = 0; i < GC_n_heap_sects; i++) { |
| start = GC_heap_sects[i].hs_start; |
| len = GC_heap_sects[i].hs_bytes; |
| if (protect_all) { |
| PROTECT(start, len); |
| } else { |
| GC_ASSERT(PAGE_ALIGNED(len)) |
| GC_ASSERT(PAGE_ALIGNED(start)) |
| current_start = current = (struct hblk *)start; |
| limit = (struct hblk *)(start + len); |
| while (current < limit) { |
| hdr * hhdr; |
| word nhblks; |
| GC_bool is_ptrfree; |
| |
| GC_ASSERT(PAGE_ALIGNED(current)); |
| GET_HDR(current, hhdr); |
| if (IS_FORWARDING_ADDR_OR_NIL(hhdr)) { |
| /* This can happen only if we're at the beginning of a */ |
| /* heap segment, and a block spans heap segments. */ |
| /* We will handle that block as part of the preceding */ |
| /* segment. */ |
| GC_ASSERT(current_start == current); |
| current_start = ++current; |
| continue; |
| } |
| if (HBLK_IS_FREE(hhdr)) { |
| GC_ASSERT(PAGE_ALIGNED(hhdr -> hb_sz)); |
| nhblks = divHBLKSZ(hhdr -> hb_sz); |
| is_ptrfree = TRUE; /* dirty on alloc */ |
| } else { |
| nhblks = OBJ_SZ_TO_BLOCKS(hhdr -> hb_sz); |
| is_ptrfree = IS_PTRFREE(hhdr); |
| } |
| if (is_ptrfree) { |
| if (current_start < current) { |
| PROTECT(current_start, (ptr_t)current - (ptr_t)current_start); |
| } |
| current_start = (current += nhblks); |
| } else { |
| current += nhblks; |
| } |
| } |
| if (current_start < current) { |
| PROTECT(current_start, (ptr_t)current - (ptr_t)current_start); |
| } |
| } |
| } |
| } |
| |
| /* We assume that either the world is stopped or its OK to lose dirty */ |
| /* bits while this is happenning (as in GC_enable_incremental). */ |
| void GC_read_dirty(void) |
| { |
| # if defined(GWW_VDB) |
| if (GC_GWW_AVAILABLE()) { |
| GC_gww_read_dirty(); |
| return; |
| } |
| # endif |
| BCOPY((word *)GC_dirty_pages, GC_grungy_pages, |
| (sizeof GC_dirty_pages)); |
| BZERO((word *)GC_dirty_pages, (sizeof GC_dirty_pages)); |
| GC_protect_heap(); |
| } |
| |
| GC_bool GC_page_was_dirty(struct hblk *h) |
| { |
| register word index; |
| |
| # if defined(GWW_VDB) |
| if (GC_GWW_AVAILABLE()) |
| return GC_gww_page_was_dirty(h); |
| # endif |
| |
| index = PHT_HASH(h); |
| return(HDR(h) == 0 || get_pht_entry_from_index(GC_grungy_pages, index)); |
| } |
| |
| /* |
| * Acquiring the allocation lock here is dangerous, since this |
| * can be called from within GC_call_with_alloc_lock, and the cord |
| * package does so. On systems that allow nested lock acquisition, this |
| * happens to work. |
| * On other systems, SET_LOCK_HOLDER and friends must be suitably defined. |
| */ |
| |
| static GC_bool syscall_acquired_lock = FALSE; /* Protected by GC lock. */ |
| |
| #if 0 |
| void GC_begin_syscall(void) |
| { |
| /* FIXME: Resurrecting this code would require fixing the */ |
| /* test, which can spuriously return TRUE. */ |
| if (!I_HOLD_LOCK()) { |
| LOCK(); |
| syscall_acquired_lock = TRUE; |
| } |
| } |
| |
| void GC_end_syscall(void) |
| { |
| if (syscall_acquired_lock) { |
| syscall_acquired_lock = FALSE; |
| UNLOCK(); |
| } |
| } |
| |
| void GC_unprotect_range(ptr_t addr, word len) |
| { |
| struct hblk * start_block; |
| struct hblk * end_block; |
| register struct hblk *h; |
| ptr_t obj_start; |
| |
| if (!GC_dirty_maintained) return; |
| obj_start = GC_base(addr); |
| if (obj_start == 0) return; |
| if (GC_base(addr + len - 1) != obj_start) { |
| ABORT("GC_unprotect_range(range bigger than object)"); |
| } |
| start_block = (struct hblk *)((word)addr & ~(GC_page_size - 1)); |
| end_block = (struct hblk *)((word)(addr + len - 1) & ~(GC_page_size - 1)); |
| end_block += GC_page_size/HBLKSIZE - 1; |
| for (h = start_block; h <= end_block; h++) { |
| register word index = PHT_HASH(h); |
| |
| async_set_pht_entry_from_index(GC_dirty_pages, index); |
| } |
| UNPROTECT(start_block, |
| ((ptr_t)end_block - (ptr_t)start_block) + HBLKSIZE); |
| } |
| |
| |
| /* We no longer wrap read by default, since that was causing too many */ |
| /* problems. It is preferred that the client instead avoids writing */ |
| /* to the write-protected heap with a system call. */ |
| /* This still serves as sample code if you do want to wrap system calls.*/ |
| |
| #if !defined(MSWIN32) && !defined(MSWINCE) && !defined(GC_USE_LD_WRAP) |
| /* Replacement for UNIX system call. */ |
| /* Other calls that write to the heap should be handled similarly. */ |
| /* Note that this doesn't work well for blocking reads: It will hold */ |
| /* the allocation lock for the entire duration of the call. Multithreaded */ |
| /* clients should really ensure that it won't block, either by setting */ |
| /* the descriptor nonblocking, or by calling select or poll first, to */ |
| /* make sure that input is available. */ |
| /* Another, preferred alternative is to ensure that system calls never */ |
| /* write to the protected heap (see above). */ |
| # include <unistd.h> |
| # include <sys/uio.h> |
| ssize_t read(int fd, void *buf, size_t nbyte) |
| { |
| int result; |
| |
| GC_begin_syscall(); |
| GC_unprotect_range(buf, (word)nbyte); |
| # if defined(IRIX5) || defined(GC_LINUX_THREADS) |
| /* Indirect system call may not always be easily available. */ |
