diff options
Diffstat (limited to 'libc/stdlib/malloc-simple/alloc.c')
| -rw-r--r-- | libc/stdlib/malloc-simple/alloc.c | 40 |
1 files changed, 31 insertions, 9 deletions
diff --git a/libc/stdlib/malloc-simple/alloc.c b/libc/stdlib/malloc-simple/alloc.c index 79ea17794..b6a3cfcb6 100644 --- a/libc/stdlib/malloc-simple/alloc.c +++ b/libc/stdlib/malloc-simple/alloc.c @@ -1,3 +1,9 @@ + +/* + * For MMU hosts we need to track the size of the allocations otherwise + * munmap will fail to free the memory (EINVAL). + */ + #include <features.h> #include <unistd.h> #include <stdio.h> @@ -68,23 +74,28 @@ void *calloc(size_t num, size_t size) void *malloc(size_t size) { void *result; -#if 1 + /* Some programs will call malloc (0). Lets be strict and return NULL */ if (size == 0) - return NULL; -#endif - result = mmap((void *) 0, size, PROT_READ | PROT_WRITE, + return NULL; + #ifdef __UCLIBC_HAS_MMU__ - MAP_PRIVATE | MAP_ANONYMOUS, 0, 0 + result = mmap((void *) 0, size + sizeof(size_t), PROT_READ | PROT_WRITE, + MAP_PRIVATE | MAP_ANONYMOUS, 0, 0); #else - MAP_SHARED | MAP_ANONYMOUS, 0, 0 + result = mmap((void *) 0, size, PROT_READ | PROT_WRITE, + MAP_SHARED | MAP_ANONYMOUS, 0, 0); #endif - ); if (result == MAP_FAILED) return 0; - - return result; + +#ifdef __UCLIBC_HAS_MMU__ + * (size_t *) result = size; + return(result + sizeof(size_t)); +#else + return(result); +#endif } #endif @@ -93,7 +104,14 @@ void *malloc(size_t size) void free(void *ptr) { +#ifdef __UCLIBC_HAS_MMU__ + if (ptr) { + ptr -= sizeof(size_t); + munmap(ptr, * (size_t *) ptr); + } +#else munmap(ptr, 0); +#endif } #endif @@ -107,7 +125,11 @@ void *realloc(void *ptr, size_t size) if (size > 0) { newptr = malloc(size); if (newptr && ptr) { +#ifdef __UCLIBC_HAS_MMU__ + memcpy(newptr, ptr, * ((size_t *) (ptr - sizeof(size_t)))); +#else memcpy(newptr, ptr, size); +#endif free(ptr); } } |