/* * Copyright (c) 1991-1995 by Xerox Corporation. All rights reserved. * Copyright (c) 1996-1997 by Silicon Graphics. 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 "gc_priv.h" # if defined(LINUX) && !defined(POWERPC) # include # 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 # 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 # if 2 <= __GLIBC__ && 0 == __GLIBC_MINOR__ # include # else /* not 2 <= __GLIBC__ */ /* libc5 doesn't have : go directly with the kernel */ /* one. Check LINUX_VERSION_CODE to see which we should reference. */ # include # endif /* 2 <= __GLIBC__ */ # endif # endif # if !defined(OS2) && !defined(PCR) && !defined(AMIGA) && !defined(MACOS) # include # if !defined(MSWIN32) && !defined(SUNOS4) # include # endif # endif # include # include /* Blatantly OS dependent routines, except for those that are related */ /* dynamic loading. */ # if !defined(THREADS) && !defined(STACKBOTTOM) && defined(HEURISTIC2) # define NEED_FIND_LIMIT # endif # if defined(IRIX_THREADS) # 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(PCR) # define NEED_FIND_LIMIT # endif # if defined(LINUX) && (defined(POWERPC) || defined(ALPHA)) # define NEED_FIND_LIMIT # endif #ifdef NEED_FIND_LIMIT # include #endif #ifdef FREEBSD # include #endif #ifdef AMIGA # include # include # include # include #endif #ifdef MSWIN32 # define WIN32_LEAN_AND_MEAN # define NOSERVICE # include #endif #ifdef MACOS # include #endif #ifdef IRIX5 # include # include /* for locking */ #endif #ifdef USE_MMAP # include # include # include # include #endif #ifdef SUNOS5SIGS # include # undef setjmp # undef longjmp # define setjmp(env) sigsetjmp(env, 1) # define longjmp(env, val) siglongjmp(env, val) # define jmp_buf sigjmp_buf #endif #ifdef DJGPP /* Apparently necessary for djgpp 2.01. May casuse 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(POWERPC) ptr_t GC_data_start; void GC_init_linuxppc() { 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 #if defined(LINUX) && defined(ALPHA) ptr_t GC_data_start; void GC_init_linuxalpha() { # ifdef USE_PROC FILE *fp = fopen("/proc/self/maps", "r"); if (fp) { extern void *_etext; ptr_t stacktop = 0, stackbottom = 0; ptr_t textstart = 0, textend = 0; ptr_t datastart = 0, dataend = 0; ptr_t bssstart = 0, bssend = 0; while (!feof(fp)) { ptr_t start, end, offset; unsigned short major, minor; char r, w, x, p; unsigned int inode; int n = fscanf(fp, "%lx-%lx %c%c%c%c %lx %hx:%hx %d", &start, &end, &r, &w, &x, &p, &offset, &major, &minor, &inode); if (n < 10) break; /* * If local variable lies within segment, it is stack. * Else if segment lies below _end and is executable, * it is text. Otherwise, if segment start lies between * _etext and _end and segment is writable and is mapped * to the executable image it is data, otherwise bss. */ if (start < (ptr_t)&fp && end > (ptr_t)&fp && w == 'w') { stacktop = start; stackbottom = end; } else if (start < (ptr_t)&_end && w == '-' && x == 'x') { textstart = start; textend = end; } else if (start >= (ptr_t)&_etext && start < (ptr_t)&_end && w == 'w') { if (inode > 0) { datastart = start; dataend = end; } else { bssstart = start; bssend = end; } } //printf("%016lx-%016lx %c%c%c%c %016lx %02hx:%02hx %d\n", // start, end, r, w, x, p, offset, major, minor, inode); while (fgetc(fp) != '\n') ; } fclose(fp); //fprintf(stderr, "text: %lx-%lx\n", textstart, textend); //fprintf(stderr, "data: %lx-%lx\n", datastart, dataend); //fprintf(stderr, "bss: %lx-%lx\n", bssstart, bssend); //fprintf(stderr, "stack: %lx-%lx\n", stacktop, stackbottom); GC_data_start = datastart; } else { # endif extern ptr_t GC_find_limit(); extern int _edata; /* This may need to be environ, without the underscore, for */ /* some versions. */ GC_data_start = GC_find_limit((ptr_t)&_edata, FALSE); # ifdef USE_PROC } # endif //fprintf(stderr, "GC_data_start = %p\n", GC_data_start); } #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 #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 */ # ifdef OS2 # include # 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 # include # endif /* __IBMC__ */ # define INCL_DOSEXCEPTIONS # define INCL_DOSPROCESS # define INCL_DOSERRORS # define INCL_DOSMODULEMGR # define INCL_DOSMEMMGR # include /* 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(MACOS) && !defined(DJGPP) && !defined(DOS4GW) \ && !defined(NO_SIGSET) # if defined(sigmask) && !defined(UTS4) /* 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 /* 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)) # 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) || defined (NO_SIGSET) void GC_disable_signals() { } void GC_enable_signals() { } #endif /* Find the page size */ word GC_page_size; # ifdef MSWIN32 void GC_setpagesize() { SYSTEM_INFO sysinfo; GetSystemInfo(&sysinfo); GC_page_size = sysinfo.dwPageSize; } # else # if defined(MPROTECT_VDB) || defined(PROC_VDB) || defined(USE_MMAP) 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. */ # ifdef MSWIN32 # 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); } # else # 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)); } # else # ifdef AMIGA ptr_t GC_get_stack_base() { extern struct WBStartup *_WBenchMsg; extern long __base; extern long __stack; struct Task *task; struct Process *proc; struct CommandLineInterface *cli; long size; if ((task = FindTask(0)) == 0) { GC_err_puts("Cannot find own task structure\n"); ABORT("task missing"); } proc = (struct Process *)task; cli = BADDR(proc->pr_CLI); if (_WBenchMsg != 0 || cli == 0) { size = (char *)task->tc_SPUpper - (char *)task->tc_SPLower; } else { size = cli->cli_DefaultStack * 4; } return (ptr_t)(__base + GC_max(size, __stack)); } # else # 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); } # ifdef __STDC__ typedef void (*handler)(int); # else typedef void (*handler)(); # endif # if defined(SUNOS5SIGS) || defined(IRIX5) static struct sigaction old_segv_act; static struct sigaction old_bus_act; # else static handler old_segv_handler, old_bus_handler; # endif void GC_setup_temporary_fault_handler() { # ifndef ECOS # if defined(SUNOS5SIGS) || defined(IRIX5) struct sigaction act; act.sa_handler = GC_fault_handler; act.sa_flags = SA_RESTART | SA_NODEFER; /* The presence of SA_NODEFER represents yet another gross */ /* hack. Under Solaris 2.3, siglongjmp doesn't appear to */ /* interact correctly with -lthread. We hide the confusion */ /* by making sure that signal handling doesn't affect the */ /* signal mask. */ (void) sigemptyset(&act.sa_mask); # ifdef IRIX_THREADS /* Older versions have a bug related to retrieving and */ /* and setting a handler at the same time. */ (void) sigaction(SIGSEGV, 0, &old_segv_act); (void) sigaction(SIGSEGV, &act, 0); # else (void) sigaction(SIGSEGV, &act, &old_segv_act); # ifdef _sigargs /* Irix 5.x, not 6.x */ /* Under 5.x, we may get SIGBUS. */ /* Pthreads doesn't exist under 5.x, so we don't */ /* have to worry in the threads case. */ (void) sigaction(SIGBUS, &act, &old_bus_act); # endif # endif /* IRIX_THREADS */ # else old_segv_handler = signal(SIGSEGV, GC_fault_handler); # ifdef SIGBUS old_bus_handler = signal(SIGBUS, GC_fault_handler); # endif # endif # endif /* ECOS */ } void GC_reset_fault_handler() { # ifndef ECOS # if defined(SUNOS5SIGS) || defined(IRIX5) (void) sigaction(SIGSEGV, &old_segv_act, 0); # ifdef _sigargs /* Irix 5.x, not 6.x */ (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 # endif /* ECOS */ } /* Return the first nonaddressible location > p (up) or */ /* the smallest location q s.t. [q,p] is addressible (!up). */ ptr_t GC_find_limit(p, up) ptr_t p; GC_bool up; { # ifndef ECOS 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); # else /* ECOS */ abort(); # endif /* ECOS */ } # endif # ifndef ECOS ptr_t GC_get_stack_base() { word dummy; ptr_t result; # define STACKBOTTOM_ALIGNMENT_M1 ((word)STACK_GRAN - 1) # if defined(STACKBASE) extern ptr_t STACKBASE; return(STACKBASE); # else # 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 