# define NEED_FIND_LIMIT
# endif
-# if defined(IRIX_THREADS) || defined(HPUX_THREADS)
-# define NEED_FIND_LIMIT
-# endif
-
# if (defined(SUNOS4) && defined(DYNAMIC_LOADING)) && !defined(PCR)
# define NEED_FIND_LIMIT
# endif
# define NEED_FIND_LIMIT
# endif
-#ifdef NEED_FIND_LIMIT
-# include <setjmp.h>
+#if defined(FREEBSD) && defined(I386)
+# include <machine/trap.h>
+# if !defined(PCR)
+# define NEED_FIND_LIMIT
+# endif
#endif
-#ifdef FREEBSD
-# include <machine/trap.h>
+#ifdef NEED_FIND_LIMIT
+# include <setjmp.h>
#endif
#ifdef AMIGA
# define jmp_buf sigjmp_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. */
# 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.
+ */
+
+word GC_apply_to_maps(word (*fn)(char *))
+{
+ int f;
+ int result;
+ int maps_size;
+ char maps_temp[32768];
+ char *maps_buf;
+
+ /* Read /proc/self/maps */
+ /* Note that we may not allocate, and thus can't use stdio. */
+ f = open("/proc/self/maps", O_RDONLY);
+ if (-1 == f) return 0;
+ /* stat() doesn't work for /proc/self/maps, so we have to
+ read it to find out how large it is... */
+ maps_size = 0;
+ do {
+ result = GC_repeat_read(f, maps_temp, sizeof(maps_temp));
+ if (result <= 0) return 0;
+ maps_size += result;
+ } while (result == sizeof(maps_temp));
+
+ if (maps_size > sizeof(maps_temp)) {
+ /* If larger than our buffer, close and re-read it. */
+ close(f);
+ f = open("/proc/self/maps", O_RDONLY);
+ if (-1 == f) return 0;
+ maps_buf = alloca(maps_size);
+ if (NULL == maps_buf) return 0;
+ result = GC_repeat_read(f, maps_buf, maps_size);
+ if (result <= 0) return 0;
+ } else {
+ /* Otherwise use the fixed size buffer */
+ maps_buf = maps_temp;
+ }
+
+ close(f);
+ maps_buf[result] = '\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
+// 0 9 18 32
+//
+// For 64 bit ABIs:
+// 0 17 34 56
+//
+// The parser is called with a pointer to the entry and the return value
+// is either NULL or is advanced to the next entry(the byte after the
+// trailing '\n'.)
+//
+#if CPP_WORDSZ == 32
+# define OFFSET_MAP_START 0
+# define OFFSET_MAP_END 9
+# define OFFSET_MAP_PROT 18
+# define OFFSET_MAP_MAJDEV 32
+# define ADDR_WIDTH 8
+#endif
+
+#if CPP_WORDSZ == 64
+# define OFFSET_MAP_START 0
+# define OFFSET_MAP_END 17
+# define OFFSET_MAP_PROT 34
+# define OFFSET_MAP_MAJDEV 56
+# define ADDR_WIDTH 16
+#endif
+
+/*
+ * 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)
+{
+ int i;
+ char *tok;
+
+ if (buf_ptr == NULL || *buf_ptr == '\0') {
+ return NULL;
+ }
+
+ memcpy(prot_buf, buf_ptr+OFFSET_MAP_PROT, 4);
+ /* do the protections first. */
+ prot_buf[4] = '\0';
+
+ if (prot_buf[1] == 'w') {/* we can skip all of this if it's not writable. */
+
+ tok = buf_ptr;
+ buf_ptr[OFFSET_MAP_START+ADDR_WIDTH] = '\0';
+ *start = strtoul(tok, NULL, 16);
+
+ tok = buf_ptr+OFFSET_MAP_END;
+ buf_ptr[OFFSET_MAP_END+ADDR_WIDTH] = '\0';
+ *end = strtoul(tok, NULL, 16);
+
+ buf_ptr += OFFSET_MAP_MAJDEV;
+ tok = buf_ptr;
+ while (*buf_ptr != ':') buf_ptr++;
+ *buf_ptr++ = '\0';
+ *maj_dev = strtoul(tok, NULL, 16);
+ }
+
+ while (*buf_ptr && *buf_ptr++ != '\n');
+
+ return buf_ptr;
+}
+
+#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 */
/* 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;
+ extern int __data_start[];
# pragma weak data_start
- extern int data_start;
+ extern int data_start[];
# endif /* LINUX */
- extern int _end;
+ extern int _end[];
ptr_t GC_data_start;
# ifdef LINUX
/* Try the easy approaches first: */
- if (&__data_start != 0) {
- GC_data_start = (ptr_t)(&__data_start);
+ if ((ptr_t)__data_start != 0) {
+ GC_data_start = (ptr_t)(__data_start);
return;
}
- if (&data_start != 0) {
- GC_data_start = (ptr_t)(&data_start);
+ 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);
+ GC_data_start = GC_find_limit((ptr_t)(_end), FALSE);
}
#endif
#define sbrk tiny_sbrk
# endif /* ECOS */
-#if defined(NETBSD) && defined(__ELF__)
+#if (defined(NETBSD) || defined(OPENBSD)) && defined(__ELF__)
ptr_t GC_data_start;
void GC_init_netbsd_elf()
