diff options
| author | Otto Moerbeek <otto@cvs.openbsd.org> | 2008-11-13 07:38:46 +0000 |
|---|---|---|
| committer | Otto Moerbeek <otto@cvs.openbsd.org> | 2008-11-13 07:38:46 +0000 |
| commit | 3e2dcbc5dc574c40c954f56ccb55a0baea37ad29 (patch) | |
| tree | f29250b397c518d53a876c9d24ea94eb9a8e7d89 /lib/libc/stdlib | |
| parent | 1b4f4f7f732e0f1212550e5f5664d88c6e272efb (diff) | |
To allow for easier playing with more strict settings introduce
a separate symbolic constant for the leeway we allow when moving
allocations towards the end of a page. No functional change.
Diffstat (limited to 'lib/libc/stdlib')
| -rw-r--r-- | lib/libc/stdlib/malloc.c | 19 |
1 files changed, 14 insertions, 5 deletions
diff --git a/lib/libc/stdlib/malloc.c b/lib/libc/stdlib/malloc.c index f5f0ab730f2..b6e4ada3124 100644 --- a/lib/libc/stdlib/malloc.c +++ b/lib/libc/stdlib/malloc.c @@ -1,4 +1,4 @@ -/* $OpenBSD: malloc.c,v 1.107 2008/11/12 09:41:49 otto Exp $ */ +/* $OpenBSD: malloc.c,v 1.108 2008/11/13 07:38:45 otto Exp $ */ /* * Copyright (c) 2008 Otto Moerbeek <otto@drijf.net> * @@ -64,6 +64,13 @@ #define MALLOC_MAXCHUNK (1 << (MALLOC_PAGESHIFT-1)) #define MALLOC_MAXCACHE 256 #define MALLOC_DELAYED_CHUNKS 16 /* should be power of 2 */ +/* + * When the P option is active, we move allocations between half a page + * and a whole page towards the end, subject to alignment constraints. + * This is the extra headroom we allow. Set to zero to be the most + * strict. + */ +#define MALLOC_LEEWAY 16 #define PAGEROUND(x) (((x) + (MALLOC_PAGEMASK)) & ~MALLOC_PAGEMASK) @@ -1081,12 +1088,12 @@ omalloc(size_t sz, int zero_fill) } if (malloc_move && - sz - malloc_guard < MALLOC_PAGESIZE - MALLOC_MINSIZE) { + sz - malloc_guard < MALLOC_PAGESIZE - MALLOC_LEEWAY) { /* fill whole allocation */ if (malloc_junk) memset(p, SOME_JUNK, psz - malloc_guard); /* shift towards the end */ - p = ((char *)p) + ((MALLOC_PAGESIZE - MALLOC_MINSIZE - + p = ((char *)p) + ((MALLOC_PAGESIZE - MALLOC_LEEWAY - (sz - malloc_guard)) & ~(MALLOC_MINSIZE-1)); /* fill zeros if needed and overwritten above */ if (zero_fill && malloc_junk) @@ -1177,9 +1184,11 @@ ofree(void *p) } REALSIZE(sz, r); if (sz > MALLOC_MAXCHUNK) { - if (sz - malloc_guard >= MALLOC_PAGESIZE - MALLOC_MINSIZE) { - if (r->p != p) + if (sz - malloc_guard >= MALLOC_PAGESIZE - MALLOC_LEEWAY) { + if (r->p != p) { wrterror("bogus pointer"); + return; + } } else { #if notyetbecause_of_realloc /* shifted towards the end */ |