summaryrefslogtreecommitdiffstats
path: root/mm/slab_common.c (follow)
Commit message (Collapse)AuthorAgeFilesLines
* Merge tag 'hardening-v6.2-rc1' of ↵Linus Torvalds2022-12-141-16/+10
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux Pull kernel hardening updates from Kees Cook: - Convert flexible array members, fix -Wstringop-overflow warnings, and fix KCFI function type mismatches that went ignored by maintainers (Gustavo A. R. Silva, Nathan Chancellor, Kees Cook) - Remove the remaining side-effect users of ksize() by converting dma-buf, btrfs, and coredump to using kmalloc_size_roundup(), add more __alloc_size attributes, and introduce full testing of all allocator functions. Finally remove the ksize() side-effect so that each allocation-aware checker can finally behave without exceptions - Introduce oops_limit (default 10,000) and warn_limit (default off) to provide greater granularity of control for panic_on_oops and panic_on_warn (Jann Horn, Kees Cook) - Introduce overflows_type() and castable_to_type() helpers for cleaner overflow checking - Improve code generation for strscpy() and update str*() kern-doc - Convert strscpy and sigphash tests to KUnit, and expand memcpy tests - Always use a non-NULL argument for prepare_kernel_cred() - Disable structleak plugin in FORTIFY KUnit test (Anders Roxell) - Adjust orphan linker section checking to respect CONFIG_WERROR (Xin Li) - Make sure siginfo is cleared for forced SIGKILL (haifeng.xu) - Fix um vs FORTIFY warnings for always-NULL arguments * tag 'hardening-v6.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: (31 commits) ksmbd: replace one-element arrays with flexible-array members hpet: Replace one-element array with flexible-array member um: virt-pci: Avoid GCC non-NULL warning signal: Initialize the info in ksignal lib: fortify_kunit: build without structleak plugin panic: Expose "warn_count" to sysfs panic: Introduce warn_limit panic: Consolidate open-coded panic_on_warn checks exit: Allow oops_limit to be disabled exit: Expose "oops_count" to sysfs exit: Put an upper limit on how often we can oops panic: Separate sysctl logic from CONFIG_SMP mm/pgtable: Fix multiple -Wstringop-overflow warnings mm: Make ksize() a reporting-only function kunit/fortify: Validate __alloc_size attribute results drm/sti: Fix return type of sti_{dvo,hda,hdmi}_connector_mode_valid() drm/fsl-dcu: Fix return type of fsl_dcu_drm_connector_mode_valid() driver core: Add __alloc_size hint to devm allocators overflow: Introduce overflows_type() and castable_to_type() coredump: Proactively round up to kmalloc bucket size ...
| * mm: Make ksize() a reporting-only functionKees Cook2022-12-011-16/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With all "silently resizing" callers of ksize() refactored, remove the logic in ksize() that would allow it to be used to effectively change the size of an allocation (bypassing __alloc_size hints, etc). Users wanting this feature need to either use kmalloc_size_roundup() before an allocation, or use krealloc() directly. For kfree_sensitive(), move the unpoisoning logic inline. Replace the some of the partially open-coded ksize() in __do_krealloc with ksize() now that it doesn't perform unpoisoning. Adjust the KUnit tests to match the new ksize() behavior. Execution tested with: $ ./tools/testing/kunit/kunit.py run \ --kconfig_add CONFIG_KASAN=y \ --kconfig_add CONFIG_KASAN_GENERIC=y \ --arch x86_64 kasan Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Alexander Potapenko <glider@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> Cc: linux-mm@kvack.org Cc: kasan-dev@googlegroups.com Acked-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: David Rientjes <rientjes@google.com> Enhanced-by: Andrey Konovalov <andreyknvl@gmail.com> Signed-off-by: Kees Cook <keescook@chromium.org>
* | Merge branch 'slub-tiny-v1r6' into slab/for-nextVlastimil Babka2022-12-011-5/+18
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Merge my series [1] to deprecate the SLOB allocator. - Renames CONFIG_SLOB to CONFIG_SLOB_DEPRECATED with deprecation notice. - The recommended replacement is CONFIG_SLUB, optionally with the new CONFIG_SLUB_TINY tweaks for systems with 16MB or less RAM. - Use cases that stopped working with CONFIG_SLUB_TINY instead of SLOB should be reported to linux-mm@kvack.org and slab maintainers, otherwise SLOB will be removed in few cycles. [1] https://lore.kernel.org/all/20221121171202.22080-1-vbabka@suse.cz/
| * | mm, slub: don't create kmalloc-rcl caches with CONFIG_SLUB_TINYVlastimil Babka2022-11-271-2/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Distinguishing kmalloc(__GFP_RECLAIMABLE) can help against fragmentation by grouping pages by mobility, but on tiny systems the extra memory overhead of separate set of kmalloc-rcl caches will probably be worse, and mobility grouping likely disabled anyway. Thus with CONFIG_SLUB_TINY, don't create kmalloc-rcl caches and use the regular ones. Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Mike Rapoport <rppt@linux.ibm.com> Reviewed-by: Christoph Lameter <cl@linux.com>
| * | mm, slab: ignore hardened usercopy parameters when disabledVlastimil Babka2022-11-271-3/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With CONFIG_HARDENED_USERCOPY not enabled, there are no __check_heap_object() checks happening that would use the struct kmem_cache useroffset and usersize fields. Yet the fields are still initialized, preventing merging of otherwise compatible caches. Also the fields contribute to struct kmem_cache size unnecessarily when unused. Thus #ifdef them out completely when CONFIG_HARDENED_USERCOPY is disabled. In kmem_dump_obj() print object_size instead of usersize, as that's actually the intention. In a quick virtme boot test, this has reduced the number of caches in /proc/slabinfo from 131 to 111. Cc: Kees Cook <keescook@chromium.org> Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Roman Gushchin <roman.gushchin@linux.dev> Acked-by: Mike Rapoport <rppt@linux.ibm.com> Reviewed-by: Christoph Lameter <cl@linux.com>
* | | mm/slub: extend redzone check to extra allocated kmalloc space than requestedFeng Tang2022-11-111-0/+4
|/ / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | kmalloc will round up the request size to a fixed size (mostly power of 2), so there could be a extra space than what is requested, whose size is the actual buffer size minus original request size. To better detect out of bound access or abuse of this space, add redzone sanity check for it. In current kernel, some kmalloc user already knows the existence of the space and utilizes it after calling 'ksize()' to know the real size of the allocated buffer. So we skip the sanity check for objects which have been called with ksize(), as treating them as legitimate users. Kees Cook is working on sanitizing all these user cases, by using kmalloc_size_roundup() to avoid ambiguous usages. And after this is done, this special handling for ksize() can be removed. In some cases, the free pointer could be saved inside the latter part of object data area, which may overlap the redzone part(for small sizes of kmalloc objects). As suggested by Hyeonggon Yoo, force the free pointer to be in meta data area when kmalloc redzone debug is enabled, to make all kmalloc objects covered by redzone check. Suggested-by: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Feng Tang <feng.tang@intel.com> Acked-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
