diff options
| author | Thomas Vanbesien <tvanbesi@proton.me> | 2026-02-27 11:45:06 +0100 |
|---|---|---|
| committer | Thomas Vanbesien <tvanbesi@proton.me> | 2026-02-27 11:45:06 +0100 |
| commit | 5ba7a73f97fe6880dc5328807a1cb9353e77b863 (patch) | |
| tree | eecedfad2887dc717d1771ed3e7a9bc8b7ba1ff7 /README.md | |
| parent | fb19b1c35f6ec52c075b214d2f0416900a7c1bbe (diff) | |
| download | malloc-5ba7a73f97fe6880dc5328807a1cb9353e77b863.tar.gz malloc-5ba7a73f97fe6880dc5328807a1cb9353e77b863.zip | |
Implement free and add testing notes to README
free now locates the chunk matching the pointer, marks it as
free for TINY/SMALL zones, and munmaps LARGE allocations.
Document why ASan is incompatible and list alternatives.
Diffstat (limited to 'README.md')
| -rw-r--r-- | README.md | 16 |
1 files changed, 16 insertions, 0 deletions
@@ -53,3 +53,19 @@ are allocated on demand when the current one is full. LARGE allocations each get their own `mmap` region and are released individually via `munmap`. All returned pointers are 16-byte aligned. + +## Testing + +AddressSanitizer (ASan) cannot be used to test this allocator. ASan intercepts +`malloc`/`free` itself and expects specific allocator metadata (redzones, +quarantine zones) that a custom allocator does not provide. The two +implementations would conflict. Since allocations go through `mmap`, they also +bypass ASan's shadow memory tracking entirely. + +Alternatives for catching bugs: +- **Valgrind** — operates at the binary level without replacing `malloc`, so it + can detect issues in the allocator's own internal logic. +- **Custom tests** — targeted checks for write-after-free, double free, boundary + writes, and stress scenarios. +- **`show_alloc_mem()`** — inspect zone and chunk state visually after + operations. |