# if !defined(PCR) && !defined(AMIGA) && !defined(MSWIN32) \
&& !defined(MSWINCE) \
- && !defined(MACOS) && !defined(DJGPP) && !defined(DOS4GW)
+ && !defined(MACOS) && !defined(DJGPP) && !defined(DOS4GW) \
+ && !defined(NOSYS) && !defined(ECOS)
# if defined(sigmask) && !defined(UTS4) && !defined(HURD)
/* Use the traditional BSD interface */
# undef GC_AMIGA_SB
# endif /* AMIGA */
-# if defined(NEED_FIND_LIMIT) || (defined(UNIX_LIKE) && !defined(ECOS))
+# if defined(NEED_FIND_LIMIT) || defined(UNIX_LIKE)
# ifdef __STDC__
typedef void (*handler)(int);
handler h;
# endif
{
-# ifndef ECOS
-# if defined(SUNOS5SIGS) || defined(IRIX5) \
+# if defined(SUNOS5SIGS) || defined(IRIX5) \
|| defined(OSF1) || defined(HURD)
struct sigaction act;
/* signal mask. */
(void) sigemptyset(&act.sa_mask);
-# ifdef IRIX_THREADS
+# 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);
/* don't have to worry in the threads case. */
(void) sigaction(SIGBUS, &act, &old_bus_act);
# endif
-# endif /* IRIX_THREADS */
+# endif /* GC_IRIX_THREADS */
# else
old_segv_handler = signal(SIGSEGV, h);
# ifdef SIGBUS
old_bus_handler = signal(SIGBUS, h);
# endif
# endif
-# endif /* ECOS */
}
# endif /* NEED_FIND_LIMIT || UNIX_LIKE */
void GC_reset_fault_handler()
{
-# ifndef ECOS
-# if defined(SUNOS5SIGS) || defined(IRIX5) \
- || defined(OSF1) || defined(HURD)
- (void) sigaction(SIGSEGV, &old_segv_act, 0);
-# if defined(IRIX5) && defined(_sigargs) /* Irix 5.x, not 6.x */ \
- || defined(HPUX) || defined(HURD)
- (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 */
+# if defined(SUNOS5SIGS) || defined(IRIX5) \
+ || defined(OSF1) || defined(HURD)
+ (void) sigaction(SIGSEGV, &old_segv_act, 0);
+# if defined(IRIX5) && defined(_sigargs) /* Irix 5.x, not 6.x */ \
+ || defined(HPUX) || defined(HURD)
+ (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 addressible (!up). */
+ /* 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;
{
-# 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) {
+ 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;
- }
- return(result);
-# else /* ECOS */
- abort();
-# endif /* ECOS */
+ } else {
+ result -= MIN_PAGE_SIZE;
+ }
+ GC_noop1((word)(*result));
+ }
+ }
+ GC_reset_fault_handler();
+ if (!up) {
+ result += MIN_PAGE_SIZE;
+ }
+ return(result);
}
# endif
-# ifndef ECOS
+#if defined(ECOS) || defined(NOSYS)
+ ptr_t GC_get_stack_base()
+ {
+ return STACKBOTTOM;
+ }
+#endif
#ifdef LINUX_STACKBOTTOM
#include <sys/types.h>
#include <sys/stat.h>
+#include <ctype.h>
# define STAT_SKIP 27 /* Number of fields preceding startstack */
/* field in /proc/self/stat */
extern ptr_t __libc_stack_end;
# 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);
+ }
+
# pragma weak __libc_ia64_register_backing_store_base
extern ptr_t __libc_ia64_register_backing_store_base;
ptr_t GC_get_register_stack_base(void)
{
- if (0 != &__libc_ia64_register_backing_store_base) {
+ 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;
} else {
- word result = (word)GC_stackbottom - BACKING_STORE_DISPLACEMENT;
- result += BACKING_STORE_ALIGNMENT - 1;
- result &= ~(BACKING_STORE_ALIGNMENT - 1);
+ 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;
}
}
/* using direct I/O system calls in order to avoid calling malloc */
/* in case REDIRECT_MALLOC is defined. */
# define STAT_BUF_SIZE 4096
-# if defined(GC_USE_LD_WRAP)
-# define STAT_READ __real_read
-# else
-# define STAT_READ read
-# endif
+# define STAT_READ read
+ /* Should probably call the real read, if read is wrapped. */
char stat_buf[STAT_BUF_SIZE];
int f;
char c;
/* First try the easy way. This should work for glibc 2.2 */
if (0 != &__libc_stack_end) {
- return __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
+ return __libc_stack_end;
+# endif
}
f = open("/proc/self/stat", O_RDONLY);
if (f < 0 || STAT_READ(f, stat_buf, STAT_BUF_SIZE) < 2 * STAT_SKIP) {
ptr_t GC_freebsd_stack_base(void)
{
- int nm[2] = { CTL_KERN, KERN_USRSTACK}, base, len, r;
-
- len = sizeof(int);
