diff options
| -rw-r--r-- | Misc/NEWS.d/next/Core and Builtins/2018-11-30-17-50-28.bpo-35368.DNaDao.rst | 1 | ||||
| -rw-r--r-- | Objects/obmalloc.c | 59 |
2 files changed, 54 insertions, 6 deletions
diff --git a/Misc/NEWS.d/next/Core and Builtins/2018-11-30-17-50-28.bpo-35368.DNaDao.rst b/Misc/NEWS.d/next/Core and Builtins/2018-11-30-17-50-28.bpo-35368.DNaDao.rst new file mode 100644 index 0000000000..4bcf608fdd --- /dev/null +++ b/Misc/NEWS.d/next/Core and Builtins/2018-11-30-17-50-28.bpo-35368.DNaDao.rst @@ -0,0 +1 @@ +:c:func:`PyMem_Malloc` is now also thread-safe in debug mode. diff --git a/Objects/obmalloc.c b/Objects/obmalloc.c index 9adcff7a27..0778c851fa 100644 --- a/Objects/obmalloc.c +++ b/Objects/obmalloc.c @@ -1413,6 +1413,38 @@ pool_is_in_list(const poolp target, poolp list) #endif /* Py_DEBUG */ +static void * +_PyMem_Malloc(size_t nbytes) +{ + if (nbytes > (size_t)PY_SSIZE_T_MAX) { + return NULL; + } + if (nbytes == 0) { + nbytes = 1; + } + return malloc(nbytes); +} + +static void * +_PyMem_Realloc(void *p, size_t nbytes) +{ + if (nbytes > (size_t)PY_SSIZE_T_MAX) { + return NULL; + } + if (nbytes == 0) { + nbytes = 1; + } + return realloc(p, nbytes); +} + + +static void +_PyMem_Free(void *p) +{ + free(p); +} + + /* Let S = sizeof(size_t). The debug malloc asks for 4*S extra bytes and fills them with useful stuff, here calling the underlying malloc's result p: @@ -1479,7 +1511,7 @@ _PyObject_DebugCheckAddress(const void *p) /* generic debug memory api, with an "id" to identify the API in use */ void * -_PyObject_DebugMallocApi(char id, size_t nbytes) +_PyObject_DebugMallocApi(char api, size_t nbytes) { uchar *p; /* base address of malloc'ed block */ uchar *tail; /* p + 2*SST + nbytes == pointer to tail pad bytes */ @@ -1491,13 +1523,18 @@ _PyObject_DebugMallocApi(char id, size_t nbytes) /* overflow: can't represent total as a size_t */ return NULL; - p = (uchar *)PyObject_Malloc(total); + if (api == _PYMALLOC_OBJ_ID) { + p = (uchar *)PyObject_Malloc(total); + } + else { + p = (uchar *)_PyMem_Malloc(total); + } if (p == NULL) return NULL; - /* at p, write size (SST bytes), id (1 byte), pad (SST-1 bytes) */ + /* at p, write size (SST bytes), api (1 byte), pad (SST-1 bytes) */ write_size_t(p, nbytes); - p[SST] = (uchar)id; + p[SST] = (uchar)api; memset(p + SST + 1 , FORBIDDENBYTE, SST-1); if (nbytes > 0) @@ -1529,7 +1566,12 @@ _PyObject_DebugFreeApi(char api, void *p) nbytes += 4*SST; if (nbytes > 0) memset(q, DEADBYTE, nbytes); - PyObject_Free(q); + if (api == _PYMALLOC_OBJ_ID) { + PyObject_Free(q); + } + else { + _PyMem_Free(q); + } } void * @@ -1561,7 +1603,12 @@ _PyObject_DebugReallocApi(char api, void *p, size_t nbytes) * case we didn't get the chance to mark the old memory with DEADBYTE, * but we live with that. */ - q = (uchar *)PyObject_Realloc(q - 2*SST, total); + if (api == _PYMALLOC_OBJ_ID) { + q = (uchar *)PyObject_Realloc(q - 2*SST, total); + } + else { + q = (uchar *)_PyMem_Realloc(q - 2*SST, total); + } if (q == NULL) { if (nbytes <= original_nbytes) { /* bpo-31626: the memset() above expects that realloc never fails |