| /* We could call _read, but that would interfere with the */ |
| /* libpthread interception of read. */ |
| /* On Linux, we have to be careful with the linuxthreads */ |
| /* read interception. */ |
| { |
| struct iovec iov; |
| |
| iov.iov_base = buf; |
| iov.iov_len = nbyte; |
| result = readv(fd, &iov, 1); |
| } |
| # else |
| # if defined(HURD) |
| result = __read(fd, buf, nbyte); |
| # else |
| /* The two zero args at the end of this list are because one |
| IA-64 syscall() implementation actually requires six args |
| to be passed, even though they aren't always used. */ |
| result = syscall(SYS_read, fd, buf, nbyte, 0, 0); |
| # endif /* !HURD */ |
| # endif |
| GC_end_syscall(); |
| return(result); |
| } |
| #endif /* !MSWIN32 && !MSWINCE && !GC_LINUX_THREADS */ |
| |
| #if defined(GC_USE_LD_WRAP) && !defined(THREADS) |
| /* We use the GNU ld call wrapping facility. */ |
| /* This requires that the linker be invoked with "--wrap read". */ |
| /* This can be done by passing -Wl,"--wrap read" to gcc. */ |
| /* I'm not sure that this actually wraps whatever version of read */ |
| /* is called by stdio. That code also mentions __read. */ |
| # include <unistd.h> |
| ssize_t __wrap_read(int fd, void *buf, size_t nbyte) |
| { |
| int result; |
| |
| GC_begin_syscall(); |
| GC_unprotect_range(buf, (word)nbyte); |
| result = __real_read(fd, buf, nbyte); |
| GC_end_syscall(); |
| return(result); |
| } |
| |
| /* We should probably also do this for __read, or whatever stdio */ |
| /* actually calls. */ |
| #endif |
| |
| #endif /* 0 */ |
| |
| /*ARGSUSED*/ |
| GC_bool GC_page_was_ever_dirty(struct hblk *h) |
| { |
| # if defined(GWW_VDB) |
| if (GC_GWW_AVAILABLE()) |
| return GC_gww_page_was_ever_dirty(h); |
| # endif |
| return(TRUE); |
| } |
| |
| # endif /* MPROTECT_VDB */ |
| |
| # ifdef PROC_VDB |
| |
| /* |
| * See DEFAULT_VDB for interface descriptions. |
| */ |
| |
| /* |
| * This implementaion assumes a Solaris 2.X like /proc pseudo-file-system |
| * from which we can read page modified bits. This facility is far from |
| * optimal (e.g. we would like to get the info for only some of the |
| * address space), but it avoids intercepting system calls. |
| */ |
| |
| #include <errno.h> |
| #include <sys/types.h> |
| #include <sys/signal.h> |
| #include <sys/fault.h> |
| #include <sys/syscall.h> |
| #include <sys/procfs.h> |
| #include <sys/stat.h> |
| |
| #define INITIAL_BUF_SZ 16384 |
| word GC_proc_buf_size = INITIAL_BUF_SZ; |
| char *GC_proc_buf; |
| |
| int GC_proc_fd; |
| |
| void GC_dirty_init(void) |
| { |
| int fd; |
| char buf[30]; |
| |
| GC_dirty_maintained = TRUE; |
| if (GC_bytes_allocd != 0 || GC_bytes_allocd_before_gc != 0) { |
| register int i; |
| |
| for (i = 0; i < PHT_SIZE; i++) GC_written_pages[i] = (word)(-1); |
| if (GC_print_stats == VERBOSE) |
| GC_log_printf( |
| "Allocated bytes:%lu:all pages may have been written\n", |
| (unsigned long) |
| (GC_bytes_allocd + GC_bytes_allocd_before_gc)); |
| } |
| sprintf(buf, "/proc/%d", getpid()); |
| fd = open(buf, O_RDONLY); |
| if (fd < 0) { |
| ABORT("/proc open failed"); |
| } |
| GC_proc_fd = syscall(SYS_ioctl, fd, PIOCOPENPD, 0); |
| close(fd); |
| syscall(SYS_fcntl, GC_proc_fd, F_SETFD, FD_CLOEXEC); |
| if (GC_proc_fd < 0) { |
| ABORT("/proc ioctl failed"); |
| } |
| GC_proc_buf = GC_scratch_alloc(GC_proc_buf_size); |
| } |
| |
| /* Ignore write hints. They don't help us here. */ |
| /*ARGSUSED*/ |
| void GC_remove_protection(h, nblocks, is_ptrfree) |
| struct hblk *h; |
| word nblocks; |
| GC_bool is_ptrfree; |
| { |
| } |
| |
| # define READ(fd,buf,nbytes) read(fd, buf, nbytes) |
| |
| void GC_read_dirty(void) |
| { |
| unsigned long ps, np; |
| int nmaps; |
| ptr_t vaddr; |
| struct prasmap * map; |
| char * bufp; |
| ptr_t current_addr, limit; |
| int i; |
| |
| BZERO(GC_grungy_pages, (sizeof GC_grungy_pages)); |
| |
| bufp = GC_proc_buf; |
| if (READ(GC_proc_fd, bufp, GC_proc_buf_size) <= 0) { |
| if (GC_print_stats) |
| GC_log_printf("/proc read failed: GC_proc_buf_size = %lu\n", |
| (unsigned long)GC_proc_buf_size); |
| { |
| /* Retry with larger buffer. */ |
| word new_size = 2 * GC_proc_buf_size; |
| char * new_buf = GC_scratch_alloc(new_size); |
| |
| if (new_buf != 0) { |
| GC_proc_buf = bufp = new_buf; |
| GC_proc_buf_size = new_size; |
| } |
| if (READ(GC_proc_fd, bufp, GC_proc_buf_size) <= 0) { |
| WARN("Insufficient space for /proc read\n", 0); |
| /* Punt: */ |
| memset(GC_grungy_pages, 0xff, sizeof (page_hash_table)); |
| memset(GC_written_pages, 0xff, sizeof(page_hash_table)); |
| return; |
| } |
| } |
| } |
| /* Copy dirty bits into GC_grungy_pages */ |
| nmaps = ((struct prpageheader *)bufp) -> pr_nmap; |
| /* printf( "nmaps = %d, PG_REFERENCED = %d, PG_MODIFIED = %d\n", |
| nmaps, PG_REFERENCED, PG_MODIFIED); */ |
| bufp = bufp + sizeof(struct prpageheader); |
| for (i = 0; i < nmaps; i++) { |
| map = (struct prasmap *)bufp; |
| vaddr = (ptr_t)(map -> pr_vaddr); |
| ps = map -> pr_pagesize; |
| np = map -> pr_npage; |
| /* printf("vaddr = 0x%X, ps = 0x%X, np = 0x%X\n", vaddr, ps, np); */ |
| limit = vaddr + ps * np; |
