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* Merge tag 'slab-for-6.9' of ↵Linus Torvalds2024-03-121-16/+6
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab Pull slab updates from Vlastimil Babka: - Freelist loading optimization (Chengming Zhou) When the per-cpu slab is depleted and a new one loaded from the cpu partial list, optimize the loading to avoid an irq enable/disable cycle. This results in a 3.5% performance improvement on the "perf bench sched messaging" test. - Kernel boot parameters cleanup after SLAB removal (Xiongwei Song) Due to two different main slab implementations we've had boot parameters prefixed either slab_ and slub_ with some later becoming an alias as both implementations gained the same functionality (i.e. slab_nomerge vs slub_nomerge). In order to eventually get rid of the implementation-specific names, the canonical and documented parameters are now all prefixed slab_ and the slub_ variants become deprecated but still working aliases. - SLAB_ kmem_cache creation flags cleanup (Vlastimil Babka) The flags had hardcoded #define values which became tedious and error-prone when adding new ones. Assign the values via an enum that takes care of providing unique bit numbers. Also deprecate SLAB_MEM_SPREAD which was only used by SLAB, so it's a no-op since SLAB removal. Assign it an explicit zero value. The removals of the flag usage are handled independently in the respective subsystems, with a final removal of any leftover usage planned for the next release. - Misc cleanups and fixes (Chengming Zhou, Xiaolei Wang, Zheng Yejian) Includes removal of unused code or function parameters and a fix of a memleak. * tag 'slab-for-6.9' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab: slab: remove PARTIAL_NODE slab_state mm, slab: remove memcg_from_slab_obj() mm, slab: remove the corner case of inc_slabs_node() mm/slab: Fix a kmemleak in kmem_cache_destroy() mm, slab, kasan: replace kasan_never_merge() with SLAB_NO_MERGE mm, slab: use an enum to define SLAB_ cache creation flags mm, slab: deprecate SLAB_MEM_SPREAD flag mm, slab: fix the comment of cpu partial list mm, slab: remove unused object_size parameter in kmem_cache_flags() mm/slub: remove parameter 'flags' in create_kmalloc_caches() mm/slub: remove unused parameter in next_freelist_entry() mm/slub: remove full list manipulation for non-debug slab mm/slub: directly load freelist from cpu partial slab in the likely case mm/slub: make the description of slab_min_objects helpful in doc mm/slub: replace slub_$params with slab_$params in slub.rst mm/slub: unify all sl[au]b parameters with "slab_$param" Documentation: kernel-parameters: remove noaliencache
| * mm, slab, kasan: replace kasan_never_merge() with SLAB_NO_MERGEVlastimil Babka2024-02-261-16/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | The SLAB_KASAN flag prevents merging of caches in some configurations, which is handled in a rather complicated way via kasan_never_merge(). Since we now have a generic SLAB_NO_MERGE flag, we can instead use it for KASAN caches in addition to SLAB_KASAN in those configurations, and simplify the SLAB_NEVER_MERGE handling. Tested-by: Xiongwei Song <xiongwei.song@windriver.com> Reviewed-by: Chengming Zhou <chengming.zhou@linux.dev> Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com> Tested-by: David Rientjes <rientjes@google.com> Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
* | kasan: revert eviction of stack traces in generic modeMarco Elver2024-02-231-61/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This partially reverts commits cc478e0b6bdf, 63b85ac56a64, 08d7c94d9635, a414d4286f34, and 773688a6cb24 to make use of variable-sized stack depot records, since eviction of stack entries from stack depot forces fixed- sized stack records. Care was taken to retain the code cleanups by the above commits. Eviction was added to generic KASAN as a response to alleviating the additional memory usage from fixed-sized stack records, but this still uses more memory than previously. With the re-introduction of variable-sized records for stack depot, we can just switch back to non-evictable stack records again, and return back to the previous performance and memory usage baseline. Before (observed after a KASAN kernel boot): pools: 597 refcounted_allocations: 17547 refcounted_frees: 6477 refcounted_in_use: 11070 freelist_size: 3497 persistent_count: 12163 persistent_bytes: 1717008 After: pools: 319 refcounted_allocations: 0 refcounted_frees: 0 refcounted_in_use: 0 freelist_size: 0 persistent_count: 29397 persistent_bytes: 5183536 As can be seen from the counters, with a generic KASAN config, refcounted allocations and evictions are no longer used. Due to using variable-sized records, I observe a reduction of 278 stack depot pools (saving 4448 KiB) with my test setup. Link: https://lkml.kernel.org/r/20240129100708.39460-2-elver@google.com Fixes: cc478e0b6bdf ("kasan: avoid resetting aux_lock") Fixes: 63b85ac56a64 ("kasan: stop leaking stack trace handles") Fixes: 08d7c94d9635 ("kasan: memset free track in qlink_free") Fixes: a414d4286f34 ("kasan: handle concurrent kasan_record_aux_stack calls") Fixes: 773688a6cb24 ("kasan: use stack_depot_put for Generic mode") Signed-off-by: Marco Elver <elver@google.com> Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com> Tested-by: Mikhail Gavrilov <mikhail.v.gavrilov@gmail.com> Cc: Alexander Potapenko <glider@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* | kasan: guard release_free_meta() shadow access with kasan_arch_is_ready()Benjamin Gray2024-02-201-0/+3
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | release_free_meta() accesses the shadow directly through the path kasan_slab_free __kasan_slab_free kasan_release_object_meta release_free_meta kasan_mem_to_shadow There are no kasan_arch_is_ready() guards here, allowing an oops when the shadow is not initialized. The oops can be seen on a Power8 KVM guest. This patch adds the guard to release_free_meta(), as it's the first level that specifically requires the shadow. It is safe to put the guard at the start of this function, before the stack put: only kasan_save_free_info() can initialize the saved stack, which itself is guarded with kasan_arch_is_ready() by its caller poison_slab_object(). If the arch becomes ready before release_free_meta() then we will not observe KASAN_SLAB_FREE_META in the object's shadow, so we will not put an uninitialized stack either. Link: https://lkml.kernel.org/r/20240213033958.139383-1-bgray@linux.ibm.com Fixes: 63b85ac56a64 ("kasan: stop leaking stack trace handles") Signed-off-by: Benjamin Gray <bgray@linux.ibm.com> Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* kasan: avoid resetting aux_lockAndrey Konovalov2024-01-121-2/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | With commit 63b85ac56a64 ("kasan: stop leaking stack trace handles"), KASAN zeroes out alloc meta when an object is freed. The zeroed out data purposefully includes alloc and auxiliary stack traces but also accidentally includes aux_lock. As aux_lock is only initialized for each object slot during slab creation, when the freed slot is reallocated, saving auxiliary stack traces for the new object leads to lockdep reports when taking the zeroed out aux_lock. Arguably, we could reinitialize aux_lock when the object is reallocated, but a simpler solution is to avoid zeroing out aux_lock when an object gets freed. Link: https://lkml.kernel.org/r/20240109221234.90929-1-andrey.konovalov@linux.dev Fixes: 63b85ac56a64 ("kasan: stop leaking stack trace handles") Signed-off-by: Andrey Konovalov <andreyknvl@gmail.com> Reported-by: Paul E. McKenney <paulmck@kernel.org> Closes: https://lore.kernel.org/linux-next/5cc0f83c-e1d6-45c5-be89-9b86746fe731@paulmck-laptop/ Reviewed-by: Marco Elver <elver@google.com> Tested-by: Paul E. McKenney <paulmck@kernel.org> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Liam R. Howlett <Liam.Howlett@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* kasan: stop leaking stack trace handlesAndrey Konovalov2024-01-051-9/+51