* | mm, slab: remove duplicate kernel-doc comment for ksize()Vlastimil Babka2022-11-071-14/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Akira reports: > "make htmldocs" reports duplicate C declaration of ksize() as follows: > /linux/Documentation/core-api/mm-api:43: ./mm/slab_common.c:1428: WARNING: Duplicate C declaration, also defined at core-api/mm-api:212. > Declaration is '.. c:function:: size_t ksize (const void *objp)'. > This is due to the kernel-doc comment for ksize() declaration added in > include/linux/slab.h by commit 05a940656e1e ("slab: Introduce > kmalloc_size_roundup()"). There is an older kernel-doc comment for ksize() definition in mm/slab_common.c, which is not only duplicated, but also contradicts the new one - the additional storage discovered by ksize() should not be used by callers anymore. Delete the old kernel-doc. Reported-by: Akira Yokosawa <akiyks@gmail.com> Link: https://lore.kernel.org/all/d33440f6-40cf-9747-3340-e54ffaf7afb8@gmail.com/ Fixes: 05a940656e1e ("slab: Introduce kmalloc_size_roundup()") Cc: Kees Cook <keescook@chromium.org> Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
* | mm/slab_common: Restore passing "caller" for tracingKees Cook2022-11-061-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The "caller" argument was accidentally being ignored in a few places that were recently refactored. Restore these "caller" arguments, instead of _RET_IP_. Fixes: 11e9734bcb6a ("mm/slab_common: unify NUMA and UMA version of tracepoints") Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: linux-mm@kvack.org Signed-off-by: Kees Cook <keescook@chromium.org> Acked-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
* | mm/slab: remove !CONFIG_TRACING variants of kmalloc_[node_]trace()Vlastimil Babka2022-11-041-2/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | For !CONFIG_TRACING kernels, the kmalloc() implementation tries (in cases where the allocation size is build-time constant) to save a function call, by inlining kmalloc_trace() to a kmem_cache_alloc() call. However since commit 6edf2576a6cc ("mm/slub: enable debugging memory wasting of kmalloc") this path now fails to pass the original request size to be eventually recorded (for kmalloc caches with debugging enabled). We could adjust the code to call __kmem_cache_alloc_node() as the CONFIG_TRACING variant, but that would as a result inline a call with 5 parameters, bloating the kmalloc() call sites. The cost of extra function call (to kmalloc_trace()) seems like a lesser evil. It also appears that the !CONFIG_TRACING variant is incompatible with upcoming hardening efforts [1] so it's easier if we just remove it now. Kernels with no tracing are rare these days and the benefit is dubious anyway. [1] https://lore.kernel.org/linux-mm/20221101222520.never.109-kees@kernel.org/T/#m20ecf14390e406247bde0ea9cce368f469c539ed Link: https://lore.kernel.org/all/097d8fba-bd10-a312-24a3-a4068c4f424c@suse.cz/ Suggested-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
* | mm/slab_common: repair kernel-doc for __ksize()Lukas Bulwahn2022-11-031-2/+2
|/ | | | | | | | | | | | | | | | Commit 445d41d7a7c1 ("Merge branch 'slab/for-6.1/kmalloc_size_roundup' into slab/for-next") resolved a conflict of two concurrent changes to __ksize(). However, it did not adjust the kernel-doc comment of __ksize(), while the name of the argument to __ksize() was renamed. Hence, ./scripts/ kernel-doc -none mm/slab_common.c warns about it. Adjust the kernel-doc comment for __ksize() for make W=1 happiness. Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com> Acked-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
* Merge tag 'mm-stable-2022-10-08' of ↵Linus Torvalds2022-10-111-0/+2
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM updates from Andrew Morton: - Yu Zhao's Multi-Gen LRU patches are here. They've been under test in linux-next for a couple of months without, to my knowledge, any negative reports (or any positive ones, come to that). - Also the Maple Tree from Liam Howlett. An overlapping range-based tree for vmas. It it apparently slightly more efficient in its own right, but is mainly targeted at enabling work to reduce mmap_lock contention. Liam has identified a number of other tree users in the kernel which could be beneficially onverted to mapletrees. Yu Zhao has identified a hard-to-hit but "easy to fix" lockdep splat at [1]. This has yet to be addressed due to Liam's unfortunately timed vacation. He is now back and we'll get this fixed up. - Dmitry Vyukov introduces KMSAN: the Kernel Memory Sanitizer. It uses clang-generated instrumentation to detect used-unintialized bugs down to the single bit level. KMSAN keeps finding bugs. New ones, as well as the legacy ones. - Yang Shi adds a userspace mechanism (madvise) to induce a collapse of memory into THPs. - Zach O'Keefe has expanded Yang Shi's madvise(MADV_COLLAPSE) to support file/shmem-backed pages. - userfaultfd updates from Axel Rasmussen - zsmalloc cleanups from Alexey Romanov - cleanups from Miaohe Lin: vmscan, hugetlb_cgroup, hugetlb and memory-failure - Huang Ying adds enhancements to NUMA balancing memory tiering mode's page promotion, with a new way of detecting hot pages. - memcg updates from Shakeel Butt: charging optimizations and reduced memory consumption. - memcg cleanups from Kairui Song. - memcg fixes and cleanups from Johannes Weiner. - Vishal Moola provides more folio conversions - Zhang Yi removed ll_rw_block() :( - migration enhancements from Peter Xu - migration error-path bugfixes from Huang Ying - Aneesh Kumar added ability for a device driver to alter the memory tiering promotion paths. For optimizations by PMEM drivers, DRM drivers, etc. - vma merging improvements from Jakub Matěn. - NUMA hinting cleanups from David Hildenbrand. - xu xin added aditional userspace visibility into KSM merging activity. - THP & KSM code consolidation from Qi Zheng. - more folio work from Matthew Wilcox. - KASAN updates from Andrey Konovalov. - DAMON cleanups from Kaixu Xia. - DAMON work from SeongJae Park: fixes, cleanups. - hugetlb sysfs cleanups from Muchun Song. - Mike Kravetz fixes locking issues in hugetlbfs and in hugetlb core. Link: https://lkml.kernel.org/r/CAOUHufZabH85CeUN-MEMgL8gJGzJEWUrkiM58JkTbBhh-jew0Q@mail.gmail.com [1] * tag 'mm-stable-2022-10-08' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (555 commits) hugetlb: allocate vma lock for all sharable vmas hugetlb: take hugetlb vma_lock when clearing vma_lock->vma pointer hugetlb: fix vma lock handling during split vma and range unmapping mglru: mm/vmscan.c: fix imprecise comments mm/mglru: don't sync disk for each aging cycle mm: memcontrol: drop dead CONFIG_MEMCG_SWAP config symbol mm: memcontrol: use do_memsw_account() in a few more places mm: memcontrol: deprecate swapaccounting=0 mode mm: memcontrol: don't allocate cgroup swap arrays when memcg is disabled mm/secretmem: remove reduntant return value mm/hugetlb: add available_huge_pages() func mm: remove unused inline functions from include/linux/mm_inline.h selftests/vm: add selftest for MADV_COLLAPSE of uffd-minor memory selftests/vm: add file/shmem MADV_COLLAPSE selftest for cleared pmd selftests/vm: add thp collapse shmem testing selftests/vm: add thp collapse file and tmpfs testing selftests/vm: modularize thp collapse memory operations selftests/vm: dedup THP helpers mm/khugepaged: add tracepoint to hpage_collapse_scan_file() mm/madvise: add file and shmem support to MADV_COLLAPSE ...
