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2024-04-03kasan/test: avoid gcc warning for intentional overflowArnd Bergmann1-1/+2
[ Upstream commit e10aea105e9ed14b62a11844fec6aaa87c6935a3 ] The out-of-bounds test allocates an object that is three bytes too short in order to validate the bounds checking. Starting with gcc-14, this causes a compile-time warning as gcc has grown smart enough to understand the sizeof() logic: mm/kasan/kasan_test.c: In function 'kmalloc_oob_16': mm/kasan/kasan_test.c:443:14: error: allocation of insufficient size '13' for type 'struct <anonymous>' with size '16' [-Werror=alloc-size] 443 | ptr1 = kmalloc(sizeof(*ptr1) - 3, GFP_KERNEL); | ^ Hide the actual computation behind a RELOC_HIDE() that ensures the compiler misses the intentional bug. Link: https://lkml.kernel.org/r/20240212111609.869266-1-arnd@kernel.org Fixes: 3f15801cdc23 ("lib: add kasan test module") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Andrey Konovalov <andreyknvl@gmail.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: Vincenzo Frascino <vincenzo.frascino@arm.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-10-18kasan: disable kasan_non_canonical_hook() for HW tagsArnd Bergmann1-1/+3
On arm64, building with CONFIG_KASAN_HW_TAGS now causes a compile-time error: mm/kasan/report.c: In function 'kasan_non_canonical_hook': mm/kasan/report.c:637:20: error: 'KASAN_SHADOW_OFFSET' undeclared (first use in this function) 637 | if (addr < KASAN_SHADOW_OFFSET) | ^~~~~~~~~~~~~~~~~~~ mm/kasan/report.c:637:20: note: each undeclared identifier is reported only once for each function it appears in mm/kasan/report.c:640:77: error: expected expression before ';' token 640 | orig_addr = (addr - KASAN_SHADOW_OFFSET) << KASAN_SHADOW_SCALE_SHIFT; This was caused by removing the dependency on CONFIG_KASAN_INLINE that used to prevent this from happening. Use the more specific dependency on KASAN_SW_TAGS || KASAN_GENERIC to only ignore the function for hwasan mode. Link: https://lkml.kernel.org/r/20231016200925.984439-1-arnd@kernel.org Fixes: 12ec6a919b0f ("kasan: print the original fault addr when access invalid shadow") 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: Haibo Li <haibo.li@mediatek.com> Cc: Kees Cook <keescook@chromium.org> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> Cc: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com> Cc: Matthias Brugger <matthias.bgg@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-10-18kasan: print the original fault addr when access invalid shadowHaibo Li1-3/+1
when the checked address is illegal,the corresponding shadow address from kasan_mem_to_shadow may have no mapping in mmu table. Access such shadow address causes kernel oops. Here is a sample about oops on arm64(VA 39bit) with KASAN_SW_TAGS and KASAN_OUTLINE on: [ffffffb80aaaaaaa] pgd=000000005d3ce003, p4d=000000005d3ce003, pud=000000005d3ce003, pmd=0000000000000000 Internal error: Oops: 0000000096000006 [#1] PREEMPT SMP Modules linked in: CPU: 3 PID: 100 Comm: sh Not tainted 6.6.0-rc1-dirty #43 Hardware name: linux,dummy-virt (DT) pstate: 80000005 (Nzcv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : __hwasan_load8_noabort+0x5c/0x90 lr : do_ib_ob+0xf4/0x110 ffffffb80aaaaaaa is the shadow address for efffff80aaaaaaaa. The problem is reading invalid shadow in kasan_check_range. The generic kasan also has similar oops. It only reports the shadow address which causes oops but not the original address. Commit 2f004eea0fc8("x86/kasan: Print original address on #GP") introduce to kasan_non_canonical_hook but limit it to KASAN_INLINE. This patch extends it to KASAN_OUTLINE mode. Link: https://lkml.kernel.org/r/20231009073748.159228-1-haibo.li@mediatek.com Fixes: 2f004eea0fc8("x86/kasan: Print original address on #GP") Signed-off-by: Haibo Li <haibo.li@mediatek.com> Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Haibo Li <haibo.li@mediatek.com> Cc: Matthias Brugger <matthias.bgg@gmail.com> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Kees Cook <keescook@chromium.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-09-20kasan: Cleanup the __HAVE_ARCH_SHADOW_MAP usageHuacai Chen1-5/+3
As Linus suggested, __HAVE_ARCH_XYZ is "stupid" and "having historical uses of it doesn't make it good". So migrate __HAVE_ARCH_SHADOW_MAP to separate macros named after the respective functions. Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Reviewed-by: WANG Xuerui <git@xen0n.name> Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2023-09-06kasan: Add (pmd|pud)_init for LoongArch zero_(pud|p4d)_populate processQing Zhang1-4/+14
LoongArch populates pmd/pud with invalid_pmd_table/invalid_pud_table in pagetable_init, So pmd_init/pud_init(p) is required, define them as __weak in mm/kasan/init.c, like mm/sparse-vmemmap.c. Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com> Signed-off-by: Qing Zhang <zhangqing@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2023-09-06kasan: Add __HAVE_ARCH_SHADOW_MAP to support arch specific mappingQing Zhang1-0/+6
MIPS, LoongArch and some other architectures have many holes between different segments and the valid address space (256T available) is insufficient to map all these segments to kasan shadow memory with the common formula provided by kasan core. So we need architecture specific mapping formulas to ensure different segments are mapped individually, and only limited space lengths of those specific segments are mapped to shadow. Therefore, when the incoming address is converted to a shadow, we need to add a condition to determine whether it is valid. Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com> Signed-off-by: Qing Zhang <zhangqing@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
2023-07-08kasan, slub: fix HW_TAGS zeroing with slub_debugAndrey Konovalov1-12/+0
Commit 946fa0dbf2d8 ("mm/slub: extend redzone check to extra allocated kmalloc space than requested") added precise kmalloc redzone poisoning to the slub_debug functionality. However, this commit didn't account for HW_TAGS KASAN fully initializing the object via its built-in memory initialization feature. Even though HW_TAGS KASAN memory initialization contains special memory initialization handling for when slub_debug is enabled, it does not account for in-object slub_debug redzones. As a result, HW_TAGS KASAN can overwrite these redzones and cause false-positive slub_debug reports. To fix the issue, avoid HW_TAGS KASAN memory initialization when slub_debug is enabled altogether. Implement this by moving the __slub_debug_enabled check to slab_post_alloc_hook. Common slab code seems like a more appropriate place for a slub_debug check anyway. Link: https://lkml.kernel.org/r/678ac92ab790dba9198f9ca14f405651b97c8502.1688561016.git.andreyknvl@google.com Fixes: 946fa0dbf2d8 ("mm/slub: extend redzone check to extra allocated kmalloc space than requested") Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Reported-by: Will Deacon <will@kernel.org> Acked-by: Marco Elver <elver@google.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.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: Feng Tang <feng.tang@intel.com> Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: kasan-dev@googlegroups.com Cc: Pekka Enberg <penberg@kernel.org> Cc: Peter Collingbourne <pcc@google.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-07-08kasan: fix type cast in memory_is_poisoned_nAndrey Konovalov1-1/+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>
2023-06-24kasan,kmsan: remove __GFP_KSWAPD_RECLAIM usage from kasan/kmsanTetsuo Handa2-3/+3
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>
2023-06-20kasan: add support for kasan.fault=panic_on_writeMarco Elver1-5/+26
