-
-\f
-#if defined(LISP_FEATURE_X86) || defined(LISP_FEATURE_X86_64)
-
-#ifdef LISP_FEATURE_GENCGC
-/*
- * enhanced x86/GENCGC stack scavenging by Douglas Crosher
- *
- * Scavenging the stack on the i386 is problematic due to conservative
- * roots and raw return addresses. Here it is handled in two passes:
- * the first pass runs before any objects are moved and tries to
- * identify valid pointers and return address on the stack, the second
- * pass scavenges these.
- */
-
-static unsigned pointer_filter_verbose = 0;
-
-/* FIXME: This is substantially the same code as
- * possibly_valid_dynamic_space_pointer in gencgc.c. The only
- * relevant difference seems to be that the gencgc code also checks
- * for raw pointers into Code objects, whereas in purify these are
- * checked separately in setup_i386_stack_scav - they go onto
- * valid_stack_ra_locations instead of just valid_stack_locations */
-
-static int
-valid_dynamic_space_pointer(lispobj *pointer, lispobj *start_addr)
-{
- /* If it's not a return address then it needs to be a valid Lisp
- * pointer. */
- if (!is_lisp_pointer((lispobj)pointer))
- return 0;
-
- /* Check that the object pointed to is consistent with the pointer
- * low tag. */
- switch (lowtag_of((lispobj)pointer)) {
- case FUN_POINTER_LOWTAG:
- /* Start_addr should be the enclosing code object, or a closure
- * header. */
- switch (widetag_of(*start_addr)) {
- case CODE_HEADER_WIDETAG:
- /* This case is probably caught above. */
- break;
- case CLOSURE_HEADER_WIDETAG:
- case FUNCALLABLE_INSTANCE_HEADER_WIDETAG:
- if ((long)pointer != ((long)start_addr+FUN_POINTER_LOWTAG)) {
- if (pointer_filter_verbose) {
- fprintf(stderr,"*Wf2: %p %p %p\n",
- pointer, start_addr, (void *)*start_addr);
- }
- return 0;
- }
- break;
- default:
- if (pointer_filter_verbose) {
- fprintf(stderr,"*Wf3: %p %p %p\n",
- pointer, start_addr, (void *)*start_addr);
- }
- return 0;
- }
- break;
- case LIST_POINTER_LOWTAG:
- if ((long)pointer != ((long)start_addr+LIST_POINTER_LOWTAG)) {
- if (pointer_filter_verbose)
- fprintf(stderr,"*Wl1: %p %p %p\n",
- pointer, start_addr, (void *)*start_addr);
- return 0;
- }
- /* Is it plausible cons? */
- if ((is_lisp_pointer(start_addr[0])
- || ((start_addr[0] & FIXNUM_TAG_MASK) == 0) /* fixnum */
- || (widetag_of(start_addr[0]) == CHARACTER_WIDETAG)
-#if N_WORD_BITS == 64
- || (widetag_of(start_addr[0]) == SINGLE_FLOAT_WIDETAG)
-#endif
- || (widetag_of(start_addr[0]) == UNBOUND_MARKER_WIDETAG))
- && (is_lisp_pointer(start_addr[1])
- || ((start_addr[1] & FIXNUM_TAG_MASK) == 0) /* fixnum */
- || (widetag_of(start_addr[1]) == CHARACTER_WIDETAG)
-#if N_WORD_BITS == 64