* \ Merge branch 'slab/for-6.1/kmalloc_size_roundup' into slab/for-nextVlastimil Babka2022-09-291-3/+34
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The first two patches from a series by Kees Cook [1] that introduce kmalloc_size_roundup(). This will allow merging of per-subsystem patches using the new function and ultimately stop (ab)using ksize() in a way that causes ongoing trouble for debugging functionality and static checkers. [1] https://lore.kernel.org/all/20220923202822.2667581-1-keescook@chromium.org/ -- Resolved a conflict of modifying mm/slab.c __ksize() comment with a commit that unifies __ksize() implementation into mm/slab_common.c
| * | slab: Introduce kmalloc_size_roundup()Kees Cook2022-09-291-0/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In the effort to help the compiler reason about buffer sizes, the __alloc_size attribute was added to allocators. This improves the scope of the compiler's ability to apply CONFIG_UBSAN_BOUNDS and (in the near future) CONFIG_FORTIFY_SOURCE. For most allocations, this works well, as the vast majority of callers are not expecting to use more memory than what they asked for. There is, however, one common exception to this: anticipatory resizing of kmalloc allocations. These cases all use ksize() to determine the actual bucket size of a given allocation (e.g. 128 when 126 was asked for). This comes in two styles in the kernel: 1) An allocation has been determined to be too small, and needs to be resized. Instead of the caller choosing its own next best size, it wants to minimize the number of calls to krealloc(), so it just uses ksize() plus some additional bytes, forcing the realloc into the next bucket size, from which it can learn how large it is now. For example: data = krealloc(data, ksize(data) + 1, gfp); data_len = ksize(data); 2) The minimum size of an allocation is calculated, but since it may grow in the future, just use all the space available in the chosen bucket immediately, to avoid needing to reallocate later. A good example of this is skbuff's allocators: data = kmalloc_reserve(size, gfp_mask, node, &pfmemalloc); ... /* kmalloc(size) might give us more room than requested. * Put skb_shared_info exactly at the end of allocated zone, * to allow max possible filling before reallocation. */ osize = ksize(data); size = SKB_WITH_OVERHEAD(osize); In both cases, the "how much was actually allocated?" question is answered _after_ the allocation, where the compiler hinting is not in an easy place to make the association any more. This mismatch between the compiler's view of the buffer length and the code's intention about how much it is going to actually use has already caused problems[1]. It is possible to fix this by reordering the use of the "actual size" information. We can serve the needs of users of ksize() and still have accurate buffer length hinting for the compiler by doing the bucket size calculation _before_ the allocation. Code can instead ask "how large an allocation would I get for a given size?". Introduce kmalloc_size_roundup(), to serve this function so we can start replacing the "anticipatory resizing" uses of ksize(). [1] https://github.com/ClangBuiltLinux/linux/issues/1599 https://github.com/KSPP/linux/issues/183 [ vbabka@suse.cz: add SLOB version ] Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: linux-mm@kvack.org Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
| * | slab: Remove __malloc attribute from realloc functionsKees Cook2022-09-291-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The __malloc attribute should not be applied to "realloc" functions, as the returned pointer may alias the storage of the prior pointer. Instead of splitting __malloc from __alloc_size, which would be a huge amount of churn, just create __realloc_size for the few cases where it is needed. Thanks to Geert Uytterhoeven <geert@linux-m68k.org> for reporting build failures with gcc-8 in earlier version which tried to remove the #ifdef. While the "alloc_size" attribute is available on all GCC versions, I forgot that it gets disabled explicitly by the kernel in GCC < 9.1 due to misbehaviors. Add a note to the compiler_attributes.h entry for it. Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com> Cc: Marco Elver <elver@google.com> Cc: linux-mm@kvack.org Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
* | | Merge branch 'slab/for-6.1/slub_debug_waste' into slab/for-nextVlastimil Babka2022-09-291-1/+2
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | A patch from Feng Tang that enhances the existing debugfs alloc_traces file for kmalloc caches with information about how much space is wasted by allocations that needs less space than the particular kmalloc cache provides.