KASAN's boot time kernel parameter 'kasan.fault=' currently supports 'report' and 'panic', which results in either only reporting bugs or also panicking on reports. However, some users may wish to have more control over when KASAN reports result in a kernel panic: in particular, KASAN reported invalid _writes_ are of special interest, because they have greater potential to corrupt random kernel memory or be more easily exploited. To panic on invalid writes only, introduce 'kasan.fault=panic_on_write', which allows users to choose to continue running on invalid reads, but panic only on invalid writes. Link: https://lkml.kernel.org/r/20230614095158.1133673-1-elver@google.com Signed-off-by: Marco Elver <elver@google.com> Reviewed-by: Alexander Potapenko <glider@google.com> Cc: Aleksandr Nogikh <nogikh@google.com> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Taras Madan <tarasmadan@google.com> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-20mm: ptep_get() conversionRyan Roberts2-8/+11
Convert all instances of direct pte_t* dereferencing to instead use ptep_get() helper. This means that by default, the accesses change from a C dereference to a READ_ONCE(). This is technically the correct thing to do since where pgtables are modified by HW (for access/dirty) they are volatile and therefore we should always ensure READ_ONCE() semantics. But more importantly, by always using the helper, it can be overridden by the architecture to fully encapsulate the contents of the pte. Arch code is deliberately not converted, as the arch code knows best. It is intended that arch code (arm64) will override the default with its own implementation that can (e.g.) hide certain bits from the core code, or determine young/dirty status by mixing in state from another source. Conversion was done using Coccinelle: ---- // $ make coccicheck \ // COCCI=ptepget.cocci \ // SPFLAGS="--include-headers" \ // MODE=patch virtual patch @ depends on patch @ pte_t *v; @@ - *v + ptep_get(v) ---- Then reviewed and hand-edited to avoid multiple unnecessary calls to ptep_get(), instead opting to store the result of a single call in a variable, where it is correct to do so. This aims to negate any cost of READ_ONCE() and will benefit arch-overrides that may be more complex. Included is a fix for an issue in an earlier version of this patch that was pointed out by kernel test robot. The issue arose because config MMU=n elides definition of the ptep helper functions, including ptep_get(). HUGETLB_PAGE=n configs still define a simple huge_ptep_clear_flush() for linking purposes, which dereferences the ptep. So when both configs are disabled, this caused a build error because ptep_get() is not defined. Fix by continuing to do a direct dereference when MMU=n. This is safe because for this config the arch code cannot be trying to virtualize the ptes because none of the ptep helpers are defined. Link: https://lkml.kernel.org/r/20230612151545.3317766-4-ryan.roberts@arm.com Reported-by: kernel test robot <lkp@intel.com> Link: https://lore.kernel.org/oe-kbuild-all/202305120142.yXsNEo6H-lkp@intel.com/ Signed-off-by: Ryan Roberts <ryan.roberts@arm.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Potapenko <glider@google.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Alex Williamson <alex.williamson@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Christian Brauner <brauner@kernel.org> Cc: Christoph Hellwig <hch@infradead.org> Cc: Daniel Vetter <daniel@ffwll.ch> Cc: Dave Airlie <airlied@gmail.com> Cc: Dimitri Sivanich <dimitri.sivanich@hpe.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Ian Rogers <irogers@google.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Jérôme Glisse <jglisse@redhat.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Lorenzo Stoakes <lstoakes@gmail.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Mike Rapoport (IBM) <rppt@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Naoya Horiguchi <naoya.horiguchi@nec.com> Cc: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: SeongJae Park <sj@kernel.org> Cc: Shakeel Butt <shakeelb@google.com> Cc: Uladzislau Rezki (Sony) <urezki@gmail.com> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> Cc: Yu Zhao <yuzhao@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-06-10kasan: use internal prototypes matching gcc-13 builtinsArnd Bergmann9-162/+161
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>
2023-06-10kasan: add kasan_tag_mismatch prototypeArnd Bergmann1-0/+3
The kasan sw-tags implementation contains one function that is only called from assembler and has no prototype in a header. This causes a W=1 warning: mm/kasan/sw_tags.c:171:6: warning: no previous prototype for 'kasan_tag_mismatch' [-Wmissing-prototypes] 171 | void kasan_tag_mismatch(unsigned long addr, unsigned long access_info, Add a prototype in the local header to get a clean build. Link: https://lkml.kernel.org/r/20230509145735.9263-1-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>
2023-05-03kasan: hw_tags: avoid invalid virt_to_page()Mark Rutland1-2/+2
When booting with 'kasan.vmalloc=off', a kernel configured with support for KASAN_HW_TAGS will explode at boot time due to bogus use of virt_to_page() on a vmalloc adddress. With CONFIG_DEBUG_VIRTUAL selected this will be reported explicitly, and with or without CONFIG_DEBUG_VIRTUAL the kernel will dereference a bogus address: | ------------[ cut here ]------------ | virt_to_phys used for non-linear address: (____ptrval____) (0xffff800008000000) | WARNING: CPU: 0 PID: 0 at arch/arm64/mm/physaddr.c:15 __virt_to_phys+0x78/0x80 | Modules linked in: | CPU: 0 PID: 0 Comm: swapper/0 Not tainted 6.3.0-rc3-00073-g83865133300d-dirty #4 | Hardware name: linux,dummy-virt (DT) | pstate: 600000c5 (nZCv daIF -PAN -UAO -TCO -DIT -SSBS BTYPE=--) | pc : __virt_to_phys+0x78/0x80 | lr : __virt_to_phys+0x78/0x80 | sp : ffffcd076afd3c80 | x29: ffffcd076afd3c80 x28: 0068000000000f07 x27: ffff800008000000 | x26: fffffbfff0000000 x25: fffffbffff000000 x24: ff00000000000000 | x23: ffffcd076ad3c000 x22: fffffc0000000000 x21: ffff800008000000 | x20: ffff800008004000 x19: ffff800008000000 x18: ffff800008004000 | x17: 666678302820295f x16: ffffffffffffffff x15: 0000000000000004 | x14: ffffcd076b009e88 x13: 0000000000000fff x12: 0000000000000003 | x11: 00000000ffffefff x10: c0000000ffffefff x9 : 0000000000000000 | x8 : 0000000000000000 x7 : 205d303030303030 x6 : 302e30202020205b | x5 : ffffcd076b41d63f x4 : ffffcd076afd3827 x3 : 0000000000000000 | x2 : 0000000000000000 x1 : ffffcd076afd3a30 x0 : 000000000000004f | Call trace: | __virt_to_phys+0x78/0x80 | __kasan_unpoison_vmalloc+0xd4/0x478 | __vmalloc_node_range+0x77c/0x7b8 | __vmalloc_node+0x54/0x64 | init_IRQ+0x94/0xc8 | start_kernel+0x194/0x420 | __primary_switched+0xbc/0xc4 | ---[ end trace 0000000000000000 ]--- | Unable to handle kernel paging request at virtual address 03fffacbe27b8000 | Mem abort info: | ESR = 0x0000000096000004 | EC = 0x25: DABT (current EL), IL = 32 bits | SET = 0, FnV = 0 | EA = 0, S1PTW = 0 | FSC = 0x04: level 0 translation fault | Data abort info: | ISV = 0, ISS = 0x00000004 | CM = 0, WnR = 0 | swapper pgtable: 4k pages, 48-bit VAs, pgdp=0000000041bc5000 | [03fffacbe27b8000] pgd=0000000000000000, p4d=0000000000000000 | Internal error: Oops: 0000000096000004 [#1] PREEMPT SMP | Modules linked in: | CPU: 0 PID: 0 Comm: swapper/0 Tainted: G W 6.3.0-rc3-00073-g83865133300d-dirty #4 | Hardware name: linux,dummy-virt (DT) | pstate: 200000c5 (nzCv daIF -PAN -UAO -TCO -DIT -SSBS BTYPE=--) | pc : __kasan_unpoison_vmalloc+0xe4/0x478 | lr : __kasan_unpoison_vmalloc+0xd4/0x478 | sp : ffffcd076afd3ca0 | x29: ffffcd076afd3ca0 x28: 0068000000000f07 x27: ffff800008000000 | x26: 0000000000000000 x25: 03fffacbe27b8000 x24: ff00000000000000 | x23: ffffcd076ad3c000 x22: fffffc0000000000 x21: ffff800008000000 | x20: ffff800008004000 x19: ffff800008000000 x18: ffff800008004000 | x17: 666678302820295f