diff options
Diffstat (limited to 'gcc-4.7/boehm-gc/os_dep.c')
| -rw-r--r-- | gcc-4.7/boehm-gc/os_dep.c | 4294 |
1 files changed, 0 insertions, 4294 deletions
diff --git a/gcc-4.7/boehm-gc/os_dep.c b/gcc-4.7/boehm-gc/os_dep.c deleted file mode 100644 index ca8be1a82..000000000 --- a/gcc-4.7/boehm-gc/os_dep.c +++ /dev/null @@ -1,4294 +0,0 @@ -/* - * 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" - -# 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) && !defined(SUNOS4) -# include <unistd.h> -# endif -# endif - -# include <stdio.h> -# if defined(MSWINCE) -# define SIGSEGV 0 /* value is irrelevant */ -# else -# include <signal.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. */ - -# if defined(HEURISTIC2) || defined(SEARCH_FOR_DATA_START) -# define NEED_FIND_LIMIT -# endif - -# if !defined(STACKBOTTOM) && defined(HEURISTIC2) -# define NEED_FIND_LIMIT -# endif - -# if (defined(SUNOS4) && defined(DYNAMIC_LOADING)) && !defined(PCR) -# define NEED_FIND_LIMIT -# endif - -# if (defined(SVR4) || defined(AUX) || defined(DGUX) \ - || (defined(LINUX) && defined(SPARC))) && !defined(PCR) -# define NEED_FIND_LIMIT -# endif - -#if defined(FREEBSD) && (defined(I386) || defined(X86_64) || defined(powerpc) || defined(__powerpc__)) -# include <machine/trap.h> -# if !defined(PCR) -# define NEED_FIND_LIMIT -# endif -#endif - -#if (defined(NETBSD) || defined(OPENBSD)) && defined(__ELF__) \ - && !defined(NEED_FIND_LIMIT) - /* Used by GC_init_netbsd_elf() below. */ -# define NEED_FIND_LIMIT -#endif - -#ifdef NEED_FIND_LIMIT -# include <setjmp.h> -#endif - -#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> -#endif - -#ifdef MACOS -# include <Processes.h> -#endif - -#ifdef IRIX5 -# include <sys/uio.h> -# include <malloc.h> /* for locking */ -#endif -#if defined(USE_MMAP) || defined(USE_MUNMAP) -# ifndef 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 UNIX_LIKE -# include <fcntl.h> -# if defined(SUNOS5SIGS) && !defined(FREEBSD) -# include <sys/siginfo.h> -# endif - /* Define SETJMP and friends to be the version that restores */ - /* the signal mask. */ -# define SETJMP(env) sigsetjmp(env, 1) -# define LONGJMP(env, val) siglongjmp(env, val) -# define JMP_BUF sigjmp_buf -#else -# define SETJMP(env) setjmp(env) -# define LONGJMP(env, val) longjmp(env, val) -# define JMP_BUF jmp_buf -#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)) - -/* 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; -} - -/* - * Apply fn to a buffer containing the contents of /proc/self/maps. - * Return the result of fn or, if we failed, 0. - * We currently do nothing to /proc/self/maps other than simply read - * it. This code could be simplified if we could determine its size - * ahead of time. - */ - -word GC_apply_to_maps(word (*fn)(char *)) -{ - int f; - int result; - size_t maps_size = 4000; /* Initial guess. */ - static char init_buf[1]; - static char *maps_buf = init_buf; - static size_t maps_buf_sz = 1; - - /* Read /proc/self/maps, growing maps_buf as necessary. */ - /* Note that we may not allocate conventionally, and */ - /* thus can't use stdio. */ - do { - if (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); - if (maps_buf == 0) return 0; - } - f = open("/proc/self/maps", O_RDONLY); - if (-1 == f) return 0; - 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); - } while (maps_size >= maps_buf_sz); - maps_buf[maps_size] = '\0'; - - /* Apply fn to result. */ - return fn(maps_buf); -} - -#endif /* Need GC_apply_to_maps */ - -#if defined(LINUX) && (defined(USE_PROC_FOR_LIBRARIES) || defined(IA64)) -// -// 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 auguat 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_buf and *maj_dev. Only *prot_buf may be set for unwritable maps. - */ -char *GC_parse_map_entry(char *buf_ptr, word *start, word *end, - char *prot_buf, unsigned int *maj_dev) -{ - char *start_start, *end_start, *prot_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 = strtoul(start_start, &endp, 16); p = endp; - GC_ASSERT(*p=='-'); - - ++p; - end_start = p; - GC_ASSERT(isxdigit(*end_start)); - *end = strtoul(end_start, &endp, 16); p = endp; - GC_ASSERT(isspace(*p)); - - while (isspace(*p)) ++p; - prot_start = p; - GC_ASSERT(*prot_start == 'r' || *prot_start == '-'); - memcpy(prot_buf, prot_start, 4); - prot_buf[4] = '\0'; - if (prot_buf[1] == 'w') {/* we can skip the rest if it's not writable. */ - /* 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); - } - - while (*p && *p++ != '\n'); - - return p; -} - -#endif /* Need to parse /proc/self/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. */ - -# ifdef LINUX - /* 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(); - -# ifdef LINUX - /* 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 */ - -// setjmp() function, as described in ANSI para 7.6.1.1 -#undef SETJMP -#define SETJMP( __env__ ) hal_setjmp( __env__ ) - -// 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() - { - extern ptr_t GC_find_limit(); - 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 defined(SIG_BLOCK) - /* 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)) -# elif defined(sigmask) && !defined(UTS4) && !defined(HURD) - /* 