- r = sysctl(nm, 2, &base, &len, NULL, 0);
+ 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 (ptr_t)base;
+ return base;
}
#endif /* FREEBSD_STACKBOTTOM */
#if !defined(BEOS) && !defined(AMIGA) && !defined(MSWIN32) \
- && !defined(MSWINCE) && !defined(OS2) && !defined(ECOS)
+ && !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)
return(result);
# endif /* STACKBOTTOM */
}
-# endif /* ECOS */
-# endif /* ! AMIGA, !OS 2, ! MS Windows, !BEOS */
+# endif /* ! AMIGA, !OS 2, ! MS Windows, !BEOS, !NOSYS, !ECOS */
/*
* Register static data segment(s) as roots.
/* 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 */
+ /* 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 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);
- }
+ /* 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. */
void GC_init_win32()
{
- GC_win32s = GC_is_win32s();
+ /* if we're running under win32s, assume that no DLLs will be loaded */
+ DWORD v = GetVersion();
+ GC_no_win32_dlls |= ((v & 0x80000000) && (v & 0xff) <= 3);
}
/* Return the smallest address a such that VirtualQuery */
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)
{
- register unsigned i;
+ unsigned i;
# ifndef REDIRECT_MALLOC
- static ptr_t malloc_heap_pointer = 0;
+ static word last_gc_no = -1;
- if (0 == malloc_heap_pointer) {
- MEMORY_BASIC_INFORMATION buf;
- void *pTemp = malloc( 1 );
- register DWORD result = VirtualQuery(pTemp, &buf, sizeof(buf));
-
- free( pTemp );
-
-
- if (result != sizeof(buf)) {
- ABORT("Weird VirtualQuery result");
- }
- malloc_heap_pointer = (ptr_t)(buf.AllocationBase);
+ if (last_gc_no != GC_gc_no) {
+ GC_add_current_malloc_heap();
+ last_gc_no = GC_gc_no;
}
- if (p == malloc_heap_pointer) return(TRUE);
+ 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);
+ if (GC_heap_bases[i] == p) return TRUE;
}
- return(FALSE);
+ return FALSE ;
}
# ifdef MSWIN32
char * base;
char * limit, * new_limit;
- if (!GC_win32s) return;
+ 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 (defined(SVR4) || defined(AUX) || defined(DGUX) \
|| (defined(LINUX) && defined(SPARC))) && !defined(PCR)
-char * GC_SysVGetDataStart(max_page_size, etext_addr)
+ptr_t GC_SysVGetDataStart(max_page_size, etext_addr)
int max_page_size;
int * etext_addr;
{
/* 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);
+ result = (char *)GC_find_limit((ptr_t)(DATAEND), FALSE);
}
- return((char *)result);
+ return((ptr_t)result);
}
# endif
+# if defined(FREEBSD) && defined(I386) && !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
void GC_register_data_segments()
{
-# if !defined(PCR) && !defined(SRC_M3) && !defined(NEXT) && !defined(MACOS) \
- && !defined(MACOSX)
-# if defined(REDIRECT_MALLOC) && defined(SOLARIS_THREADS)
+# 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 */
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(PCR) && (defined(NEXT) || defined(MACOSX))
- GC_add_roots_inner(DATASTART, (char *) get_end(), FALSE);
-# endif
# if defined(MACOS)
{
# if defined(THINK_C)
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;
- }
+# ifndef USE_MMAP_ANON
+ static GC_bool initialized = FALSE;
+ static int fd;
+
+ if (!initialized) {
+ fd = open("/dev/zero", O_RDONLY);
+ fcntl(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, fd, 0/* offset */);
+# ifdef USE_MMAP_ANON
+ result = mmap(last_addr, bytes, PROT_READ | PROT_WRITE | OPT_PROT_EXEC,
+ GC_MMAP_FLAGS | MAP_ANON, -1, 0/* offset */);
+# else
+ result = mmap(last_addr, bytes, PROT_READ | PROT_WRITE | OPT_PROT_EXEC,
+ GC_MMAP_FLAGS, fd, 0/* offset */);
+# endif
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));
SYSTEM_INFO GC_sysinfo;
# endif
-
# ifdef MSWIN32
+
+# ifdef USE_GLOBAL_ALLOC
+# define GLOBAL_ALLOC_TEST 1
+# else
+# define GLOBAL_ALLOC_TEST GC_no_win32_dlls
+# endif
+
word GC_n_heap_bases = 0;
ptr_t GC_win32_get_mem(bytes)
{
ptr_t result;
- if (GC_win32s) {
+ 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 {
- result = (ptr_t) VirtualAlloc(NULL, bytes,