x16: ffffffffffffffff x15: 0000000000000004 | x14: ffffcd076b009e88 x13: 0000000000000fff x12: 0000000000000001 | x11: 0000800008000000 x10: ffff800008000000 x9 : ffffb2f8dee00000 | x8 : 000ffffb2f8dee00 x7 : 205d303030303030 x6 : 302e30202020205b | x5 : ffffcd076b41d63f x4 : ffffcd076afd3827 x3 : 0000000000000000 | x2 : 0000000000000000 x1 : ffffcd076afd3a30 x0 : ffffb2f8dee00000 | Call trace: | __kasan_unpoison_vmalloc+0xe4/0x478 | __vmalloc_node_range+0x77c/0x7b8 | __vmalloc_node+0x54/0x64 | init_IRQ+0x94/0xc8 | start_kernel+0x194/0x420 | __primary_switched+0xbc/0xc4 | Code: d34cfc08 aa1f03fa 8b081b39 d503201f (f9400328) | ---[ end trace 0000000000000000 ]--- | Kernel panic - not syncing: Attempted to kill the idle task! This is because init_vmalloc_pages() erroneously calls virt_to_page() on a vmalloc address, while virt_to_page() is only valid for addresses in the linear/direct map. Since init_vmalloc_pages() expects virtual addresses in the vmalloc range, it must use vmalloc_to_page() rather than virt_to_page(). We call init_vmalloc_pages() from __kasan_unpoison_vmalloc(), where we check !is_vmalloc_or_module_addr(), suggesting that we might encounter a non-vmalloc address. Luckily, this never happens. By design, we only call __kasan_unpoison_vmalloc() on pointers in the vmalloc area, and I have verified that we don't violate that expectation. Given that, is_vmalloc_or_module_addr() must always be true for any legitimate argument to __kasan_unpoison_vmalloc(). Correct init_vmalloc_pages() to use vmalloc_to_page(), and remove the redundant and misleading use of is_vmalloc_or_module_addr() in __kasan_unpoison_vmalloc(). Link: https://lkml.kernel.org/r/20230418164212.1775741-1-mark.rutland@arm.com Fixes: 6c2f761dad7851d8 ("kasan: fix zeroing vmalloc memory with HW_TAGS") Signed-off-by: Mark Rutland <mark.rutland@arm.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Konovalov <andreyknvl@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> 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>
2023-04-22kasan: fix lockdep report invalid wait contextZqiang1-26/+8
For kernels built with the following options and booting CONFIG_SLUB=y CONFIG_DEBUG_LOCKDEP=y CONFIG_PROVE_LOCKING=y CONFIG_PROVE_RAW_LOCK_NESTING=y [ 0.523115] [ BUG: Invalid wait context ] [ 0.523315] 6.3.0-rc1-yocto-standard+ #739 Not tainted [ 0.523649] ----------------------------- [ 0.523663] swapper/0/0 is trying to lock: [ 0.523663] ffff888035611360 (&c->lock){....}-{3:3}, at: put_cpu_partial+0x2e/0x1e0 [ 0.523663] other info that might help us debug this: [ 0.523663] context-{2:2} [ 0.523663] no locks held by swapper/0/0. [ 0.523663] stack backtrace: [ 0.523663] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 6.3.0-rc1-yocto-standard+ #739 [ 0.523663] Call Trace: [ 0.523663] <IRQ> [ 0.523663] dump_stack_lvl+0x64/0xb0 [ 0.523663] dump_stack+0x10/0x20 [ 0.523663] __lock_acquire+0x6c4/0x3c10 [ 0.523663] lock_acquire+0x188/0x460 [ 0.523663] put_cpu_partial+0x5a/0x1e0 [ 0.523663] __slab_free+0x39a/0x520 [ 0.523663] ___cache_free+0xa9/0xc0 [ 0.523663] qlist_free_all+0x7a/0x160 [ 0.523663] per_cpu_remove_cache+0x5c/0x70 [ 0.523663] __flush_smp_call_function_queue+0xfc/0x330 [ 0.523663] generic_smp_call_function_single_interrupt+0x13/0x20 [ 0.523663] __sysvec_call_function+0x86/0x2e0 [ 0.523663] sysvec_call_function+0x73/0x90 [ 0.523663] </IRQ> [ 0.523663] <TASK> [ 0.523663] asm_sysvec_call_function+0x1b/0x20 [ 0.523663] RIP: 0010:default_idle+0x13/0x20 [ 0.523663] RSP: 0000:ffffffff83e07dc0 EFLAGS: 00000246 [ 0.523663] RAX: 0000000000000000 RBX: ffffffff83e1e200 RCX: ffffffff82a83293 [ 0.523663] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8119a6b1 [ 0.523663] RBP: ffffffff83e07dc8 R08: 0000000000000001 R09: ffffed1006ac0d66 [ 0.523663] R10: ffff888035606b2b R11: ffffed1006ac0d65 R12: 0000000000000000 [ 0.523663] R13: ffffffff83e1e200 R14: ffffffff84a7d980 R15: 0000000000000000 [ 0.523663] default_idle_call+0x6c/0xa0 [ 0.523663] do_idle+0x2e1/0x330 [ 0.523663] cpu_startup_entry+0x20/0x30 [ 0.523663] rest_init+0x152/0x240 [ 0.523663] arch_call_rest_init+0x13/0x40 [ 0.523663] start_kernel+0x331/0x470 [ 0.523663] x86_64_start_reservations+0x18/0x40 [ 0.523663] x86_64_start_kernel+0xbb/0x120 [ 0.523663] secondary_startup_64_no_verify+0xe0/0xeb [ 0.523663] </TASK> The local_lock_irqsave() is invoked in put_cpu_partial() and happens in IPI context, due to the CONFIG_PROVE_RAW_LOCK_NESTING=y (the LD_WAIT_CONFIG not equal to LD_WAIT_SPIN), so acquire local_lock in IPI context will trigger above calltrace. This commit therefore moves qlist_free_all() from hard-irq context to task context. Link: https://lkml.kernel.org/r/20230327120019.1027640-1-qiang1.zhang@intel.com Signed-off-by: Zqiang <qiang1.zhang@intel.com> Acked-by: Marco Elver <elver@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> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-19printk: export console trace point for kcsan/kasan/kfence/kmsanPavankumar Kondeti1-20/+2
The console tracepoint is used by kcsan/kasan/kfence/kmsan test modules. Since this tracepoint is not exported, these modules iterate over all available tracepoints to find the console trace point. Export the trace point so that it can be directly used. Link: https://lkml.kernel.org/r/20230413100859.1492323-1-quic_pkondeti@quicinc.com Signed-off-by: Pavankumar Kondeti <quic_pkondeti@quicinc.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: John Ogness <john.ogness@linutronix.de> Cc: Marco Elver <elver@google.com> Cc: Petr Mladek <pmladek@suse.com> Cc: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-06kasan: suppress recursive reports for HW_TAGSAndrey Konovalov1-11/+48
KASAN suppresses reports for bad accesses done by the KASAN reporting code. The reporting code might access poisoned memory for reporting purposes. Software KASAN modes do this by suppressing reports during reporting via current->kasan_depth, the same way they suppress reports during accesses to poisoned slab metadata. Hardware Tag-Based KASAN does not use current->kasan_depth, and instead resets pointer tags for accesses to poisoned memory done by the reporting code. Despite that, a recursive report can still happen: 1. On hardware with faulty MTE support. This was observed by Weizhao Ouyang on a faulty hardware that caused memory tags to randomly change from time to time. 2. Theoretically, due to a previous MTE-undetected memory corruption. A recursive report can happen via: 1. Accessing a pointer with a non-reset tag in the reporting code, e.g. slab->slab_cache, which is what Weizhao Ouyang observed. 2. Theoretically, via external non-annotated routines, e.g. stackdepot. To resolve this issue, resetting tags for all of the pointers in the reporting code and all the used external routines would be impractical. Instead, disable tag checking done by the CPU for the duration of KASAN reporting for Hardware Tag-Based KASAN. Without this fix, Hardware Tag-Based KASAN reporting code might deadlock. [andreyknvl@google.com: disable preemption instead of migration, fix comment typo] Link: https://lkml.kernel.org/r/d14417c8bc5eea7589e99381203432f15c0f9138.1680114854.git.andreyknvl@google.com Link: https://lkml.kernel.org/r/59f433e00f7fa985e8bf9f7caf78574db16b67ab.1678491668.git.andreyknvl@google.com Fixes: 2e903b914797 ("kasan, arm64: implement HW_TAGS runtime") Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Reported-by: Weizhao Ouyang <ouyangweizhao@zeku.com> Reviewed-by: Marco Elver <elver@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Evgenii Stepanov <eugenis@google.com> Cc: Peter Collingbourne <pcc@google.com> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-06kasan, arm64: add arch_suppress_tag_checks_start/stopAndrey Konovalov1-0/+2