| bufp += sizeof (struct prasmap); |
| for (current_addr = vaddr; |
| current_addr < limit; current_addr += ps){ |
| if ((*bufp++) & PG_MODIFIED) { |
| register struct hblk * h = (struct hblk *) current_addr; |
| |
| while ((ptr_t)h < current_addr + ps) { |
| register word index = PHT_HASH(h); |
| |
| set_pht_entry_from_index(GC_grungy_pages, index); |
| h++; |
| } |
| } |
| } |
| bufp += sizeof(long) - 1; |
| bufp = (char *)((unsigned long)bufp & ~(sizeof(long)-1)); |
| } |
| /* Update GC_written_pages. */ |
| GC_or_pages(GC_written_pages, GC_grungy_pages); |
| } |
| |
| #undef READ |
| |
| GC_bool GC_page_was_dirty(struct hblk *h) |
| { |
| register word index = PHT_HASH(h); |
| register GC_bool result; |
| |
| result = get_pht_entry_from_index(GC_grungy_pages, index); |
| return(result); |
| } |
| |
| GC_bool GC_page_was_ever_dirty(struct hblk *h) |
| { |
| register word index = PHT_HASH(h); |
| register GC_bool result; |
| |
| result = get_pht_entry_from_index(GC_written_pages, index); |
| return(result); |
| } |
| |
| # endif /* PROC_VDB */ |
| |
| |
| # ifdef PCR_VDB |
| |
| # include "vd/PCR_VD.h" |
| |
| # define NPAGES (32*1024) /* 128 MB */ |
| |
| PCR_VD_DB GC_grungy_bits[NPAGES]; |
| |
| ptr_t GC_vd_base; /* Address corresponding to GC_grungy_bits[0] */ |
| /* HBLKSIZE aligned. */ |
| |
| void GC_dirty_init(void) |
| { |
| GC_dirty_maintained = TRUE; |
| /* For the time being, we assume the heap generally grows up */ |
| GC_vd_base = GC_heap_sects[0].hs_start; |
| if (GC_vd_base == 0) { |
| ABORT("Bad initial heap segment"); |
| } |
| if (PCR_VD_Start(HBLKSIZE, GC_vd_base, NPAGES*HBLKSIZE) |
| != PCR_ERes_okay) { |
| ABORT("dirty bit initialization failed"); |
| } |
| } |
| |
| void GC_read_dirty(void) |
| { |
| /* lazily enable dirty bits on newly added heap sects */ |
| { |
| static int onhs = 0; |
| int nhs = GC_n_heap_sects; |
| for( ; onhs < nhs; onhs++ ) { |
| PCR_VD_WriteProtectEnable( |
| GC_heap_sects[onhs].hs_start, |
| GC_heap_sects[onhs].hs_bytes ); |
| } |
| } |
| |
| |
| if (PCR_VD_Clear(GC_vd_base, NPAGES*HBLKSIZE, GC_grungy_bits) |
| != PCR_ERes_okay) { |
| ABORT("dirty bit read failed"); |
| } |
| } |
| |
| GC_bool GC_page_was_dirty(struct hblk *h) |
| { |
| if((ptr_t)h < GC_vd_base || (ptr_t)h >= GC_vd_base + NPAGES*HBLKSIZE) { |
| return(TRUE); |
| } |
| return(GC_grungy_bits[h - (struct hblk *)GC_vd_base] & PCR_VD_DB_dirtyBit); |
| } |
| |
| /*ARGSUSED*/ |
| void GC_remove_protection(struct hblk *h, word nblocks, GC_bool is_ptrfree) |
| { |
| PCR_VD_WriteProtectDisable(h, nblocks*HBLKSIZE); |
| PCR_VD_WriteProtectEnable(h, nblocks*HBLKSIZE); |
| } |
| |
| # endif /* PCR_VDB */ |
| |
| #if defined(MPROTECT_VDB) && defined(DARWIN) |
| /* The following sources were used as a *reference* for this exception handling |
| code: |
| 1. Apple's mach/xnu documentation |
| 2. Timothy J. Wood's "Mach Exception Handlers 101" post to the |
| omnigroup's macosx-dev list. |
| www.omnigroup.com/mailman/archive/macosx-dev/2000-June/014178.html |
| 3. macosx-nat.c from Apple's GDB source code. |
| */ |
| |
| /* The bug that caused all this trouble should now be fixed. This should |
| eventually be removed if all goes well. */ |
| |
| /* #define BROKEN_EXCEPTION_HANDLING */ |
| |
| #include <mach/mach.h> |
| #include <mach/mach_error.h> |
| #include <mach/thread_status.h> |
| #include <mach/exception.h> |
| #include <mach/task.h> |
| #include <pthread.h> |
| |
| extern void GC_darwin_register_mach_handler_thread(mach_port_t); |
| |
| /* These are not defined in any header, although they are documented */ |
| extern boolean_t |
| exc_server(mach_msg_header_t *, mach_msg_header_t *); |
| |
| extern kern_return_t |
| exception_raise(mach_port_t, mach_port_t, mach_port_t, exception_type_t, |
| exception_data_t, mach_msg_type_number_t); |
| |
| extern kern_return_t |
| exception_raise_state(mach_port_t, mach_port_t, mach_port_t, exception_type_t, |
| exception_data_t, mach_msg_type_number_t, |
| thread_state_flavor_t*, thread_state_t, |
| mach_msg_type_number_t, thread_state_t, |
| mach_msg_type_number_t*); |
| |
| extern kern_return_t |
| exception_raise_state_identity(mach_port_t, mach_port_t, mach_port_t, |
| exception_type_t, exception_data_t, |
| mach_msg_type_number_t, thread_state_flavor_t*, |
| thread_state_t, mach_msg_type_number_t, |
| thread_state_t, mach_msg_type_number_t*); |
| |
| |
| #define MAX_EXCEPTION_PORTS 16 |
| |
| static struct { |
| mach_msg_type_number_t count; |
| exception_mask_t masks[MAX_EXCEPTION_PORTS]; |
| exception_handler_t ports[MAX_EXCEPTION_PORTS]; |
| exception_behavior_t behaviors[MAX_EXCEPTION_PORTS]; |
| thread_state_flavor_t flavors[MAX_EXCEPTION_PORTS]; |
| } GC_old_exc_ports; |
| |
| static struct { |
| mach_port_t exception; |
| #if defined(THREADS) |
| mach_port_t reply; |
| #endif |
| } GC_ports; |
| |
| typedef struct { |
| mach_msg_header_t head; |
| } GC_msg_t; |
| |
| typedef enum { |
| GC_MP_NORMAL, GC_MP_DISCARDING, GC_MP_STOPPED |
| } GC_mprotect_state_t; |
| |
| /* FIXME: 1 and 2 seem to be safe to use in the msgh_id field, |
| but it isn't documented. Use the source and see if they |