+ /* 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);
}
void GC_win32_free_heap ()
{
- if (GC_win32s) {
+ if (GC_no_win32_dlls) {
while (GC_n_heap_bases > 0) {
GlobalFree (GC_heap_bases[--GC_n_heap_bases]);
GC_heap_bases[GC_n_heap_bases] = 0;
/* 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);
}
# else
if (-1 == zero_descr) zero_descr = open("/dev/zero", O_RDWR);
+ fcntl(zero_descr, F_SETFD, FD_CLOEXEC);
if (0 == start_addr) return;
result = mmap(start_addr, len, PROT_READ | PROT_WRITE | OPT_PROT_EXEC,
MAP_FIXED | MAP_PRIVATE, zero_descr, 0);
# endif /* SRC_M3 */
-# if defined(SOLARIS_THREADS) || defined(WIN32_THREADS) \
- || defined(IRIX_THREADS) || defined(LINUX_THREADS) \
- || defined(HPUX_THREADS)
+# if defined(GC_SOLARIS_THREADS) || defined(GC_PTHREADS) || \
+ defined(GC_WIN32_THREADS)
extern void GC_push_all_stacks();
GC_push_all_stacks();
}
-# endif /* SOLARIS_THREADS || ... */
+# endif /* GC_SOLARIS_THREADS || GC_PTHREADS */
void (*GC_push_other_roots) GC_PROTO((void)) = GC_default_push_other_roots;
-#endif
+#endif /* THREADS */
/*
* Routines for accessing dirty bits on virtual pages.
* make sure that other system calls are similarly protected
* or write only to the stack.
*/
-
GC_bool GC_dirty_maintained = FALSE;
# ifdef DEFAULT_VDB
/* Initialize virtual dirty bit implementation. */
void GC_dirty_init()
{
+# ifdef PRINTSTATS
+ GC_printf0("Initializing DEFAULT_VDB...\n");
+# endif
GC_dirty_maintained = TRUE;
}
{
}
-/* A call hints that h is about to be written. */
-/* May speed up some dirty bit implementations. */
+/* 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_write_hint(h)
+void GC_remove_protection(h, nblocks, is_ptrfree)
struct hblk *h;
+word nblocks;
+GC_bool is_ptrfree;
{
}
/*
* 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.
+ * 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.
- * 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.
+ * We prefer them to be the same. We avoid protecting POINTERFREE
+ * objects only if they are the same.
*/
-# if !defined(MSWIN32) && !defined(MSWINCE)
+# if !defined(MSWIN32) && !defined(MSWINCE) && !defined(DARWIN)
# include <sys/mman.h>
# include <signal.h>
# 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
&protect_junk)) { \
ABORT("un-VirtualProtect failed"); \
}
-
-# endif
+# endif /* !DARWIN */
+# endif /* MSWIN32 || MSWINCE || DARWIN */
#if defined(SUNOS4) || defined(FREEBSD)
typedef void (* SIG_PF)();
-#endif
+#endif /* SUNOS4 || FREEBSD */
+
#if defined(SUNOS5SIGS) || defined(OSF1) || defined(LINUX) \
- || defined(MACOSX) || defined(HURD)
+ || defined(HURD)
# ifdef __STDC__
typedef void (* SIG_PF)(int);
# else
typedef void (* SIG_PF)();
# endif
-#endif
+#endif /* SUNOS5SIGS || OSF1 || LINUX || HURD */
+
#if defined(MSWIN32)
typedef LPTOP_LEVEL_EXCEPTION_FILTER SIG_PF;
# undef SIG_DFL
#if defined(IRIX5) || defined(OSF1) || defined(HURD)
typedef void (* REAL_SIG_PF)(int, int, struct sigcontext *);
-#endif
+#endif /* IRIX5 || OSF1 || HURD */
+
#if defined(SUNOS5SIGS)
# ifdef HPUX
# define SIGINFO __siginfo
# else
typedef void (* REAL_SIG_PF)();
# endif
-#endif
+#endif /* SUNOS5SIGS */
+
#if defined(LINUX)
-# include <linux/version.h>
-# if (LINUX_VERSION_CODE >= 0x20100) && !defined(M68K) || defined(ALPHA) || defined(IA64)
+# if __GLIBC__ > 2 || __GLIBC__ == 2 && __GLIBC_MINOR__ >= 2
typedef struct sigcontext s_c;
-# else
- typedef struct sigcontext_struct s_c;
-# endif
+# 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
return (char *)faultaddr;
}
# endif /* !ALPHA */
-# endif
-
-# if defined(MACOSX) /* Should also test for PowerPC? */
- typedef void (* REAL_SIG_PF)(int, int, struct sigcontext *);
-
-/* Decodes the machine instruction which was responsible for the sending of the
- SIGBUS signal. Sadly this is the only way to find the faulting address because
- the signal handler doesn't get it directly from the kernel (although it is
- available on the Mach level, but droppped by the BSD personality before it
- calls our signal handler...)