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) -# else -# error undetectable signal API -# endif - -static GC_bool mask_initialized = FALSE; - -static SIGSET_T new_mask; - -static SIGSET_T old_mask; - -static SIGSET_T dummy; - -#if defined(PRINTSTATS) && !defined(THREADS) -# define CHECK_SIGNALS - int GC_sig_disabled = 0; -#endif - -void GC_disable_signals() -{ - 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() -{ -# 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) || defined (CYGWIN32) - void GC_setpagesize() - { - GetSystemInfo(&GC_sysinfo); - GC_page_size = GC_sysinfo.dwPageSize; - } - -# else -# if defined(MPROTECT_VDB) || defined(PROC_VDB) || defined(USE_MMAP) \ - || defined(USE_MUNMAP) - void GC_setpagesize() - { - GC_page_size = GETPAGESIZE(); - } -# else - /* It's acceptable to fake it. */ - void GC_setpagesize() - { - 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) -# 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); -} - -ptr_t GC_get_stack_base() -{ - 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); - - return(trunc_sp + size); -} - - -# endif /* MS Windows */ - -# ifdef BEOS -# include <kernel/OS.h> -ptr_t GC_get_stack_base(){ - thread_info th; - get_thread_info(find_thread(NULL),&th); - return th.stack_end; -} -# endif /* BEOS */ - - -# ifdef OS2 - -ptr_t GC_get_stack_base() -{ - PTIB ptib; - PPIB ppib; - - if (DosGetInfoBlocks(&ptib, &ppib) != NO_ERROR) { - GC_err_printf0("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) - -# ifdef __STDC__ - typedef void (*handler)(int); -# else - typedef void (*handler)(); -# endif - -# if defined(SUNOS5SIGS) || defined(IRIX5) || defined(OSF1) \ - || defined(HURD) || defined(NETBSD) - static struct sigaction old_segv_act; -# if defined(IRIX5) || defined(HPUX) \ - || defined(HURD) || defined(NETBSD) - static struct sigaction old_bus_act; -# endif -# else - static handler old_segv_handler, old_bus_handler; -# endif - -# ifdef __STDC__ - void GC_set_and_save_fault_handler(handler h) -# else - void GC_set_and_save_fault_handler(h) - handler h; -# endif - { -# 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); - (void) sigaction(SIGBUS, 0, &old_bus_act); - (void) sigaction(SIGBUS, &act, 0); -# else - (void) sigaction(SIGSEGV, &act, &old_segv_act); -# if defined(IRIX5) \ - || 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 */ - -# ifdef NEED_FIND_LIMIT - /* Some tools to implement HEURISTIC2 */ -# define MIN_PAGE_SIZE 256 /* Smallest conceivable page size, bytes */ - /* static */ JMP_BUF GC_jmp_buf; - - /*ARGSUSED*/ - void GC_fault_handler(sig) - int sig; - { - LONGJMP(GC_jmp_buf, 1); - } - - void GC_setup_temporary_fault_handler() - { - GC_set_and_save_fault_handler(GC_fault_handler); - } - - void GC_reset_fault_handler() - { -# if defined(SUNOS5SIGS) || defined(IRIX5) \ - || defined(OSF1) || defined(HURD) || defined(NETBSD) - (void) sigaction(SIGSEGV, &old_segv_act, 0); -# if defined(IRIX5) \ - || 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. */ - ptr_t GC_find_limit(p, up) - ptr_t p; - GC_bool up; - { - static VOLATILE ptr_t result; - /* Needs to be static, since otherwise it may not be */ - /* preserved across the longjmp. Can safely be */ - /* static since it's only called once, with the */ - /* allocation lock held. */ - - - 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; - } else { - result -= MIN_PAGE_SIZE; - } - GC_noop1((word)(*result)); - } - } - GC_reset_fault_handler(); - if (!up) { - result += MIN_PAGE_SIZE; - } - return(result); - } -# endif - -#if defined(ECOS) || defined(NOSYS) - ptr_t GC_get_stack_base() - { - 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 - /* Try to read the backing store base from /proc/self/maps. */ - /* We look for the writable mapping with a 0 major device, */ - /* which is as close to our frame as possible, but below it.*/ - static word backing_store_base_from_maps(char *maps) - { - char prot_buf[5]; - char *buf_ptr = maps; - word start, end; - unsigned int maj_dev; - word current_best = 0; - word dummy; - - for (;;) { - buf_ptr = GC_parse_map_entry(buf_ptr, &start, &end, prot_buf, &maj_dev); - if (buf_ptr == NULL) return current_best; - if (prot_buf[1] == 'w' && maj_dev == 0) { - if (end < (word)(&dummy) && start > current_best) current_best = start; - } - } - return current_best; - } - - static word backing_store_base_from_proc(void) - { - return GC_apply_to_maps(backing_store_base_from_maps); - } - -# 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) - { -# 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 - word result = backing_store_base_from_proc(); - if (0 == result) { - /* Use dumb heuristics. Works only for default configuration. */ - result = (word)GC_stackbottom - BACKING_STORE_DISPLACEMENT; - result += BACKING_STORE_ALIGNMENT - 1; - result &= ~(BACKING_STORE_ALIGNMENT - 1); - /* Verify that it's at least readable. If not, we goofed. */ - GC_noop1(*(word *)result); - } - return (ptr_t)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 ) { -# ifdef 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. */ -# else -# ifdef 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 - } -# 