diff options
| -rw-r--r-- | lib/ds/plarena.c | 9 | ||||
| -rw-r--r-- | lib/ds/plarena.h | 84 |
2 files changed, 86 insertions, 7 deletions
diff --git a/lib/ds/plarena.c b/lib/ds/plarena.c index 40531951..211dd671 100644 --- a/lib/ds/plarena.c +++ b/lib/ds/plarena.c @@ -157,6 +157,7 @@ PR_IMPLEMENT(void *) PL_ArenaAllocate(PLArenaPool *pool, PRUint32 nb) pool->current = a; rp = (char *)a->avail; a->avail += nb; + PL_MAKE_MEM_UNDEFINED(rp, nb); return rp; } } while( NULL != (a = a->next) ); @@ -187,6 +188,7 @@ PR_IMPLEMENT(void *) PL_ArenaAllocate(PLArenaPool *pool, PRUint32 nb) pool->current = a; if ( NULL == pool->first.next ) pool->first.next = a; + PL_MAKE_MEM_UNDEFINED(rp, nb); return(rp); } } @@ -201,6 +203,7 @@ PR_IMPLEMENT(void *) PL_ArenaAllocate(PLArenaPool *pool, PRUint32 nb) if ( NULL != a ) { a->limit = (PRUword)a + sz; a->base = a->avail = (PRUword)PL_ARENA_ALIGN(pool, a + 1); + PL_MAKE_MEM_NOACCESS((void*)a->avail, a->limit - a->avail); rp = (char *)a->avail; a->avail += nb; /* the newly allocated arena is linked after pool->current @@ -212,6 +215,7 @@ PR_IMPLEMENT(void *) PL_ArenaAllocate(PLArenaPool *pool, PRUint32 nb) pool->first.next = a; PL_COUNT_ARENA(pool,++); COUNT(pool, nmallocs); + PL_MAKE_MEM_UNDEFINED(rp, nb); return(rp); } } @@ -237,7 +241,8 @@ static void ClearArenaList(PLArena *a, PRInt32 pattern) for (; a; a = a->next) { PR_ASSERT(a->base <= a->avail && a->avail <= a->limit); a->avail = a->base; - PL_CLEAR_UNUSED_PATTERN(a, pattern); + PL_CLEAR_UNUSED_PATTERN(a, pattern); + PL_MAKE_MEM_NOACCESS((void*)a->avail, a->limit - a->avail); } } @@ -273,6 +278,8 @@ static void FreeArenaList(PLArenaPool *pool, PLArena *head, PRBool reallyFree) } else { /* Insert the whole arena chain at the front of the freelist. */ do { + PL_MAKE_MEM_NOACCESS((void*)(*ap)->base, + (*ap)->limit - (*ap)->base); ap = &(*ap)->next; } while (*ap); LockArena(); diff --git a/lib/ds/plarena.h b/lib/ds/plarena.h index 4d54cc46..c4974304 100644 --- a/lib/ds/plarena.h +++ b/lib/ds/plarena.h @@ -58,6 +58,68 @@ struct PLArenaPool { }; /* + * WARNING: The PL_MAKE_MEM_ macros are for internal use by NSPR. Do NOT use + * them in your code. + * + * NOTE: Valgrind support to be added. + * + * The PL_MAKE_MEM_ macros are modeled after the MOZ_MAKE_MEM_ macros in + * Mozilla's mfbt/MemoryChecking.h. Only AddressSanitizer is supported now. + * + * Provides a common interface to the ASan (AddressSanitizer) and Valgrind + * functions used to mark memory in certain ways. In detail, the following + * three macros are provided: + * + * PL_MAKE_MEM_NOACCESS - Mark memory as unsafe to access (e.g. freed) + * PL_MAKE_MEM_UNDEFINED - Mark memory as accessible, with content undefined + * PL_MAKE_MEM_DEFINED - Mark memory as accessible, with content defined + * + * With Valgrind in use, these directly map to the three respective Valgrind + * macros. With ASan in use, the NOACCESS macro maps to poisoning the memory, + * while the UNDEFINED/DEFINED macros unpoison memory. + * + * With no memory checker available, all macros expand to the empty statement. + */ + +/* WARNING: PL_SANITIZE_ADDRESS is for internal use by this header. Do