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 773688a6cb24 ("kasan: use stack_depot_put for Generic mode") added support for stack trace eviction for Generic KASAN. However, that commit didn't evict stack traces when the object is not put into quarantine. As a result, some stack traces are never evicted from the stack depot. In addition, with the "kasan: save mempool stack traces" series, the free stack traces for mempool objects are also not properly evicted from the stack depot. Fix both issues by: 1. Evicting all stack traces when an object if freed if it was not put into quarantine; 2. Always evicting an existing free stack trace when a new one is saved. Also do a few related clean-ups: - Do not zero out free track when initializing/invalidating free meta: set a value in shadow memory instead; - Rename KASAN_SLAB_FREETRACK to KASAN_SLAB_FREE_META; - Drop the kasan_init_cache_meta function as it's not used by KASAN; - Add comments for the kasan_alloc_meta and kasan_free_meta structs. [akpm@linux-foundation.org: make release_free_meta() and release_alloc_meta() static] Link: https://lkml.kernel.org/r/20231226225121.235865-1-andrey.konovalov@linux.dev Fixes: 773688a6cb24 ("kasan: use stack_depot_put for Generic mode") Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Marco Elver <elver@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* kasan: simplify saving extra info into tracksAndrey Konovalov2023-12-291-2/+2
| | | | | | | | | | | | | | | Avoid duplicating code for saving extra info into tracks: reuse the common function for this. Link: https://lkml.kernel.org/r/20231221183540.168428-3-andrey.konovalov@linux.dev Fixes: 5d4c6ac94694 ("kasan: record and report more information") Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Reviewed-by: Marco Elver <elver@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Juntong Deng <juntong.deng@outlook.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* kasan: clean up kasan_cache_createAndrey Konovalov2023-12-291-28/+39
| | | | | | | | | | | | | | | | | | | Reorganize the code to avoid nested if/else checks to improve the readability. Also drop the confusing comments about KMALLOC_MAX_SIZE checks: they are relevant for both SLUB and SLAB (originally, the comments likely confused KMALLOC_MAX_SIZE with KMALLOC_MAX_CACHE_SIZE). Link: https://lkml.kernel.org/r/20231221183540.168428-1-andrey.konovalov@linux.dev Fixes: a5989d4ed40c ("kasan: improve free meta storage in Generic KASAN") Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Reviewed-by: Marco Elver <elver@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Juntong Deng <juntong.deng@outlook.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* kasan: handle concurrent kasan_record_aux_stack callsAndrey Konovalov2023-12-291-3/+29
| | | | | | | | | | | | | | | | | | | | | | | kasan_record_aux_stack can be called concurrently on the same object. This might lead to a race condition when rotating the saved aux stack trace handles, which in turns leads to incorrect accounting of stack depot handles and refcount underflows in the stack depot code. Fix by introducing a raw spinlock to protect the aux stack trace handles in kasan_record_aux_stack. Link: https://lkml.kernel.org/r/1606b960e2f746862d1f459515972f9695bf448a.1703020707.git.andreyknvl@google.com Fixes: 773688a6cb24 ("kasan: use stack_depot_put for Generic mode") Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Reported-by: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp> Reported-by: syzbot+186b55175d8360728234@syzkaller.appspotmail.com Closes: https://lore.kernel.org/all/000000000000784b1c060b0074a2@google.com/ Reviewed-by: Marco Elver <elver@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Evgenii Stepanov <eugenis@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* kasan: improve free meta storage in Generic KASANJuntong Deng2023-12-101-10/+29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently free meta can only be stored in object if the object is not smaller than free meta. After the improvement, when the object is smaller than free meta and SLUB DEBUG is not enabled, it is possible to store part of the free meta in the object, reducing the increased size of the red zone. Example: free meta size: 16 bytes alloc meta size: 16 bytes object size: 8 bytes optimal redzone size (object_size <= 64): 16 bytes Before improvement: actual redzone size = alloc meta size + free meta size = 32 bytes After improvement: actual redzone size = alloc meta size + (free meta size - object size) = 24 bytes [juntong.deng@outlook.com: make kasan_metadata_size() adapt to the improved free meta storage] Link: https://lkml.kernel.org/r/VI1P193MB0752675D6E0A2D16CE656F8299BAA@VI1P193MB0752.EURP193.PROD.OUTLOOK.COM Link: https://lkml.kernel.org/r/VI1P193MB0752DE2CCD9046B5FED0AA8E99B5A@VI1P193MB0752.EURP193.PROD.OUTLOOK.COM Signed-off-by: Juntong Deng <juntong.deng@outlook.com> Suggested-by: Dmitry Vyukov <dvyukov@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* kasan: use stack_depot_put for Generic modeAndrey Konovalov2023-12-101-4/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | Evict alloc/free stack traces from the stack depot for Generic KASAN once they are evicted from the quaratine. For auxiliary stack traces, evict the oldest stack trace once a new one is saved (KASAN only keeps references to the last two). Also evict all saved stack traces on krealloc. To avoid double-evicting and mis-evicting stack traces (in case KASAN's metadata was corrupted), reset KASAN's per-object metadata that stores stack depot handles when the object is initialized and when it's evicted from the quarantine. Note that stack_depot_put is no-op if the handle is 0. Link: https://lkml.kernel.org/r/5cef104d9b842899489b4054fe8d1339a71acee0.1700502145.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Reviewed-by: Marco Elver <elver@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Evgenii Stepanov <eugenis@google.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* lib/stackdepot, kasan: add flags to __stack_depot_save and renameAndrey Konovalov2023-12-101-4/+5
| | | | | | | | | | | | | | | | | | | | | Change the bool can_alloc argument of __stack_depot_save to a u32 argument that accepts a set of flags. The following patch will add another flag to stack_depot_save_flags besides the existing STACK_DEPOT_FLAG_CAN_ALLOC. Also rename the function to stack_depot_save_flags, as __stack_depot_save is a cryptic name, Link: https://lkml.kernel.org/r/645fa15239621eebbd3a10331e5864b718839512.1700502145.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Reviewed-by: Alexander Potapenko <glider@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Evgenii Stepanov <eugenis@google.com> Cc: Marco Elver <elver@google.