| * | | mm/slub: enable debugging memory wasting of kmallocFeng Tang2022-09-231-1/+2
| | |/ | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | kmalloc's API family is critical for mm, with one nature that it will round up the request size to a fixed one (mostly power of 2). Say when user requests memory for '2^n + 1' bytes, actually 2^(n+1) bytes could be allocated, so in worst case, there is around 50% memory space waste. The wastage is not a big issue for requests that get allocated/freed quickly, but may cause problems with objects that have longer life time. We've met a kernel boot OOM panic (v5.10), and from the dumped slab info: [ 26.062145] kmalloc-2k 814056KB 814056KB From debug we found there are huge number of 'struct iova_magazine', whose size is 1032 bytes (1024 + 8), so each allocation will waste 1016 bytes. Though the issue was solved by giving the right (bigger) size of RAM, it is still nice to optimize the size (either use a kmalloc friendly size or create a dedicated slab for it). And from lkml archive, there was another crash kernel OOM case [1] back in 2019, which seems to be related with the similar slab waste situation, as the log is similar: [ 4.332648] iommu: Adding device 0000:20:02.0 to group 16 [ 4.338946] swapper/0 invoked oom-killer: gfp_mask=0x6040c0(GFP_KERNEL|__GFP_COMP), nodemask=(null), order=0, oom_score_adj=0 ... [ 4.857565] kmalloc-2048 59164KB 59164KB The crash kernel only has 256M memory, and 59M is pretty big here. (Note: the related code has been changed and optimised in recent kernel [2], these logs are just picked to demo the problem, also a patch changing its size to 1024 bytes has been merged) So add an way to track each kmalloc's memory waste info, and leverage the existing SLUB debug framework (specifically SLUB_STORE_USER) to show its call stack of original allocation, so that user can evaluate the waste situation, identify some hot spots and optimize accordingly, for a better utilization of memory. The waste info is integrated into existing interface: '/sys/kernel/debug/slab/kmalloc-xx/alloc_traces', one example of 'kmalloc-4k' after boot is: 126 ixgbe_alloc_q_vector+0xbe/0x830 [ixgbe] waste=233856/1856 age=280763/281414/282065 pid=1330 cpus=32 nodes=1 __kmem_cache_alloc_node+0x11f/0x4e0 __kmalloc_node+0x4e/0x140 ixgbe_alloc_q_vector+0xbe/0x830 [ixgbe] ixgbe_init_interrupt_scheme+0x2ae/0xc90 [ixgbe] ixgbe_probe+0x165f/0x1d20 [ixgbe] local_pci_probe+0x78/0xc0 work_for_cpu_fn+0x26/0x40 ... which means in 'kmalloc-4k' slab, there are 126 requests of 2240 bytes which got a 4KB space (wasting 1856 bytes each and 233856 bytes in total), from ixgbe_alloc_q_vector(). And when system starts some real workload like multiple docker instances, there could are more severe waste. [1]. https://lkml.org/lkml/2019/8/12/266 [2]. https://lore.kernel.org/lkml/2920df89-9975-5785-f79b-257d3052dfaf@huawei.com/ [Thanks Hyeonggon for pointing out several bugs about sorting/format] [Thanks Vlastimil for suggesting way to reduce memory usage of orig_size and keep it only for kmalloc objects] Signed-off-by: Feng Tang <feng.tang@intel.com> Reviewed-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Cc: Robin Murphy <robin.murphy@arm.com> Cc: John Garry <john.garry@huawei.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
* | | Merge branch 'slab/for-6.1/common_kmalloc' into slab/for-nextVlastimil Babka2022-09-231-24/+169
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The "common kmalloc v4" series [1] by Hyeonggon Yoo. - Improves the mm/slab_common.c wrappers to allow deleting duplicated code between SLAB and SLUB. - Large kmalloc() allocations in SLAB are passed to page allocator like in SLUB, reducing number of kmalloc caches. - Removes the {kmem_cache_alloc,kmalloc}_node variants of tracepoints, node id parameter added to non-_node variants. - 8 files changed, 341 insertions(+), 651 deletions(-) [1] https://lore.kernel.org/all/20220817101826.236819-1-42.hyeyoo@gmail.com/ -- Merge resolves trivial conflict in mm/slub.c with commit 5373b8a09d6e ("kasan: call kasan_malloc() from __kmalloc_*track_caller()")
| * | | mm/sl[au]b: check if large object is valid in __ksize()Hyeonggon Yoo2022-09-011-1/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If address of large object is not beginning of folio or size of the folio is too small, it must be invalid. WARN() and return 0 in such cases. Cc: Marco Elver <elver@google.com> Suggested-by: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
| * | | mm/slab_common: move declaration of __ksize() to mm/slab.hHyeonggon Yoo2022-09-011-10/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | __ksize() is only called by KASAN. Remove export symbol and move declaration to mm/slab.h as we don't want to grow its callers. Signed-off-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
| * | | mm/slab_common: drop kmem_alloc & avoid dereferencing fields when not usingHyeonggon Yoo2022-09-011-8/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Drop kmem_alloc event class, and define kmalloc and kmem_cache_alloc using TRACE_EVENT() macro. And then this patch does: - Do not pass pointer to struct kmem_cache to trace_kmalloc. gfp flag is enough to know if it's accounted or not. - Avoid dereferencing s->object_size and s->size when not using kmem_cache_alloc event. - Avoid dereferencing s->name in when not using kmem_cache_free event. - Adjust s->size to SLOB_UNITS(s->size) * SLOB_UNIT in SLOB Cc: Vasily Averin <vasily.averin@linux.dev> Suggested-by: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
| * | | mm/slab_common: unify NUMA and UMA version of tracepointsHyeonggon Yoo2022-09-011-13/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Drop kmem_alloc event class, rename kmem_alloc_node to kmem_alloc, and remove _node postfix for NUMA version of tracepoints. This will break some tools that depend on {kmem_cache_alloc,kmalloc}_node, but at this point maintaining both kmem_alloc and kmem_alloc_node event classes does not makes sense at all. Signed-off-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
| * | | mm/sl[au]b: cleanup kmem_cache_alloc[_node]_trace()Hyeonggon Yoo2022-09-011-0/+27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Despite its name, kmem_cache_alloc[_node]_trace() is hook for inlined kmalloc. So rename it to kmalloc[_node]_trace(). Move its implementation to slab_common.c by using __kmem_cache_alloc_node(), but keep CONFIG_TRACING=n varients to save a function call when CONFIG_TRACING=n. Use __assume_kmalloc_alignment for kmalloc[_node]_trace instead of __assume_slab_alignement. Generally kmalloc has larger alignment requirements. Suggested-by: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
| * | | mm/sl[au]b: generalize kmalloc subsystemHyeonggon Yoo2022-09-011-3/+106
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now everything in kmalloc subsystem can be generalized. Let's do it! Generalize __do_kmalloc_node(), __kmalloc_node_track_caller(), kfree(), __ksize(), __kmalloc(), __kmalloc_node() and move them to slab_common.c. In the meantime, rename kmalloc_large_node_notrace() to __kmalloc_large_node() and make it static as it's now only called in slab_common.c. [ feng.tang@intel.com: adjust kfence skip list to include __kmem_cache_free so that kfence kunit tests do not fail ] Signed-off-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