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 */ return(result); # endif /* STACKBOTTOM */ # endif /* STACKBASE */ } # endif /* ECOS */ # endif /* ! AMIGA */ # endif /* ! OS2 */ # endif /* ! MSWIN32 */ /* * 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 # 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 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 rgister the main data segment here. */ GC_bool GC_win32s = FALSE; /* We're running under win32s. */ GC_bool GC_is_win32s() { DWORD v = GetVersion(); /* Check that this is not NT, and Windows major version <= 3 */ return ((v & 0x80000000) && (v & 0xff) <= 3); } void GC_init_win32() { GC_win32s = GC_is_win32s(); } /* 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; SYSTEM_INFO sysinfo; DWORD result; LPVOID limit; ptr_t p; LPVOID q; GetSystemInfo(&sysinfo); limit = 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); } /* 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) { register unsigned i; # ifndef REDIRECT_MALLOC static ptr_t malloc_heap_pointer = 0; if (0 == malloc_heap_pointer) { MEMORY_BASIC_INFORMATION buf; register DWORD result = VirtualQuery(malloc(1), &buf, sizeof(buf)); if (result != sizeof(buf)) { ABORT("Weird VirtualQuery result"); } malloc_heap_pointer = (ptr_t)(buf.AllocationBase); } if (p == malloc_heap_pointer) return(TRUE); # endif for (i = 0; i < GC_n_heap_bases; i++) { if (GC_heap_bases[i] == p) return(TRUE); } return(FALSE); } void GC_register_root_section(ptr_t static_root) { MEMORY_BASIC_INFORMATION buf; SYSTEM_INFO sysinfo; DWORD result; DWORD protect; LPVOID p; char * base; char * limit, * new_limit; if (!GC_win32s) return; p = base = limit = GC_least_described_address(static_root); GetSystemInfo(&sysinfo); while (p < 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); } void GC_register_data_segments() { static char dummy; GC_register_root_section((ptr_t)(&dummy)); } # else # ifdef AMIGA void GC_register_data_segments() { extern struct WBStartup *_WBenchMsg; struct Process *proc; struct CommandLineInterface *cli; BPTR myseglist; ULONG *data; if ( _WBenchMsg != 0 ) { if ((myseglist = _WBenchMsg->sm_Segment) == 0) { GC_err_puts("No seglist from workbench\n"); return; } } else { if ((proc = (struct Process *)FindTask(0)) == 0) { GC_err_puts("Cannot find process structure\n"); return; } if ((cli = BADDR(proc->pr_CLI)) == 0) { GC_err_puts("No CLI\n"); return; } if ((myseglist = cli->cli_Module) == 0) { GC_err_puts("No seglist from CLI\n"); return; } } for (data = (ULONG *)BADDR(myseglist); data != 0; data = (ULONG *)BADDR(data[0])) { # ifdef AMIGA_SKIP_SEG if (((ULONG) GC_register_data_segments < (ULONG) &data[1]) || ((ULONG) GC_register_data_segments > (ULONG) &data[1] + data[-1])) { # else { # endif /* AMIGA_SKIP_SEG */ GC_add_roots_inner((char *)&data[1], ((char *)&data[1]) + data[-1], FALSE); } } } # else # if (defined(SVR4) || defined(AUX) || defined(DGUX)) && !defined(PCR) char * 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) - MIN_PAGE_SIZE, FALSE); } return((char *)result); } # endif void GC_register_data_segments() { # if !defined(PCR) && !defined(SRC_M3) && !defined(NEXT) && !defined(MACOS) # if defined(REDIRECT_MALLOC) && defined(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); # endif # endif # if !defined(PCR) && defined(NEXT) GC_add_roots_inner(DATASTART, (char *) get_end(), FALSE); # 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); /* globals begin above stack and end at a5. */ GC_add_roots_inner((ptr_t)GC_MacGetDataStart(), (ptr_t)LMGetCurrentA5(), FALSE); # 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 */ # endif /* ! OS2 */ /* * Auxiliary routines for obtaining memory from OS. */ # if !defined(OS2) && !defined(PCR) && !defined(AMIGA) \ && !defined(MSWIN32) && !