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* kasan: fix type cast in memory_is_poisoned_nAndrey Konovalov2023-07-081-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | Commit bb6e04a173f0 ("kasan: use internal prototypes matching gcc-13 builtins") introduced a bug into the memory_is_poisoned_n implementation: it effectively removed the cast to a signed integer type after applying KASAN_GRANULE_MASK. As a result, KASAN started failing to properly check memset, memcpy, and other similar functions. Fix the bug by adding the cast back (through an additional signed integer variable to make the code more readable). Link: https://lkml.kernel.org/r/8c9e0251c2b8b81016255709d4ec42942dcaf018.1688431866.git.andreyknvl@google.com Fixes: bb6e04a173f0 ("kasan: use internal prototypes matching gcc-13 builtins") Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Marco Elver <elver@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* kasan,kmsan: remove __GFP_KSWAPD_RECLAIM usage from kasan/kmsanTetsuo Handa2023-06-231-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | syzbot is reporting lockdep warning in __stack_depot_save(), for the caller of __stack_depot_save() (i.e. __kasan_record_aux_stack() in this report) is responsible for masking __GFP_KSWAPD_RECLAIM flag in order not to wake kswapd which in turn wakes kcompactd. Since kasan/kmsan functions might be called with arbitrary locks held, mask __GFP_KSWAPD_RECLAIM flag from all GFP_NOWAIT/GFP_ATOMIC allocations in kasan/kmsan. Note that kmsan_save_stack_with_flags() is changed to mask both __GFP_DIRECT_RECLAIM flag and __GFP_KSWAPD_RECLAIM flag, for wakeup_kswapd() from wake_all_kswapds() from __alloc_pages_slowpath() calls wakeup_kcompactd() if __GFP_KSWAPD_RECLAIM flag is set and __GFP_DIRECT_RECLAIM flag is not set. Link: https://lkml.kernel.org/r/656cb4f5-998b-c8d7-3c61-c2d37aa90f9a@I-love.SAKURA.ne.jp Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Reported-by: syzbot <syzbot+ece2915262061d6e0ac1@syzkaller.appspotmail.com> Closes: https://syzkaller.appspot.com/bug?extid=ece2915262061d6e0ac1 Reviewed-by: "Huang, Ying" <ying.huang@intel.com> Reviewed-by: Alexander Potapenko <glider@google.com> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Marco Elver <elver@google.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* kasan: use internal prototypes matching gcc-13 builtinsArnd Bergmann2023-06-091-36/+36
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | gcc-13 warns about function definitions for builtin interfaces that have a different prototype, e.g.: In file included from kasan_test.c:31: kasan.h:574:6: error: conflicting types for built-in function '__asan_register_globals'; expected 'void(void *, long int)' [-Werror=builtin-declaration-mismatch] 574 | void __asan_register_globals(struct kasan_global *globals, size_t size); kasan.h:577:6: error: conflicting types for built-in function '__asan_alloca_poison'; expected 'void(void *, long int)' [-Werror=builtin-declaration-mismatch] 577 | void __asan_alloca_poison(unsigned long addr, size_t size); kasan.h:580:6: error: conflicting types for built-in function '__asan_load1'; expected 'void(void *)' [-Werror=builtin-declaration-mismatch] 580 | void __asan_load1(unsigned long addr); kasan.h:581:6: error: conflicting types for built-in function '__asan_store1'; expected 'void(void *)' [-Werror=builtin-declaration-mismatch] 581 | void __asan_store1(unsigned long addr); kasan.h:643:6: error: conflicting types for built-in function '__hwasan_tag_memory'; expected 'void(void *, unsigned char, long int)' [-Werror=builtin-declaration-mismatch] 643 | void __hwasan_tag_memory(unsigned long addr, u8 tag, unsigned long size); The two problems are: - Addresses are passes as 'unsigned long' in the kernel, but gcc-13 expects a 'void *'. - sizes meant to use a signed ssize_t rather than size_t. Change all the prototypes to match these. Using 'void *' consistently for addresses gets rid of a couple of type casts, so push that down to the leaf functions where possible. This now passes all randconfig builds on arm, arm64 and x86, but I have not tested it on the other architectures that support kasan, since they tend to fail randconfig builds in other ways. This might fail if any of the 32-bit architectures expect a 'long' instead of 'int' for the size argument. The __asan_allocas_unpoison() function prototype is somewhat weird, since it uses a pointer for 'stack_top' and an size_t for 'stack_bottom'. This looks like it is meant to be 'addr' and 'size' like the others, but the implementation clearly treats them as 'top' and 'bottom'. Link: https://lkml.kernel.org/r/20230509145735.9263-2-arnd@kernel.org Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Marco Elver <elver@google.com> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* Merge branch 'mm-hotfixes-stable' into mm-stableAndrew Morton2023-02-101-1/+6
|\ | | | | | | To pick up depended-upon changes
| * kasan: fix Oops due to missing calls to kasan_arch_is_ready()Christophe Leroy2023-02-091-1/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | On powerpc64, you can build a kernel with KASAN as soon as you build it with RADIX MMU support. However if the CPU doesn't have RADIX MMU, KASAN isn't enabled at init and the following Oops is encountered. [ 0.000000][ T0] KASAN not enabled as it requires radix! [ 4.484295][ T26] BUG: Unable to handle kernel data access at 0xc00e000000804a04 [ 4.485270][ T26] Faulting instruction address: 0xc00000000062ec6c [ 4.485748][ T26] Oops: Kernel access of bad area, sig: 11 [#1] [ 4.485920][ T26] BE PAGE_SIZE=64K MMU=Hash SMP NR_CPUS=2048 NUMA pSeries [ 4.486259][ T26] Modules linked in: [ 4.486637][ T26] CPU: 0 PID: 26 Comm: kworker/u2:2 Not tainted 6.2.0-rc3-02590-gf8a023b0a805 #249 [ 4.486907][ T26] Hardware name: IBM pSeries (emulated by qemu) POWER9 (raw) 0x4e1200 0xf000005 of:SLOF,HEAD pSeries [ 4.487445][ T26] Workqueue: eval_map_wq .tracer_init_tracefs_work_func [ 4.488744][ T26] NIP: c00000000062ec6c LR: c00000000062bb84 CTR: c0000000002ebcd0 [ 4.488867][ T26] REGS: c0000000049175c0 TRAP: 0380 Not tainted (6.2.0-rc3-02590-gf8a023b0a805) [ 4.489028][ T26] MSR: 8000000002009032 <SF,VEC,EE,ME,IR,DR,RI> CR: 44002808 XER: 00000000 [ 4.489584][ T26] CFAR: c00000000062bb80 IRQMASK: 0 [ 4.489584][ T26] GPR00: c0000000005624d4 c000000004917860 c000000001cfc000 1800000000804a04 [ 4.489584][ T26] GPR04: c0000000003a2650 0000000000000cc0 c00000000000d3d8 c00000000000d3d8 [ 4.489584][ T26] GPR08: c0000000049175b0 a80e000000000000 0000000000000000 0000000017d78400 [ 4.489584][ T26] GPR12: 0000000044002204 c000000003790000 c00000000435003c c0000000043f1c40 [ 4.489584][ T26] GPR16: c0000000043f1c68 c0000000043501a0 c000000002106138 c0000000043f1c08 [ 4.489584][ T26] GPR20: c0000000043f1c10 c0000000043f1c20 c000000004146c40 c000000002fdb7f8 [ 4.489584][ T26] GPR24: c000000002fdb834 c000000003685e00 c000000004025030 c000000003522e90 [ 4.489584][ T26] GPR28: 0000000000000cc0 c0000000003a2650 c000000004025020 c000000004025020 [ 4.491201][ T26] NIP [c00000000062ec6c] .kasan_byte_accessible+0xc/0x20 [ 4.491430][ T26] LR [c00000000062bb84] .__kasan_check_byte+0x24/0x90 [ 4.491767][ T26] Call Trace: [ 4.491941][ T26] [c000000004917860] [c00000000062ae70] .__kasan_kmalloc+0xc0/0x110 (unreliable) [ 4.492270][ T26] [c0000000049178f0] [c0000000005624d4] .krealloc+0x54/0x1c0 [ 4.492453][ T26] [c000000004917990] [c0000000003a2650] .create_trace_option_files+0x280/0x530 [ 4.492613][ T26] [c000000004917a90] [c000000002050d90] .tracer_init_tracefs_work_func+0x274/0x2c0 [ 4.492771][ T26] [c000000004917b40] [c0000000001f9948] .process_one_work+0x578/0x9f0 [ 4.492927][ T26] [c000000004917c30] [c0000000001f9ebc] .worker_thread+0xfc/0x950 [ 4.493084][ T26] [c000000004917d60] [c00000000020be84] .kthread+0x1a4/0x1b0 [ 4.493232][ T26] [c000000004917e10] [c00000000000d3d8] .ret_from_kernel_thread+0x58/0x60 [ 4.495642][ T26] Code: 60000000 7cc802a6 38a00000 4bfffc78 60000000 7cc802a6 38a00001 4bfffc68 60000000 3d20a80e 7863e8c2 792907c6 <7c6348ae> 20630007 78630fe0 68630001 [ 4.496704][ T26] ---[ end trace 0000000000000000 ]--- The Oops is due to kasan_byte_accessible() not checking the readiness of KASAN. Add missing call to kasan_arch_is_ready() and bail out when not ready. The same problem is observed with ____kasan_kfree_large() so fix it the same. Also, as KASAN is not available and no shadow area is allocated for linear memory mapping, there is no point in allocating shadow mem for vmalloc memory as shown below in /sys/kernel/debug/kernel_page_tables ---[ kasan shadow mem start ]--- 0xc00f000000000000-0xc00f00000006ffff 0x00000000040f0000 448K r w pte valid present dirty accessed 0xc00f000000860000-0xc00f00000086ffff 0x000000000ac10000 64K r w pte valid present dirty accessed 0xc00f3ffffffe0000-0xc00f3fffffffffff 0x0000000004d10000 128K r w pte valid present dirty accessed ---[ kasan shadow mem end ]--- So, also verify KASAN readiness before allocating and poisoning shadow mem for VMAs. Link: https://lkml.kernel.org/r/150768c55722311699fdcf8f5379e8256749f47d.1674716617.git.christophe.leroy@csgroup.eu Fixes: 41b7a347bf14 ("powerpc: Book3S 64-bit outline-only KASAN support") Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu> Reported-by: Nathan Lynch <nathanl@linux.ibm.com> Suggested-by: Michael Ellerman <mpe@ellerman.id.au> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> Cc: <stable@vger.kernel.org> [5.19+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* | kasan: infer allocation size by scanning metadataKuan-Ying Lee2023-02-091-3/+1