| * | | mm/slab: kmalloc: pass requests larger than order-1 page to page allocatorHyeonggon Yoo2022-08-241-7/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There is not much benefit for serving large objects in kmalloc(). Let's pass large requests to page allocator like SLUB for better maintenance of common code. Signed-off-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
| * | | mm/slab_common: cleanup kmalloc_large()Hyeonggon Yoo2022-08-241-22/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now that kmalloc_large() and kmalloc_large_node() do mostly same job, make kmalloc_large() wrapper of kmalloc_large_node_notrace(). In the meantime, add missing flag fix code in kmalloc_large_node_notrace(). Signed-off-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
| * | | mm/slab_common: kmalloc_node: pass large requests to page allocatorHyeonggon Yoo2022-08-241-1/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now that kmalloc_large_node() is in common code, pass large requests to page allocator in kmalloc_node() using kmalloc_large_node(). One problem is that currently there is no tracepoint in kmalloc_large_node(). Instead of simply putting tracepoint in it, use kmalloc_large_node{,_notrace} depending on its caller to show useful address for both inlined kmalloc_node() and __kmalloc_node_track_caller() when large objects are allocated. Signed-off-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
| * | | mm/slub: move kmalloc_large_node() to slab_common.cHyeonggon Yoo2022-08-241-0/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In later patch SLAB will also pass requests larger than order-1 page to page allocator. Move kmalloc_large_node() to slab_common.c. Fold kmalloc_large_node_hook() into kmalloc_large_node() as there is no other caller. Signed-off-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
| * | | mm/slab_common: fold kmalloc_order_trace() into kmalloc_large()Hyeonggon Yoo2022-08-241-13/+4
| |/ / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There is no caller of kmalloc_order_trace() except kmalloc_large(). Fold it into kmalloc_large() and remove kmalloc_order{,_trace}(). Also add tracepoint in kmalloc_large() that was previously in kmalloc_order_trace(). Signed-off-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
* | | Merge branch 'slab/for-6.1/trivial' into slab/for-nextVlastimil Babka2022-09-231-5/+1
|\ \ \ | |_|/ |/| | | | | | | | Trivial fixes and cleanups: - unneeded variable removals, by ye xingchen
| * | mm/slab_common: Remove the unneeded result variableye xingchen2022-08-231-5/+1
| |/ | | | | | | | | | | | | | | | | | | Return the value from __kmem_cache_shrink() directly instead of storing it in another redundant variable. Reported-by: Zeal Robot <zealci@zte.com.cn> Signed-off-by: ye xingchen <ye.xingchen@zte.com.cn> Acked-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
* | mm/slab_common: fix possible double free of kmem_cacheFeng Tang2022-09-191-1/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When doing slub_debug test, kfence's 'test_memcache_typesafe_by_rcu' kunit test case cause a use-after-free error: BUG: KASAN: use-after-free in kobject_del+0x14/0x30 Read of size 8 at addr ffff888007679090 by task kunit_try_catch/261 CPU: 1 PID: 261 Comm: kunit_try_catch Tainted: G B N 6.0.0-rc5-next-20220916 #17 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 Call Trace: <TASK> dump_stack_lvl+0x34/0x48 print_address_description.constprop.0+0x87/0x2a5 print_report+0x103/0x1ed kasan_report+0xb7/0x140 kobject_del+0x14/0x30 kmem_cache_destroy+0x130/0x170 test_exit+0x1a/0x30 kunit_try_run_case+0xad/0xc0 kunit_generic_run_threadfn_adapter+0x26/0x50 kthread+0x17b/0x1b0 </TASK> The cause is inside kmem_cache_destroy(): kmem_cache_destroy acquire lock/mutex shutdown_cache schedule_work(kmem_cache_release) (if RCU flag set) release lock/mutex kmem_cache_release (if RCU flag not set) In some certain timing, the scheduled work could be run before the next RCU flag checking, which can then get a wrong value and lead to double kmem_cache_release(). Fix it by caching the RCU flag inside protected area, just like 'refcnt' Fixes: 0495e337b703 ("mm/slab_common: Deleting kobject in kmem_cache_destroy() without holding slab_mutex/cpu_hotplug_lock") Signed-off-by: Feng Tang <feng.tang@intel.com> Reviewed-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Reviewed-by: Waiman Long <longman@redhat.com> Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
* | mm/slab_common: Deleting kobject in kmem_cache_destroy() without holding ↵Waiman Long2022-09-011-16/+29
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | slab_mutex/cpu_hotplug_lock A circular locking problem is reported by lockdep due to the following circular locking dependency. +--> cpu_hotplug_lock --> slab_mutex --> kn->active --+ | | +-----------------------------------------------------+ The forward cpu_hotplug_lock ==> slab_mutex ==> kn->active dependency happens in kmem_cache_destroy(): cpus_read_lock(); mutex_lock(&slab_mutex); ==> sysfs_slab_unlink() ==> kobject_del() ==> kernfs_remove() ==> __kernfs_remove() ==> kernfs_drain(): rwsem_acquire(&kn->dep_map, ...); The backward kn->active ==> cpu_hotplug_lock dependency happens in kernfs_fop_write_iter(): kernfs_get_active(); ==> slab_attr_store() ==> cpu_partial_store() ==> flush_all(): cpus_read_lock() One way to break this circular locking chain is to avoid holding cpu_hotplug_lock and slab_mutex while deleting the kobject in sysfs_slab_unlink() which should be equivalent to doing a write_lock and write_unlock pair of the kn->active virtual lock. Since the kobject structures are not protected by slab_mutex or the cpu_hotplug_lock, we can certainly release those locks before doing the delete operation. Move sysfs_slab_unlink() and sysfs_slab_release() to the newly created kmem_cache_release() and call it outside the slab_mutex & cpu_hotplug_lock critical sections. There will be a slight delay in the deletion of sysfs files if kmem_cache_release() is called indirectly from a work function. Fixes: 5a836bf6b09f ("mm: slub: move flush_cpu_slab() invocations __free_slab() invocations out of IRQ context") Signed-off-by: Waiman Long <longman@redhat.com> Reviewed-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Reviewed-by: Roman Gushchin <roman.gushchin@linux.dev> Acked-by: David Rientjes <rientjes@google.com> Link: https://lore.kernel.org/all/YwOImVd+nRUsSAga@hyeyoo/ Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
* mm/slab_common: move generic bulk alloc/free functions to SLOBHyeonggon Yoo2022-07-201-27/+0
| | | | | | | | Now that only SLOB use __kmem_cache_{alloc,free}_bulk(), move them to SLOB. No functional change intended. Signed-off-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
* mm/tracing: add 'accounted' entry into output of allocation tracepointsVasily Averin2022-07-041-5/+4