- This code should be able to deal correctly with all PPCs starting from the
- 601 up to and including the G4s (including Velocity Engine). */
-#define EXTRACT_OP1(iw) (((iw) & 0xFC000000) >> 26)
-#define EXTRACT_OP2(iw) (((iw) & 0x000007FE) >> 1)
-#define EXTRACT_REGA(iw) (((iw) & 0x001F0000) >> 16)
-#define EXTRACT_REGB(iw) (((iw) & 0x03E00000) >> 21)
-#define EXTRACT_REGC(iw) (((iw) & 0x0000F800) >> 11)
-#define EXTRACT_DISP(iw) ((short *) &(iw))[1]
-
-static char *get_fault_addr(struct sigcontext *scp)
-{
- unsigned int instr = *((unsigned int *) scp->sc_ir);
- unsigned int * regs = &((unsigned int *) scp->sc_regs)[2];
- int disp = 0, tmp;
- unsigned int baseA = 0, baseB = 0;
- unsigned int addr, alignmask = 0xFFFFFFFF;
-
-#ifdef GC_DEBUG_DECODER
- GC_err_printf1("Instruction: 0x%lx\n", instr);
- GC_err_printf1("Opcode 1: d\n", (int)EXTRACT_OP1(instr));
-#endif
- switch(EXTRACT_OP1(instr)) {
- case 38: /* stb */
- case 39: /* stbu */
- case 54: /* stfd */
- case 55: /* stfdu */
- case 52: /* stfs */
- case 53: /* stfsu */
- case 44: /* sth */
- case 45: /* sthu */
- case 47: /* stmw */
- case 36: /* stw */
- case 37: /* stwu */
- tmp = EXTRACT_REGA(instr);
- if(tmp > 0)
- baseA = regs[tmp];
- disp = EXTRACT_DISP(instr);
- break;
- case 31:
-#ifdef GC_DEBUG_DECODER
- GC_err_printf1("Opcode 2: %d\n", (int)EXTRACT_OP2(instr));
-#endif
- switch(EXTRACT_OP2(instr)) {
- case 86: /* dcbf */
- case 54: /* dcbst */
- case 1014: /* dcbz */
- case 247: /* stbux */
- case 215: /* stbx */
- case 759: /* stfdux */
- case 727: /* stfdx */
- case 983: /* stfiwx */
- case 695: /* stfsux */
- case 663: /* stfsx */
- case 918: /* sthbrx */
- case 439: /* sthux */
- case 407: /* sthx */
- case 661: /* stswx */
- case 662: /* stwbrx */
- case 150: /* stwcx. */
- case 183: /* stwux */
- case 151: /* stwx */
- case 135: /* stvebx */
- case 167: /* stvehx */
- case 199: /* stvewx */
- case 231: /* stvx */
- case 487: /* stvxl */
- tmp = EXTRACT_REGA(instr);
- if(tmp > 0)
- baseA = regs[tmp];
- baseB = regs[EXTRACT_REGC(instr)];
- /* determine Altivec alignment mask */
- switch(EXTRACT_OP2(instr)) {
- case 167: /* stvehx */
- alignmask = 0xFFFFFFFE;
- break;
- case 199: /* stvewx */
- alignmask = 0xFFFFFFFC;
- break;
- case 231: /* stvx */
- alignmask = 0xFFFFFFF0;
- break;
- case 487: /* stvxl */
- alignmask = 0xFFFFFFF0;
- break;
- }
- break;
- case 725: /* stswi */
- tmp = EXTRACT_REGA(instr);
- if(tmp > 0)
- baseA = regs[tmp];
- break;
- default: /* ignore instruction */
-#ifdef GC_DEBUG_DECODER
- GC_err_printf("Ignored by inner handler\n");
-#endif
- return NULL;
- break;
- }
- break;
- default: /* ignore instruction */
-#ifdef GC_DEBUG_DECODER
- GC_err_printf("Ignored by main handler\n");
-#endif
- return NULL;
- break;
- }
-
- addr = (baseA + baseB) + disp;
- addr &= alignmask;
-#ifdef GC_DEBUG_DECODER
- GC_err_printf1("BaseA: %d\n", baseA);
- GC_err_printf1("BaseB: %d\n", baseB);
- GC_err_printf1("Disp: %d\n", disp);