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Make KASAN scan metadata to infer the requested allocation size instead of printing cache->object_size. This patch fixes confusing slab-out-of-bounds reports as reported in: https://bugzilla.kernel.org/show_bug.cgi?id=216457 As an example of the confusing behavior, the report below hints that the allocation size was 192, while the kernel actually called kmalloc(184): ================================================================== BUG: KASAN: slab-out-of-bounds in _find_next_bit+0x143/0x160 lib/find_bit.c:109 Read of size 8 at addr ffff8880175766b8 by task kworker/1:1/26 ... The buggy address belongs to the object at ffff888017576600 which belongs to the cache kmalloc-192 of size 192 The buggy address is located 184 bytes inside of 192-byte region [ffff888017576600, ffff8880175766c0) ... Memory state around the buggy address: ffff888017576580: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff888017576600: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff888017576680: 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fc ^ ffff888017576700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888017576780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ================================================================== With this patch, the report shows: ================================================================== ... The buggy address belongs to the object at ffff888017576600 which belongs to the cache kmalloc-192 of size 192 The buggy address is located 0 bytes to the right of allocated 184-byte region [ffff888017576600, ffff8880175766b8) ... ================================================================== Also report slab use-after-free bugs as "slab-use-after-free" and print "freed" instead of "allocated" in the report when describing the accessed memory region. Also improve the metadata-related comment in kasan_find_first_bad_addr and use addr_has_metadata across KASAN code instead of open-coding KASAN_SHADOW_START checks. [akpm@linux-foundation.org: fix printk warning] Link: https://bugzilla.kernel.org/show_bug.cgi?id=216457 Link: https://lkml.kernel.org/r/20230129021437.18812-1-Kuan-Ying.Lee@mediatek.com Signed-off-by: Kuan-Ying Lee <Kuan-Ying.Lee@mediatek.com> Co-developed-by: Andrey Konovalov <andreyknvl@gmail.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Chinwen Chang <chinwen.chang@mediatek.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Matthias Brugger <matthias.bgg@gmail.com> Cc: Qun-Wei Lin <qun-wei.lin@mediatek.com> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* mm: kasan: Extend kasan_metadata_size() to also cover in-object sizeFeng Tang2022-11-101-6/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When kasan is enabled for slab/slub, it may save kasan' free_meta data in the former part of slab object data area in slab object's free path, which works fine. There is ongoing effort to extend slub's debug function which will redzone the latter part of kmalloc object area, and when both of the debug are enabled, there is possible conflict, especially when the kmalloc object has small size, as caught by 0Day bot [1]. To solve it, slub code needs to know the in-object kasan's meta data size. Currently, there is existing kasan_metadata_size() which returns the kasan's metadata size inside slub's metadata area, so extend it to also cover the in-object meta size by adding a boolean flag 'in_object'. There is no functional change to existing code logic. [1]. https://lore.kernel.org/lkml/YuYm3dWwpZwH58Hu@xsang-OptiPlex-9020/ Reported-by: kernel test robot <oliver.sang@intel.com> Suggested-by: Andrey Konovalov <andreyknvl@gmail.com> Signed-off-by: Feng Tang <feng.tang@intel.com> Reviewed-by: Andrey Konovalov <andreyknvl@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> Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
* kasan: move kasan_get_alloc/free_track definitionsAndrey Konovalov2022-10-031-21/+0
| | | | | | | | | | | | | | | Move the definitions of kasan_get_alloc/free_track() to report_*.c, as they belong with other the reporting code. Link: https://lkml.kernel.org/r/0cb15423956889b3905a0174b58782633bbbd72e.1662411799.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Reviewed-by: Marco Elver <elver@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Evgenii Stepanov <eugenis@google.com> Cc: Peter Collingbourne <pcc@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* kasan: pass tagged pointers to kasan_save_alloc/free_infoAndrey Konovalov2022-10-031-2/+1
| | | | | | | | | | | | | | | | Pass tagged pointers to kasan_save_alloc/free_info(). This is a preparatory patch to simplify other changes in the series. Link: https://lkml.kernel.org/r/d5bc48cfcf0dca8269dc3ed863047e4d4d2030f1.1662411799.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Reviewed-by: Marco Elver <elver@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Evgenii Stepanov <eugenis@google.com> Cc: Peter Collingbourne <pcc@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* kasan: only define kasan_cache_create for Generic modeAndrey Konovalov2022-10-031-1/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Right now, kasan_cache_create() assigns SLAB_KASAN for all KASAN modes and then sets up metadata-related cache parameters for the Generic mode. SLAB_KASAN is used in two places: 1. In slab_ksize() to account for per-object metadata when calculating the size of the accessible memory within the object. 2. In slab_common.c via kasan_never_merge() to prevent merging of caches with per-object metadata. Both cases are only relevant when per-object metadata is present, which is only the case with the Generic mode. Thus, assign SLAB_KASAN and define kasan_cache_create() only for the Generic mode. Also update the SLAB_KASAN-related comment. Link: https://lkml.kernel.org/r/61faa2aa1906e2d02c97d00ddf99ce8911dda095.1662411799.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Reviewed-by: Marco Elver <elver@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Evgenii Stepanov <eugenis@google.com> Cc: Peter Collingbourne <pcc@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* kasan: only define kasan_never_merge for Generic modeAndrey Konovalov2022-10-031-0/+8
| | | | | | | | | | | | | | | | | | KASAN prevents merging of slab caches whose objects have per-object metadata stored in redzones. As now only the Generic mode uses per-object metadata, define kasan_never_merge() only for this mode. Link: https://lkml.kernel.org/r/81ed01f29ff3443580b7e2fe362a8b47b1e8006d.1662411799.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Reviewed-by: Marco Elver <elver@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Evgenii Stepanov <eugenis@google.com> Cc: Peter Collingbourne <pcc@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* kasan: only define kasan_metadata_size for Generic modeAndrey Konovalov2022-10-031-0/+11