| should be ok. */ |
| #define ID_STOP 1 |
| #define ID_RESUME 2 |
| |
| /* These values are only used on the reply port */ |
| #define ID_ACK 3 |
| |
| #if defined(THREADS) |
| |
| GC_mprotect_state_t GC_mprotect_state; |
| |
| /* The following should ONLY be called when the world is stopped */ |
| static void GC_mprotect_thread_notify(mach_msg_id_t id) |
| { |
| |
| struct { |
| GC_msg_t msg; |
| mach_msg_trailer_t trailer; |
| } buf; |
| |
| mach_msg_return_t r; |
| /* remote, local */ |
| buf.msg.head.msgh_bits = MACH_MSGH_BITS(MACH_MSG_TYPE_MAKE_SEND, 0); |
| buf.msg.head.msgh_size = sizeof(buf.msg); |
| buf.msg.head.msgh_remote_port = GC_ports.exception; |
| buf.msg.head.msgh_local_port = MACH_PORT_NULL; |
| buf.msg.head.msgh_id = id; |
| |
| r = mach_msg(&buf.msg.head, MACH_SEND_MSG | MACH_RCV_MSG | MACH_RCV_LARGE, |
| sizeof(buf.msg), sizeof(buf), GC_ports.reply, |
| MACH_MSG_TIMEOUT_NONE, MACH_PORT_NULL); |
| if(r != MACH_MSG_SUCCESS) |
| ABORT("mach_msg failed in GC_mprotect_thread_notify"); |
| if(buf.msg.head.msgh_id != ID_ACK) |
| ABORT("invalid ack in GC_mprotect_thread_notify"); |
| } |
| |
| /* Should only be called by the mprotect thread */ |
| static void GC_mprotect_thread_reply(void) |
| { |
| |
| GC_msg_t msg; |
| mach_msg_return_t r; |
| /* remote, local */ |
| msg.head.msgh_bits = MACH_MSGH_BITS(MACH_MSG_TYPE_MAKE_SEND, 0); |
| msg.head.msgh_size = sizeof(msg); |
| msg.head.msgh_remote_port = GC_ports.reply; |
| msg.head.msgh_local_port = MACH_PORT_NULL; |
| msg.head.msgh_id = ID_ACK; |
| |
| r = mach_msg(&msg.head, MACH_SEND_MSG, sizeof(msg), 0, MACH_PORT_NULL, |
| MACH_MSG_TIMEOUT_NONE, MACH_PORT_NULL); |
| if(r != MACH_MSG_SUCCESS) |
| ABORT("mach_msg failed in GC_mprotect_thread_reply"); |
| } |
| |
| void GC_mprotect_stop(void) |
| { |
| GC_mprotect_thread_notify(ID_STOP); |
| } |
| void GC_mprotect_resume(void) |
| { |
| GC_mprotect_thread_notify(ID_RESUME); |
| } |
| |
| #else /* !THREADS */ |
| /* The compiler should optimize away any GC_mprotect_state computations */ |
| #define GC_mprotect_state GC_MP_NORMAL |
| #endif |
| |
| static void *GC_mprotect_thread(void *arg) |
| { |
| mach_msg_return_t r; |
| /* These two structures contain some private kernel data. We don't need to |
| access any of it so we don't bother defining a proper struct. The |
| correct definitions are in the xnu source code. */ |
| struct { |
| mach_msg_header_t head; |
| char data[256]; |
| } reply; |
| struct { |
| mach_msg_header_t head; |
| mach_msg_body_t msgh_body; |
| char data[1024]; |
| } msg; |
| |
| mach_msg_id_t id; |
| |
| GC_darwin_register_mach_handler_thread(mach_thread_self()); |
| |
| for(;;) { |
| r = mach_msg(&msg.head, MACH_RCV_MSG | MACH_RCV_LARGE | |
| (GC_mprotect_state == GC_MP_DISCARDING ? MACH_RCV_TIMEOUT : 0), |
| 0, sizeof(msg), GC_ports.exception, |
| GC_mprotect_state == GC_MP_DISCARDING ? 0 |
| : MACH_MSG_TIMEOUT_NONE, MACH_PORT_NULL); |
| |
| id = r == MACH_MSG_SUCCESS ? msg.head.msgh_id : -1; |
| |
| # if defined(THREADS) |
| if(GC_mprotect_state == GC_MP_DISCARDING) { |
| if(r == MACH_RCV_TIMED_OUT) { |
| GC_mprotect_state = GC_MP_STOPPED; |
| GC_mprotect_thread_reply(); |
| continue; |
| } |
| if(r == MACH_MSG_SUCCESS && (id == ID_STOP || id == ID_RESUME)) |
| ABORT("out of order mprotect thread request"); |
| } |
| # endif /* THREADS */ |
| |
| if(r != MACH_MSG_SUCCESS) { |
| GC_err_printf("mach_msg failed with %d %s\n", (int)r, |
| mach_error_string(r)); |
| ABORT("mach_msg failed"); |
| } |
| |
| switch(id) { |
| # if defined(THREADS) |
| case ID_STOP: |
| if(GC_mprotect_state != GC_MP_NORMAL) |
| ABORT("Called mprotect_stop when state wasn't normal"); |
| GC_mprotect_state = GC_MP_DISCARDING; |
| break; |
| case ID_RESUME: |
| if(GC_mprotect_state != GC_MP_STOPPED) |
| ABORT("Called mprotect_resume when state wasn't stopped"); |
| GC_mprotect_state = GC_MP_NORMAL; |
| GC_mprotect_thread_reply(); |
| break; |
| # endif /* THREADS */ |
| default: |
| /* Handle the message (calls catch_exception_raise) */ |
| if(!exc_server(&msg.head, &reply.head)) |
| ABORT("exc_server failed"); |
| /* Send the reply */ |
| r = mach_msg(&reply.head, MACH_SEND_MSG, reply.head.msgh_size, 0, |
| MACH_PORT_NULL, MACH_MSG_TIMEOUT_NONE, |
| MACH_PORT_NULL); |
| if(r != MACH_MSG_SUCCESS) { |
| /* This will fail if the thread dies, but the thread */ |
| /* shouldn't die... */ |
| # ifdef BROKEN_EXCEPTION_HANDLING |
| GC_err_printf("mach_msg failed with %d %s while sending" |
| "exc reply\n", (int)r,mach_error_string(r)); |
| # else |
| ABORT("mach_msg failed while sending exception reply"); |
| # endif |
| } |
| } /* switch */ |
| } /* for(;;) */ |
| /* NOT REACHED */ |
| return NULL; |
| } |
| |
| /* All this SIGBUS code shouldn't be necessary. All protection faults should |
| be going throught the mach exception handler. However, it seems a SIGBUS is |
| occasionally sent for some unknown reason. Even more odd, it seems to be |
| meaningless and safe to ignore. */ |
| #ifdef BROKEN_EXCEPTION_HANDLING |
| |
| static SIG_HNDLR_PTR GC_old_bus_handler; |
| |