- GC_err_printf1("Address: %d\n", addr);
-#endif
- return (char *)addr;
-}
-#endif /* MACOSX */
+# endif /* LINUX */
+#ifndef DARWIN
SIG_PF GC_old_bus_handler;
SIG_PF GC_old_segv_handler; /* Also old MSWIN32 ACCESS_VIOLATION filter */
+#endif /* !DARWIN */
-#ifdef THREADS
+#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 */
#endif /* !THREADS */
/*ARGSUSED*/
+#if !defined(DARWIN)
# if defined (SUNOS4) || defined(FREEBSD)
void GC_write_fault_handler(sig, code, scp, addr)
int sig, code;
# define SIG_OK (sig == SIGBUS)
# define CODE_OK (code == BUS_PAGE_FAULT)
# endif
-# endif
+# endif /* SUNOS4 || FREEBSD */
+
# if defined(IRIX5) || defined(OSF1) || defined(HURD)
# include <errno.h>
void GC_write_fault_handler(int sig, int code, struct sigcontext *scp)
# define SIG_OK (sig == SIGBUS || sig == SIGSEGV)
# define CODE_OK TRUE
# endif
-# 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)
# if defined(IA64) || defined(HP_PA)
void GC_write_fault_handler(int sig, siginfo_t * si, s_c * scp)
# else
- void GC_write_fault_handler(int sig, s_c sc)
+# 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)
/* Empirically c.trapno == 14, on IA32, but is that useful? */
/* Should probably consider alignment issues on other */
/* architectures. */
-# endif
+# endif /* LINUX */
+
# if defined(SUNOS5SIGS)
# ifdef __STDC__
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
-# endif
-
-# if defined(MACOSX)
- void GC_write_fault_handler(int sig, int code, struct sigcontext *scp)
-# define SIG_OK (sig == SIGBUS)
-# define CODE_OK (code == 0 /* experimentally determined */)
-# endif
+# endif /* SUNOS5SIGS */
# if defined(MSWIN32) || defined(MSWINCE)
LONG WINAPI GC_write_fault_handler(struct _EXCEPTION_POINTERS *exc_info)
STATUS_ACCESS_VIOLATION)
# define CODE_OK (exc_info -> ExceptionRecord -> ExceptionInformation[0] == 1)
/* Write fault */
-# endif
+# endif /* MSWIN32 || MSWINCE */
{
register unsigned i;
# if defined(HURD)
char * addr = (char *) (scp -> si_addr);
# endif
# ifdef LINUX
-# ifdef I386
+# if defined(I386) || defined (X86_64)
char * addr = (char *) (sc.cr2);
# else
# if defined(M68K)
# if defined(POWERPC)
char * addr = (char *) (sc.regs->dar);
# else
- --> architecture not supported
+# if defined(ARM32)
+ char * addr = (char *)sc.fault_address;
+# else
+ --> architecture not supported
+# endif
# endif
# endif
# endif
# endif
# endif
# endif
-# if defined(MACOSX)
- char * addr = get_fault_addr(scp);
-# endif
# if defined(MSWIN32) || defined(MSWINCE)
char * addr = (char *) (exc_info -> ExceptionRecord
-> ExceptionInformation[1]);
(*(REAL_SIG_PF)old_handler) (sig, code, scp);
return;
# endif
-# ifdef MACOSX
- (*(REAL_SIG_PF)old_handler) (sig, code, scp);
-# endif
# ifdef MSWIN32
return((*old_handler)(exc_info));
# endif
ABORT("Unexpected bus error or segmentation fault");
#endif
}
+#endif /* !DARWIN */
/*
* We hold the allocation lock. We expect block h to be written
- * shortly.