- || (widetag_of(start_addr[1]) == SINGLE_FLOAT_WIDETAG)
-#endif
- || (widetag_of(start_addr[1]) == UNBOUND_MARKER_WIDETAG))) {
- break;
- } else {
- if (pointer_filter_verbose) {
- fprintf(stderr,"*Wl2: %p %p %p\n",
- pointer, start_addr, (void *)*start_addr);
- }
- return 0;
- }
- case INSTANCE_POINTER_LOWTAG:
- if ((long)pointer != ((long)start_addr+INSTANCE_POINTER_LOWTAG)) {
- if (pointer_filter_verbose) {
- fprintf(stderr,"*Wi1: %p %p %p\n",
- pointer, start_addr, (void *)*start_addr);
- }
- return 0;
- }
- if (widetag_of(start_addr[0]) != INSTANCE_HEADER_WIDETAG) {
- if (pointer_filter_verbose) {
- fprintf(stderr,"*Wi2: %p %p %p\n",
- pointer, start_addr, (void *)*start_addr);
- }
- return 0;
- }
- break;
- case OTHER_POINTER_LOWTAG:
- if ((long)pointer != ((long)start_addr+OTHER_POINTER_LOWTAG)) {
- if (pointer_filter_verbose) {
- fprintf(stderr,"*Wo1: %p %p %p\n",
- pointer, start_addr, (void *)*start_addr);
- }
- return 0;
- }
- /* Is it plausible? Not a cons. XXX should check the headers. */
- if (is_lisp_pointer(start_addr[0]) || ((start_addr[0] & FIXNUM_TAG_MASK) == 0)) {
- if (pointer_filter_verbose) {
- fprintf(stderr,"*Wo2: %p %p %p\n",
- pointer, start_addr, (void *)*start_addr);
- }
- return 0;
- }
- switch (widetag_of(start_addr[0])) {
- case UNBOUND_MARKER_WIDETAG:
- case CHARACTER_WIDETAG:
-#if N_WORD_BITS == 64
- case SINGLE_FLOAT_WIDETAG:
-#endif
- if (pointer_filter_verbose) {
- fprintf(stderr,"*Wo3: %p %p %p\n",
- pointer, start_addr, (void *)*start_addr);
- }
- return 0;
-
- /* only pointed to by function pointers? */
- case CLOSURE_HEADER_WIDETAG:
- case FUNCALLABLE_INSTANCE_HEADER_WIDETAG:
- if (pointer_filter_verbose) {
- fprintf(stderr,"*Wo4: %p %p %p\n",
- pointer, start_addr, (void *)*start_addr);
- }
- return 0;
-
- case INSTANCE_HEADER_WIDETAG:
- if (pointer_filter_verbose) {
- fprintf(stderr,"*Wo5: %p %p %p\n",
- pointer, start_addr, (void *)*start_addr);
- }
- return 0;
-
- /* the valid other immediate pointer objects */
- case SIMPLE_VECTOR_WIDETAG:
- case RATIO_WIDETAG:
- case COMPLEX_WIDETAG:
-#ifdef COMPLEX_SINGLE_FLOAT_WIDETAG
- case COMPLEX_SINGLE_FLOAT_WIDETAG:
-#endif
-#ifdef COMPLEX_DOUBLE_FLOAT_WIDETAG
- case COMPLEX_DOUBLE_FLOAT_WIDETAG:
-#endif
-#ifdef COMPLEX_LONG_FLOAT_WIDETAG
- case COMPLEX_LONG_FLOAT_WIDETAG:
-#endif
- case SIMPLE_ARRAY_WIDETAG:
- case COMPLEX_BASE_STRING_WIDETAG:
-#ifdef COMPLEX_CHARACTER_STRING_WIDETAG
- case COMPLEX_CHARACTER_STRING_WIDETAG:
-#endif
- case COMPLEX_VECTOR_NIL_WIDETAG:
- case COMPLEX_BIT_VECTOR_WIDETAG:
- case COMPLEX_VECTOR_WIDETAG:
- case COMPLEX_ARRAY_WIDETAG:
- case VALUE_CELL_HEADER_WIDETAG:
- case SYMBOL_HEADER_WIDETAG:
- case FDEFN_WIDETAG:
- case CODE_HEADER_WIDETAG:
- case BIGNUM_WIDETAG:
-#if N_WORD_BITS != 64
- case SINGLE_FLOAT_WIDETAG:
-#endif
- case DOUBLE_FLOAT_WIDETAG:
-#ifdef LONG_FLOAT_WIDETAG
- case LONG_FLOAT_WIDETAG:
-#endif
- case SIMPLE_ARRAY_NIL_WIDETAG:
- case SIMPLE_BASE_STRING_WIDETAG:
-#ifdef SIMPLE_CHARACTER_STRING_WIDETAG
- case SIMPLE_CHARACTER_STRING_WIDETAG:
-#endif
- case SIMPLE_BIT_VECTOR_WIDETAG:
- case SIMPLE_ARRAY_UNSIGNED_BYTE_2_WIDETAG:
- case SIMPLE_ARRAY_UNSIGNED_BYTE_4_WIDETAG:
- case SIMPLE_ARRAY_UNSIGNED_BYTE_7_WIDETAG:
- case SIMPLE_ARRAY_UNSIGNED_BYTE_8_WIDETAG:
- case SIMPLE_ARRAY_UNSIGNED_BYTE_15_WIDETAG:
- case SIMPLE_ARRAY_UNSIGNED_BYTE_16_WIDETAG:
-#ifdef SIMPLE_ARRAY_UNSIGNED_BYTE_29_WIDETAG
- case SIMPLE_ARRAY_UNSIGNED_BYTE_29_WIDETAG:
-#endif
- case SIMPLE_ARRAY_UNSIGNED_BYTE_31_WIDETAG:
- case SIMPLE_ARRAY_UNSIGNED_BYTE_32_WIDETAG:
-#ifdef SIMPLE_ARRAY_UNSIGNED_BYTE_60_WIDETAG
- case SIMPLE_ARRAY_UNSIGNED_BYTE_60_WIDETAG:
-#endif
-#ifdef SIMPLE_ARRAY_UNSIGNED_BYTE_63_WIDETAG
- case SIMPLE_ARRAY_UNSIGNED_BYTE_63_WIDETAG:
-#endif
-#ifdef SIMPLE_ARRAY_UNSIGNED_BYTE_64_WIDETAG
- case SIMPLE_ARRAY_UNSIGNED_BYTE_64_WIDETAG:
-#endif
-#ifdef SIMPLE_ARRAY_SIGNED_BYTE_8_WIDETAG
- case SIMPLE_ARRAY_SIGNED_BYTE_8_WIDETAG:
-#endif
-#ifdef SIMPLE_ARRAY_SIGNED_BYTE_16_WIDETAG
- case SIMPLE_ARRAY_SIGNED_BYTE_16_WIDETAG:
-#endif
-#ifdef SIMPLE_ARRAY_SIGNED_BYTE_30_WIDETAG
- case SIMPLE_ARRAY_SIGNED_BYTE_30_WIDETAG:
-#endif
-#ifdef SIMPLE_ARRAY_SIGNED_BYTE_32_WIDETAG
- case SIMPLE_ARRAY_SIGNED_BYTE_32_WIDETAG:
-#endif
-#ifdef SIMPLE_ARRAY_SIGNED_BYTE_61_WIDETAG
- case SIMPLE_ARRAY_SIGNED_BYTE_61_WIDETAG:
-#endif
-#ifdef SIMPLE_ARRAY_SIGNED_BYTE_64_WIDETAG
- case SIMPLE_ARRAY_SIGNED_BYTE_64_WIDETAG:
-#endif
- case SIMPLE_ARRAY_SINGLE_FLOAT_WIDETAG:
- case SIMPLE_ARRAY_DOUBLE_FLOAT_WIDETAG:
-#ifdef SIMPLE_ARRAY_LONG_FLOAT_WIDETAG
- case SIMPLE_ARRAY_LONG_FLOAT_WIDETAG:
-#endif
-#ifdef SIMPLE_ARRAY_COMPLEX_SINGLE_FLOAT_WIDETAG
- case SIMPLE_ARRAY_COMPLEX_SINGLE_FLOAT_WIDETAG:
-#endif
-#ifdef SIMPLE_ARRAY_COMPLEX_DOUBLE_FLOAT_WIDETAG
- case SIMPLE_ARRAY_COMPLEX_DOUBLE_FLOAT_WIDETAG:
-#endif
-#ifdef SIMPLE_ARRAY_COMPLEX_LONG_FLOAT_WIDETAG
- case SIMPLE_ARRAY_COMPLEX_LONG_FLOAT_WIDETAG:
-#endif
- case SAP_WIDETAG:
- case WEAK_POINTER_WIDETAG:
-#ifdef LUTEX_WIDETAG
- case LUTEX_WIDETAG:
-#endif
- break;
-
- default:
- if (pointer_filter_verbose) {
- fprintf(stderr,"*Wo6: %p %p %p\n",
- pointer, start_addr, (void *)*start_addr);
- }
- return 0;
- }
- break;
- default:
- if (pointer_filter_verbose) {
- fprintf(stderr,"*W?: %p %p %p\n",
- pointer, start_addr, (void *)*start_addr);