NOT + * define or test this macro in your code. + */ +#if defined(__has_feature) +#if __has_feature(address_sanitizer) +#define PL_SANITIZE_ADDRESS 1 +#endif +#elif defined(__SANITIZE_ADDRESS__) +#define PL_SANITIZE_ADDRESS 1 +#endif + +#if defined(PL_SANITIZE_ADDRESS) + +/* These definitions are usually provided through the + * sanitizer/asan_interface.h header installed by ASan. + * See https://code.google.com/p/address-sanitizer/wiki/ManualPoisoning + */ + +void __asan_poison_memory_region(void const volatile *addr, size_t size); +void __asan_unpoison_memory_region(void const volatile *addr, size_t size); + +#define PL_MAKE_MEM_NOACCESS(addr, size) \ + __asan_poison_memory_region((addr), (size)) + +#define PL_MAKE_MEM_UNDEFINED(addr, size) \ + __asan_unpoison_memory_region((addr), (size)) + +#define PL_MAKE_MEM_DEFINED(addr, size) \ + __asan_unpoison_memory_region((addr), (size)) + +#else + +#define PL_MAKE_MEM_NOACCESS(addr, size) +#define PL_MAKE_MEM_UNDEFINED(addr, size) +#define PL_MAKE_MEM_DEFINED(addr, size) + +#endif + +/* * If the including .c file uses only one power-of-2 alignment, it may define * PL_ARENA_CONST_ALIGN_MASK to the alignment mask and save a few instructions * per ALLOCATE and GROW. @@ -78,10 +140,12 @@ struct PLArenaPool { PRUint32 _nb = PL_ARENA_ALIGN(pool, nb); \ PRUword _p = _a->avail; \ PRUword _q = _p + _nb; \ - if (_q > _a->limit) \ + if (_q > _a->limit) { \ _p = (PRUword)PL_ArenaAllocate(pool, _nb); \ - else \ + } else { \ + PL_MAKE_MEM_UNDEFINED((void *)_p, nb); \ _a->avail = _q; \ + } \ p = (void *)_p; \ PL_ArenaCountAllocation(pool, nb); \ PR_END_MACRO @@ -94,6 +158,7 @@ struct PLArenaPool { PRUword _q = _p + _incr; \ if (_p == (PRUword)(p) + PL_ARENA_ALIGN(pool, size) && \ _q <= _a->limit) { \ + PL_MAKE_MEM_UNDEFINED((void *)((PRUword)(p) + size), incr); \ _a->avail = _q; \ PL_ArenaCountInplaceGrowth(pool, size, incr); \ } else { \ @@ -106,13 +171,19 @@ struct PLArenaPool { #define PR_UPTRDIFF(p,q) ((PRUword)(p) - (PRUword)(q)) #define PL_CLEAR_UNUSED_PATTERN(a, pattern) \ - (PR_ASSERT((a)->avail <= (a)->limit), \ - memset((void*)(a)->avail, (pattern), (a)->limit - (a)->avail)) + PR_BEGIN_MACRO \ + PR_ASSERT((a)->avail <= (a)->limit); \ + PL_MAKE_MEM_UNDEFINED((void*)(a)->avail, (a)->limit - (a)->avail); \ + memset((void*)(a)->avail, (pattern), (a)->limit - (a)->avail); \ + PR_END_MACRO #ifdef DEBUG #define PL_FREE_PATTERN 0xDA #define PL_CLEAR_UNUSED(a) PL_CLEAR_UNUSED_PATTERN((a), PL_FREE_PATTERN) -#define PL_CLEAR_ARENA(a) memset((void*)(a), PL_FREE_PATTERN, \ - (a)->limit - (PRUword)(a)) +#define PL_CLEAR_ARENA(a) \ + PR_BEGIN_MACRO \ + PL_MAKE_MEM_UNDEFINED((void*)(a), (a)->limit - (PRUword)(a)); \ + memset((void*)(a), PL_FREE_PATTERN, (a)->limit - (PRUword)(a)); \ + PR_END_MACRO #else #define PL_CLEAR_UNUSED(a) #define PL_CLEAR_ARENA(a) @@ -125,6 +196,7 @@ struct PLArenaPool { if (PR_UPTRDIFF(_m, _a->base) <= PR_UPTRDIFF(_a->avail, _a->base)) { \ _a->avail = (PRUword)PL_ARENA_ALIGN(pool, _m); \ PL_CLEAR_UNUSED(_a); \ + PL_MAKE_MEM_NOACCESS((void*)_a->avail, _a->limit - _a->avail); \ PL_ArenaCountRetract(pool, _m); \ } else { \ PL_ArenaRelease(pool, _m); \ |