+ * 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_write_hint(h)
+void GC_remove_protection(h, nblocks, is_ptrfree)
struct hblk *h;
+word nblocks;
+GC_bool is_ptrfree;
{
- register struct hblk * h_trunc;
- register unsigned i;
- register GC_bool found_clean;
+ 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 (i = 0; i < divHBLKSZ(GC_page_size); i++) {
- register int index = PHT_HASH(h_trunc+i);
+ for (current = h_trunc; current < h_end; ++current) {
+ int index = PHT_HASH(current);
- if (!get_pht_entry_from_index(GC_dirty_pages, index)) {
- found_clean = TRUE;
+ if (!is_ptrfree || current < h || current >= h + nblocks) {
async_set_pht_entry_from_index(GC_dirty_pages, index);
}
}
- if (found_clean) {
- UNPROTECT(h_trunc, GC_page_size);
- }
+ 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) || \
(void)sigaddset(&act.sa_mask, SIG_SUSPEND);
# endif /* SIG_SUSPEND */
# endif
-# if defined(MACOSX)
- struct sigaction act, oldact;
-
- act.sa_flags = SA_RESTART;
- act.sa_handler = GC_write_fault_handler;
- sigemptyset(&act.sa_mask);
-# endif
# ifdef PRINTSTATS
GC_printf0("Inititalizing mprotect virtual dirty bit implementation\n");
# endif
# if defined(SUNOS5SIGS) || defined(IRIX5) || defined(LINUX) \
|| defined(OSF1) || defined(HURD)
/* SUNOS5SIGS includes HPUX */
-# if defined(IRIX_THREADS)
+# if defined(GC_IRIX_THREADS)
sigaction(SIGSEGV, 0, &oldact);
sigaction(SIGSEGV, &act, 0);
# else
- sigaction(SIGSEGV, &act, &oldact);
+ {
+ int res = sigaction(SIGSEGV, &act, &oldact);
+ if (res != 0) ABORT("Sigaction failed");
+ }
# endif
-# if defined(_sigargs) || defined(HURD)
+# 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;
# endif
}
# endif
-# if defined(MACOSX) || defined(HPUX) || defined(LINUX) || defined(HURD)
+# if defined(HPUX) || defined(LINUX) || defined(HURD)
sigaction(SIGBUS, &act, &oldact);
GC_old_bus_handler = oldact.sa_handler;
if (GC_old_bus_handler == SIG_IGN) {
GC_err_printf0("Replaced other SIGBUS handler\n");
# endif
}
-# endif /* MACOS || HPUX || LINUX */
+# endif /* HPUX || LINUX || HURD */
# if defined(MSWIN32)
GC_old_segv_handler = SetUnhandledExceptionFilter(GC_write_fault_handler);
if (GC_old_segv_handler != NULL) {
}
# 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;
- PROTECT(start, len);
+ 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);
+ }
+ }
}
}
register struct hblk *h;
ptr_t obj_start;
- if (!GC_incremental) return;
+ if (!GC_dirty_maintained) return;
obj_start = GC_base(addr);
if (obj_start == 0) return;
if (GC_base(addr + len - 1) != obj_start) {
((ptr_t)end_block - (ptr_t)start_block) + HBLKSIZE);
}
-#if !defined(MSWIN32) && !defined(MSWINCE) && !defined(LINUX_THREADS) \
- && !defined(GC_USE_LD_WRAP)
-/* Replacement for UNIX system call. */
-/* Other calls that write to the heap */
-/* should be handled similarly. */
+#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>
GC_begin_syscall();
GC_unprotect_range(buf, (word)nbyte);
-# if defined(IRIX5) || defined(LINUX_THREADS)
+# 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. */
GC_end_syscall();
return(result);
}
-#endif /* !MSWIN32 && !MSWINCE && !LINUX_THREADS */
+#endif /* !MSWIN32 && !MSWINCE && !GC_LINUX_THREADS */
-#ifdef GC_USE_LD_WRAP
+#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. */
/* actually calls. */
#endif
+#endif /* 0 */
+
/*ARGSUSED*/
GC_bool GC_page_was_ever_dirty(h)
struct hblk *h;
{
}
-# else /* !MPROTECT_VDB */
-
-# ifdef GC_USE_LD_WRAP
- ssize_t __wrap_read(int fd, void *buf, size_t nbyte)
- { return __real_read(fd, buf, nbyte); }
-# endif
-
# endif /* MPROTECT_VDB */
# ifdef PROC_VDB
word GC_proc_buf_size = INITIAL_BUF_SZ;
char *GC_proc_buf;
-#ifdef SOLARIS_THREADS
+#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 */
}
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 SOLARIS_THREADS
+# ifdef GC_SOLARIS_THREADS
GC_fresh_pages = (struct hblk **)
GC_scratch_alloc(MAX_FRESH_PAGES * sizeof (struct hblk *));
if (GC_fresh_pages == 0) {
/* Ignore write hints. They don't help us here. */
/*ARGSUSED*/
-void GC_write_hint(h)
+void GC_remove_protection(h, nblocks, is_ptrfree)
struct hblk *h;
+word nblocks;
+GC_bool is_ptrfree;
{
}
-#ifdef SOLARIS_THREADS
+#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)
/* Punt: */
memset(GC_grungy_pages, 0xff, sizeof (page_hash_table));
memset(GC_written_pages, 0xff, sizeof(page_hash_table));
-# ifdef SOLARIS_THREADS
+# ifdef GC_SOLARIS_THREADS
BZERO(GC_fresh_pages,