- }
- return 0;
- }
-
- /* looks good */
- return 1;
-}
-
-#define MAX_STACK_POINTERS 256
-lispobj *valid_stack_locations[MAX_STACK_POINTERS];
-unsigned long num_valid_stack_locations;
-
-#define MAX_STACK_RETURN_ADDRESSES 128
-lispobj *valid_stack_ra_locations[MAX_STACK_RETURN_ADDRESSES];
-lispobj *valid_stack_ra_code_objects[MAX_STACK_RETURN_ADDRESSES];
-unsigned long num_valid_stack_ra_locations;
-
-/* Identify valid stack slots. */
-static void
-setup_i386_stack_scav(lispobj *lowaddr, lispobj *base)
-{
- lispobj *sp = lowaddr;
- num_valid_stack_locations = 0;
- num_valid_stack_ra_locations = 0;
- for (sp = lowaddr; sp < base; sp++) {
- lispobj thing = *sp;
- /* Find the object start address */
- lispobj *start_addr = search_dynamic_space((void *)thing);
- if (start_addr) {
- /* We need to allow raw pointers into Code objects for
- * return addresses. This will also pick up pointers to
- * functions in code objects. */
- if (widetag_of(*start_addr) == CODE_HEADER_WIDETAG) {
- /* FIXME asserting here is a really dumb thing to do.
- * If we've overflowed some arbitrary static limit, we
- * should just refuse to purify, instead of killing
- * the whole lisp session
- */
- gc_assert(num_valid_stack_ra_locations <
- MAX_STACK_RETURN_ADDRESSES);
- valid_stack_ra_locations[num_valid_stack_ra_locations] = sp;
- valid_stack_ra_code_objects[num_valid_stack_ra_locations++] =
- (lispobj *)((long)start_addr + OTHER_POINTER_LOWTAG);
- } else {
- if (valid_dynamic_space_pointer((void *)thing, start_addr)) {
- gc_assert(num_valid_stack_locations < MAX_STACK_POINTERS);
- valid_stack_locations[num_valid_stack_locations++] = sp;
- }
- }
- }
- }
- if (pointer_filter_verbose) {
- fprintf(stderr, "number of valid stack pointers = %ld\n",
- num_valid_stack_locations);
- fprintf(stderr, "number of stack return addresses = %ld\n",
- num_valid_stack_ra_locations);
- }
-}
-
-static void
-pscav_i386_stack(void)
-{
- long i;
-
- for (i = 0; i < num_valid_stack_locations; i++)
- pscav(valid_stack_locations[i], 1, 0);
-
- for (i = 0; i < num_valid_stack_ra_locations; i++) {
- lispobj code_obj = (lispobj)valid_stack_ra_code_objects[i];
- pscav(&code_obj, 1, 0);
- if (pointer_filter_verbose) {
- fprintf(stderr,"*C moved RA %p to %p; for code object %p to %p\n",
- (void *)*valid_stack_ra_locations[i],
- (void *)(*valid_stack_ra_locations[i]) -
- ((void *)valid_stack_ra_code_objects[i] -
- (void *)code_obj),
- valid_stack_ra_code_objects[i], (void *)code_obj);
- }
- *valid_stack_ra_locations[i] =
- ((long)(*valid_stack_ra_locations[i])
- - ((long)valid_stack_ra_code_objects[i] - (long)code_obj));
- }
-}
-#endif
-#endif
-