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) - -ptr_t GC_get_stack_base() -{ -# if defined(HEURISTIC1) || defined(HEURISTIC2) || \ - defined(LINUX_STACKBOTTOM) || defined(FREEBSD_STACKBOTTOM) - word dummy; - ptr_t result; -# endif - -# 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 */ - -/* - * 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() -{ - 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_printf0("DosGetInfoBlocks failed\n"); - ABORT("DosGetInfoBlocks failed\n"); - } - module_handle = ppib -> pib_hmte; - if (DosQueryModuleName(module_handle, PBUFSIZ, path) != NO_ERROR) { - GC_err_printf0("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_printf0("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) || defined (CYGWIN32) - -# ifdef CYGWIN32 -# define GC_no_win32_dlls (FALSE) -# endif - -# 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. */ - GC_bool GC_wnt = FALSE; - /* This is a Windows NT derivative, i.e. NT, W2K, XP or later. */ - - void GC_init_win32() - { - /* if we're running under win32s, assume that no DLLs will be loaded */ - 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; - DWORD 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; - DWORD 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; - } - } -# ifdef CONDPRINT - if (GC_print_stats) - GC_printf1("Found new system malloc AllocationBase at 0x%lx\n", - candidate); -# endif - 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 = -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; - DWORD 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(max_page_size, etext_addr) -int max_page_size; -int * 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(max_page_size, etext_addr) -int max_page_size; -int * 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() -{ -# if !defined(PCR) && !defined(SRC_M3) && !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, (char *)sbrk(0), FALSE); -# else - GC_add_roots_inner(DATASTART, (char *)(DATAEND), FALSE); -# if defined(DATASTART2) - GC_add_roots_inner(DATASTART2, (char *)(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) - -# ifdef SUNOS4 - extern caddr_t sbrk(); -# endif -# ifdef __STDC__ -# define SBRK_ARG_T ptrdiff_t -# else -# define SBRK_ARG_T int -# endif - - -# if 0 && defined(RS6000) /* We now use mmap */ -/* The compiler seems to generate speculative reads one past the end of */ -/* an allocated object. Hence we need to make sure that the page */ -/* following the last heap page is also mapped. */ -ptr_t GC_unix_get_mem(bytes) -word bytes; -{ - caddr_t cur_brk = (caddr_t)sbrk(0); - caddr_t result; - SBRK_ARG_T lsbs = (word)cur_brk & (GC_page_size-1); - static caddr_t my_brk_val = 0; - - if ((SBRK_ARG_T)bytes < 0) return(0); /* too big */ - if (lsbs != 0) { - if((caddr_t)(sbrk(GC_page_size - lsbs)) == (caddr_t)(-1)) return(0); - } - if (cur_brk == my_brk_val) { - /* Use the extra block we allocated last time. */ - result = (ptr_t)sbrk((SBRK_ARG_T)bytes); - if (result == (caddr_t)(-1)) return(0); - result -= GC_page_size; - } else { - result = (ptr_t)sbrk(GC_page_size + (SBRK_ARG_T)bytes); - if (result == (caddr_t)(-1)) return(0); - } - my_brk_val = result + bytes + GC_page_size; /* Always page aligned */ - return((ptr_t)result); -} - -#else /* Not RS6000 */ - -#if defined(USE_MMAP) || defined(USE_MUNMAP) - -#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 - -#endif /* defined(USE_MMAP) || defined(USE_MUNMAP) */ - -#if defined(USE_MMAP) -/* Tested only under Linux, IRIX5 and Solaris 2 */ - -#ifndef HEAP_START -# define HEAP_START 0 -#endif - -ptr_t GC_unix_get_mem(bytes) -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_get_mem(bytes); - } -# else - GC_ASSERT(last_addr != 0); -# endif - return((ptr_t)result); -} - -#else /* Not RS6000, not USE_MMAP */ -ptr_t GC_unix_get_mem(bytes) -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) return(0); /* too big */ - if (lsbs != 0) { - if((ptr_t)sbrk(GC_page_size - lsbs) == (ptr_t)(-1)) return(0); - } - result = (ptr_t)sbrk((SBRK_ARG_T)bytes); - if (result == (ptr_t)(-1)) result = 0; - } -# ifdef IRIX5 - __UNLOCK_MALLOC(); -# endif - return(result); -} - -#endif /* Not USE_MMAP */ -#endif /* Not RS6000 */ - -# 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) || defined(CYGWIN32) -SYSTEM_INFO GC_sysinfo; -# endif - -# if defined(MSWIN32) || defined(CYGWIN32) - -word GC_n_heap_bases = 0; - -# ifdef USE_GLOBAL_ALLOC -# define GLOBAL_ALLOC_TEST 1 -# else -# define GLOBAL_ALLOC_TEST GC_no_win32_dlls -# endif - -ptr_t GC_win32_get_mem(bytes) -word bytes; -{ - ptr_t result; - -# ifdef CYGWIN32 - result = GC_unix_get_mem (bytes); -# else - 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) & ~(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. */ - result = (ptr_t) VirtualAlloc(NULL, bytes + 1, - MEM_COMMIT | MEM_RESERVE, - PAGE_EXECUTE_READWRITE); - } -#endif - 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 () -{ - if (GC_no_win32_dlls) { - while (GC_n_heap_bases > 0) { -# ifdef CYGWIN32 - free (GC_heap_bases[--GC_n_heap_bases]); -# else - GlobalFree (GC_heap_bases[--GC_n_heap_bases]); -# endif - 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(bytes) -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, word 