Add two new tagging-related routines arch_suppress_tag_checks_start/stop that suppress MTE tag checking via the TCO register. These rouines are used in the next patch. [andreyknvl@google.com: drop __ from mte_disable/enable_tco names] Link: https://lkml.kernel.org/r/7ad5e5a9db79e3aba08d8f43aca24350b04080f6.1680114854.git.andreyknvl@google.com Link: https://lkml.kernel.org/r/75a362551c3c54b70ae59a3492cabb51c105fa6b.1678491668.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Evgenii Stepanov <eugenis@google.com> Cc: Marco Elver <elver@google.com> Cc: Peter Collingbourne <pcc@google.com> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> Cc: Weizhao Ouyang <ouyangweizhao@zeku.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-06kasan, arm64: rename tagging-related routinesAndrey Konovalov3-12/+12
Rename arch_enable_tagging_sync/async/asymm to arch_enable_tag_checks_sync/async/asymm, as the new name better reflects their function. Also rename kasan_enable_tagging to kasan_enable_hw_tags for the same reason. Link: https://lkml.kernel.org/r/069ef5b77715c1ac8d69b186725576c32b149491.1678491668.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Evgenii Stepanov <eugenis@google.com> Cc: Marco Elver <elver@google.com> Cc: Peter Collingbourne <pcc@google.com> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> Cc: Weizhao Ouyang <ouyangweizhao@zeku.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-06kasan: drop empty tagging-related definesAndrey Konovalov1-26/+0
mm/kasan/kasan.h provides a number of empty defines for a few arch-specific tagging-related routines, in case the architecture code didn't define them. The original idea was to simplify integration in case another architecture starts supporting memory tagging. However, right now, if any of those routines are not provided by an architecture, Hardware Tag-Based KASAN won't work. Drop the empty defines, as it would be better to get compiler errors rather than runtime crashes when adding support for a new architecture. Also drop empty hw_enable_tagging_sync/async/asymm defines for !CONFIG_KASAN_HW_TAGS case, as those are only used in mm/kasan/hw_tags.c. Link: https://lkml.kernel.org/r/bc919c144f8684a7fd9ba70c356ac2a75e775e29.1678491668.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Catalin Marinas <catalin.marinas@arm.com> [arm64] Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Evgenii Stepanov <eugenis@google.com> Cc: Marco Elver <elver@google.com> Cc: Peter Collingbourne <pcc@google.com> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> Cc: Weizhao Ouyang <ouyangweizhao@zeku.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-03-29kasan: remove PG_skip_kasan_poison flagPeter Collingbourne1-1/+1
Code inspection reveals that PG_skip_kasan_poison is redundant with kasantag, because the former is intended to be set iff the latter is the match-all tag. It can also be observed that it's basically pointless to poison pages which have kasantag=0, because any pages with this tag would have been pointed to by pointers with match-all tags, so poisoning the pages would have little to no effect in terms of bug detection. Therefore, change the condition in should_skip_kasan_poison() to check kasantag instead, and remove PG_skip_kasan_poison and associated flags. Link: https://lkml.kernel.org/r/20230310042914.3805818-3-pcc@google.com Link: https://linux-review.googlesource.com/id/I57f825f2eaeaf7e8389d6cf4597c8a5821359838 Signed-off-by: Peter Collingbourne <pcc@google.com> Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Evgenii Stepanov <eugenis@google.com> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-03-03kasan: test: fix test for new meminstrinsic instrumentationMarco Elver2-1/+37
The tests for memset/memmove have been failing since they haven't been instrumented in 69d4c0d32186. Fix the test to recognize when memintrinsics aren't instrumented, and skip test cases accordingly. We also need to conditionally pass -fno-builtin to the test, otherwise the instrumentation pass won't recognize memintrinsics and end up not instrumenting them either. Link: https://lkml.kernel.org/r/20230224085942.1791837-3-elver@google.com Fixes: 69d4c0d32186 ("entry, kasan, x86: Disallow overriding mem*() functions") Reported-by: Linux Kernel Functional Testing <lkft@linaro.org> Signed-off-by: Marco Elver <elver@google.com> Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com> Tested-by: Linux Kernel Functional Testing <lkft@linaro.org> Tested-by: Naresh Kamboju <naresh.kamboju@linaro.org> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Borislav Petkov (AMD) <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jakub Jelinek <jakub@redhat.com> Cc: Kees Cook <keescook@chromium.org> Cc: Nathan Chancellor <nathan@kernel.org> Cc: Nick Desaulniers <ndesaulniers@google.com> Cc: Nicolas Schier <nicolas@fjasle.eu> Cc: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-03-03kasan: treat meminstrinsic as builtins in uninstrumented filesMarco Elver1-1/+4
Where the compiler instruments meminstrinsics by generating calls to __asan/__hwasan_ prefixed functions, let the compiler consider memintrinsics as builtin again. To do so, never override memset/memmove/memcpy if the compiler does the correct instrumentation - even on !GENERIC_ENTRY architectures. [elver@google.com: powerpc: don't rename memintrinsics if compiler adds prefixes] Link: https://lore.kernel.org/all/20230224085942.1791837-1-elver@google.com/ [1] Link: https://lkml.kernel.org/r/20230227094726.3833247-1-elver@google.com Link: https://lkml.kernel.org/r/20230224085942.1791837-2-elver@google.com Fixes: 69d4c0d32186 ("entry, kasan, x86: Disallow overriding mem*() functions") Signed-off-by: Marco Elver <elver@google.com> Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com> Tested-by: Linux Kernel Functional Testing <lkft@linaro.org> Tested-by: Naresh Kamboju <naresh.kamboju@linaro.org> Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc) Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Borislav Petkov (AMD) <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jakub Jelinek <jakub@redhat.com> Cc: Kees Cook <keescook@chromium.org> Cc: Nathan Chancellor <nathan@kernel.org> Cc: Nick Desaulniers <ndesaulniers@google.com> Cc: Nicolas Schier <nicolas@fjasle.eu> Cc: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-03-03kasan: emit different calls for instrumentable memintrinsicsMarco Elver2-0/+15
Clang 15 provides an option to prefix memcpy/memset/memmove calls with __asan_/__hwasan_ in instrumented functions: https://reviews.llvm.org/D122724 GCC will add support in future: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108777 Use it to regain KASAN instrumentation of memcpy/memset/memmove on architectures that require noinstr to be really free from instrumented mem*() functions (all GENERIC_ENTRY architectures). Link: https://lkml.kernel.org/r/20230224085942.1791837-1-elver@google.com Fixes: 69d4c0d32186 ("entry, kasan, x86: Disallow overriding mem*() functions") Signed-off-by: Marco Elver <elver@google.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com> Tested-by: Linux Kernel Functional Testing <lkft@linaro.org> Tested-by: Naresh Kamboju <naresh.kamboju@linaro.org> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Borislav Petkov (AMD) <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jakub Jelinek <jakub@redhat.com> Cc: kasan-dev@googlegroups.com Cc: Kees Cook <keescook@chromium.org> Cc: Linux Kernel Functional Testing <lkft@linaro.org> Cc: Nathan Chancellor <nathan@kernel.org> # build only Cc: Nick Desaulniers <ndesaulniers@google.com> Cc: Nicolas Schier <nicolas@fjasle.eu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-02-24Merge tag 'mm-stable-2023-02-20-13-37' of ↵Linus Torvalds10-33/+226