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 # ifdef RS6000 /* 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) /* Tested only under IRIX5 */ ptr_t GC_unix_get_mem(bytes) word bytes; { static GC_bool initialized = FALSE; static int fd; void *result; static ptr_t last_addr = HEAP_START; if (!initialized) { fd = open("/dev/zero", O_RDONLY); initialized = TRUE; } if (bytes & (GC_page_size -1)) ABORT("Bad GET_MEM arg"); result = mmap(last_addr, bytes, PROT_READ | PROT_WRITE | OPT_PROT_EXEC, MAP_PRIVATE | MAP_FIXED, 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)); 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 */ # ifdef MSWIN32 word GC_n_heap_bases = 0; ptr_t GC_win32_get_mem(bytes) word bytes; { ptr_t result; if (GC_win32s) { /* 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 { result = (ptr_t) VirtualAlloc(NULL, bytes, MEM_COMMIT | MEM_RESERVE, PAGE_EXECUTE_READWRITE); } if (HBLKDISPL(result) != 0) ABORT("Bad VirtualAlloc result"); /* If I read the documentation correctly, this can */ /* only happen if HBLKSIZE > 64k or not a power of 2. */ if (GC_n_heap_bases >= MAX_HEAP_SECTS) ABORT("Too many heap sections"); GC_heap_bases[GC_n_heap_bases++] = result; return(result); } # endif /* Routine for pushing any additional roots. In THREADS */ /* environment, this is also responsible for marking from */ /* thread stacks. In the SRC_M3 case, it also handles */ /* global variables. */ #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() { /* 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 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; if ((ptr_t)(q) >= GC_least_plausible_heap_addr && (ptr_t)(q) < GC_greatest_plausible_heap_addr) { GC_push_one_checked(q,FALSE); } } /* M3 set equivalent to RTHeap.TracedRefTypes */ typedef struct { int elts[1]; } RefTypeSet; RefTypeSet GC_TracedRefTypes = {{0x1}}; /* From finalize.c */ extern void GC_push_finalizer_structures(); /* From stubborn.c: */ # ifdef STUBBORN_ALLOC extern GC_PTR * GC_changing_list_start; # endif void GC_default_push_other_roots() { /* 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. */ { # ifdef STUBBORN_ALLOC GC_push_one(GC_changing_list_start); # endif GC_push_finalizer_structures(); 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(SOLARIS_THREADS) || defined(WIN32_THREADS) \ || defined(IRIX_THREADS) || defined(LINUX_THREADS) \ || defined(QUICK_THREADS) extern void GC_push_all_stacks(); void GC_default_push_other_roots() { GC_push_all_stacks(); } # endif /* SOLARIS_THREADS || ... */ void (*GC_push_other_roots)() = GC_default_push_other_roots; #endif /* * Routines for accessing dirty bits on virtual pages. * We plan to eventaually 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() { 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 hints that h is about to be written. */ /* May speed up some dirty bit implementations. */ /*ARGSUSED*/ void GC_write_hint(h) struct hblk *h; { } # 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 * except as a result of a read system call. This means clients must * either ensure that system calls do not touch the heap, or must * provide their own wrappers analogous to the one for read. * We assume the page size is a multiple of HBLKSIZE. * This implementation is currently SunOS 4.X and IRIX 5.X specific, though we * tried to use portable code where easily possible. It is known * not to work under a number of other systems. */ # ifndef MSWIN32 # include # include # include # define PROTECT(addr, len) \ if (mprotect((caddr_t)(addr), (int)(len), \ PROT_READ | OPT_PROT_EXEC) < 0) { \ ABORT("mprotect failed"); \ } # define UNPROTECT(addr, len) \ if (mprotect((caddr_t)(addr), (int)(len), \ PROT_WRITE | PROT_READ | OPT_PROT_EXEC ) < 0) { \ ABORT("un-mprotect failed"); \ } # else # include 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 VOLATILE page_hash_table GC_dirty_pages; /* Pages dirtied since last GC_read_dirty. */ #if defined(SUNOS4) || defined(FREEBSD) typedef void (* SIG_PF)(); #endif #if defined(SUNOS5SIGS) || defined(OSF1) || defined(LINUX) typedef void (* SIG_PF)(int); #endif #if defined(MSWIN32) typedef LPTOP_LEVEL_EXCEPTION_FILTER