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, word 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, word 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, word 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_printf3( - "Mprotect failed at 0x%lx (length %ld) with errno %ld\n", - start_addr, 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, word bytes1, ptr_t start2, word 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; - word 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)() = 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 GC_PROTO((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 */ - -# ifdef SRC_M3 - -# ifdef ALL_INTERIOR_POINTERS - --> misconfigured -# endif - -void GC_push_thread_structures GC_PROTO((void)) -{ - /* Not our responsibibility. */ -} - -extern void ThreadF__ProcessStacks(); - -void GC_push_thread_stack(start, stop) -word start, stop; -{ - GC_push_all_stack((ptr_t)start, (ptr_t)stop + sizeof(word)); -} - -/* Push routine with M3 specific calling convention. */ -GC_m3_push_root(dummy1, p, dummy2, dummy3) -word *p; -ptr_t dummy1, dummy2; -int dummy3; -{ - word q = *p; - - GC_PUSH_ONE_STACK(q, p); -} - -/* M3 set equivalent to RTHeap.TracedRefTypes */ -typedef struct { int elts[1]; } RefTypeSet; -RefTypeSet GC_TracedRefTypes = {{0x1}}; - -void GC_default_push_other_roots GC_PROTO((void)) -{ - /* Use the M3 provided routine for finding static roots. */ - /* This is a bit dubious, since it presumes no C roots. */ - /* We handle the collector roots explicitly in GC_push_roots */ - RTMain__GlobalMapProc(GC_m3_push_root, 0, GC_TracedRefTypes); - if (GC_words_allocd > 0) { - ThreadF__ProcessStacks(GC_push_thread_stack); - } - /* Otherwise this isn't absolutely necessary, and we have */ - /* startup ordering problems. */ -} - -# endif /* SRC_M3 */ - -# if defined(GC_SOLARIS_THREADS) || defined(GC_PTHREADS) || \ - defined(GC_WIN32_THREADS) - -extern void GC_push_all_stacks(); - -void GC_default_push_other_roots GC_PROTO((void)) -{ - GC_push_all_stacks(); -} - -# endif /* GC_SOLARIS_THREADS || GC_PTHREADS */ - -void (*GC_push_other_roots) GC_PROTO((void)) = GC_default_push_other_roots; - -#endif /* THREADS */ - -/* - * Routines for accessing dirty bits on virtual pages. - * We plan to eventually implement four strategies for doing so: - * DEFAULT_VDB: A simple dummy implementation that treats every page - * as possibly dirty. This makes incremental collection - * useless, but the implementation is still correct. - * 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. - */ -GC_bool GC_dirty_maintained = FALSE; - -# 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() -{ -# ifdef PRINTSTATS - GC_printf0("Initializing DEFAULT_VDB...\n"); -# endif - 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() -{} - -/* 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(h) -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(h) -struct hblk *h; -{ - return(TRUE); -} - -/* Reset the n pages starting at h to "was never dirty" status. */ -void GC_is_fresh(h, n) -struct hblk *h; -word n; -{ -} - -/* 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(h, nblocks, is_ptrfree) -struct hblk *h; -word nblocks; -GC_bool is_ptrfree; -{ -} - -# endif /* DEFAULT_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 - * a lock across blocking calls, making it problematic for multithreaded - * 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_printf1("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(SUNOS4) || (defined(FREEBSD) && !defined(SUNOS5SIGS)) - typedef void (* SIG_PF)(); -#endif /* SUNOS4 || (FREEBSD && !SUNOS5SIGS) */ - -#if defined(SUNOS5SIGS) || defined(OSF1) || defined(LINUX) \ - || defined(HURD) -# ifdef __STDC__ - typedef void (* SIG_PF)(int); -# else - typedef void (* SIG_PF)(); -# endif -#endif /* SUNOS5SIGS || OSF1 || LINUX || HURD */ - -#if defined(MSWIN32) - typedef LPTOP_LEVEL_EXCEPTION_FILTER SIG_PF; -# undef SIG_DFL -# define SIG_DFL (LPTOP_LEVEL_EXCEPTION_FILTER) (-1) -#endif -#if defined(MSWINCE) - typedef LONG (WINAPI *SIG_PF)(struct _EXCEPTION_POINTERS *); -# undef SIG_DFL -# define SIG_DFL (SIG_PF) (-1) -#endif - -#if defined(IRIX5) || defined(OSF1) || defined(HURD) - typedef void (* REAL_SIG_PF)(int, int, struct sigcontext *); -#endif /* IRIX5 || OSF1 || HURD */ - -#if defined(SUNOS5SIGS) -# if defined(HPUX) || defined(FREEBSD) -# define SIGINFO_T siginfo_t -# else -# define SIGINFO_T struct siginfo -# endif -# ifdef __STDC__ - typedef void (* REAL_SIG_PF)(int, SIGINFO_T *, void *); -# else - typedef void (* REAL_SIG_PF)(); -# endif -#endif /* SUNOS5SIGS */ - -#if defined(LINUX) -# if __GLIBC__ > 2 || __GLIBC__ == 2 && __GLIBC_MINOR__ >= 2 - typedef struct sigcontext s_c; -# else /* glibc < 2.2 */ -# include <linux/version.h> -# if (LINUX_VERSION_CODE >= 0x20100) && !defined(M68K) || defined(ALPHA) || defined(ARM32) - typedef struct sigcontext s_c; -# else - typedef struct sigcontext_struct s_c; -# endif -# endif /* glibc < 2.2 */ -# if defined(ALPHA) || defined(M68K) - typedef void (* REAL_SIG_PF)(int, int, s_c *); -# else -# if