| /* Updates to this aren't atomic, but the SIGBUSs seem pretty rare. |
| Even if this doesn't get updated property, it isn't really a problem */ |
| static int GC_sigbus_count; |
| |
| static void GC_darwin_sigbus(int num, siginfo_t *sip, void *context) |
| { |
| if(num != SIGBUS) |
| ABORT("Got a non-sigbus signal in the sigbus handler"); |
| |
| /* Ugh... some seem safe to ignore, but too many in a row probably means |
| trouble. GC_sigbus_count is reset for each mach exception that is |
| handled */ |
| if(GC_sigbus_count >= 8) { |
| ABORT("Got more than 8 SIGBUSs in a row!"); |
| } else { |
| GC_sigbus_count++; |
| WARN("Ignoring SIGBUS.\n", 0); |
| } |
| } |
| #endif /* BROKEN_EXCEPTION_HANDLING */ |
| |
| void GC_dirty_init(void) |
| { |
| kern_return_t r; |
| mach_port_t me; |
| pthread_t thread; |
| pthread_attr_t attr; |
| exception_mask_t mask; |
| |
| if (GC_print_stats == VERBOSE) |
| GC_log_printf("Inititalizing mach/darwin mprotect virtual dirty bit " |
| "implementation\n"); |
| # ifdef BROKEN_EXCEPTION_HANDLING |
| WARN("Enabling workarounds for various darwin " |
| "exception handling bugs.\n", 0); |
| # endif |
| GC_dirty_maintained = TRUE; |
| if (GC_page_size % HBLKSIZE != 0) { |
| GC_err_printf("Page size not multiple of HBLKSIZE\n"); |
| ABORT("Page size not multiple of HBLKSIZE"); |
| } |
| |
| GC_task_self = me = mach_task_self(); |
| |
| r = mach_port_allocate(me, MACH_PORT_RIGHT_RECEIVE, &GC_ports.exception); |
| if(r != KERN_SUCCESS) |
| ABORT("mach_port_allocate failed (exception port)"); |
| |
| r = mach_port_insert_right(me, GC_ports.exception, GC_ports.exception, |
| MACH_MSG_TYPE_MAKE_SEND); |
| if(r != KERN_SUCCESS) |
| ABORT("mach_port_insert_right failed (exception port)"); |
| |
| # if defined(THREADS) |
| r = mach_port_allocate(me, MACH_PORT_RIGHT_RECEIVE, &GC_ports.reply); |
| if(r != KERN_SUCCESS) |
| ABORT("mach_port_allocate failed (reply port)"); |
| # endif |
| |
| /* The exceptions we want to catch */ |
| mask = EXC_MASK_BAD_ACCESS; |
| |
| r = task_get_exception_ports(me, mask, GC_old_exc_ports.masks, |
| &GC_old_exc_ports.count, GC_old_exc_ports.ports, |
| GC_old_exc_ports.behaviors, |
| GC_old_exc_ports.flavors); |
| if(r != KERN_SUCCESS) |
| ABORT("task_get_exception_ports failed"); |
| |
| r = task_set_exception_ports(me, mask, GC_ports.exception, EXCEPTION_DEFAULT, |
| GC_MACH_THREAD_STATE); |
| if(r != KERN_SUCCESS) |
| ABORT("task_set_exception_ports failed"); |
| if(pthread_attr_init(&attr) != 0) |
| ABORT("pthread_attr_init failed"); |
| if(pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED) != 0) |
| ABORT("pthread_attr_setdetachedstate failed"); |
| |
| # undef pthread_create |
| /* This will call the real pthread function, not our wrapper */ |
| if(pthread_create(&thread, &attr, GC_mprotect_thread, NULL) != 0) |
| ABORT("pthread_create failed"); |
| pthread_attr_destroy(&attr); |
| |
| /* Setup the sigbus handler for ignoring the meaningless SIGBUSs */ |
| # ifdef BROKEN_EXCEPTION_HANDLING |
| { |
| struct sigaction sa, oldsa; |
| sa.sa_handler = (SIG_HNDLR_PTR)GC_darwin_sigbus; |
| sigemptyset(&sa.sa_mask); |
| sa.sa_flags = SA_RESTART|SA_SIGINFO; |
| if(sigaction(SIGBUS, &sa, &oldsa) < 0) |
| ABORT("sigaction"); |
| GC_old_bus_handler = (SIG_HNDLR_PTR)oldsa.sa_handler; |
| if (GC_old_bus_handler != SIG_DFL) { |
| if (GC_print_stats == VERBOSE) |
| GC_err_printf("Replaced other SIGBUS handler\n"); |
| } |
| } |
| # endif /* BROKEN_EXCEPTION_HANDLING */ |
| } |
| |
| /* The source code for Apple's GDB was used as a reference for the exception |
| forwarding code. This code is similar to be GDB code only because there is |
| only one way to do it. */ |
| static kern_return_t GC_forward_exception(mach_port_t thread, mach_port_t task, |
| exception_type_t exception, |
| exception_data_t data, |
| mach_msg_type_number_t data_count) |
| { |
| unsigned int i; |
| kern_return_t r; |
| mach_port_t port; |
| exception_behavior_t behavior; |
| thread_state_flavor_t flavor; |
| |
| thread_state_t thread_state = NULL; |
| mach_msg_type_number_t thread_state_count = THREAD_STATE_MAX; |
| |
| for(i=0; i < GC_old_exc_ports.count; i++) |
| if(GC_old_exc_ports.masks[i] & (1 << exception)) |
| break; |
| if(i==GC_old_exc_ports.count) |
| ABORT("No handler for exception!"); |
| |
| port = GC_old_exc_ports.ports[i]; |
| behavior = GC_old_exc_ports.behaviors[i]; |
| flavor = GC_old_exc_ports.flavors[i]; |
| |
| if(behavior != EXCEPTION_DEFAULT) { |
| r = thread_get_state(thread, flavor, thread_state, &thread_state_count); |
| if(r != KERN_SUCCESS) |
| ABORT("thread_get_state failed in forward_exception"); |
| } |
| |
| switch(behavior) { |
| case EXCEPTION_DEFAULT: |
| r = exception_raise(port, thread, task, exception, data, data_count); |
| break; |
| case EXCEPTION_STATE: |
| r = exception_raise_state(port, thread, task, exception, data, data_count, |
| &flavor, thread_state, thread_state_count, |
| thread_state, &thread_state_count); |
| break; |
| case EXCEPTION_STATE_IDENTITY: |
| r = exception_raise_state_identity(port, thread, task, exception, data, |
| data_count, &flavor, thread_state, |