SIG_PF; # undef SIG_DFL # define SIG_DFL (LPTOP_LEVEL_EXCEPTION_FILTER) (-1) #endif #if defined(IRIX5) || defined(OSF1) typedef void (* REAL_SIG_PF)(int, int, struct sigcontext *); #endif #if defined(SUNOS5SIGS) typedef void (* REAL_SIG_PF)(int, struct siginfo *, void *); #endif #if defined(LINUX) # include # if (LINUX_VERSION_CODE >= 0x20100) typedef void (* REAL_SIG_PF)(int, struct sigcontext); # else typedef void (* REAL_SIG_PF)(int, struct sigcontext_struct); # endif # endif SIG_PF GC_old_bus_handler; SIG_PF GC_old_segv_handler; /* Also old MSWIN32 ACCESS_VIOLATION filter */ /*ARGSUSED*/ # if defined (SUNOS4) || defined(FREEBSD) 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 (code == BUS_PAGE_FAULT) # endif # endif # if defined(IRIX5) || defined(OSF1) # include void GC_write_fault_handler(int sig, int code, struct sigcontext *scp) # define SIG_OK (sig == SIGSEGV) # ifdef OSF1 # define CODE_OK (code == 2 /* experimentally determined */) # endif # ifdef IRIX5 # define CODE_OK (code == EACCES) # endif # endif # if defined(LINUX) # if (LINUX_VERSION_CODE >= 0x20100) void GC_write_fault_handler(int sig, struct sigcontext sc) # else void GC_write_fault_handler(int sig, struct sigcontext_struct sc) # endif # define SIG_OK (sig == SIGSEGV) # define CODE_OK TRUE /* Empirically c.trapno == 14, but is that useful? */ /* We assume Intel architecture, so alignment */ /* faults are not possible. */ # endif # if defined(SUNOS5SIGS) void GC_write_fault_handler(int sig, struct siginfo *scp, void * context) # define SIG_OK (sig == SIGSEGV) # define CODE_OK (scp -> si_code == SEGV_ACCERR) # endif # if defined(MSWIN32) LONG WINAPI GC_write_fault_handler(struct _EXCEPTION_POINTERS *exc_info) # define SIG_OK (exc_info -> ExceptionRecord -> ExceptionCode == \ EXCEPTION_ACCESS_VIOLATION) # define CODE_OK (exc_info -> ExceptionRecord -> ExceptionInformation[0] == 1) /* Write fault */ # endif { register unsigned i; # 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 # ifdef I386 char * addr = (char *) (sc.cr2); # else char * addr = /* As of 1.3.90 there seemed to be no way to do this. */; # endif # endif # if defined(MSWIN32) 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) { /* 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) { # ifndef MSWIN32 ABORT("Unexpected bus error or segmentation fault"); # else return(EXCEPTION_CONTINUE_SEARCH); # endif } else { # if defined (SUNOS4) || defined(FREEBSD) (*old_handler) (sig, code, scp, addr); return; # endif # if defined (SUNOS5SIGS) (*(REAL_SIG_PF)old_handler) (sig, scp, context); return; # endif # if defined (LINUX) (*(REAL_SIG_PF)old_handler) (sig, sc); return; # endif # if defined (IRIX5) || defined(OSF1) (*(REAL_SIG_PF)old_handler) (sig, code, scp); return; # endif # ifdef MSWIN32 return((*old_handler)(exc_info)); # endif } } for (i = 0; i < divHBLKSZ(GC_page_size); i++) { register int index = PHT_HASH(h+i); set_pht_entry_from_index(GC_dirty_pages, index); } UNPROTECT(h, GC_page_size); # if defined(OSF1) || defined(LINUX) /* 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 ... */ # ifdef MSWIN32 return(EXCEPTION_CONTINUE_EXECUTION); # else return; # endif } #ifdef MSWIN32 return EXCEPTION_CONTINUE_SEARCH; #else ABORT("Unexpected bus error or segmentation fault"); #endif } /* * We hold the allocation lock. We expect block h to be written * shortly. */ void GC_write_hint(h) struct hblk *h; { register struct hblk * h_trunc; register unsigned i; register GC_bool found_clean; if (!GC_dirty_maintained) return; h_trunc = (struct hblk *)((word)h & ~(GC_page_size-1)); found_clean = FALSE; for (i = 0; i < divHBLKSZ(GC_page_size); i++) { register int index = PHT_HASH(h_trunc+i); if (!get_pht_entry_from_index(GC_dirty_pages, index)) { found_clean = TRUE; set_pht_entry_from_index(GC_dirty_pages, index); } } if (found_clean) { UNPROTECT(h_trunc, GC_page_size); } } void GC_dirty_init() { #if defined(SUNOS5SIGS) || defined(IRIX5) struct sigaction act, oldact; # ifdef