| | | | | | | | | | | | | | | | | | | | Slab caches marked with SLAB_ACCOUNT force accounting for every allocation from this cache even if __GFP_ACCOUNT flag is not passed. Unfortunately, at the moment this flag is not visible in ftrace output, and this makes it difficult to analyze the accounted allocations. This patch adds boolean "accounted" entry into trace output, and set it to 'true' for calls used __GFP_ACCOUNT flag and for allocations from caches marked with SLAB_ACCOUNT. Set it to 'false' if accounting is disabled in configs. Signed-off-by: Vasily Averin <vvs@openvz.org> Acked-by: Shakeel Butt <shakeelb@google.com> Acked-by: Roman Gushchin <roman.gushchin@linux.dev> Acked-by: Muchun Song <songmuchun@bytedance.com> Reviewed-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Link: https://lore.kernel.org/r/c418ed25-65fe-f623-fbf8-1676528859ed@openvz.org Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
* Merge tag 'mm-stable-2022-05-25' of ↵Linus Torvalds2022-05-261-2/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM updates from Andrew Morton: "Almost all of MM here. A few things are still getting finished off, reviewed, etc. - Yang Shi has improved the behaviour of khugepaged collapsing of readonly file-backed transparent hugepages. - Johannes Weiner has arranged for zswap memory use to be tracked and managed on a per-cgroup basis. - Munchun Song adds a /proc knob ("hugetlb_optimize_vmemmap") for runtime enablement of the recent huge page vmemmap optimization feature. - Baolin Wang contributes a series to fix some issues around hugetlb pagetable invalidation. - Zhenwei Pi has fixed some interactions between hwpoisoned pages and virtualization. - Tong Tiangen has enabled the use of the presently x86-only page_table_check debugging feature on arm64 and riscv. - David Vernet has done some fixup work on the memcg selftests. - Peter Xu has taught userfaultfd to handle write protection faults against shmem- and hugetlbfs-backed files. - More DAMON development from SeongJae Park - adding online tuning of the feature and support for monitoring of fixed virtual address ranges. Also easier discovery of which monitoring operations are available. - Nadav Amit has done some optimization of TLB flushing during mprotect(). - Neil Brown continues to labor away at improving our swap-over-NFS support. - David Hildenbrand has some fixes to anon page COWing versus get_user_pages(). - Peng Liu fixed some errors in the core hugetlb code. - Joao Martins has reduced the amount of memory consumed by device-dax's compound devmaps. - Some cleanups of the arch-specific pagemap code from Anshuman Khandual. - Muchun Song has found and fixed some errors in the TLB flushing of transparent hugepages. - Roman Gushchin has done more work on the memcg selftests. ... and, of course, many smaller fixes and cleanups. Notably, the customary million cleanup serieses from Miaohe Lin" * tag 'mm-stable-2022-05-25' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (381 commits) mm: kfence: use PAGE_ALIGNED helper selftests: vm: add the "settings" file with timeout variable selftests: vm: add "test_hmm.sh" to TEST_FILES selftests: vm: check numa_available() before operating "merge_across_nodes" in ksm_tests selftests: vm: add migration to the .gitignore selftests/vm/pkeys: fix typo in comment ksm: fix typo in comment selftests: vm: add process_mrelease tests Revert "mm/vmscan: never demote for memcg reclaim" mm/kfence: print disabling or re-enabling message include/trace/events/percpu.h: cleanup for "percpu: improve percpu_alloc_percpu event trace" include/trace/events/mmflags.h: cleanup for "tracing: incorrect gfp_t conversion" mm: fix a potential infinite loop in start_isolate_page_range() MAINTAINERS: add Muchun as co-maintainer for HugeTLB zram: fix Kconfig dependency warning mm/shmem: fix shmem folio swapoff hang cgroup: fix an error handling path in alloc_pagecache_max_30M() mm: damon: use HPAGE_PMD_SIZE tracing: incorrect isolate_mote_t cast in mm_vmscan_lru_isolate nodemask.h: fix compilation error with GCC12 ...
| * mm: make minimum slab alignment a runtime propertyPeter Collingbourne2022-05-131-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When CONFIG_KASAN_HW_TAGS is enabled we currently increase the minimum slab alignment to 16. This happens even if MTE is not supported in hardware or disabled via kasan=off, which creates an unnecessary memory overhead in those cases. Eliminate this overhead by making the minimum slab alignment a runtime property and only aligning to 16 if KASAN is enabled at runtime. On a DragonBoard 845c (non-MTE hardware) with a kernel built with CONFIG_KASAN_HW_TAGS, waiting for quiescence after a full Android boot I see the following Slab measurements in /proc/meminfo (median of 3 reboots): Before: 169020 kB After: 167304 kB [akpm@linux-foundation.org: make slab alignment type `unsigned int' to avoid casting] Link: https://linux-review.googlesource.com/id/I752e725179b43b144153f4b6f584ceb646473ead Link: https://lkml.kernel.org/r/20220427195820.1716975-2-pcc@google.com Signed-off-by: Peter Collingbourne <pcc@google.com> Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com> Reviewed-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Tested-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Acked-by: David Rientjes <rientjes@google.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Pekka Enberg <penberg@kernel.org> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Alexander Potapenko <glider@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Kees Cook <keescook@chromium.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* | Merge tag 'slab-for-5.19' of ↵Linus Torvalds2022-05-251-15/+8
|\ \ | |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab Pull slab updates from Vlastimil Babka: - Conversion of slub_debug stack traces to stackdepot, allowing more useful debugfs-based inspection for e.g. memory leak debugging. Allocation and free debugfs info now includes full traces and is sorted by the unique trace frequency. The stackdepot conversion was already attempted last year but reverted by ae14c63a9f20. The memory overhead (while not actually enabled on boot) has been meanwhile solved by making the large stackdepot allocation dynamic. The xfstest issues haven't been reproduced on current kernel locally nor in -next, so the slab cache layout changes that originally made that bug manifest were probably not the root cause. - Refactoring of dma-kmalloc caches creation. - Trivial cleanups such as removal of unused parameters, fixes and clarifications of comments. - Hyeonggon Yoo joins as a reviewer. * tag 'slab-for-5.19' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab: MAINTAINERS: add myself as reviewer for slab mm/slub: remove unused kmem_cache_order_objects max mm: slab: fix comment for __assume_kmalloc_alignment mm: slab: fix comment for ARCH_KMALLOC_MINALIGN mm/slub: remove unneeded return value of slab_pad_check mm/slab_common: move dma-kmalloc caches creation into new_kmalloc_cache() mm/slub: remove meaningless node check in ___slab_alloc() mm/slub: remove duplicate flag in allocate_slab() mm/slub: remove unused parameter in setup_object*() mm/slab.c: fix comments slab, documentation: add description of debugfs files for SLUB caches mm/slub: sort debugfs output by frequency of stack traces mm/slub: distinguish and print stack traces in debugfs files mm/slub: use stackdepot to save stack trace in objects mm/slub: move struct track init out of set_track() lib/stackdepot: allow requesting early initialization dynamically mm/slub, kunit: Make slub_kunit unaffected by user specified flags mm/slab: remove some unused functions