| | | | | | | | | | | | | | | | | | KASAN provides a helper for calculating the size of per-object metadata stored in the redzone. As now only the Generic mode uses per-object metadata, only define kasan_metadata_size() for this mode. Link: https://lkml.kernel.org/r/8f81d4938b80446bc72538a08217009f328a3e23.1662411799.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Reviewed-by: Marco Elver <elver@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Evgenii Stepanov <eugenis@google.com> Cc: Peter Collingbourne <pcc@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* kasan: drop CONFIG_KASAN_GENERIC check from kasan_init_cache_metaAndrey Konovalov2022-10-031-6/+0
| | | | | | | | | | | | | | | As kasan_init_cache_meta() is only defined for the Generic mode, it does not require the CONFIG_KASAN_GENERIC check. Link: https://lkml.kernel.org/r/211f8f2b213aa91e9148ca63342990b491c4917a.1662411799.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Reviewed-by: Marco Elver <elver@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Evgenii Stepanov <eugenis@google.com> Cc: Peter Collingbourne <pcc@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* kasan: introduce kasan_init_cache_metaAndrey Konovalov2022-10-031-0/+79
| | | | | | | | | | | | | | | | | | Add a kasan_init_cache_meta() helper that initializes metadata-related cache parameters and use this helper in the common KASAN code. Put the implementation of this new helper into generic.c, as only the Generic mode uses per-object metadata. Link: https://lkml.kernel.org/r/a6d7ea01876eb36472c9879f7b23f1b24766276e.1662411799.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Reviewed-by: Marco Elver <elver@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Evgenii Stepanov <eugenis@google.com> Cc: Peter Collingbourne <pcc@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* kasan: move kasan_get_*_meta to generic.cAndrey Konovalov2022-10-031-0/+17
| | | | | | | | | | | | | | | | | | Move the implementations of kasan_get_alloc/free_meta() to generic.c, as the common KASAN code does not use these functions anymore. Also drop kasan_reset_tag() from the implementation, as the Generic mode does not tag pointers. Link: https://lkml.kernel.org/r/ffcfc0ad654d78a2ef4ca054c943ddb4e5ca477b.1662411799.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Reviewed-by: Marco Elver <elver@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Evgenii Stepanov <eugenis@google.com> Cc: Peter Collingbourne <pcc@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* kasan: introduce kasan_init_object_metaAndrey Konovalov2022-10-031-0/+9
| | | | | | | | | | | | | | | | | | | | | | Add a kasan_init_object_meta() helper that initializes metadata for a slab object and use it in the common code. For now, the implementations of this helper are the same for the Generic and tag-based modes, but they will diverge later in the series. This change hides references to alloc_meta from the common code. This is desired as only the Generic mode will be using per-object metadata after this series. Link: https://lkml.kernel.org/r/47c12938fc7f8105e7aaa592527c0e9d3c81fc37.1662411799.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Reviewed-by: Marco Elver <elver@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Evgenii Stepanov <eugenis@google.com> Cc: Peter Collingbourne <pcc@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* kasan: introduce kasan_get_alloc_trackAndrey Konovalov2022-10-031-1/+13
| | | | | | | | | | | | | | | | | | | | | | Add a kasan_get_alloc_track() helper that fetches alloc_track for a slab object and use this helper in the common reporting code. For now, the implementations of this helper are the same for the Generic and tag-based modes, but they will diverge later in the series. This change hides references to alloc_meta from the common reporting code. This is desired as only the Generic mode will be using per-object metadata after this series. Link: https://lkml.kernel.org/r/0c365a35f4a833fff46f9d42c3212b32f7166556.1662411799.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Reviewed-by: Marco Elver <elver@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Evgenii Stepanov <eugenis@google.com> Cc: Peter Collingbourne <pcc@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* kasan: split save_alloc_info implementationsAndrey Konovalov2022-10-031-0/+9
| | | | | | | | | | | | | | | | | | Provide standalone implementations of save_alloc_info() for the Generic and tag-based modes. For now, the implementations are the same, but they will diverge later in the series. Link: https://lkml.kernel.org/r/77f1a078489c1e859aedb5403f772e5e1f7410a0.1662411799.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Reviewed-by: Marco Elver <elver@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Evgenii Stepanov <eugenis@google.com> Cc: Peter Collingbourne <pcc@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* kasan: rename kasan_set_*_info to kasan_save_*_infoAndrey Konovalov2022-10-031-1/+1
| | | | | | | | | | | | | | | Rename set_alloc_info() and kasan_set_free_info() to save_alloc_info() and kasan_save_free_info(). The new names make more sense. Link: https://lkml.kernel.org/r/9f04777a15cb9d96bf00331da98e021d732fe1c9.1662411799.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Reviewed-by: Marco Elver <elver@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Evgenii Stepanov <eugenis@google.com> Cc: Peter Collingbourne <pcc@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* kasan: give better names to shadow valuesAndrey Konovalov2022-05-131-3/+3
| | | | | | | | | | | | | | | | Rename KASAN_KMALLOC_* shadow values to KASAN_SLAB_*, as they are used for all slab allocations, not only for kmalloc. Also rename KASAN_FREE_PAGE to KASAN_PAGE_FREE to be consistent with KASAN_PAGE_REDZONE and KASAN_SLAB_FREE. Link: https://lkml.kernel.org/r/bebcaf4eafdb0cabae0401a69c0af956aa87fcaa.1652111464.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Reviewed-by: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Marco Elver <elver@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* mm/kasan: Convert to struct folio and struct slabMatthew Wilcox (Oracle)2022-01-061-4/+4
| | | | | | | | | | | | | | | | | | | | | | | KASAN accesses some slab related struct page fields so we need to convert it to struct slab. Some places are a bit simplified thanks to kasan_addr_to_slab() encapsulating the PageSlab flag check through virt_to_slab(). When resolving object address to either a real slab or a large kmalloc, use struct folio as the intermediate type for testing the slab flag to avoid unnecessary implicit compound_head(). [ vbabka@suse.cz: use struct folio, adjust to differences in previous patches ] Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com> Reviewed-by: Roman Gushchin <guro@fb.com> Tested-by: Hyeongogn Yoo <42.hyeyoo@gmail.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: <kasan-dev@googlegroups.com>
