diff options
Diffstat (limited to 'patches/uClibc/0.9.30.2/270-malloc-fix-race-condition-and-other-bugs-in-the-no-m.patch')
| -rw-r--r-- | patches/uClibc/0.9.30.2/270-malloc-fix-race-condition-and-other-bugs-in-the-no-m.patch | 89 |
1 files changed, 89 insertions, 0 deletions
diff --git a/patches/uClibc/0.9.30.2/270-malloc-fix-race-condition-and-other-bugs-in-the-no-m.patch b/patches/uClibc/0.9.30.2/270-malloc-fix-race-condition-and-other-bugs-in-the-no-m.patch new file mode 100644 index 0000000..aa9c2f4 --- /dev/null +++ b/patches/uClibc/0.9.30.2/270-malloc-fix-race-condition-and-other-bugs-in-the-no-m.patch @@ -0,0 +1,89 @@ +From fa476d01f1c1990a92ee49d1f1c557b83805d0e9 Mon Sep 17 00:00:00 2001 +From: Freeman Wang <xwang@ubicom.com> +Date: Sat, 19 Dec 2009 13:43:00 -0800 +Subject: [PATCH 09/15] malloc: fix race condition and other bugs in the no-mmu malloc + +Fixes multiple race conditions on mmb list. This was done by +making the mmb_heap_lock into a recursive lock and making the +regular heap_lock extend to cover the mmb heap handling. + +Also move the new_mmb allocation up to before the mmb list is +iterated through to find the insertion point. When the mmb_heap +also runs out and needs to be extended when the regular heap is +just extended, the mmb list could be messed up. + +Signed-off-by: Freeman Wang <xwang@ubicom.com> +Signed-off-by: Austin Foxley <austinf@cetoncorp.com> +--- + libc/stdlib/malloc/free.c | 6 +++--- + libc/stdlib/malloc/malloc.c | 7 ++++--- + 2 files changed, 7 insertions(+), 6 deletions(-) + +diff --git a/libc/stdlib/malloc/free.c b/libc/stdlib/malloc/free.c +index 90e18f4..741248a 100644 +--- a/libc/stdlib/malloc/free.c ++++ b/libc/stdlib/malloc/free.c +@@ -179,14 +179,14 @@ __free_to_heap (void *mem, struct heap_free_area **heap + /* Start searching again from the end of this block. */ + start = mmb_end; + ++ /* Release the descriptor block we used. */ ++ free_to_heap (mmb, &__malloc_mmb_heap, &__malloc_mmb_heap_lock); ++ + /* We have to unlock the heap before we recurse to free the mmb + descriptor, because we might be unmapping from the mmb + heap. */ + __heap_unlock (heap_lock); + +- /* Release the descriptor block we used. */ +- free_to_heap (mmb, &__malloc_mmb_heap, &__malloc_mmb_heap_lock); +- + /* Do the actual munmap. */ + munmap ((void *)mmb_start, mmb_end - mmb_start); + +diff --git a/libc/stdlib/malloc/malloc.c b/libc/stdlib/malloc/malloc.c +index 71f9e58..84a6acd 100644 +--- a/libc/stdlib/malloc/malloc.c ++++ b/libc/stdlib/malloc/malloc.c +@@ -48,7 +48,7 @@ struct malloc_mmb *__malloc_mmapped_blocks = 0; + HEAP_DECLARE_STATIC_FREE_AREA (initial_mmb_fa, 48); /* enough for 3 mmbs */ + struct heap_free_area *__malloc_mmb_heap = HEAP_INIT_WITH_FA (initial_mmb_fa); + #ifdef HEAP_USE_LOCKING +-pthread_mutex_t __malloc_mmb_heap_lock = PTHREAD_MUTEX_INITIALIZER; ++pthread_mutex_t __malloc_mmb_heap_lock = PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP; + #endif + #endif /* __UCLIBC_UCLINUX_BROKEN_MUNMAP__ */ + +@@ -151,19 +151,19 @@ __malloc_from_heap (size_t size, struct heap_free_area **heap + /* Try again to allocate. */ + mem = __heap_alloc (heap, &size); + +- __heap_unlock (heap_lock); + + #if !defined(MALLOC_USE_SBRK) && defined(__UCLIBC_UCLINUX_BROKEN_MUNMAP__) + /* Insert a record of BLOCK in sorted order into the + __malloc_mmapped_blocks list. */ + ++ new_mmb = malloc_from_heap (sizeof *new_mmb, &__malloc_mmb_heap, &__malloc_mmb_heap_lock); ++ + for (prev_mmb = 0, mmb = __malloc_mmapped_blocks; + mmb; + prev_mmb = mmb, mmb = mmb->next) + if (block < mmb->mem) + break; + +- new_mmb = malloc_from_heap (sizeof *new_mmb, &__malloc_mmb_heap, &__malloc_mmb_heap_lock); + new_mmb->next = mmb; + new_mmb->mem = block; + new_mmb->size = block_size; +@@ -177,6 +177,7 @@ __malloc_from_heap (size_t size, struct heap_free_area **heap + (unsigned)new_mmb, + (unsigned)new_mmb->mem, block_size); + #endif /* !MALLOC_USE_SBRK && __UCLIBC_UCLINUX_BROKEN_MUNMAP__ */ ++ __heap_unlock (heap_lock); + } + } + +-- +1.6.6.1 + |