| thread_state_count, thread_state, |
| &thread_state_count); |
| break; |
| default: |
| r = KERN_FAILURE; /* make gcc happy */ |
| ABORT("forward_exception: unknown behavior"); |
| break; |
| } |
| |
| if(behavior != EXCEPTION_DEFAULT) { |
| r = thread_set_state(thread, flavor, thread_state, thread_state_count); |
| if(r != KERN_SUCCESS) |
| ABORT("thread_set_state failed in forward_exception"); |
| } |
| |
| return r; |
| } |
| |
| #define FWD() GC_forward_exception(thread, task, exception, code, code_count) |
| |
| /* This violates the namespace rules but there isn't anything that can be done |
| about it. The exception handling stuff is hard coded to call this */ |
| kern_return_t |
| catch_exception_raise(mach_port_t exception_port, mach_port_t thread, |
| mach_port_t task, exception_type_t exception, |
| exception_data_t code, mach_msg_type_number_t code_count) |
| { |
| kern_return_t r; |
| char *addr; |
| struct hblk *h; |
| unsigned int i; |
| # if defined(POWERPC) |
| # if CPP_WORDSZ == 32 |
| thread_state_flavor_t flavor = PPC_EXCEPTION_STATE; |
| mach_msg_type_number_t exc_state_count = PPC_EXCEPTION_STATE_COUNT; |
| ppc_exception_state_t exc_state; |
| # else |
| thread_state_flavor_t flavor = PPC_EXCEPTION_STATE64; |
| mach_msg_type_number_t exc_state_count = PPC_EXCEPTION_STATE64_COUNT; |
| ppc_exception_state64_t exc_state; |
| # endif |
| # elif defined(I386) || defined(X86_64) |
| # if CPP_WORDSZ == 32 |
| thread_state_flavor_t flavor = x86_EXCEPTION_STATE32; |
| mach_msg_type_number_t exc_state_count = x86_EXCEPTION_STATE32_COUNT; |
| x86_exception_state32_t exc_state; |
| # else |
| thread_state_flavor_t flavor = x86_EXCEPTION_STATE64; |
| mach_msg_type_number_t exc_state_count = x86_EXCEPTION_STATE64_COUNT; |
| x86_exception_state64_t exc_state; |
| # endif |
| # else |
| # error FIXME for non-ppc/x86 darwin |
| # endif |
| |
| |
| if(exception != EXC_BAD_ACCESS || code[0] != KERN_PROTECTION_FAILURE) { |
| # ifdef DEBUG_EXCEPTION_HANDLING |
| /* We aren't interested, pass it on to the old handler */ |
| GC_printf("Exception: 0x%x Code: 0x%x 0x%x in catch....\n", exception, |
| code_count > 0 ? code[0] : -1, code_count > 1 ? code[1] : -1); |
| # endif |
| return FWD(); |
| } |
| |
| r = thread_get_state(thread, flavor, (natural_t*)&exc_state, |
| &exc_state_count); |
| if(r != KERN_SUCCESS) { |
| /* The thread is supposed to be suspended while the exception handler |
| is called. This shouldn't fail. */ |
| # ifdef BROKEN_EXCEPTION_HANDLING |
| GC_err_printf("thread_get_state failed in catch_exception_raise\n"); |
| return KERN_SUCCESS; |
| # else |
| ABORT("thread_get_state failed in catch_exception_raise"); |
| # endif |
| } |
| |
| /* This is the address that caused the fault */ |
| # if defined(POWERPC) |
| addr = (char*) exc_state. THREAD_FLD(dar); |
| # elif defined (I386) || defined (X86_64) |
| addr = (char*) exc_state. THREAD_FLD(faultvaddr); |
| # else |
| # error FIXME for non POWERPC/I386 |
| # endif |
| |
| if((HDR(addr)) == 0) { |
| /* Ugh... just like the SIGBUS problem above, it seems we get a bogus |
| KERN_PROTECTION_FAILURE every once and a while. We wait till we get |
| a bunch in a row before doing anything about it. If a "real" fault |
| ever occurres it'll just keep faulting over and over and we'll hit |
| the limit pretty quickly. */ |
| # ifdef BROKEN_EXCEPTION_HANDLING |
| static char *last_fault; |
| static int last_fault_count; |
| |
| if(addr != last_fault) { |
| last_fault = addr; |
| last_fault_count = 0; |
| } |
| if(++last_fault_count < 32) { |
| if(last_fault_count == 1) |
| WARN("Ignoring KERN_PROTECTION_FAILURE at %lx\n", (GC_word)addr); |
| return KERN_SUCCESS; |
| } |
| |
| GC_err_printf("Unexpected KERN_PROTECTION_FAILURE at %p\n",addr); |
| /* Can't pass it along to the signal handler because that is |
| ignoring SIGBUS signals. We also shouldn't call ABORT here as |
| signals don't always work too well from the exception handler. */ |
| GC_err_printf("Aborting\n"); |
| exit(EXIT_FAILURE); |
| # else /* BROKEN_EXCEPTION_HANDLING */ |
| /* Pass it along to the next exception handler |
| (which should call SIGBUS/SIGSEGV) */ |
| return FWD(); |
| # endif /* !BROKEN_EXCEPTION_HANDLING */ |
| } |
| |
| # ifdef BROKEN_EXCEPTION_HANDLING |
| /* Reset the number of consecutive SIGBUSs */ |
| GC_sigbus_count = 0; |
| # endif |
| |
| if(GC_mprotect_state == GC_MP_NORMAL) { /* common case */ |
| h = (struct hblk*)((word)addr & ~(GC_page_size-1)); |
| UNPROTECT(h, GC_page_size); |
| for (i = 0; i < divHBLKSZ(GC_page_size); i++) { |
| register int index = PHT_HASH(h+i); |
| async_set_pht_entry_from_index(GC_dirty_pages, index); |
| } |
| } else if(GC_mprotect_state == GC_MP_DISCARDING) { |
| /* Lie to the thread for now. No sense UNPROTECT()ing the memory |
| when we're just going to PROTECT() it again later. The thread |
| will just fault again once it resumes */ |
| } else { |
| /* Shouldn't happen, i don't think */ |
| GC_printf("KERN_PROTECTION_FAILURE while world is stopped\n"); |
| return FWD(); |
| } |
| return KERN_SUCCESS; |
| } |
| #undef FWD |
| |