defined(IA64) || defined(HP_PA) || defined(X86_64) - typedef void (* REAL_SIG_PF)(int, siginfo_t *, s_c *); - /* FIXME: */ - /* According to SUSV3, the last argument should have type */ - /* void * or ucontext_t * */ -# else - typedef void (* REAL_SIG_PF)(int, s_c); -# endif -# endif -# ifdef ALPHA - /* Retrieve fault address from sigcontext structure by decoding */ - /* instruction. */ - char * get_fault_addr(s_c *sc) { - unsigned instr; - word faultaddr; - - instr = *((unsigned *)(sc->sc_pc)); - faultaddr = sc->sc_regs[(instr >> 16) & 0x1f]; - faultaddr += (word) (((int)instr << 16) >> 16); - return (char *)faultaddr; - } -# endif /* !ALPHA */ -# endif /* LINUX */ - -#ifndef DARWIN -SIG_PF GC_old_bus_handler; -SIG_PF GC_old_segv_handler; /* Also old MSWIN32 ACCESS_VIOLATION filter */ -#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 GC_TEST_AND_SET_DEFINED - static VOLATILE unsigned int fault_handler_lock = 0; - void async_set_pht_entry_from_index(VOLATILE page_hash_table db, int index) { - while (GC_test_and_set(&fault_handler_lock)) {} - /* Could also revert to set_pht_entry_from_index_safe if initial */ - /* GC_test_and_set fails. */ - set_pht_entry_from_index(db, index); - GC_clear(&fault_handler_lock); - } -#else /* !GC_TEST_AND_SET_DEFINED */ - /* THIS IS 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, int 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 /* !GC_TEST_AND_SET_DEFINED */ -#else /* !THREADS */ -# define async_set_pht_entry_from_index(db, index) \ - set_pht_entry_from_index(db, index) -#endif /* !THREADS */ - -/*ARGSUSED*/ -#if !defined(DARWIN) -# if defined (SUNOS4) || (defined(FREEBSD) && !defined(SUNOS5SIGS)) - void GC_write_fault_handler(sig, code, scp, addr) - int sig, code; - struct sigcontext *scp; - char * addr; -# ifdef SUNOS4 -# define SIG_OK (sig == SIGSEGV || sig == SIGBUS) -# define CODE_OK (FC_CODE(code) == FC_PROT \ - || (FC_CODE(code) == FC_OBJERR \ - && FC_ERRNO(code) == FC_PROT)) -# endif -# ifdef FREEBSD -# define SIG_OK (sig == SIGBUS) -# define CODE_OK TRUE -# endif -# endif /* SUNOS4 || (FREEBSD && !SUNOS5SIGS) */ - -# if defined(IRIX5) || defined(OSF1) || defined(HURD) -# include <errno.h> - void GC_write_fault_handler(int sig, int code, struct sigcontext *scp) -# ifdef OSF1 -# define SIG_OK (sig == SIGSEGV) -# define CODE_OK (code == 2 /* experimentally determined */) -# endif -# ifdef IRIX5 -# define SIG_OK (sig == SIGSEGV) -# define CODE_OK (code == EACCES) -# endif -# ifdef HURD -# define SIG_OK (sig == SIGBUS || sig == SIGSEGV) -# define CODE_OK TRUE -# endif -# endif /* IRIX5 || OSF1 || HURD */ - -# if defined(LINUX) -# if defined(ALPHA) || defined(M68K) - void GC_write_fault_handler(int sig, int code, s_c * sc) -# else -# if defined(IA64) || defined(HP_PA) || defined(X86_64) - void GC_write_fault_handler(int sig, siginfo_t * si, s_c * scp) -# else -# if defined(ARM32) - void GC_write_fault_handler(int sig, int a2, int a3, int a4, s_c sc) -# else - void GC_write_fault_handler(int sig, s_c sc) -# endif -# endif -# endif -# 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. */ -# endif /* LINUX */ - -# if defined(SUNOS5SIGS) -# ifdef __STDC__ - void GC_write_fault_handler(int sig, SIGINFO_T *scp, void * context) -# else - void GC_write_fault_handler(sig, scp, context) - int sig; - SIGINFO_T *scp; - void * context; -# endif -# ifdef HPUX -# define SIG_OK (sig == SIGSEGV || sig == SIGBUS) -# define CODE_OK (scp -> si_code == SEGV_ACCERR) \ - || (scp -> si_code == BUS_ADRERR) \ - || (scp -> si_code == BUS_UNKNOWN) \ - || (scp -> si_code == SEGV_UNKNOWN) \ - || (scp -> si_code == BUS_OBJERR) -# else -# ifdef FREEBSD -# define SIG_OK (sig == SIGBUS) -# define CODE_OK (scp -> si_code == BUS_PAGE_FAULT) -# else -# define SIG_OK (sig == SIGSEGV) -# define CODE_OK (scp -> si_code == SEGV_ACCERR) -# endif -# endif -# endif /* SUNOS5SIGS */ - -# if defined(MSWIN32) || defined(MSWINCE) - LONG WINAPI GC_write_fault_handler(struct _EXCEPTION_POINTERS *exc_info) -# define SIG_OK (exc_info -> ExceptionRecord -> ExceptionCode == \ - STATUS_ACCESS_VIOLATION) -# define CODE_OK (exc_info -> ExceptionRecord -> ExceptionInformation[0] == 1) - /* Write fault */ -# endif /* MSWIN32 || MSWINCE */ -{ - register unsigned i; -# if defined(HURD) - char *addr = (char *) code; -# endif -# ifdef IRIX5 - char * addr = (char *) (size_t) (scp -> sc_badvaddr); -# endif -# if defined(OSF1) && defined(ALPHA) - char * addr = (char *) (scp -> sc_traparg_a0); -# endif -# ifdef SUNOS5SIGS - char * addr = (char *) (scp -> si_addr); -# endif -# ifdef LINUX -# if defined(I386) - char * addr = (char *) (sc.cr2); -# else -# if defined(M68K) - char * addr = NULL; - - struct sigcontext *scp = (struct sigcontext *)(sc); - - int format = (scp->sc_formatvec >> 12) & 0xf; - unsigned long *framedata = (unsigned long *)(scp + 1); - unsigned long ea; - - if (format == 0xa || format == 0xb) { - /* 68020/030 */ - ea = framedata[2]; - } else if (format == 7) { - /* 68040 */ - ea = framedata[3]; - if (framedata[1] & 0x08000000) { - /* correct addr on misaligned access */ - ea = (ea+4095)&(~4095); - } - } else if (format == 4) { - /* 68060 */ - ea = framedata[0]; - if (framedata[1] & 0x08000000) { - /* correct