* mm: Convert struct page to struct slab in functions used by other subsystemsVlastimil Babka2022-01-061-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | KASAN, KFENCE and memcg interact with SLAB or SLUB internals through functions nearest_obj(), obj_to_index() and objs_per_slab() that use struct page as parameter. This patch converts it to struct slab including all callers, through a coccinelle semantic patch. // Options: --include-headers --no-includes --smpl-spacing include/linux/slab_def.h include/linux/slub_def.h mm/slab.h mm/kasan/*.c mm/kfence/kfence_test.c mm/memcontrol.c mm/slab.c mm/slub.c // Note: needs coccinelle 1.1.1 to avoid breaking whitespace @@ @@ -objs_per_slab_page( +objs_per_slab( ... ) { ... } @@ @@ -objs_per_slab_page( +objs_per_slab( ... ) @@ identifier fn =~ "obj_to_index|objs_per_slab"; @@ fn(..., - const struct page *page + const struct slab *slab ,...) { <... ( - page_address(page) + slab_address(slab) | - page + slab ) ...> } @@ identifier fn =~ "nearest_obj"; @@ fn(..., - struct page *page + const struct slab *slab ,...) { <... ( - page_address(page) + slab_address(slab) | - page + slab ) ...> } @@ identifier fn =~ "nearest_obj|obj_to_index|objs_per_slab"; expression E; @@ fn(..., ( - slab_page(E) + E | - virt_to_page(E) + virt_to_slab(E) | - virt_to_head_page(E) + virt_to_slab(E) | - page + page_slab(page) ) ,...) Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com> Reviewed-by: Roman Gushchin <guro@fb.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Julia Lawall <julia.lawall@inria.fr> Cc: Luis Chamberlain <mcgrof@kernel.org> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Marco Elver <elver@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: <kasan-dev@googlegroups.com> Cc: <cgroups@vger.kernel.org>
* kasan: generic: introduce kasan_record_aux_stack_noalloc()Marco Elver2021-11-061-2/+12
| | | | | | | | | | | | | | | | | | | | | | | | | Introduce a variant of kasan_record_aux_stack() that does not do any memory allocation through stackdepot. This will permit using it in contexts that cannot allocate any memory. Link: https://lkml.kernel.org/r/20210913112609.2651084-6-elver@google.com Signed-off-by: Marco Elver <elver@google.com> Tested-by: Shuah Khan <skhan@linuxfoundation.org> Acked-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: "Gustavo A. R. Silva" <gustavoars@kernel.org> Cc: Lai Jiangshan <jiangshanlai@gmail.com> Cc: Taras Madan <tarasmadan@google.com> Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vijayanand Jitta <vjitta@codeaurora.org> Cc: Vinayak Menon <vinmenon@codeaurora.org> Cc: Walter Wu <walter-zh.wu@mediatek.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* kasan: common: provide can_alloc in kasan_save_stack()Marco Elver2021-11-061-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | Add another argument, can_alloc, to kasan_save_stack() which is passed as-is to __stack_depot_save(). No functional change intended. Link: https://lkml.kernel.org/r/20210913112609.2651084-5-elver@google.com Signed-off-by: Marco Elver <elver@google.com> Tested-by: Shuah Khan <skhan@linuxfoundation.org> Acked-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: "Gustavo A. R. Silva" <gustavoars@kernel.org> Cc: Lai Jiangshan <jiangshanlai@gmail.com> Cc: Taras Madan <tarasmadan@google.com> Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vijayanand Jitta <vjitta@codeaurora.org> Cc: Vinayak Menon <vinmenon@codeaurora.org> Cc: Walter Wu <walter-zh.wu@mediatek.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* kasan: allow architectures to provide an outline readiness checkDaniel Axtens2021-06-291-0/+3
| | | | | | | | | | | | | | | | | | | | | | | Allow architectures to define a kasan_arch_is_ready() hook that bails out of any function that's about to touch the shadow unless the arch says that it is ready for the memory to be accessed. This is fairly uninvasive and should have a negligible performance penalty. This will only work in outline mode, so an arch must specify ARCH_DISABLE_KASAN_INLINE if it requires this. Link: https://lkml.kernel.org/r/20210624034050.511391-3-dja@axtens.net Signed-off-by: Daniel Axtens <dja@axtens.net> Reviewed-by: Marco Elver <elver@google.com> Suggested-by: Christophe Leroy <christophe.leroy@csgroup.eu> Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* kasan: init memory in kasan_(un)poison for HW_TAGSAndrey Konovalov2021-04-301-6/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This change adds an argument to kasan_poison() and kasan_unpoison() that allows initializing memory along with setting the tags for HW_TAGS. Combining setting allocation tags with memory initialization will improve HW_TAGS KASAN performance when init_on_alloc/free is enabled. This change doesn't integrate memory initialization with KASAN, this is done is subsequent patches in this series. Link: https://lkml.kernel.org/r/3054314039fa64510947e674180d675cab1b4c41.1615296150.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Reviewed-by: Marco Elver <elver@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Branislav Rankov <Branislav.Rankov@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christoph Lameter <cl@linux.com> Cc: David Rientjes <rientjes@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Evgenii Stepanov <eugenis@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Kevin Brodsky <kevin.brodsky@arm.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Peter Collingbourne <pcc@google.com> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* kfence, kasan: make KFENCE compatible with KASANAlexander Potapenko2021-02-261-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Make KFENCE compatible with KASAN. Currently this helps test KFENCE itself, where KASAN can catch potential corruptions to KFENCE state, or other corruptions that may be a result of freepointer corruptions in the main allocators. [akpm@linux-foundation.org: merge fixup] [andreyknvl@google.com: untag addresses for KFENCE] Link: https://lkml.kernel.org/r/9dc196006921b191d25d10f6e611316db7da2efc.1611946152.git.andreyknvl@google.com Link: https://lkml.kernel.org/r/20201103175841.3495947-7-elver@google.com Signed-off-by: Marco Elver <elver@google.com> Signed-off-by: Alexander Potapenko <glider@google.com> Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Reviewed-by: Dmitry Vyukov <dvyukov@google.com> Reviewed-by: Jann Horn <jannh@google.com> Co-developed-by: Marco Elver <elver@google.com> Cc: Andrey Konovalov <andreyknvl@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christopher Lameter <cl@linux.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Rientjes <rientjes@google.com> Cc: Eric Dumazet <edumazet@google.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Hillf Danton <hdanton@sina.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Joern Engel <joern@purestorage.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Kees Cook <keescook@chromium.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Pekka Enberg <penberg@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: SeongJae Park <sjpark@amazon.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* kasan: fix bug detection via ksize for HW_TAGS modeAndrey Konovalov2021-02-241-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The currently existing kasan_check_read/write() annotations are intended to be used for kernel modules that have KASAN compiler instrumentation disabled. Thus, they are only relevant for the software KASAN modes that rely on compiler instrumentation. However there's another use case for these annotations: ksize() checks that the object passed to it is indeed accessible before unpoisoning the whole object. This is currently done via __kasan_check_read(), which is compiled away for the hardware tag-based mode that doesn't rely on compiler instrumentation. This leads to KASAN missing detecting some memory corruptions. Provide another annotation called kasan_check_byte() that is available for all KASAN modes. As the implementation rename and reuse kasan_check_invalid_free(). Use this new annotation in ksize(). To avoid having ksize() as the top frame in the reported stack trace pass _RET_IP_ to __kasan_check_byte(). Also add a new ksize_uaf() test that checks that a use-after-free is detected via ksize() itself, and via plain accesses that happen later. Link: https://linux-review.googlesource.com/id/Iaabf771881d0f9ce1b969f2a62938e99d3308ec5 Link: https://lkml.kernel.org/r/f32ad74a60b28d8402482a38476f02bb7600f620.1610733117.