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM updates from Andrew Morton: - Daniel Verkamp has contributed a memfd series ("mm/memfd: add F_SEAL_EXEC") which permits the setting of the memfd execute bit at memfd creation time, with the option of sealing the state of the X bit. - Peter Xu adds a patch series ("mm/hugetlb: Make huge_pte_offset() thread-safe for pmd unshare") which addresses a rare race condition related to PMD unsharing. - Several folioification patch serieses from Matthew Wilcox, Vishal Moola, Sidhartha Kumar and Lorenzo Stoakes - Johannes Weiner has a series ("mm: push down lock_page_memcg()") which does perform some memcg maintenance and cleanup work. - SeongJae Park has added DAMOS filtering to DAMON, with the series "mm/damon/core: implement damos filter". These filters provide users with finer-grained control over DAMOS's actions. SeongJae has also done some DAMON cleanup work. - Kairui Song adds a series ("Clean up and fixes for swap"). - Vernon Yang contributed the series "Clean up and refinement for maple tree". - Yu Zhao has contributed the "mm: multi-gen LRU: memcg LRU" series. It adds to MGLRU an LRU of memcgs, to improve the scalability of global reclaim. - David Hildenbrand has added some userfaultfd cleanup work in the series "mm: uffd-wp + change_protection() cleanups". - Christoph Hellwig has removed the generic_writepages() library function in the series "remove generic_writepages". - Baolin Wang has performed some maintenance on the compaction code in his series "Some small improvements for compaction". - Sidhartha Kumar is doing some maintenance work on struct page in his series "Get rid of tail page fields". - David Hildenbrand contributed some cleanup, bugfixing and generalization of pte management and of pte debugging in his series "mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE on all architectures with swap PTEs". - Mel Gorman and Neil Brown have removed the __GFP_ATOMIC allocation flag in the series "Discard __GFP_ATOMIC". - Sergey Senozhatsky has improved zsmalloc's memory utilization with his series "zsmalloc: make zspage chain size configurable". - Joey Gouly has added prctl() support for prohibiting the creation of writeable+executable mappings. The previous BPF-based approach had shortcomings. See "mm: In-kernel support for memory-deny-write-execute (MDWE)". - Waiman Long did some kmemleak cleanup and bugfixing in the series "mm/kmemleak: Simplify kmemleak_cond_resched() & fix UAF". - T.J. Alumbaugh has contributed some MGLRU cleanup work in his series "mm: multi-gen LRU: improve". - Jiaqi Yan has provided some enhancements to our memory error statistics reporting, mainly by presenting the statistics on a per-node basis. See the series "Introduce per NUMA node memory error statistics". - Mel Gorman has a second and hopefully final shot at fixing a CPU-hog regression in compaction via his series "Fix excessive CPU usage during compaction". - Christoph Hellwig does some vmalloc maintenance work in the series "cleanup vfree and vunmap". - Christoph Hellwig has removed block_device_operations.rw_page() in ths series "remove ->rw_page". - We get some maple_tree improvements and cleanups in Liam Howlett's series "VMA tree type safety and remove __vma_adjust()". - Suren Baghdasaryan has done some work on the maintainability of our vm_flags handling in the series "introduce vm_flags modifier functions". - Some pagemap cleanup and generalization work in Mike Rapoport's series "mm, arch: add generic implementation of pfn_valid() for FLATMEM" and "fixups for generic implementation of pfn_valid()" - Baoquan He has done some work to make /proc/vmallocinfo and /proc/kcore better represent the real state of things in his series "mm/vmalloc.c: allow vread() to read out vm_map_ram areas". - Jason Gunthorpe rationalized the GUP system's interface to the rest of the kernel in the series "Simplify the external interface for GUP". - SeongJae Park wishes to migrate people from DAMON's debugfs interface over to its sysfs interface. To support this, we'll temporarily be printing warnings when people use the debugfs interface. See the series "mm/damon: deprecate DAMON debugfs interface". - Andrey Konovalov provided the accurately named "lib/stackdepot: fixes and clean-ups" series. - Huang Ying has provided a dramatic reduction in migration's TLB flush IPI rates with the series "migrate_pages(): batch TLB flushing". - Arnd Bergmann has some objtool fixups in "objtool warning fixes". * tag 'mm-stable-2023-02-20-13-37' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (505 commits) include/linux/migrate.h: remove unneeded externs mm/memory_hotplug: cleanup return value handing in do_migrate_range() mm/uffd: fix comment in handling pte markers mm: change to return bool for isolate_movable_page() mm: hugetlb: change to return bool for isolate_hugetlb() mm: change to return bool for isolate_lru_page() mm: change to return bool for folio_isolate_lru() objtool: add UACCESS exceptions for __tsan_volatile_read/write kmsan: disable ftrace in kmsan core code kasan: mark addr_has_metadata __always_inline mm: memcontrol: rename memcg_kmem_enabled() sh: initialize max_mapnr m68k/nommu: add missing definition of ARCH_PFN_OFFSET mm: percpu: fix incorrect size in pcpu_obj_full_size() maple_tree: reduce stack usage with gcc-9 and earlier mm: page_alloc: call panic() when memoryless node allocation fails mm: multi-gen LRU: avoid futile retries migrate_pages: move THP/hugetlb migration support check to simplify code migrate_pages: batch flushing TLB migrate_pages: share more code between _unmap and _move ...
2023-02-21Merge tag 'sched-core-2023-02-20' of ↵Linus Torvalds2-0/+42
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler updates from Ingo Molnar: - Improve the scalability of the CFS bandwidth unthrottling logic with large number of CPUs. - Fix & rework various cpuidle routines, simplify interaction with the generic scheduler code. Add __cpuidle methods as noinstr to objtool's noinstr detection and fix boatloads of cpuidle bugs & quirks. - Add new ABI: introduce MEMBARRIER_CMD_GET_REGISTRATIONS, to query previously issued registrations. - Limit scheduler slice duration to the sysctl_sched_latency period, to improve scheduling granularity with a large number of SCHED_IDLE tasks. - Debuggability enhancement on sys_exit(): warn about disabled IRQs, but also enable them to prevent a cascade of followup problems and repeat warnings. - Fix the rescheduling logic in prio_changed_dl(). - Micro-optimize cpufreq and sched-util methods. - Micro-optimize ttwu_runnable() - Micro-optimize the idle-scanning in update_numa_stats(), select_idle_capacity() and steal_cookie_task(). - Update the RSEQ code & self-tests - Constify various scheduler methods - Remove unused methods - Refine __init tags - Documentation updates - Misc other cleanups, fixes * tag 'sched-core-2023-02-20' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (110 commits) sched/rt: pick_next_rt_entity(): check list_entry sched/deadline: Add more reschedule cases to prio_changed_dl() sched/fair: sanitize vruntime of entity being placed sched/fair: Remove capacity inversion detection sched/fair: unlink misfit task from cpu overutilized objtool: mem*() are not uaccess safe cpuidle: Fix poll_idle() noinstr annotation sched/clock: Make local_clock() noinstr sched/clock/x86: Mark sched_clock() noinstr x86/pvclock: Improve atomic update of last_value in pvclock_clocksource_read() x86/atomics: Always inline arch_atomic64*() cpuidle: tracing, preempt: Squash _rcuidle tracing cpuidle: tracing: Warn about !rcu_is_watching() cpuidle: lib/bug: Disable rcu_is_watching() during WARN/BUG cpuidle: drivers: firmware: psci: Dont instrument suspend code KVM: selftests: Fix build of rseq test exit: Detect and fix irq disabled state in oops cpuidle, arm64: Fix the ARM64 cpuidle logic cpuidle: mvebu: Fix duplicate flags assignment sched/fair: Limit sched slice duration ...