addr on misaligned access */ - ea = (ea+4095)&(~4095); - } - } - addr = (char *)ea; -# else -# ifdef ALPHA - char * addr = get_fault_addr(sc); -# else -# if defined(IA64) || defined(HP_PA) || defined(X86_64) - char * addr = si -> si_addr; - /* I believe this is claimed to work on all platforms for */ - /* Linux 2.3.47 and later. Hopefully we don't have to */ - /* worry about earlier kernels on IA64. */ -# else -# if defined(POWERPC) - char * addr = (char *) (sc.regs->dar); -# else -# if defined(ARM32) - char * addr = (char *)sc.fault_address; -# else -# if defined(CRIS) - char * addr = (char *)sc.regs.csraddr; -# else - --> architecture not supported -# endif -# endif -# endif -# endif -# endif -# endif -# endif -# endif -# if defined(MSWIN32) || defined(MSWINCE) - char * addr = (char *) (exc_info -> ExceptionRecord - -> ExceptionInformation[1]); -# define sig SIGSEGV -# endif - - 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_PF old_handler; - - if (sig == SIGSEGV) { - old_handler = GC_old_segv_handler; - } else { - old_handler = GC_old_bus_handler; - } - if (old_handler == SIG_DFL) { -# if !defined(MSWIN32) && !defined(MSWINCE) - GC_err_printf1("Segfault at 0x%lx\n", addr); - ABORT("Unexpected bus error or segmentation fault"); -# else - return(EXCEPTION_CONTINUE_SEARCH); -# endif - } else { -# if defined (SUNOS4) \ - || (defined(FREEBSD) && !defined(SUNOS5SIGS)) - (*old_handler) (sig, code, scp, addr); - return; -# endif -# if defined (SUNOS5SIGS) - /* - * FIXME: For FreeBSD, this code should check if the - * old signal handler used the traditional BSD style and - * if so call it using that style. - */ - (*(REAL_SIG_PF)old_handler) (sig, scp, context); - return; -# endif -# if defined (LINUX) -# if defined(ALPHA) || defined(M68K) - (*(REAL_SIG_PF)old_handler) (sig, code, sc); -# else -# if defined(IA64) || defined(HP_PA) || defined(X86_64) - (*(REAL_SIG_PF)old_handler) (sig, si, scp); -# else - (*(REAL_SIG_PF)old_handler) (sig, sc); -# endif -# endif - return; -# endif -# if defined (IRIX5) || defined(OSF1) || defined(HURD) - (*(REAL_SIG_PF)old_handler) (sig, code, scp); - return; -# endif -# ifdef MSWIN32 - return((*old_handler)(exc_info)); -# 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++) { - register int index = PHT_HASH(h+i); - - async_set_pht_entry_from_index(GC_dirty_pages, index); - } -# if defined(OSF1) - /* These reset the signal handler each time by default. */ - signal(SIGSEGV, (SIG_PF) GC_write_fault_handler); -# endif - /* 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_printf1("Segfault at 0x%lx\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(h, nblocks, is_ptrfree) -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 (!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) { - int 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() -{ -# if defined(SUNOS5SIGS) || defined(IRIX5) || defined(LINUX) || \ - defined(OSF1) || defined(HURD) - struct sigaction act, oldact; - /* We should probably specify SA_SIGINFO for Linux, and handle */ - /* the different architectures more uniformly. */ -# if defined(IRIX5) || defined(LINUX) && !defined(X86_64) \ - || defined(OSF1) || defined(HURD) - act.sa_flags = SA_RESTART; - act.sa_handler = (SIG_PF)GC_write_fault_handler; -# else - act.sa_flags = SA_RESTART | SA_SIGINFO; - act.sa_sigaction = GC_write_fault_handler; -# endif - (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 -# ifdef PRINTSTATS - GC_printf0("Inititalizing mprotect virtual dirty bit implementation\n"); -# endif - GC_dirty_maintained = TRUE; - if (GC_page_size % HBLKSIZE != 0) { - GC_err_printf0("Page size not multiple of HBLKSIZE\n"); - ABORT("Page size not multiple of HBLKSIZE"); - } -# if defined(SUNOS4) || (defined(FREEBSD) && !defined(SUNOS5SIGS)) - GC_old_bus_handler = signal(SIGBUS, GC_write_fault_handler); - if (GC_old_bus_handler == SIG_IGN) { - GC_err_printf0("Previously ignored bus error!?"); - GC_old_bus_handler = SIG_DFL; - } - if (GC_old_bus_handler != SIG_DFL) { -# ifdef PRINTSTATS - GC_err_printf0("Replaced other SIGBUS handler\n"); -# endif - } -# endif -# if defined(SUNOS4) - GC_old_segv_handler = signal(SIGSEGV, (SIG_PF)GC_write_fault_handler); - if (GC_old_segv_handler == SIG_IGN) { - GC_err_printf0("Previously ignored segmentation violation!?"); - GC_old_segv_handler = SIG_DFL; - } - if (GC_old_segv_handler != SIG_DFL) { -# ifdef PRINTSTATS - GC_err_printf0("Replaced other SIGSEGV handler\n"); -# endif - } -# endif -# if (defined(SUNOS5SIGS) && !defined(FREEBSD)) || defined(IRIX5) \ - || defined(LINUX) || defined(OSF1) || defined(HURD) - /* SUNOS5SIGS includes HPUX */ -# 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 defined(_sigargs) || defined(HURD) || !defined(SA_SIGINFO) - /* This is Irix 5.x, not 6.x. Irix 5.x does not have */ - /* sa_sigaction. */ - GC_old_segv_handler = oldact.sa_handler; -# else /* Irix 6.x or SUNOS5SIGS or LINUX */ - if (oldact.sa_flags & SA_SIGINFO) { - GC_old_segv_handler = (SIG_PF)(oldact.sa_sigaction); - } else { - GC_old_segv_handler = oldact.sa_handler; - } -# endif - if (GC_old_segv_handler == SIG_IGN) { - GC_err_printf0("Previously ignored segmentation