diff options
| -rw-r--r-- | src/include/stdlib.h | 3 | ||||
| -rw-r--r-- | src/lib/malloc.c | 29 |
2 files changed, 30 insertions, 2 deletions
diff --git a/src/include/stdlib.h b/src/include/stdlib.h index a8297f82a5..f6369bf0f4 100644 --- a/src/include/stdlib.h +++ b/src/include/stdlib.h @@ -5,7 +5,6 @@ void *memalign(size_t boundary, size_t size); void *malloc(size_t size); -/* We never free memory */ -static inline void free(void *ptr) {} +void free(void *ptr); #endif /* STDLIB_H */ diff --git a/src/lib/malloc.c b/src/lib/malloc.c index aa266b44dc..ddc7ea5739 100644 --- a/src/lib/malloc.c +++ b/src/lib/malloc.c @@ -11,6 +11,8 @@ extern unsigned char _heap, _eheap; static void *free_mem_ptr = &_heap; /* Start of heap */ static void *free_mem_end_ptr = &_eheap; /* End of heap */ +static void *free_last_alloc_ptr = &_heap; /* End of heap before + last allocation */ /* We don't restrict the boundary. This is firmware, * you are supposed to know what you are doing. @@ -26,6 +28,12 @@ void *memalign(size_t boundary, size_t size) p = free_mem_ptr; free_mem_ptr += size; + /* + * Store last allocation pointer after ALIGN, as malloc() will + * return it. This may cause n bytes of gap between allocations + * where n < boundary. + */ + free_last_alloc_ptr = p; if (free_mem_ptr >= free_mem_end_ptr) { printk(BIOS_ERR, "memalign(boundary=%zu, size=%zu): failed: ", @@ -46,3 +54,24 @@ void *malloc(size_t size) { return memalign(sizeof(u64), size); } + +void free(void *ptr) +{ + if (ptr == NULL) + return; + + if (ptr < (void *)&_heap || ptr >= free_mem_end_ptr) { + printk(BIOS_WARNING, "Warning - Pointer passed to %s is not " + "pointing to the heap\n", __func__); + return; + } + + /* + * Rewind the heap pointer to the end of heap + * before the last successful malloc(). + */ + if (ptr == free_last_alloc_ptr) { + free_mem_ptr = free_last_alloc_ptr; + free_last_alloc_ptr = NULL; + } +} |