2023-02-20kasan: mark addr_has_metadata __always_inlineArnd Bergmann1-2/+2
Patch series "objtool warning fixes", v2. These are three of the easier fixes for objtool warnings around kasan/kmsan/kcsan. I dropped one patch since Peter had come up with a better fix, and adjusted the changelog text based on feedback. This patch (of 3): When the compiler decides not to inline this function, objtool complains about incorrect UACCESS state: mm/kasan/generic.o: warning: objtool: __asan_load2+0x11: call to addr_has_metadata() with UACCESS enabled Link: https://lore.kernel.org/all/20230208164011.2287122-1-arnd@kernel.org/ Link: https://lkml.kernel.org/r/20230215130058.3836177-2-arnd@kernel.org Signed-off-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Marco Elver <elver@google.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: Josh Poimboeuf <jpoimboe@kernel.org> Cc: Kuan-Ying Lee <Kuan-Ying.Lee@mediatek.com> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-02-17lib/stacktrace, kasan, kmsan: rework extra_bits interfaceAndrey Konovalov1-1/+1
The current implementation of the extra_bits interface is confusing: passing extra_bits to __stack_depot_save makes it seem that the extra bits are somehow stored in stack depot. In reality, they are only embedded into a stack depot handle and are not used within stack depot. Drop the extra_bits argument from __stack_depot_save and instead provide a new stack_depot_set_extra_bits function (similar to the exsiting stack_depot_get_extra_bits) that saves extra bits into a stack depot handle. Update the callers of __stack_depot_save to use the new interace. This change also fixes a minor issue in the old code: __stack_depot_save does not return NULL if saving stack trace fails and extra_bits is used. Link: https://lkml.kernel.org/r/317123b5c05e2f82854fc55d8b285e0869d3cb77.1676063693.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Reviewed-by: Alexander Potapenko <glider@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-02-11Merge branch 'mm-hotfixes-stable' into mm-stableAndrew Morton3-1/+21
To pick up depended-upon changes
2023-02-10kasan: infer allocation size by scanning metadataKuan-Ying Lee8-21/+127
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>
2023-02-10kasan: fix Oops due to missing calls to kasan_arch_is_ready()Christophe Leroy3-1/+21
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>
2023-01-31Merge tag 'v6.2-rc6' into sched/core, to pick up fixesIngo Molnar1-1/+1
Pick up fixes before merging another batch of cpuidle updates. Signed-off-by: Ingo Molnar <mingo@kernel.org>
2023-01-19mm/kasan: simplify and refine kasan_cache codeFeng Tang1-7/+2
struct 'kasan_cache' has a member 'is_kmalloc' indicating whether its host kmem_cache is a kmalloc cache. With newly introduced is_kmalloc_cache() helper, 'is_kmalloc' and its related function can be replaced and removed. Also 'kasan_cache' is only needed by KASAN generic mode, and not by SW/HW tag modes, so refine its protection macro accordingly, suggested by Andrey Konoval. Link: https://lkml.kernel.org/r/20230104060605.930910-2-feng.tang@intel.com Signed-off-by: Feng Tang <feng.tang@intel.com> Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: David Rientjes <rientjes@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Christoph Lameter <cl@linux.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-01-19kasan: allow sampling page_alloc allocations for HW_TAGSAndrey Konovalov3-2/+94
As Hardware Tag-Based KASAN is intended to be used in production, its performance impact is crucial. As page_alloc allocations tend to be big, tagging and checking all such allocations can introduce a significant slowdown. Add two new boot parameters that allow to alleviate that slowdown: - kasan.page_alloc.sample, which makes Hardware Tag-Based KASAN tag only every Nth page_alloc allocation with the order configured by the second added parameter (default: tag every such allocation). - kasan.page_alloc.sample.order, which makes sampling enabled by the first parameter only affect page_alloc allocations with the order equal or greater than the specified value (default: 3, see below). The exact performance improvement caused by using the new parameters depends on their values and the applied workload. The chosen default value for kasan.page_alloc.sample.order is 3, which matches both PAGE_ALLOC_COSTLY_ORDER and SKB_FRAG_PAGE_ORDER. This is done for two reasons: 1. PAGE_ALLOC_COSTLY_ORDER is "the order at which allocations are deemed costly to service", which corresponds to the idea that only large and thus costly allocations are supposed to sampled. 2. One of the workloads targeted by this patch is a benchmark that sends a large amount of data over a local loopback connection. Most multi-page data allocations in the networking subsystem have the order of SKB_FRAG_PAGE_ORDER (or PAGE_ALLOC_COSTLY_ORDER). When running a local loopback test on a testing MTE-enabled device in sync mode, enabling Hardware Tag-Based KASAN introduces a ~50% slowdown. Applying this patch and setting kasan.page_alloc.sampling to a value higher than 1 allows to lower the slowdown. The performance improvement saturates around the sampling interval value of 10 with the default sampling page order of 3. This lowers the slowdown to ~20%. The slowdown in real scenarios involving the network will likely be better. Enabling page_alloc sampling has a downside: KASAN misses bad accesses to a page_alloc allocation that has not been tagged. This lowers the value of KASAN as a security mitigation. However, based on measuring the number of page_alloc allocations of different orders during boot in a test build, sampling with the default kasan.page_alloc.sample.order value affects only ~7% of allocations. The rest ~93% of allocations are still checked deterministically. Link: https://lkml.kernel.org/r/129da0614123bb85ed4dd61ae30842b2dd7c903f.1671471846.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: Jann Horn <jannh@google.com> Cc: Mark Brand <markbrand@google.com> Cc: Peter Collingbourne <pcc@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-01-13entry, kasan, x86: Disallow overriding mem*() functionsPeter Zijlstra2-0/+42
KASAN cannot just hijack the mem*() functions, it needs to emit __asan_mem*() variants if it wants instrumentation (other sanitizers already do this). vmlinux.o: warning: objtool: sync_regs+0x24: call to memcpy() leaves .noinstr.text section vmlinux.o: warning: objtool: vc_switch_off_ist+0xbe: call to memcpy() leaves .noinstr.text section vmlinux.o: warning: objtool: fixup_bad_iret+0x36: call to memset() leaves .noinstr.text section vmlinux.o: warning: objtool: __sev_get_ghcb+0xa0: call to memcpy() leaves .noinstr.text section vmlinux.o: warning: objtool: __sev_put_ghcb+0x35: call to memcpy() leaves .noinstr.text section Remove the weak aliases to ensure nobody hijacks these functions and add them to the noinstr section. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Tested-by: Tony Lindgren <tony@atomide.com> Tested-by: Ulf Hansson <ulf.hansson@linaro.org> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Frederic Weisbecker <frederic@kernel.org> Link: https://lore.kernel.org/r/20230112195542.028523143@infradead.org
2023-01-12kasan: mark kasan_kunit_executing as staticAndrey Konovalov1-1/+1
Mark kasan_kunit_executing as static, as it is only used within mm/kasan/report.c. Link: https://lkml.kernel.org/r/f64778a4683b16a73bba72576f73bf4a2b45a82f.1672794398.git.andreyknvl@google.com Fixes: c8c7016f50c8 ("kasan: fail non-kasan KUnit tests on KASAN reports") Reported-by: kernel test robot <lkp@intel.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> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-12-14Merge tag 'hardening-v6.2-rc1' of ↵Linus Torvalds2-8/+15
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 ...