| *-. Merge branches 'slab/for-5.19/stackdepot' and 'slab/for-5.19/refactor' into ↵Vlastimil Babka2022-05-231-15/+8
| |\ \ | | | | | | | | | | | | slab/for-linus
| | | * mm/slab_common: move dma-kmalloc caches creation into new_kmalloc_cache()Ohhoon Kwon2022-04-131-15/+3
| | |/ | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There are four types of kmalloc_caches: KMALLOC_NORMAL, KMALLOC_CGROUP, KMALLOC_RECLAIM, and KMALLOC_DMA. While the first three types are created using new_kmalloc_cache(), KMALLOC_DMA caches are created in a separate logic. Let KMALLOC_DMA caches be also created using new_kmalloc_cache(), to enhance readability. Historically, there were only KMALLOC_NORMAL caches and KMALLOC_DMA caches in the first place, and they were initialized in two separate logics. However, when KMALLOC_RECLAIM was introduced in v4.20 via commit 1291523f2c1d ("mm, slab/slub: introduce kmalloc-reclaimable caches") and KMALLOC_CGROUP was introduced in v5.14 via commit 494c1dfe855e ("mm: memcg/slab: create a new set of kmalloc-cg-<n> caches"), their creations were merged with KMALLOC_NORMAL's only. KMALLOC_DMA creation logic should be merged with them, too. By merging KMALLOC_DMA initialization with other types, the following two changes might occur: 1. The order dma-kmalloc-<n> caches added in slab_cache list may be sorted by size. i.e. the order they appear in /proc/slabinfo may change as well. 2. slab_state will be set to UP after KMALLOC_DMA is created. In case of slub, freelist randomization is dependent on slab_state>=UP, and therefore KMALLOC_DMA cache's freelist will not be randomized in creation, but will be deferred to init_freelist_randomization(). Co-developed-by: JaeSang Yoo <jsyoo5b@gmail.com> Signed-off-by: JaeSang Yoo <jsyoo5b@gmail.com> Signed-off-by: Ohhoon Kwon <ohkwon1043@gmail.com> Reviewed-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Acked-by: David Rientjes <rientjes@google.com> Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Link: https://lore.kernel.org/r/20220410162511.656541-1-ohkwon1043@gmail.com
| | * mm/slub: use stackdepot to save stack trace in objectsOliver Glitta2022-04-061-0/+5
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Many stack traces are similar so there are many similar arrays. Stackdepot saves each unique stack only once. Replace field addrs in struct track with depot_stack_handle_t handle. Use stackdepot to save stack trace. The benefits are smaller memory overhead and possibility to aggregate per-cache statistics in the following patch using the stackdepot handle instead of matching stacks manually. [ vbabka@suse.cz: rebase to 5.17-rc1 and adjust accordingly ] This was initially merged as commit 788691464c29 and reverted by commit ae14c63a9f20 due to several issues, that should now be fixed. The problem of unconditional memory overhead by stackdepot has been addressed by commit 2dba5eb1c73b ("lib/stackdepot: allow optional init and stack_table allocation by kvmalloc()"), so the dependency on stackdepot will result in extra memory usage only when a slab cache tracking is actually enabled, and not for all CONFIG_SLUB_DEBUG builds. The build failures on some architectures were also addressed, and the reported issue with xfs/433 test did not reproduce on 5.17-rc1 with this patch. Signed-off-by: Oliver Glitta <glittao@gmail.com> Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-and-tested-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Acked-by: David Rientjes <rientjes@google.com> Cc: David Rientjes <rientjes@google.com> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
* / mm, kfence: support kmem_dump_obj() for KFENCE objectsMarco Elver2022-04-151-0/+9
|/ | | | | | | | | | | | | | | | | | | | | | | | | Calling kmem_obj_info() via kmem_dump_obj() on KFENCE objects has been producing garbage data due to the object not actually being maintained by SLAB or SLUB. Fix this by implementing __kfence_obj_info() that copies relevant information to struct kmem_obj_info when the object was allocated by KFENCE; this is called by a common kmem_obj_info(), which also calls the slab/slub/slob specific variant now called __kmem_obj_info(). For completeness, kmem_dump_obj() now displays if the object was allocated by KFENCE. Link: https://lore.kernel.org/all/20220323090520.GG16885@xsang-OptiPlex-9020/ Link: https://lkml.kernel.org/r/20220406131558.3558585-1-elver@google.com Fixes: b89fb5ef0ce6 ("mm, kfence: insert KFENCE hooks for SLUB") Fixes: d3fb45f370d9 ("mm, kfence: insert KFENCE hooks for SLAB") Signed-off-by: Marco Elver <elver@google.com> Reviewed-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Reported-by: kernel test robot <oliver.sang@intel.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> [slab] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/slab_common: use helper function is_power_of_2()Miaohe Lin2022-02-211-1/+1
| | | | | | | | | Use helper function is_power_of_2() to check if KMALLOC_MIN_SIZE is power of two. Minor readability improvement. Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Link: https://lore.kernel.org/r/20220217091609.8214-1-linmiaohe@huawei.com
* Merge branch 'akpm' (patches from Andrew)Linus Torvalds2022-01-151-25/+9
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Merge misc updates from Andrew Morton: "146 patches. Subsystems affected by this patch series: kthread, ia64, scripts, ntfs, squashfs, ocfs2, vfs, and mm (slab-generic, slab, kmemleak, dax, kasan, debug, pagecache, gup, shmem, frontswap, memremap, memcg, selftests, pagemap, dma, vmalloc, memory-failure, hugetlb, userfaultfd, vmscan, mempolicy, oom-kill, hugetlbfs, migration, thp, ksm, page-poison, percpu, rmap, zswap, zram, cleanups, hmm, and damon)" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (146 commits) mm/damon: hide kernel pointer from tracepoint event mm/damon/vaddr: hide kernel pointer from damon_va_three_regions() failure log mm/damon/vaddr: use pr_debug() for damon_va_three_regions() failure logging mm/damon/dbgfs: remove an unnecessary variable mm/damon: move the implementation of damon_insert_region to damon.h mm/damon: add access checking for hugetlb pages Docs/admin-guide/mm/damon/usage: update for schemes statistics mm/damon/dbgfs: support all DAMOS stats Docs/admin-guide/mm/damon/reclaim: document statistics parameters mm/damon/reclaim: provide reclamation statistics mm/damon/schemes: account how many times quota limit has exceeded mm/damon/schemes: account scheme actions that successfully applied mm/damon: remove a mistakenly added comment for a future feature Docs/admin-guide/mm/damon/usage: update for kdamond_pid and (mk|rm)_contexts Docs/admin-guide/mm/damon/usage: mention tracepoint at the beginning Docs/admin-guide/mm/damon/usage: remove redundant information Docs/admin-guide/mm/damon/usage: update for scheme quotas and watermarks mm/damon: convert macro functions to static inline functions mm/damon: modify damon_rand() macro to static inline function mm/damon: move damon_rand() definition into damon.h ...