violation!?"); - GC_old_segv_handler = SIG_DFL; - } - if (GC_old_segv_handler != SIG_DFL) { -# ifdef PRINTSTATS - GC_err_printf0("Replaced other SIGSEGV handler\n"); -# endif - } -# endif /* (SUNOS5SIGS && !FREEBSD) || IRIX5 || LINUX || OSF1 || HURD */ -# if defined(HPUX) || defined(LINUX) || defined(HURD) \ - || (defined(FREEBSD) && defined(SUNOS5SIGS)) - sigaction(SIGBUS, &act, &oldact); - GC_old_bus_handler = oldact.sa_handler; - if (GC_old_bus_handler == SIG_IGN) { - GC_err_printf0("Previously ignored bus error!?"); - GC_old_bus_handler = SIG_DFL; - } - if (GC_old_bus_handler != SIG_DFL) { -# ifdef PRINTSTATS - GC_err_printf0("Replaced other SIGBUS handler\n"); -# endif - } -# endif /* HPUX || LINUX || HURD || (FREEBSD && SUNOS5SIGS) */ -# if defined(MSWIN32) - GC_old_segv_handler = SetUnhandledExceptionFilter(GC_write_fault_handler); - if (GC_old_segv_handler != NULL) { -# ifdef PRINTSTATS - GC_err_printf0("Replaced other UnhandledExceptionFilter\n"); -# endif - } else { - GC_old_segv_handler = SIG_DFL; - } -# endif -} -#endif /* !DARWIN */ - -int GC_incremental_protection_needs() -{ - 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() -{ - ptr_t start; - word 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() -{ - 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(h) -struct hblk * h; -{ - register word 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. */ - -void GC_begin_syscall() -{ - if (!I_HOLD_LOCK()) { - LOCK(); - syscall_acquired_lock = TRUE; - } -} - -void GC_end_syscall() -{ - if (syscall_acquired_lock) { - syscall_acquired_lock = FALSE; - UNLOCK(); - } -} - -void GC_unprotect_range(addr, len) -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); -} - -#if 0 - -/* 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). */ -# if defined(__STDC__) && !defined(SUNOS4) -# include <unistd.h> -# include <sys/uio.h> - ssize_t read(int fd, void *buf, size_t nbyte) -# else -# ifndef LINT - int read(fd, buf, nbyte) -# else - int GC_read(fd, buf, nbyte) -# endif - int fd; - char *buf; - int nbyte; -# endif -{ - 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(h) -struct hblk *h; -{ - return(TRUE); -} - -/* Reset the n pages starting at h to "was never dirty" status. */ -/*ARGSUSED*/ -void GC_is_fresh(h, n) -struct hblk *h; -word n; -{ -} - -# 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; - -#ifdef GC_SOLARIS_THREADS -/* We don't have exact sp values for threads. So we count on */ -/* occasionally declaring stack pages to be fresh. Thus we */ -/* need a real implementation of GC_is_fresh. We can't clear */ -/* entries in GC_written_pages, since that would declare all */ -/* pages with the given hash address to be fresh. */ -# define MAX_FRESH_PAGES 8*1024 /* Must be power of 2 */ - struct hblk ** GC_fresh_pages; /* A direct mapped cache. */ - /* Collisions are dropped. */ - -# define FRESH_PAGE_SLOT(h) (divHBLKSZ((word)(h)) & (MAX_FRESH_PAGES-1)) -# define ADD_FRESH_PAGE(h) \ - GC_fresh_pages[FRESH_PAGE_SLOT(h)] = (h) -# define PAGE_IS_FRESH(h) \ - (GC_fresh_pages[FRESH_PAGE_SLOT(h)] == (h) && (h) != 0) -#endif - -/* Add all pages in pht2 to pht1 */ -void GC_or_pages(pht1, pht2) -page_hash_table pht1, pht2; -{ - register int i; - - for (i = 0; i < PHT_SIZE; i++) pht1[i] |= pht2[i]; -} - -int GC_proc_fd; - -void GC_dirty_init() -{ - int fd; - char buf[30]; - - GC_dirty_maintained = TRUE; - if (GC_words_allocd != 0 || GC_words_allocd_before_gc != 0) { - register int i; - - for (i = 0; i < PHT_SIZE; i++) GC_written_pages[i] = (word)(-1); -# ifdef PRINTSTATS - GC_printf1("Allocated words:%lu:all pages may have been written\n", - (unsigned long) - (GC_words_allocd + GC_words_allocd_before_gc)); -# endif - } - 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); -# ifdef GC_SOLARIS_THREADS - GC_fresh_pages = (struct hblk **) - GC_scratch_alloc(MAX_FRESH_PAGES * sizeof (struct hblk *)); - if (GC_fresh_pages == 0) { - GC_err_printf0("No space for fresh pages\n"); - EXIT(); - } - BZERO(GC_fresh_pages, MAX_FRESH_PAGES * sizeof (struct hblk *)); -# endif -} - -/* 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; -{ -} - -#ifdef GC_SOLARIS_THREADS -# define READ(fd,buf,nbytes) syscall(SYS_read, fd, buf, nbytes) -#else -# define READ(fd,buf,nbytes) read(fd, buf, nbytes) -#endif - -void GC_read_dirty() -{ - unsigned long ps, np; - int nmaps; - ptr_t vaddr; - struct prasmap * map; - char * bufp; - ptr_t current_addr, limit; - int i; -int dummy; - - BZERO(GC_grungy_pages, (sizeof GC_grungy_pages)); - - bufp = GC_proc_buf; - if (READ(GC_proc_fd, bufp, GC_proc_buf_size) <= 0) { -# ifdef PRINTSTATS - GC_printf1("/proc read failed: GC_proc_buf_size = %lu\n", - GC_proc_buf_size); -# endif - { - /* 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)); -# ifdef GC_SOLARIS_THREADS - BZERO(GC_fresh_pages, - MAX_FRESH_PAGES * sizeof (struct hblk *)); -# endif - 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); -# ifdef GC_SOLARIS_THREADS - { - register int slot = FRESH_PAGE_SLOT(h); - - if (GC_fresh_pages[slot] == h) { - GC_fresh_pages[slot] = 0; - } - } -# endif - 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); -# ifdef GC_SOLARIS_THREADS - /* Make sure that old