From 881abfc7fb55db2d00adf352100cc58a6a86c176 Mon Sep 17 00:00:00 2001 From: Paul Eggert Date: Sat, 9 Dec 2017 13:57:38 -0800 Subject: Port to gcc -fcheck-pointer-bounds This is a minimal port, just to get Emacs running; it does not attempt to make the pointer bounds at all tight. * src/ptr-bounds.h: New file. * src/alloc.c, src/gmalloc.c: Include it. * src/alloc.c (live_string_holding, live_cons_holding) (live_symbol_holding, live_misc_holding, garbage_collect_1) (sweep_conses, sweep_floats): * src/gmalloc.c (malloc_initialize_1, _free_internal_nolock) (_realloc_internal_nolock): Widen pointer bounds as necessary. We're in a memory allocator so this is OK. * src/lisp.h (lisp_h_XSYMBOL, make_lisp_symbol) [__CHKP__]: Do not convert from pointer to integer and back again, so that GCC does not lose track of pointer bounds. (XSYMBOL) [__CHKP__ && !USE_LSB_TAG]: Now a compile-time error. Although it's possible to support both -fcheck-pointer-bounds and --with-wide-int, it's more work; keep things simple for now. (DEFINE_LISP_SYMBOL) [__CHKP__]: Now a no-op, to avoid trouble with unbounded pointers. --- src/gmalloc.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) (limited to 'src/gmalloc.c') diff --git a/src/gmalloc.c b/src/gmalloc.c index a17d39c1eeb..97ab76561f9 100644 --- a/src/gmalloc.c +++ b/src/gmalloc.c @@ -40,6 +40,8 @@ License along with this library. If not, see . # include "lisp.h" #endif +#include "ptr-bounds.h" + #ifdef HAVE_MALLOC_H # if GNUC_PREREQ (4, 2, 0) # pragma GCC diagnostic ignored "-Wdeprecated-declarations" @@ -558,7 +560,7 @@ malloc_initialize_1 (void) _heapinfo[0].free.size = 0; _heapinfo[0].free.next = _heapinfo[0].free.prev = 0; _heapindex = 0; - _heapbase = (char *) _heapinfo; + _heapbase = (char *) ptr_bounds_init (_heapinfo); _heaplimit = BLOCK (_heapbase + heapsize * sizeof (malloc_info)); register_heapinfo (); @@ -997,6 +999,7 @@ _free_internal_nolock (void *ptr) if (ptr == NULL) return; + ptr = ptr_bounds_init (ptr); PROTECT_MALLOC_STATE (0); @@ -1308,6 +1311,7 @@ _realloc_internal_nolock (void *ptr, size_t size) else if (ptr == NULL) return _malloc_internal_nolock (size); + ptr = ptr_bounds_init (ptr); block = BLOCK (ptr); PROTECT_MALLOC_STATE (0); -- cgit v1.2.1