IRIX5 act.sa_flags = SA_RESTART; act.sa_handler = 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); #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) 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(OSF1) || defined(SUNOS4) || defined(LINUX) 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(IRIX5) # ifdef IRIX_THREADS sigaction(SIGSEGV, 0, &oldact); sigaction(SIGSEGV, &act, 0); # else sigaction(SIGSEGV, &act, &oldact); # endif # if defined(_sigargs) /* 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 */ 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 # 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 } void GC_protect_heap() { ptr_t start; word len; unsigned i; for (i = 0; i < GC_n_heap_sects; i++) { start = GC_heap_sects[i].hs_start; len = GC_heap_sects[i].hs_bytes; PROTECT(start, len); } } /* 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. */ void GC_begin_syscall() { if (!I_HOLD_LOCK()) LOCK(); } void GC_end_syscall() { if (!I_HOLD_LOCK()) 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_incremental) 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); set_pht_entry_from_index(GC_dirty_pages, index); } UNPROTECT(start_block, ((ptr_t)end_block - (ptr_t)start_block) + HBLKSIZE); } #ifndef MSWIN32 /* Replacement for UNIX system call. */ /* Other calls that write to the heap */ /* should be handled similarly. */ # if defined(__STDC__) && !defined(SUNOS4) # include 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); # ifdef IRIX5 /* Indirect system call may not always be easily available. */ /* We could call _read, but that would interfere with the */ /* libpthread interception of read. */ { struct iovec iov; iov.iov_base = buf; iov.iov_len = nbyte; result = readv(fd, &iov, 1); } # else result = syscall(SYS_read, fd, buf, nbyte); # endif GC_end_syscall(); return(result); } #endif /* !MSWIN32 */ /*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 #include #include #include #include #include #include #include #define INITIAL_BUF_SZ 4096 word GC_proc_buf_size = INITIAL_BUF_SZ; char *GC_proc_buf; page_hash_table GC_written_pages = { 0 }; /* Pages ever dirtied */ #ifdef 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); if (GC_proc_fd < 0) { ABORT("/proc ioctl failed"); } GC_proc_buf = GC_scratch_alloc(GC_proc_buf_size); # ifdef 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_write_hint(h) struct hblk *h; { } #ifdef 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 (syscall(SYS_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 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 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 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 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 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 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_write_hint(h) struct hblk *h; { PCR_VD_WriteProtectDisable(h, HBLKSIZE); PCR_VD_WriteProtectEnable(h, HBLKSIZE); } # endif /* PCR_VDB */ /* * Call stack save code for debugging. * Should probably be in mach_dep.c, but that requires reorganization. */ #if defined(SPARC) # if defined(SUNOS4) # include # else # if defined (DRSNX) # include # else # include # endif # endif # if NARGS > 6 --> We only know how to to get the first 6 arguments # endif #ifdef SAVE_CALL_CHAIN /* Fill in the pc and argument information for up to NFRAMES of my */ /* callers. Ignore my frame and my callers frame. */ void GC_save_callers (info) struct callinfo info[NFRAMES]; { struct frame *frame; struct frame *fp; int nframes = 0; word GC_save_regs_in_stack(); frame = (struct frame *) GC_save_regs_in_stack (); for (fp = frame -> fr_savfp; fp != 0 && nframes < NFRAMES; fp = fp -> fr_savfp, nframes++) { register int i; info[nframes].ci_pc = fp->fr_savpc; for (i = 0; i < NARGS; i++) { info[nframes].ci_arg[i] = ~(fp->fr_arg[i]); } } if (nframes < NFRAMES) info[nframes].ci_pc = 0; } #endif /* SAVE_CALL_CHAIN */ #endif /* SPARC */