| /* These should never be called, but just in case... */ |
| kern_return_t |
| catch_exception_raise_state(mach_port_name_t exception_port, int exception, |
| exception_data_t code, |
| mach_msg_type_number_t codeCnt, int flavor, |
| thread_state_t old_state, int old_stateCnt, |
| thread_state_t new_state, int new_stateCnt) |
| { |
| ABORT("catch_exception_raise_state"); |
| return(KERN_INVALID_ARGUMENT); |
| } |
| |
| kern_return_t |
| catch_exception_raise_state_identity(mach_port_name_t exception_port, |
| mach_port_t thread, mach_port_t task, |
| int exception, exception_data_t code, |
| mach_msg_type_number_t codeCnt, int flavor, |
| thread_state_t old_state, int old_stateCnt, |
| thread_state_t new_state, int new_stateCnt) |
| { |
| ABORT("catch_exception_raise_state_identity"); |
| return(KERN_INVALID_ARGUMENT); |
| } |
| |
| |
| #endif /* DARWIN && MPROTECT_VDB */ |
| |
| # ifndef HAVE_INCREMENTAL_PROTECTION_NEEDS |
| int GC_incremental_protection_needs() |
| { |
| return GC_PROTECTS_NONE; |
| } |
| # endif /* !HAVE_INCREMENTAL_PROTECTION_NEEDS */ |
| |
| /* |
| * Call stack save code for debugging. |
| * Should probably be in mach_dep.c, but that requires reorganization. |
| */ |
| |
| /* I suspect the following works for most X86 *nix variants, so */ |
| /* long as the frame pointer is explicitly stored. In the case of gcc, */ |
| /* compiler flags (e.g. -fomit-frame-pointer) determine whether it is. */ |
| #if defined(I386) && defined(LINUX) && defined(SAVE_CALL_CHAIN) |
| # include <features.h> |
| |
| struct frame { |
| struct frame *fr_savfp; |
| long fr_savpc; |
| long fr_arg[NARGS]; /* All the arguments go here. */ |
| }; |
| #endif |
| |
| #if defined(SPARC) |
| # if defined(LINUX) |
| # include <features.h> |
| |
| struct frame { |
| long fr_local[8]; |
| long fr_arg[6]; |
| struct frame *fr_savfp; |
| long fr_savpc; |
| # ifndef __arch64__ |
| char *fr_stret; |
| # endif |
| long fr_argd[6]; |
| long fr_argx[0]; |
| }; |
| # elif defined (DRSNX) |
| # include <sys/sparc/frame.h> |
| # elif defined(OPENBSD) |
| # include <frame.h> |
| # elif defined(FREEBSD) || defined(NETBSD) |
| # include <machine/frame.h> |
| # else |
| # include <sys/frame.h> |
| # endif |
| # if NARGS > 6 |
| # error We only know how to to get the first 6 arguments |
| # endif |
| #endif /* SPARC */ |
| |
| #ifdef NEED_CALLINFO |
| /* Fill in the pc and argument information for up to NFRAMES of my */ |
| /* callers. Ignore my frame and my callers frame. */ |
| |
| #ifdef LINUX |
| # include <unistd.h> |
| #endif |
| |
| #endif /* NEED_CALLINFO */ |
| |
| #if defined(GC_HAVE_BUILTIN_BACKTRACE) |
| # ifdef _MSC_VER |
| # include "private/msvc_dbg.h" |
| # else |
| # include <execinfo.h> |
| # endif |
| #endif |
| |
| #ifdef SAVE_CALL_CHAIN |
| |
| #if NARGS == 0 && NFRAMES % 2 == 0 /* No padding */ \ |
| && defined(GC_HAVE_BUILTIN_BACKTRACE) |
| |
| #ifdef REDIRECT_MALLOC |
| /* Deal with possible malloc calls in backtrace by omitting */ |
| /* the infinitely recursing backtrace. */ |
| # ifdef THREADS |
| __thread /* If your compiler doesn't understand this */ |
| /* you could use something like pthread_getspecific. */ |
| # endif |
| GC_in_save_callers = FALSE; |
| #endif |
| |
| void GC_save_callers (struct callinfo info[NFRAMES]) |
| { |
| void * tmp_info[NFRAMES + 1]; |
| int npcs, i; |
| # define IGNORE_FRAMES 1 |
| |
| /* We retrieve NFRAMES+1 pc values, but discard the first, since it */ |
| /* points to our own frame. */ |
| # ifdef REDIRECT_MALLOC |
| if (GC_in_save_callers) { |
| info[0].ci_pc = (word)(&GC_save_callers); |
| for (i = 1; i < NFRAMES; ++i) info[i].ci_pc = 0; |
| return; |
| } |
| GC_in_save_callers = TRUE; |
| # endif |
| GC_ASSERT(sizeof(struct callinfo) == sizeof(void *)); |
| npcs = backtrace((void **)tmp_info, NFRAMES + IGNORE_FRAMES); |
| BCOPY(tmp_info+IGNORE_FRAMES, info, (npcs - IGNORE_FRAMES) * sizeof(void *)); |
| for (i = npcs - IGNORE_FRAMES; i < NFRAMES; ++i) info[i].ci_pc = 0; |
| # ifdef REDIRECT_MALLOC |
| GC_in_save_callers = FALSE; |
| # endif |
| } |
| |
| #else /* No builtin backtrace; do it ourselves */ |
| |
| #if (defined(OPENBSD) || defined(NETBSD) || defined(FREEBSD)) && defined(SPARC) |
| # define FR_SAVFP fr_fp |
| # define FR_SAVPC fr_pc |
| #else |
| # define FR_SAVFP fr_savfp |
| # define FR_SAVPC fr_savpc |
| #endif |
| |
| #if defined(SPARC) && (defined(__arch64__) || defined(__sparcv9)) |
| # define BIAS 2047 |
| #else |
| # define BIAS 0 |
| #endif |
| |
| void GC_save_callers (struct callinfo info[NFRAMES]) |
| { |
| struct frame *frame; |
| struct frame *fp; |
| int nframes = 0; |
| # ifdef I386 |
| /* We assume this is turned on only with gcc as the compiler. */ |
| asm("movl %%ebp,%0" : "=r"(frame)); |
| fp = frame; |
| # else |
| frame = (struct frame *) GC_save_regs_in_stack (); |
| fp = (struct frame *)((long) frame -> FR_SAVFP + BIAS); |
| #endif |
| |
| for (; (!(fp HOTTER_THAN frame) && !(GC_stackbottom HOTTER_THAN (ptr_t)fp) |
| && (nframes < NFRAMES)); |
| fp = (struct frame *)((long) fp -> FR_SAVFP + BIAS), nframes++) { |
| register int i; |
| |
