3571e53040
patches for easier mirroring, to eliminate a special copy, to make www.freebsd.org/security a full copy of security.freebsd.org and be eventually be the same. For now files are just sitting there. The symlinks are missing. Discussed on: www (repository location) Discussed with: simon (so)
82 lines
2.3 KiB
Diff
82 lines
2.3 KiB
Diff
Index: lib/libc/stdlib/malloc.c
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===================================================================
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RCS file: /home/ncvs/src/lib/libc/stdlib/malloc.c,v
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retrieving revision 1.147.2.6.2.1
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retrieving revision 1.147.2.7
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diff -p -I __FBSDID -I $FreeBSD -u -r1.147.2.6.2.1 -r1.147.2.7
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--- lib/libc/stdlib/malloc.c 15 Apr 2009 03:14:26 -0000 1.147.2.6.2.1
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+++ lib/libc/stdlib/malloc.c 3 May 2009 17:51:38 -0000 1.147.2.7
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@@ -4715,16 +4715,41 @@ _malloc_thread_cleanup(void)
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void
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_malloc_prefork(void)
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{
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- unsigned i;
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+ bool again;
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+ unsigned i, j;
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+ arena_t *larenas[narenas], *tarenas[narenas];
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/* Acquire all mutexes in a safe order. */
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- malloc_spin_lock(&arenas_lock);
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- for (i = 0; i < narenas; i++) {
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- if (arenas[i] != NULL)
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- malloc_spin_lock(&arenas[i]->lock);
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- }
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- malloc_spin_unlock(&arenas_lock);
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+ /*
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+ * arenas_lock must be acquired after all of the arena mutexes, in
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+ * order to avoid potential deadlock with arena_lock_balance[_hard]().
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+ * Since arenas_lock protects the arenas array, the following code has
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+ * to race with arenas_extend() callers until it succeeds in locking
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+ * all arenas before locking arenas_lock.
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+ */
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+ memset(larenas, 0, sizeof(arena_t *) * narenas);
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+ do {
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+ again = false;
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+
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+ malloc_spin_lock(&arenas_lock);
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+ for (i = 0; i < narenas; i++) {
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+ if (arenas[i] != larenas[i]) {
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+ memcpy(tarenas, arenas, sizeof(arena_t *) *
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+ narenas);
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+ malloc_spin_unlock(&arenas_lock);
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+ for (j = 0; j < narenas; j++) {
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+ if (larenas[j] != tarenas[j]) {
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+ larenas[j] = tarenas[j];
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+ malloc_spin_lock(
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+ &larenas[j]->lock);
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+ }
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+ }
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+ again = true;
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+ break;
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+ }
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+ }
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+ } while (again);
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malloc_mutex_lock(&base_mtx);
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@@ -4739,6 +4764,7 @@ void
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_malloc_postfork(void)
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{
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unsigned i;
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+ arena_t *larenas[narenas];
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/* Release all mutexes, now that fork() has completed. */
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@@ -4750,12 +4776,12 @@ _malloc_postfork(void)
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malloc_mutex_unlock(&base_mtx);
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- malloc_spin_lock(&arenas_lock);
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+ memcpy(larenas, arenas, sizeof(arena_t *) * narenas);
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+ malloc_spin_unlock(&arenas_lock);
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for (i = 0; i < narenas; i++) {
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- if (arenas[i] != NULL)
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- malloc_spin_unlock(&arenas[i]->lock);
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+ if (larenas[i] != NULL)
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+ malloc_spin_unlock(&larenas[i]->lock);
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}
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- malloc_spin_unlock(&arenas_lock);
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}
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/*
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