On Mon, Feb 12, 2024 at 4:29 PM Kees Cook <keescook@xxxxxxxxxxxx> wrote: > > On Mon, Feb 12, 2024 at 01:38:46PM -0800, Suren Baghdasaryan wrote: > > Low overhead [1] per-callsite memory allocation profiling. Not just for debug > > kernels, overhead low enough to be deployed in production. > > What's the plan for things like devm_kmalloc() and similar relatively > simple wrappers? I was thinking it would be possible to reimplement at > least devm_kmalloc() with size and flags changing helper a while back: > > https://lore.kernel.org/all/202309111428.6F36672F57@keescook/ > > I suspect it could be possible to adapt the alloc_hooks wrapper in this > series similarly: > > #define alloc_hooks_prep(_do_alloc, _do_prepare, _do_finish, \ > ctx, size, flags) \ > ({ \ > typeof(_do_alloc) _res; \ > DEFINE_ALLOC_TAG(_alloc_tag, _old); \ > ssize_t _size = (size); \ > size_t _usable = _size; \ > gfp_t _flags = (flags); \ > \ > _res = _do_prepare(ctx, &_size, &_flags); \ > if (!IS_ERR_OR_NULL(_res) \ > _res = _do_alloc(_size, _flags); \ > if (!IS_ERR_OR_NULL(_res) \ > _res = _do_finish(ctx, _usable, _size, _flags, _res); \ > _res; \ > }) > > #define devm_kmalloc(dev, size, flags) \ > alloc_hooks_prep(kmalloc, devm_alloc_prep, devm_alloc_finish, \ > dev, size, flags) > > And devm_alloc_prep() and devm_alloc_finish() adapted from the URL > above. > > And _do_finish instances could be marked with __realloc_size(2) devm_kmalloc() is definitely a great candidate to account separately. Looks like it's currently using alloc_dr()->kmalloc_node_track_caller(), so this series will account the internal kmalloc_node_track_caller() allocation. We can easily apply alloc_hook to devm_kmalloc() and friends and replace the kmalloc_node_track_caller() call inside alloc_dr() with kmalloc_node_track_caller_noprof(). That will move accounting directly to devm_kmalloc(). > > -Kees > > -- > Kees Cook
