From 95496b974a2920369874c1cf29985723f6fc3058 Mon Sep 17 00:00:00 2001 From: Gerald Carter Date: Sat, 12 Aug 2000 14:14:40 +0000 Subject: reworked talloc() to in order to help track down invalid memory access. Tridge, I don't think using 0xdeadbeef for size allocations of 0 is going to work. I ended up having to use NULL as much code that works on UNISTR checks to see if the buffer ptr is NULL. So valid code ends up with a seg fault. Rather than rewriting it all, I added a DEBUG_TALLOC #ifdef in talloc.h that sets a macro BAD_PTR. This is the value assigned to ptr for an allocation of 0 bytes. jerry (This used to be commit 233b9cffa2350552d9f775f791d5d5e0464a1ed4) --- source3/lib/talloc.c | 51 ++++++++++++++++++++++++++------------------------- 1 file changed, 26 insertions(+), 25 deletions(-) (limited to 'source3/lib') diff --git a/source3/lib/talloc.c b/source3/lib/talloc.c index 577f761072..acc6204bed 100644 --- a/source3/lib/talloc.c +++ b/source3/lib/talloc.c @@ -55,37 +55,38 @@ TALLOC_CTX *talloc_init(void) void *talloc(TALLOC_CTX *t, size_t size) { void *p; - if (size == 0) { /* debugging value used to track down - memory problems */ - p = (void*)0xdeadbeef; + memory problems. BAD_PTR is defined + in talloc.h */ + p = BAD_PTR; + return p; } - else - { - size = (size + (TALLOC_ALIGN-1)) & ~(TALLOC_ALIGN-1); - - if (!t->list || (t->list->total_size - t->list->alloc_size) < size) { - struct talloc_chunk *c; - size_t asize = (size + (TALLOC_CHUNK_SIZE-1)) & ~(TALLOC_CHUNK_SIZE-1); - - c = (struct talloc_chunk *)malloc(sizeof(*c)); - if (!c) return NULL; - c->next = t->list; - c->ptr = (void *)malloc(asize); - if (!c->ptr) { - free(c); - return NULL; - } - c->alloc_size = 0; - c->total_size = asize; - t->list = c; - } - p = ((char *)t->list->ptr) + t->list->alloc_size; - t->list->alloc_size += size; + /* normal code path */ + size = (size + (TALLOC_ALIGN-1)) & ~(TALLOC_ALIGN-1); + + if (!t->list || (t->list->total_size - t->list->alloc_size) < size) { + struct talloc_chunk *c; + size_t asize = (size + (TALLOC_CHUNK_SIZE-1)) & ~(TALLOC_CHUNK_SIZE-1); + + c = (struct talloc_chunk *)malloc(sizeof(*c)); + if (!c) return NULL; + c->next = t->list; + c->ptr = (void *)malloc(asize); + if (!c->ptr) { + free(c); + return NULL; + } + c->alloc_size = 0; + c->total_size = asize; + t->list = c; } + + p = ((char *)t->list->ptr) + t->list->alloc_size; + t->list->alloc_size += size; + return p; } -- cgit