diff options
| -rw-r--r-- | extra/Configs/Config.in | 19 | ||||
| -rw-r--r-- | libc/stdlib/malloc-930716/malloc.c | 5 | ||||
| -rw-r--r-- | libc/stdlib/malloc/malloc.c | 5 |
3 files changed, 28 insertions, 1 deletions
diff --git a/extra/Configs/Config.in b/extra/Configs/Config.in index 92a3878ff..f77a4e4b5 100644 --- a/extra/Configs/Config.in +++ b/extra/Configs/Config.in @@ -195,11 +195,28 @@ config MALLOC_930716 endchoice +config MALLOC_GLIBC_COMPAT + bool "Malloc returns live pointer for malloc(0)" + default n + help + The behavior of malloc(0) is listed as implementation-defined by + SuSv3. Glibc returns a valid pointer to something, while uClibc + normally return a NULL. I personally feel glibc's behavior is + not particularly safe, and allows buggy applications to hide very + serious problems. + + When this option is enabled, uClibc will act just like glibc, and + return a live pointer when someone calls malloc(0). This pointer + provides a malloc'ed area with a size of 1 byte. This feature is + mostly useful when dealing with applications using autoconf's broken + AC_FUNC_MALLOC macro (which redefines malloc as rpl_malloc if it + does not detect glibc style returning-a-valid-pointer-for-malloc(0) + behavior). Most people can safely answer N. + config UCLIBC_DYNAMIC_ATEXIT bool "Dynamic atexit() Support" default y help - When this option is enabled, uClibc will support an infinite number, of atexit() and on_exit() functions, limited only by your available memory. This can be important when uClibc is used with C++, since diff --git a/libc/stdlib/malloc-930716/malloc.c b/libc/stdlib/malloc-930716/malloc.c index 2467da41c..dce32b90b 100644 --- a/libc/stdlib/malloc-930716/malloc.c +++ b/libc/stdlib/malloc-930716/malloc.c @@ -160,9 +160,14 @@ void * __malloc_unlocked (size_t size) size_t log, block, blocks, i, lastblocks, start; struct list *next; +#if defined(__MALLOC_GLIBC_COMPAT__) + if (size == 0) + size++; +#else /* Some programs will call malloc (0). Lets be strict and return NULL */ if (size == 0) return NULL; +#endif if (size < sizeof (struct list)) size = sizeof (struct list); diff --git a/libc/stdlib/malloc/malloc.c b/libc/stdlib/malloc/malloc.c index 7bbd2726b..5f88cf48e 100644 --- a/libc/stdlib/malloc/malloc.c +++ b/libc/stdlib/malloc/malloc.c @@ -184,8 +184,13 @@ malloc (size_t size) __heap_check (&__malloc_heap, "malloc"); #endif +#if defined(__MALLOC_GLIBC_COMPAT__) if (size == 0) return 0; +#else + if (size == 0) + size++; +#endif return malloc_from_heap (size, &__malloc_heap); } |