2022-12-14Merge tag 'mm-stable-2022-12-13' of ↵Linus Torvalds5-113/+185
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM updates from Andrew Morton: - More userfaultfs work from Peter Xu - Several convert-to-folios series from Sidhartha Kumar and Huang Ying - Some filemap cleanups from Vishal Moola - David Hildenbrand added the ability to selftest anon memory COW handling - Some cpuset simplifications from Liu Shixin - Addition of vmalloc tracing support by Uladzislau Rezki - Some pagecache folioifications and simplifications from Matthew Wilcox - A pagemap cleanup from Kefeng Wang: we have VM_ACCESS_FLAGS, so use it - Miguel Ojeda contributed some cleanups for our use of the __no_sanitize_thread__ gcc keyword. This series should have been in the non-MM tree, my bad - Naoya Horiguchi improved the interaction between memory poisoning and memory section removal for huge pages - DAMON cleanups and tuneups from SeongJae Park - Tony Luck fixed the handling of COW faults against poisoned pages - Peter Xu utilized the PTE marker code for handling swapin errors - Hugh Dickins reworked compound page mapcount handling, simplifying it and making it more efficient - Removal of the autonuma savedwrite infrastructure from Nadav Amit and David Hildenbrand - zram support for multiple compression streams from Sergey Senozhatsky - David Hildenbrand reworked the GUP code's R/O long-term pinning so that drivers no longer need to use the FOLL_FORCE workaround which didn't work very well anyway - Mel Gorman altered the page allocator so that local IRQs can remnain enabled during per-cpu page allocations - Vishal Moola removed the try_to_release_page() wrapper - Stefan Roesch added some per-BDI sysfs tunables which are used to prevent network block devices from dirtying excessive amounts of pagecache - David Hildenbrand did some cleanup and repair work on KSM COW breaking - Nhat Pham and Johannes Weiner have implemented writeback in zswap's zsmalloc backend - Brian Foster has fixed a longstanding corner-case oddity in file[map]_write_and_wait_range() - sparse-vmemmap changes for MIPS, LoongArch and NIOS2 from Feiyang Chen - Shiyang Ruan has done some work on fsdax, to make its reflink mode work better under xfstests. Better, but still not perfect - Christoph Hellwig has removed the .writepage() method from several filesystems. They only need .writepages() - Yosry Ahmed wrote a series which fixes the memcg reclaim target beancounting - David Hildenbrand has fixed some of our MM selftests for 32-bit machines - Many singleton patches, as usual * tag 'mm-stable-2022-12-13' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (313 commits) mm/hugetlb: set head flag before setting compound_order in __prep_compound_gigantic_folio mm: mmu_gather: allow more than one batch of delayed rmaps mm: fix typo in struct pglist_data code comment kmsan: fix memcpy tests mm: add cond_resched() in swapin_walk_pmd_entry() mm: do not show fs mm pc for VM_LOCKONFAULT pages selftests/vm: ksm_functional_tests: fixes for 32bit selftests/vm: cow: fix compile warning on 32bit selftests/vm: madv_populate: fix missing MADV_POPULATE_(READ|WRITE) definitions mm/gup_test: fix PIN_LONGTERM_TEST_READ with highmem mm,thp,rmap: fix races between updates of subpages_mapcount mm: memcg: fix swapcached stat accounting mm: add nodes= arg to memory.reclaim mm: disable top-tier fallback to reclaim on proactive reclaim selftests: cgroup: make sure reclaim target memcg is unprotected selftests: cgroup: refactor proactive reclaim code to reclaim_until() mm: memcg: fix stale protection of reclaim target memcg mm/mmap: properly unaccount memory on mas_preallocate() failure omfs: remove ->writepage jfs: remove ->writepage ...
2022-12-13Merge tag 'random-6.2-rc1-for-linus' of ↵Linus Torvalds1-3/+3
git://git.kernel.org/pub/scm/linux/kernel/git/crng/random Pull random number generator updates from Jason Donenfeld: - Replace prandom_u32_max() and various open-coded variants of it, there is now a new family of functions that uses fast rejection sampling to choose properly uniformly random numbers within an interval: get_random_u32_below(ceil) - [0, ceil) get_random_u32_above(floor) - (floor, U32_MAX] get_random_u32_inclusive(floor, ceil) - [floor, ceil] Coccinelle was used to convert all current users of prandom_u32_max(), as well as many open-coded patterns, resulting in improvements throughout the tree. I'll have a "late" 6.1-rc1 pull for you that removes the now unused prandom_u32_max() function, just in case any other trees add a new use case of it that needs to converted. According to linux-next, there may be two trivial cases of prandom_u32_max() reintroductions that are fixable with a 's/.../.../'. So I'll have for you a final conversion patch doing that alongside the removal patch during the second week. This is a treewide change that touches many files throughout. - More consistent use of get_random_canary(). - Updates to comments, documentation, tests, headers, and simplification in configuration. - The arch_get_random*_early() abstraction was only used by arm64 and wasn't entirely useful, so this has been replaced by code that works in all relevant contexts. - The kernel will use and manage random seeds in non-volatile EFI variables, refreshing a variable with a fresh seed when the RNG is initialized. The RNG GUID namespace is then hidden from efivarfs to prevent accidental leakage. These changes are split into random.c infrastructure code used in the EFI subsystem, in this pull request, and related support inside of EFISTUB, in Ard's EFI tree. These are co-dependent for full functionality, but the order of merging doesn't matter. - Part of the infrastructure added for the EFI support is also used for an improvement to the way vsprintf initializes its siphash key, replacing an sleep loop wart. - The hardware RNG framework now always calls its correct random.c input function, add_hwgenerator_randomness(), rather than sometimes going through helpers better suited for other cases. - The add_latent_entropy() function has long been called from the fork handler, but is a no-op when the latent entropy gcc plugin isn't used, which is fine for the purposes of latent entropy. But it was missing out on the cycle counter that was also being mixed in beside the latent entropy variable. So now, if the latent entropy gcc plugin isn't enabled, add_latent_entropy() will expand to a call to add_device_randomness(NULL, 0), which adds a cycle counter, without the absent latent entropy variable. - The RNG is now reseeded from a delayed worker, rather than on demand when used. Always running from a worker allows it to make use of the CPU RNG on platforms like S390x, whose instructions are too slow to do so from interrupts. It also has the effect of adding in new inputs more frequently with more regularity, amounting to a long term transcript of random values. Plus, it helps a bit with the upcoming vDSO implementation (which isn't yet ready for 6.2). - The jitter entropy algorithm now tries to execute on many different CPUs, round-robining, in hopes of hitting even more memory latencies and other unpredictable effects. It also will mix in a cycle counter when the entropy timer fires, in addition to being mixed in from the main loop, to account more explicitly for fluctuations in that timer firing. And the state it touches is now kept within the same cache line, so that it's assured that the different execution contexts will cause latencies. * tag 'random-6.2-rc1-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/crng/random: (23 commits) random: include <linux/once.h> in the right header random: align entropy_timer_state to cache line random: mix in cycle counter when jitter timer fires random: spread out jitter callback to different CPUs random: remove extraneous period and add a missing one in comments efi: random: refresh non-volatile random seed when RNG is initialized vsprintf: initialize siphash key using notifier random: add back async readiness notifier random: reseed in delayed work rather than on-demand random: always mix cycle counter in add_latent_entropy() hw_random: use add_hwgenerator_randomness() for early entropy random: modernize documentation comment on get_random_bytes() random: adjust comment to account for removed function random: remove early archrandom abstraction random: use random.trust_{bootloader,cpu} command line option only stackprotector: actually use get_random_canary() stackprotector: move get_random_canary() into stackprotector.h treewide: use get_random_u32_inclusive() when possible treewide: use get_random_u32_{above,below}() instead of manual loop treewide: use get_random_u32_below() instead of deprecated function ...