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Reviewed-by: Marco Elver <elver@google.com> Reviewed-by: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Branislav Rankov <Branislav.Rankov@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Evgenii Stepanov <eugenis@google.com> Cc: Kevin Brodsky <kevin.brodsky@arm.com> Cc: Peter Collingbourne <pcc@google.com> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* kasan: prefix global functions with kasan_Andrey Konovalov2021-02-241-18/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Patch series "kasan: HW_TAGS tests support and fixes", v4. This patchset adds support for running KASAN-KUnit tests with the hardware tag-based mode and also contains a few fixes. This patch (of 15): There's a number of internal KASAN functions that are used across multiple source code files and therefore aren't marked as static inline. To avoid littering the kernel function names list with generic function names, prefix all such KASAN functions with kasan_. As a part of this change: - Rename internal (un)poison_range() to kasan_(un)poison() (no _range) to avoid name collision with a public kasan_unpoison_range(). - Rename check_memory_region() to kasan_check_range(), as it's a more fitting name. Link: https://lkml.kernel.org/r/cover.1610733117.git.andreyknvl@google.com Link: https://linux-review.googlesource.com/id/I719cc93483d4ba288a634dba80ee6b7f2809cd26 Link: https://lkml.kernel.org/r/13777aedf8d3ebbf35891136e1f2287e2f34aaba.1610733117.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Suggested-by: Marco Elver <elver@google.com> Reviewed-by: Marco Elver <elver@google.com> Reviewed-by: Alexander Potapenko <glider@google.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Peter Collingbourne <pcc@google.com> Cc: Evgenii Stepanov <eugenis@google.com> Cc: Branislav Rankov <Branislav.Rankov@arm.com> Cc: Kevin Brodsky <kevin.brodsky@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* kasan: fix null pointer dereference in kasan_record_aux_stackWalter Wu2020-12-291-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | Syzbot reported the following [1]: BUG: kernel NULL pointer dereference, address: 0000000000000008 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 2d993067 P4D 2d993067 PUD 19a3c067 PMD 0 Oops: 0000 [#1] PREEMPT SMP KASAN CPU: 1 PID: 3852 Comm: kworker/1:2 Not tainted 5.10.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events free_ipc RIP: 0010:kasan_record_aux_stack+0x77/0xb0 Add null checking slab object from kasan_get_alloc_meta() in order to avoid null pointer dereference. [1] https://syzkaller.appspot.com/x/log.txt?x=10a82a50d00000 Link: https://lkml.kernel.org/r/20201228080018.23041-1-walter-zh.wu@mediatek.com Signed-off-by: Walter Wu <walter-zh.wu@mediatek.com> Suggested-by: Dmitry Vyukov <dvyukov@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Andrey Konovalov <andreyknvl@google.com> Cc: Alexander Potapenko <glider@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* kasan: sanitize objects when metadata doesn't fitAndrey Konovalov2020-12-221-4/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | KASAN marks caches that are sanitized with the SLAB_KASAN cache flag. Currently if the metadata that is appended after the object (stores e.g. stack trace ids) doesn't fit into KMALLOC_MAX_SIZE (can only happen with SLAB, see the comment in the patch), KASAN turns off sanitization completely. With this change sanitization of the object data is always enabled. However the metadata is only stored when it fits. Instead of checking for SLAB_KASAN flag accross the code to find out whether the metadata is there, use cache->kasan_info.alloc/free_meta_offset. As 0 can be a valid value for free_meta_offset, introduce KASAN_NO_FREE_META as an indicator that the free metadata is missing. Without this change all sanitized KASAN objects would be put into quarantine with generic KASAN. With this change, only the objects that have metadata (i.e. when it fits) are put into quarantine, the rest is freed right away. Along the way rework __kasan_cache_create() and add claryfying comments. Link: https://lkml.kernel.org/r/aee34b87a5e4afe586c2ac6a0b32db8dc4dcc2dc.1606162397.git.andreyknvl@google.com Link: https://linux-review.googlesource.com/id/Icd947e2bea054cb5cfbdc6cf6652227d97032dcb Co-developed-by: Vincenzo Frascino <Vincenzo.Frascino@arm.com> Signed-off-by: Vincenzo Frascino <Vincenzo.Frascino@arm.com> Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Reviewed-by: Marco Elver <elver@google.com> Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Branislav Rankov <Branislav.Rankov@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Evgenii Stepanov <eugenis@google.com> Cc: Kevin Brodsky <kevin.brodsky@arm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* kasan: rename get_alloc/free_infoAndrey Konovalov2020-12-221-6/+6
| | | | | | | | | | | | | | | | | | | | | | | | | Rename get_alloc_info() and get_free_info() to kasan_get_alloc_meta() and kasan_get_free_meta() to better reflect what those do and avoid confusion with kasan_set_free_info(). No functional changes. Link: https://lkml.kernel.org/r/27b7c036b754af15a2839e945f6d8bfce32b4c2f.1606162397.git.andreyknvl@google.com Link: https://linux-review.googlesource.com/id/Ib6e4ba61c8b12112b403d3479a9799ac8fff8de1 Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Reviewed-by: Dmitry Vyukov <dvyukov@google.com> Reviewed-by: Marco Elver <elver@google.com> Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Branislav Rankov <Branislav.Rankov@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Evgenii Stepanov <eugenis@google.com> Cc: Kevin Brodsky <kevin.brodsky@arm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* kasan, arm64: move initialization messageAndrey Konovalov2020-12-221-2/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | Software tag-based KASAN mode is fully initialized with kasan_init_tags(), while the generic mode only requires kasan_init(). Move the initialization message for tag-based mode into kasan_init_tags(). Also fix pr_fmt() usage for KASAN code: generic.c doesn't need it as it doesn't use any printing functions; tag-based mode should use "kasan:" instead of KBUILD_MODNAME (which stands for file name). Link: https://lkml.kernel.org/r/29a30ea4e1750450dd1f693d25b7b6cb05913ecf.1606161801.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Alexander Potapenko <glider@google.com> Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Branislav Rankov <Branislav.Rankov@arm.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Evgenii Stepanov <eugenis@google.com> Cc: Kevin Brodsky <kevin.brodsky@arm.com> Cc: Marco Elver <elver@google.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* kasan: hide invalid free check implementationAndrey Konovalov2020-12-221-0/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is a preparatory commit for the upcoming addition of a new hardware tag-based (MTE-based) KASAN mode. For software KASAN modes the check is based on the value in the shadow memory. Hardware tag-based KASAN won't be using shadow, so hide the implementation of the check in check_invalid_free(). Also simplify the code for software tag-based mode. No functional changes for software modes. Link: https://lkml.kernel.org/r/d01534a4b977f97d87515dc590e6348e1406de81.1606161801.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Reviewed-by: Marco Elver <elver@google.com> Reviewed-by: Alexander Potapenko <glider@google.com> Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Branislav Rankov <Branislav.Rankov@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Evgenii Stepanov <eugenis@google.com> Cc: Kevin Brodsky <kevin.brodsky@arm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* kasan: rename KASAN_SHADOW_* to KASAN_GRANULE_*Andrey Konovalov2020-12-221-7/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is a preparatory commit for the upcoming addition of a new hardware tag-based (MTE-based) KASAN mode. The new mode won't be using shadow memory, but will still use the concept of memory granules. Each memory granule maps to a single metadata entry: 8 bytes per one shadow byte for generic mode, 16 bytes per one shadow byte for software tag-based mode, and 16 bytes per one allocation tag for hardware tag-based mode. Rename KASAN_SHADOW_SCALE_SIZE to KASAN_GRANULE_SIZE, and KASAN_SHADOW_MASK to KASAN_GRANULE_MASK. Also use MASK when used as a mask, otherwise use SIZE. No functional changes. Link: https://lkml.kernel.org/r/939b5754e47f528a6e6a6f28ffc5815d8d128033.1606161801.