diff options
| author | Ted Unangst <tedu@cvs.openbsd.org> | 2005-06-07 04:42:43 +0000 |
|---|---|---|
| committer | Ted Unangst <tedu@cvs.openbsd.org> | 2005-06-07 04:42:43 +0000 |
| commit | 04cbf62b42ee87a16c8281c93b1379907d8ee56e (patch) | |
| tree | bae31ae03c7844cc8e4dc2c93f3c887fcd27e3e7 /lib/libc/stdlib | |
| parent | 18b04af3af812d2a0deba6da7478775abd5b0c79 (diff) | |
adding pointer protection to 'G' was too heavyweight. Since malloc guard
should be generally usable, split this out into option 'P'. ok deraadt
Diffstat (limited to 'lib/libc/stdlib')
| -rw-r--r-- | lib/libc/stdlib/malloc.3 | 9 | ||||
| -rw-r--r-- | lib/libc/stdlib/malloc.c | 12 |
2 files changed, 14 insertions, 7 deletions
diff --git a/lib/libc/stdlib/malloc.3 b/lib/libc/stdlib/malloc.3 index df62e7d3a52..2b0f5632a96 100644 --- a/lib/libc/stdlib/malloc.3 +++ b/lib/libc/stdlib/malloc.3 @@ -30,7 +30,7 @@ .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF .\" SUCH DAMAGE. .\" -.\" $OpenBSD: malloc.3,v 1.38 2005/05/24 16:48:35 tedu Exp $ +.\" $OpenBSD: malloc.3,v 1.39 2005/06/07 04:42:42 tedu Exp $ .\" .Dd August 27, 1996 .Dt MALLOC 3 @@ -204,8 +204,6 @@ Enable guard pages and chunk randomization. Each page size or larger allocation is followed by a guard page that will cause a segmentation fault upon any access. Smaller than page size chunks are returned in a random order. -Pointer sized allocations are aligned to the end of a page to catch -sizeof(ptr) errors where sizeof(*ptr) is meant. .Pp .It Cm H .Dq Hint . @@ -223,6 +221,11 @@ Currently junk is bytes of 0xd0; this is pronounced Do not output warning messages when encountering possible corruption or bad pointers. .Pp +.It Cm P +.Dq Pointer Protection . +Pointer sized allocations are aligned to the end of a page to catch +sizeof(ptr) errors where sizeof(*ptr) is meant. +.Pp .It Cm R .Dq realloc . Always reallocate when diff --git a/lib/libc/stdlib/malloc.c b/lib/libc/stdlib/malloc.c index 9f7ceba0802..e3405df39ae 100644 --- a/lib/libc/stdlib/malloc.c +++ b/lib/libc/stdlib/malloc.c @@ -8,7 +8,7 @@ */ #if defined(LIBC_SCCS) && !defined(lint) -static char rcsid[] = "$OpenBSD: malloc.c,v 1.73 2005/05/24 16:39:05 tedu Exp $"; +static char rcsid[] = "$OpenBSD: malloc.c,v 1.74 2005/06/07 04:42:42 tedu Exp $"; #endif /* LIBC_SCCS and not lint */ /* @@ -211,6 +211,8 @@ static int malloc_freeprot; /* use guard pages after allocations? */ static int malloc_guard = 0; +/* align pointers to end of page? */ +static int malloc_ptrguard; #if defined(__FreeBSD__) || (defined(__OpenBSD__) && defined(MADV_FREE)) /* pass the kernel a hint on free pages ? */ @@ -612,6 +614,8 @@ malloc_init(void) case 'J': malloc_junk = 1; break; case 'n': malloc_silent = 0; break; case 'N': malloc_silent = 1; break; + case 'p': malloc_ptrguard = 0; break; + case 'P': malloc_ptrguard = 1; break; case 'r': malloc_realloc = 0; break; case 'R': malloc_realloc = 1; break; #ifdef __FreeBSD__ @@ -1082,7 +1086,7 @@ imalloc(size_t size) if (suicide) abort(); - if (malloc_guard && size == PTR_SIZE) { + if (malloc_ptrguard && size == PTR_SIZE) { ptralloc = 1; size = malloc_pagesize; } @@ -1128,7 +1132,7 @@ irealloc(void *ptr, size_t size) return (NULL); } - if (malloc_guard && PTR_ALIGNED(ptr)) { + if (malloc_ptrguard && PTR_ALIGNED(ptr)) { if (size <= PTR_SIZE) return (ptr); else { @@ -1602,7 +1606,7 @@ ifree(void *ptr) if (suicide) return; - if (malloc_guard && PTR_ALIGNED(ptr)) + if (malloc_ptrguard && PTR_ALIGNED(ptr)) ptr = (char *)ptr - PTR_GAP; index = ptr2index(ptr); |