| info[nframes].ci_pc = fp->FR_SAVPC; |
| # if NARGS > 0 |
| for (i = 0; i < NARGS; i++) { |
| info[nframes].ci_arg[i] = ~(fp->fr_arg[i]); |
| } |
| # endif /* NARGS > 0 */ |
| } |
| if (nframes < NFRAMES) info[nframes].ci_pc = 0; |
| } |
| |
| #endif /* No builtin backtrace */ |
| |
| #endif /* SAVE_CALL_CHAIN */ |
| |
| #ifdef NEED_CALLINFO |
| |
| /* Print info to stderr. We do NOT hold the allocation lock */ |
| void GC_print_callers (struct callinfo info[NFRAMES]) |
| { |
| register int i; |
| static int reentry_count = 0; |
| GC_bool stop = FALSE; |
| |
| /* FIXME: This should probably use a different lock, so that we */ |
| /* become callable with or without the allocation lock. */ |
| LOCK(); |
| ++reentry_count; |
| UNLOCK(); |
| |
| # if NFRAMES == 1 |
| GC_err_printf("\tCaller at allocation:\n"); |
| # else |
| GC_err_printf("\tCall chain at allocation:\n"); |
| # endif |
| for (i = 0; i < NFRAMES && !stop ; i++) { |
| if (info[i].ci_pc == 0) break; |
| # if NARGS > 0 |
| { |
| int j; |
| |
| GC_err_printf("\t\targs: "); |
| for (j = 0; j < NARGS; j++) { |
| if (j != 0) GC_err_printf(", "); |
| GC_err_printf("%d (0x%X)", ~(info[i].ci_arg[j]), |
| ~(info[i].ci_arg[j])); |
| } |
| GC_err_printf("\n"); |
| } |
| # endif |
| if (reentry_count > 1) { |
| /* We were called during an allocation during */ |
| /* a previous GC_print_callers call; punt. */ |
| GC_err_printf("\t\t##PC##= 0x%lx\n", info[i].ci_pc); |
| continue; |
| } |
| { |
| # ifdef LINUX |
| FILE *pipe; |
| # endif |
| # if defined(GC_HAVE_BUILTIN_BACKTRACE) \ |
| && !defined(GC_BACKTRACE_SYMBOLS_BROKEN) |
| char **sym_name = |
| backtrace_symbols((void **)(&(info[i].ci_pc)), 1); |
| char *name = sym_name[0]; |
| # else |
| char buf[40]; |
| char *name = buf; |
| sprintf(buf, "##PC##= 0x%lx", info[i].ci_pc); |
| # endif |
| # if defined(LINUX) && !defined(SMALL_CONFIG) |
| /* Try for a line number. */ |
| { |
| # define EXE_SZ 100 |
| static char exe_name[EXE_SZ]; |
| # define CMD_SZ 200 |
| char cmd_buf[CMD_SZ]; |
| # define RESULT_SZ 200 |
| static char result_buf[RESULT_SZ]; |
| size_t result_len; |
| char *old_preload; |
| # define PRELOAD_SZ 200 |
| char preload_buf[PRELOAD_SZ]; |
| static GC_bool found_exe_name = FALSE; |
| static GC_bool will_fail = FALSE; |
| int ret_code; |
| /* Try to get it via a hairy and expensive scheme. */ |
| /* First we get the name of the executable: */ |
| if (will_fail) goto out; |
| if (!found_exe_name) { |
| ret_code = readlink("/proc/self/exe", exe_name, EXE_SZ); |
| if (ret_code < 0 || ret_code >= EXE_SZ |
| || exe_name[0] != '/') { |
| will_fail = TRUE; /* Dont try again. */ |
| goto out; |
| } |
| exe_name[ret_code] = '\0'; |
| found_exe_name = TRUE; |
| } |
| /* Then we use popen to start addr2line -e <exe> <addr> */ |
| /* There are faster ways to do this, but hopefully this */ |
| /* isn't time critical. */ |
| sprintf(cmd_buf, "/usr/bin/addr2line -f -e %s 0x%lx", exe_name, |
| (unsigned long)info[i].ci_pc); |
| old_preload = getenv ("LD_PRELOAD"); |
| if (0 != old_preload) { |
| if (strlen (old_preload) >= PRELOAD_SZ) { |
| will_fail = TRUE; |
| goto out; |
| } |
| strcpy (preload_buf, old_preload); |
| unsetenv ("LD_PRELOAD"); |
| } |
| pipe = popen(cmd_buf, "r"); |
| if (0 != old_preload |
| && 0 != setenv ("LD_PRELOAD", preload_buf, 0)) { |
| WARN("Failed to reset LD_PRELOAD\n", 0); |
| } |
| if (pipe == NULL |
| || (result_len = fread(result_buf, 1, RESULT_SZ - 1, pipe)) |
| == 0) { |
| if (pipe != NULL) pclose(pipe); |
| will_fail = TRUE; |
| goto out; |
| } |
| if (result_buf[result_len - 1] == '\n') --result_len; |
| result_buf[result_len] = 0; |
| if (result_buf[0] == '?' |
| || (result_buf[result_len-2] == ':' |
| && result_buf[result_len-1] == '0')) { |
| pclose(pipe); |
| goto out; |
| } |
| /* Get rid of embedded newline, if any. Test for "main" */ |
| { |
| char * nl = strchr(result_buf, '\n'); |
| if (nl != NULL && nl < result_buf + result_len) { |
| *nl = ':'; |
| } |
| if (strncmp(result_buf, "main", nl - result_buf) == 0) { |
| stop = TRUE; |
| } |
| } |
| if (result_len < RESULT_SZ - 25) { |
| /* Add in hex address */ |
| sprintf(result_buf + result_len, " [0x%lx]", |
| (unsigned long)info[i].ci_pc); |
| } |
| name = result_buf; |
| pclose(pipe); |
| out:; |
| } |
| # endif /* LINUX */ |
| GC_err_printf("\t\t%s\n", name); |
| # if defined(GC_HAVE_BUILTIN_BACKTRACE) \ |
| && !defined(GC_BACKTRACE_SYMBOLS_BROKEN) |
| free(sym_name); /* May call GC_free; that's OK */ |
| # endif |
| } |
| } |
| LOCK(); |
| --reentry_count; |
| UNLOCK(); |
| } |
| |
| #endif /* NEED_CALLINFO */ |
| |
| |
| |
| #if defined(LINUX) && defined(__ELF__) && !defined(SMALL_CONFIG) |
| |
| /* Dump /proc/self/maps to GC_stderr, to enable looking up names for |
| addresses in FIND_LEAK output. */ |
| |
| static word dump_maps(char *maps) |
| { |
| GC_err_write(maps, strlen(maps)); |
| return 1; |
| } |
| |
| void GC_print_address_map(void) |
| { |
| GC_err_printf("---------- Begin address map ----------\n"); |
| dump_maps(GC_get_maps()); |
| GC_err_printf("---------- End address map ----------\n"); |
| } |
| |
| #endif |
| |
| |