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Reviewed-by: Marco Elver <elver@google.com> Reviewed-by: Alexander Potapenko <glider@google.com> Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Branislav Rankov <Branislav.Rankov@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Evgenii Stepanov <eugenis@google.com> Cc: Kevin Brodsky <kevin.brodsky@arm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* kasan: rename (un)poison_shadow to (un)poison_rangeAndrey Konovalov2020-12-221-12/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | This is a preparatory commit for the upcoming addition of a new hardware tag-based (MTE-based) KASAN mode. The new mode won't be using shadow memory. Rename external annotation kasan_unpoison_shadow() to kasan_unpoison_range(), and introduce internal functions (un)poison_range() (without kasan_ prefix). Co-developed-by: Marco Elver <elver@google.com> Link: https://lkml.kernel.org/r/fccdcaa13dc6b2211bf363d6c6d499279a54fe3a.1606161801.git.andreyknvl@google.com Signed-off-by: Marco Elver <elver@google.com> Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Reviewed-by: Alexander Potapenko <glider@google.com> Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Branislav Rankov <Branislav.Rankov@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Evgenii Stepanov <eugenis@google.com> Cc: Kevin Brodsky <kevin.brodsky@arm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* kasan: drop unnecessary GPL text from comment headersAndrey Konovalov2020-12-221-5/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Patch series "kasan: add hardware tag-based mode for arm64", v11. This patchset adds a new hardware tag-based mode to KASAN [1]. The new mode is similar to the existing software tag-based KASAN, but relies on arm64 Memory Tagging Extension (MTE) [2] to perform memory and pointer tagging (instead of shadow memory and compiler instrumentation). This patchset is co-developed and tested by Vincenzo Frascino <vincenzo.frascino@arm.com>. This patchset is available here: https://github.com/xairy/linux/tree/up-kasan-mte-v11 For testing in QEMU hardware tag-based KASAN requires: 1. QEMU built from master [4] (use "-machine virt,mte=on -cpu max" arguments to run). 2. GCC version 10. [1] https://www.kernel.org/doc/html/latest/dev-tools/kasan.html [2] https://community.arm.com/developer/ip-products/processors/b/processors-ip-blog/posts/enhancing-memory-safety [3] git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux for-next/mte [4] https://github.com/qemu/qemu ====== Overview The underlying ideas of the approach used by hardware tag-based KASAN are: 1. By relying on the Top Byte Ignore (TBI) arm64 CPU feature, pointer tags are stored in the top byte of each kernel pointer. 2. With the Memory Tagging Extension (MTE) arm64 CPU feature, memory tags for kernel memory allocations are stored in a dedicated memory not accessible via normal instuctions. 3. On each memory allocation, a random tag is generated, embedded it into the returned pointer, and the corresponding memory is tagged with the same tag value. 4. With MTE the CPU performs a check on each memory access to make sure that the pointer tag matches the memory tag. 5. On a tag mismatch the CPU generates a tag fault, and a KASAN report is printed. Same as other KASAN modes, hardware tag-based KASAN is intended as a debugging feature at this point. ====== Rationale There are two main reasons for this new hardware tag-based mode: 1. Previously implemented software tag-based KASAN is being successfully used on dogfood testing devices due to its low memory overhead (as initially planned). The new hardware mode keeps the same low memory overhead, and is expected to have significantly lower performance impact, due to the tag checks being performed by the hardware. Therefore the new mode can be used as a better alternative in dogfood testing for hardware that supports MTE. 2. The new mode lays the groundwork for the planned in-kernel MTE-based memory corruption mitigation to be used in production. ====== Technical details Considering the implementation perspective, hardware tag-based KASAN is almost identical to the software mode. The key difference is using MTE for assigning and checking tags. Compared to the software mode, the hardware mode uses 4 bits per tag, as dictated by MTE. Pointer tags are stored in bits [56:60), the top 4 bits have the normal value 0xF. Having less distict tags increases the probablity of false negatives (from ~1/256 to ~1/16) in certain cases. Only synchronous exceptions are set up and used by hardware tag-based KASAN. ====== Benchmarks Note: all measurements have been performed with software emulation of Memory Tagging Extension, performance numbers for hardware tag-based KASAN on the actual hardware are expected to be better. Boot time [1]: * 2.8 sec for clean kernel * 5.7 sec for hardware tag-based KASAN * 11.8 sec for software tag-based KASAN * 11.6 sec for generic KASAN Slab memory usage after boot [2]: * 7.0 kb for clean kernel * 9.7 kb for hardware tag-based KASAN * 9.7 kb for software tag-based KASAN * 41.3 kb for generic KASAN Measurements have been performed with: * defconfig-based configs * Manually built QEMU master * QEMU arguments: -machine virt,mte=on -cpu max * CONFIG_KASAN_STACK_ENABLE disabled * CONFIG_KASAN_INLINE enabled * clang-10 as the compiler and gcc-10 as the assembler [1] Time before the ext4 driver is initialized. [2] Measured as `cat /proc/meminfo | grep Slab`. ====== Notes The cover letter for software tag-based KASAN patchset can be found here: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=0116523cfffa62aeb5aa3b85ce7419f3dae0c1b8 ===== Tags Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com> This patch (of 41): Don't mention "GNU General Public License version 2" text explicitly, as it's already covered by the SPDX-License-Identifier. Link: https://lkml.kernel.org/r/cover.1606161801.git.andreyknvl@google.com Link: https://lkml.kernel.org/r/6ea9f5f4aa9dbbffa0d0c0a780b37699a4531034.1606161801.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Reviewed-by: Marco Elver <elver@google.com> Reviewed-by: Alexander Potapenko <glider@google.com> Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Evgenii Stepanov <eugenis@google.com> Cc: Branislav Rankov <Branislav.Rankov@arm.com> Cc: Kevin Brodsky <kevin.brodsky@arm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* kasan: print workqueue stackWalter Wu2020-12-151-3/+0
| | | | | | | | | | | | | | | | | | | | | The aux_stack[2] is reused to record the call_rcu() call stack and enqueuing work call stacks. So that we need to change the auxiliary stack title for common title, print them in KASAN report. Link: https://lkml.kernel.org/r/20201203022715.30635-1-walter-zh.wu@mediatek.com Signed-off-by: Walter Wu <walter-zh.wu@mediatek.com> Suggested-by: Marco Elver <elver@google.com> Acked-by: Marco Elver <elver@google.com> Reviewed-by: Dmitry Vyukov <dvyukov@google.com> Reviewed-by: Andrey Konovalov <andreyknvl@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Alexander Potapenko <glider@google.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Lai Jiangshan <jiangshanlai@gmail.com> Cc: Matthias Brugger <matthias.bgg@gmail.com> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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