| * mm: fix some comment errorsQuanfa Fu2022-01-151-1/+1
| | | | | | | | | | | | | | Link: https://lkml.kernel.org/r/20211101040208.460810-1-fuqf0919@gmail.com Signed-off-by: Quanfa Fu <fuqf0919@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * mm: memcontrol: make cgroup_memory_nokmem staticMuchun Song2022-01-151-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 494c1dfe855e ("mm: memcg/slab: create a new set of kmalloc-cg-<n> caches") makes cgroup_memory_nokmem global, however, it is unnecessary because there is already a function mem_cgroup_kmem_disabled() which exports it. Just make it static and replace it with mem_cgroup_kmem_disabled() in mm/slab_common.c. Link: https://lkml.kernel.org/r/20211109065418.21693-1-songmuchun@bytedance.com Signed-off-by: Muchun Song <songmuchun@bytedance.com> Acked-by: Chris Down <chris@chrisdown.name> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * kasan: add ability to detect double-kmem_cache_destroy()Marco Elver2022-01-151-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Because mm/slab_common.c is not instrumented with software KASAN modes, it is not possible to detect use-after-free of the kmem_cache passed into kmem_cache_destroy(). In particular, because of the s->refcount-- and subsequent early return if non-zero, KASAN would never be able to see the double-free via kmem_cache_free(kmem_cache, s). To be able to detect a double-kmem_cache_destroy(), check accessibility of the kmem_cache, and in case of failure return early. While KASAN_HW_TAGS is able to detect such bugs, by checking accessibility and returning early we fail more gracefully and also avoid corrupting reused objects (where tags mismatch). A recent case of a double-kmem_cache_destroy() was detected by KFENCE: https://lkml.kernel.org/r/0000000000003f654905c168b09d@google.com, which was not detectable by software KASAN modes. Link: https://lkml.kernel.org/r/20211119142219.1519617-1-elver@google.com Signed-off-by: Marco Elver <elver@google.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Christoph Lameter <cl@linux.com> Cc: David Rientjes <rientjes@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Pekka Enberg <penberg@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * mm: slab: make slab iterator functions staticMuchun Song2022-01-151-14/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There is no external users of slab_start/next/stop(), so make them static. And the memory.kmem.slabinfo is deprecated, which outputs nothing now, so move memcg_slab_show() into mm/memcontrol.c and rename it to mem_cgroup_slab_show to be consistent with other function names. Link: https://lkml.kernel.org/r/20211109133359.32881-1-songmuchun@bytedance.com Signed-off-by: Muchun Song <songmuchun@bytedance.com> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * mm/slab_common: use WARN() if cache still has objects on destroyMarco Elver2022-01-151-8/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Calling kmem_cache_destroy() while the cache still has objects allocated is a kernel bug, and will usually result in the entire cache being leaked. While the message in kmem_cache_destroy() resembles a warning, it is currently not implemented using a real WARN(). This is problematic for infrastructure testing the kernel, all of which rely on the specific format of WARN()s to pick up on bugs. Some 13 years ago this used to be a simple WARN_ON() in slub, but commit d629d8195793 ("slub: improve kmem_cache_destroy() error message") changed it into an open-coded warning to avoid confusion with a bug in slub itself. Instead, turn the open-coded warning into a real WARN() with the message preserved, so that test systems can actually identify these issues, and we get all the other benefits of using a normal WARN(). The warning message is extended with "when called from <caller-ip>" to make it even clearer where the fault lies. For most configurations this is only a cosmetic change, however, note that WARN() here will now also respect panic_on_warn. Link: https://lkml.kernel.org/r/20211102170733.648216-1-elver@google.com Signed-off-by: Marco Elver <elver@google.com> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: David Rientjes <rientjes@google.com> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Ingo Molnar <mingo@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm: Use struct slab in kmem_obj_info()Matthew Wilcox (Oracle)2022-01-061-7/+7
|/ | | | | | | | | | | | | All three implementations of slab support kmem_obj_info() which reports details of an object allocated from the slab allocator. By using the slab type instead of the page type, we make it obvious that this can only be called for slabs. [ vbabka@suse.cz: also convert the related kmem_valid_obj() to folios ] Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Roman Gushchin <guro@fb.com>
* mm: remove HARDENED_USERCOPY_FALLBACKStephen Kitt2021-11-061-8/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | This has served its purpose and is no longer used. All usercopy violations appear to have been handled by now, any remaining instances (or new bugs) will cause copies to be rejected. This isn't a direct revert of commit 2d891fbc3bb6 ("usercopy: Allow strict enforcement of whitelists"); since usercopy_fallback is effectively 0, the fallback handling is removed too. This also removes the usercopy_fallback module parameter on slab_common. Link: https://github.com/KSPP/linux/issues/153 Link: https://lkml.kernel.org/r/20210921061149.1091163-1-steve@sk2.org Signed-off-by: Stephen Kitt <steve@sk2.org> Suggested-by: Kees Cook <keescook@chromium.org> Acked-by: Kees Cook <keescook@chromium.org> Reviewed-by: Joel Stanley <joel@jms.id.au> [defconfig change] Acked-by: David Rientjes <rientjes@google.com> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: James Morris <jmorris@namei.org> Cc: "Serge E . Hallyn" <serge@hallyn.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-30 11:31:19 +0100