stacks are considered completely clean */ - /* unless written again. */ - GC_old_stacks_are_fresh(); -# endif -} - -#undef READ - -GC_bool GC_page_was_dirty(h) -struct hblk *h; -{ - register word index = PHT_HASH(h); - register GC_bool result; - - result = get_pht_entry_from_index(GC_grungy_pages, index); -# ifdef GC_SOLARIS_THREADS - if (result && PAGE_IS_FRESH(h)) result = FALSE; - /* This happens only if page was declared fresh since */ - /* the read_dirty call, e.g. because it's in an unused */ - /* thread stack. It's OK to treat it as clean, in */ - /* that case. And it's consistent with */ - /* GC_page_was_ever_dirty. */ -# endif - return(result); -} - -GC_bool GC_page_was_ever_dirty(h) -struct hblk *h; -{ - register word index = PHT_HASH(h); - register GC_bool result; - - result = get_pht_entry_from_index(GC_written_pages, index); -# ifdef GC_SOLARIS_THREADS - if (result && PAGE_IS_FRESH(h)) result = FALSE; -# endif - return(result); -} - -/* Caller holds allocation lock. */ -void GC_is_fresh(h, n) -struct hblk *h; -word n; -{ - - register word index; - -# ifdef GC_SOLARIS_THREADS - register word i; - - if (GC_fresh_pages != 0) { - for (i = 0; i < n; i++) { - ADD_FRESH_PAGE(h + i); - } - } -# endif -} - -# 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() -{ - 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() -{ - /* 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(h) -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(h, nblocks, is_ptrfree) -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> - -/* 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() { - 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() { - GC_mprotect_thread_notify(ID_STOP); -} -void GC_mprotect_resume() { - 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 - - if(r != MACH_MSG_SUCCESS) { - GC_err_printf2("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_printf2( - "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 - -typedef void (* SIG_PF)(); -static SIG_PF 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++; - GC_err_printf0("GC: WARNING: Ignoring SIGBUS.\n"); - } -} -#endif /* BROKEN_EXCEPTION_HANDLING */ - -void GC_dirty_init() { - kern_return_t r; - mach_port_t me; - pthread_t thread; - pthread_attr_t attr; - exception_mask_t mask; - -# ifdef PRINTSTATS - GC_printf0("Inititalizing mach/darwin mprotect virtual dirty bit " - "implementation\n"); -# endif -# ifdef BROKEN_EXCEPTION_HANDLING - GC_err_printf0("GC: WARNING: Enabling workarounds for various darwin " - "exception handling bugs.\n"); -# endif - GC_dirty_maintained = TRUE; - if (GC_page_size % HBLKSIZE != 0) { - GC_err_printf0("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_PF)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_PF)oldsa.sa_handler; - if (GC_old_bus_handler != SIG_DFL) { -# ifdef PRINTSTATS - GC_err_printf0("Replaced other SIGBUS handler\n"); -# endif - } - } - #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 -) { - int i; - kern_return_t r; - mach_port_t port; - exception_behavior_t behavior; - thread_state_flavor_t flavor; - - thread_state_t thread_state; - 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; - 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 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_printf3("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_printf0("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) - GC_err_printf1( - "GC: WARNING: Ignoring KERN_PROTECTION_FAILURE at %p\n", - addr); - return KERN_SUCCESS; - } - - GC_err_printf1("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_printf0("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_printf0("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]; - }; -# else -# if defined(SUNOS4) -# include <machine/frame.h> -# else -# if defined (DRSNX) -# include <sys/sparc/frame.h> -# else -# if defined(OPENBSD) -# include <frame.h> -# else -# if defined(FREEBSD) || defined(NETBSD) -# include <machine/frame.h> -# else -# include <sys/frame.h> -# endif -# endif -# endif -# endif -# endif -# if NARGS > 6 - --> 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) -# include <execinfo.h> -#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 (info) -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 (info) -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 (info) -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_printf0("\tCaller at allocation:\n"); -# else - GC_err_printf0("\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_printf0("\t\targs: "); - for (j = 0; j < NARGS; j++) { - if (j != 0) GC_err_printf0(", "); - GC_err_printf2("%d (0x%X)", ~(info[i].ci_arg[j]), - ~(info[i].ci_arg[j])); - } - GC_err_printf0("\n"); - } -# endif - if (reentry_count > 1) { - /* We were called during an allocation during */ - /* a previous GC_print_callers call; punt. */ - GC_err_printf1("\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_printf1("\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() -{ - GC_err_printf0("---------- Begin address map ----------\n"); - GC_apply_to_maps(dump_maps); - GC_err_printf0("---------- End address map ----------\n"); -} - -#endif - - |