MAX_FRESH_PAGES * sizeof (struct hblk *));
# endif
register word index = PHT_HASH(h);
set_pht_entry_from_index(GC_grungy_pages, index);
-# ifdef SOLARIS_THREADS
+# ifdef GC_SOLARIS_THREADS
{
register int slot = FRESH_PAGE_SLOT(h);
}
/* Update GC_written_pages. */
GC_or_pages(GC_written_pages, GC_grungy_pages);
-# ifdef SOLARIS_THREADS
+# ifdef GC_SOLARIS_THREADS
/* Make sure that old stacks are considered completely clean */
/* unless written again. */
GC_old_stacks_are_fresh();
register GC_bool result;
result = get_pht_entry_from_index(GC_grungy_pages, index);
-# ifdef SOLARIS_THREADS
+# 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 */
register GC_bool result;
result = get_pht_entry_from_index(GC_written_pages, index);
-# ifdef SOLARIS_THREADS
+# ifdef GC_SOLARIS_THREADS
if (result && PAGE_IS_FRESH(h)) result = FALSE;
# endif
return(result);
register word index;
-# ifdef SOLARIS_THREADS
+# ifdef GC_SOLARIS_THREADS
register word i;
if (GC_fresh_pages != 0) {
}
/*ARGSUSED*/
-void GC_write_hint(h)
+void GC_remove_protection(h, nblocks, is_ptrfree)
struct hblk *h;
+word nblocks;
+GC_bool is_ptrfree;
{
- PCR_VD_WriteProtectDisable(h, HBLKSIZE);
- PCR_VD_WriteProtectEnable(h, HBLKSIZE);
+ 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/002030.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;
+
+ 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,
+ MACHINE_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_data_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;
+#ifdef POWERPC
+ 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
+# 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 */
+ addr = (char*) exc_state.dar;
+
+ 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.
/* 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;
#if defined(SPARC)
# if defined(LINUX)
+# include <features.h>
+
struct frame {
long fr_local[8];
long fr_arg[6];
# endif
#endif /* SPARC */
-#ifdef SAVE_CALL_CHAIN
+#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 */
+
+#ifdef SAVE_CALL_CHAIN
+
+#if NARGS == 0 && NFRAMES % 2 == 0 /* No padding */ \
+ && defined(GC_HAVE_BUILTIN_BACKTRACE)
+
+#include <execinfo.h>
+
+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. */
+ 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;
+}
+
+#else /* No builtin backtrace; do it ourselves */
+
#if (defined(OPENBSD) || defined(NETBSD)) && defined(SPARC)
# define FR_SAVFP fr_fp
# define FR_SAVPC fr_pc
asm("movl %%ebp,%0" : "=r"(frame));
fp = frame;
# else
- word GC_save_regs_in_stack();
-
frame = (struct frame *) GC_save_regs_in_stack ();
fp = (struct frame *)((long) frame -> FR_SAVFP + BIAS);
#endif
if (nframes < NFRAMES) info[nframes].ci_pc = 0;
}
-#endif /* SAVE_CALL_CHAIN */
+#endif /* No builtin backtrace */
-#if defined(LINUX) && defined(__ELF__) && \
- (!defined(SMALL_CONFIG) || defined(USE_PROC_FOR_LIBRARIES))
-#ifdef GC_USE_LD_WRAP
-# define READ __real_read
-#else
-# define READ read
-#endif
+#endif /* SAVE_CALL_CHAIN */
+#ifdef NEED_CALLINFO
-/* 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)
+/* Print info to stderr. We do NOT hold the allocation lock */
+void GC_print_callers (info)
+struct callinfo info[NFRAMES];
{
- ssize_t num_read = 0;
- ssize_t result;
+ register int i;
+ static int reentry_count = 0;
+ GC_bool stop = FALSE;
+
+ LOCK();
+ ++reentry_count;
+ UNLOCK();
- 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;
+# 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)
+ 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;
+ 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);
+ pipe = popen(cmd_buf, "r");
+ 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)
+ free(sym_name); /* May call GC_free; that's OK */
+# endif
+ }
}
- return num_read;
+ LOCK();
+ --reentry_count;
+ UNLOCK();
}
-#endif /* LINUX && ... */
+
+#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()
{
- int f;
- int result;
- char maps_temp[32768];
GC_err_printf0("---------- Begin address map ----------\n");
- f = open("/proc/self/maps", O_RDONLY);
- if (-1 == f) ABORT("Couldn't open /proc/self/maps");
- do {
- result = GC_repeat_read(f, maps_temp, sizeof(maps_temp));
- if (result <= 0) ABORT("Couldn't read /proc/self/maps");
- GC_err_write(maps_temp, result);
- } while (result == sizeof(maps_temp));
-
+ GC_apply_to_maps(dump_maps);
GC_err_printf0("---------- End address map ----------\n");
}
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