2022-12-12kasan: fail non-kasan KUnit tests on KASAN reportsAndrey Konovalov3-0/+69
After the recent changes done to KUnit-enabled KASAN tests, non-KASAN KUnit tests stopped being failed when KASAN report is detected. Recover that property by failing the currently running non-KASAN KUnit test when KASAN detects and prints a report for a bad memory access. Note that if the bad accesses happened in a kernel thread that doesn't have a reference to the currently running KUnit-test available via current->kunit_test, the test won't be failed. This is a limitation of KUnit, which doesn't yet provide a thread-agnostic way to find the reference to the currenly running test. Link: https://lkml.kernel.org/r/7be29a8ea967cee6b7e48d3d5a242d1d0bd96851.1669820505.git.andreyknvl@google.com Fixes: 49d9977ac909 ("kasan: check CONFIG_KASAN_KUNIT_TEST instead of CONFIG_KUNIT") Fixes: 7ce0ea19d50e ("kasan: switch kunit tests to console tracepoints") Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: David Gow <davidgow@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Marco Elver <elver@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-12-03panic: Consolidate open-coded panic_on_warn checksKees Cook1-2/+2
Several run-time checkers (KASAN, UBSAN, KFENCE, KCSAN, sched) roll their own warnings, and each check "panic_on_warn". Consolidate this into a single function so that future instrumentation can be added in a single location. Cc: Marco Elver <elver@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Vincent Guittot <vincent.guittot@linaro.org> Cc: Dietmar Eggemann <dietmar.eggemann@arm.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Ben Segall <bsegall@google.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Daniel Bristot de Oliveira <bristot@redhat.com> Cc: Valentin Schneider <vschneid@redhat.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Vincenzo Frascino <vincenzo.frascino@arm.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: David Gow <davidgow@google.com> Cc: tangmeng <tangmeng@uniontech.com> Cc: Jann Horn <jannh@google.com> Cc: Shuah Khan <skhan@linuxfoundation.org> Cc: Petr Mladek <pmladek@suse.com> Cc: "Paul E. McKenney" <paulmck@kernel.org> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: "Guilherme G. Piccoli" <gpiccoli@igalia.com> Cc: Tiezhu Yang <yangtiezhu@loongson.cn> Cc: kasan-dev@googlegroups.com Cc: linux-mm@kvack.org Reviewed-by: Luis Chamberlain <mcgrof@kernel.org> Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Marco Elver <elver@google.com> Reviewed-by: Andrey Konovalov <andreyknvl@gmail.com> Link: https://lore.kernel.org/r/20221117234328.594699-4-keescook@chromium.org
2022-12-01mm: Make ksize() a reporting-only functionKees Cook1-6/+13
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>
2022-11-18treewide: use get_random_u32_inclusive() when possibleJason A. Donenfeld1-3/+3
These cases were done with this Coccinelle: @@ expression H; expression L; @@ - (get_random_u32_below(H) + L) + get_random_u32_inclusive(L, H + L - 1) @@ expression H; expression L; expression E; @@ get_random_u32_inclusive(L, H - + E - - E ) @@ expression H; expression L; expression E; @@ get_random_u32_inclusive(L, H - - E - + E ) @@ expression H; expression L; expression E; expression F; @@ get_random_u32_inclusive(L, H - - E + F - + E ) @@ expression H; expression L; expression E; expression F; @@ get_random_u32_inclusive(L, H - + E + F - - E ) And then subsequently cleaned up by hand, with several automatic cases rejected if it didn't make sense contextually. Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> # for infiniband Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2022-11-18treewide: use get_random_u32_below() instead of deprecated functionJason A. Donenfeld1-3/+3
This is a simple mechanical transformation done by: @@ expression E; @@ - prandom_u32_max + get_random_u32_below (E) Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: Darrick J. Wong <djwong@kernel.org> # for xfs Reviewed-by: SeongJae Park <sj@kernel.org> # for damon Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> # for infiniband Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> # for arm Acked-by: Ulf Hansson <ulf.hansson@linaro.org> # for mmc Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2022-11-10mm: kasan: Extend kasan_metadata_size() to also cover in-object sizeFeng Tang1-6/+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>
2022-11-09memory: move hotplug memory notifier priority to same file for easy sortingLiu Shixin1-1/+1
The priority of hotplug memory callback is defined in a different file. And there are some callers using numbers directly. Collect them together into include/linux/memory.h for easy reading. This allows us to sort their priorities more intuitively without additional comments. Link: https://lkml.kernel.org/r/20220923033347.3935160-9-liushixin2@huawei.com Signed-off-by: Liu Shixin <liushixin2@huawei.com> Cc: Christoph Lameter <cl@linux.com> Cc: David Hildenbrand <david@redhat.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Waiman Long <longman@redhat.com> Cc: zefan li <lizefan.x@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-11-09kasan: migrate workqueue_uaf test to kunitAndrey Konovalov2-37/+33
Migrate the workqueue_uaf test to the KUnit framework. Initially, this test was intended to check that Generic KASAN prints auxiliary stack traces for workqueues. Nevertheless, the test is enabled for all modes to make that KASAN reports bad accesses in the tested scenario. The presence of auxiliary stack traces for the Generic mode needs to be inspected manually. Link: https://lkml.kernel.org/r/1d81b6cc2a58985126283d1e0de8e663716dd930.1664298455.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> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-11-09kasan: migrate kasan_rcu_uaf test to kunitAndrey Konovalov2-30/+37
Migrate the kasan_rcu_uaf test to the KUnit framework. Changes to the implementation of the test: - Call rcu_barrier() after call_rcu() to make that the RCU callbacks get triggered before the test is over. - Cast pointer passed to rcu_dereference_protected as __rcu to get rid of the Sparse warning. - Check that KASAN prints a report via KUNIT_EXPECT_KASAN_FAIL. Initially, this test was intended to check that Generic KASAN prints auxiliary stack traces for RCU objects. Nevertheless, the test is enabled for all modes to make that KASAN reports bad accesses in RCU callbacks. The presence of auxiliary stack traces for the Generic mode needs to be inspected manually. Link: https://lkml.kernel.org/r/897ee08d6cd0ba7e8a4fbfd9d8502823a2f922e6.1664298455.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> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-11-09kasan: switch kunit tests to console tracepointsAndrey Konovalov3-62/+62
Switch KUnit-compatible KASAN tests from using per-task KUnit resources to console tracepoints. This allows for two things: 1. Migrating tests that trigger a KASAN report in the context of a task other than current to KUnit framework. This is implemented in the patches that follow. 2. Parsing and matching the contents of KASAN reports. This is not yet implemented. Link: https://lkml.kernel.org/r/9345acdd11e953b207b0ed4724ff780e63afeb36.1664298455.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> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-10-17Merge tag 'random-6.1-rc1-for-linus' of ↵Linus Torvalds1-3/+3
git://git.kernel.org/pub/scm/linux/kernel/git/crng/random Pull more random number generator updates from Jason Donenfeld: "This time with some large scale treewide cleanups. The intent of this pull is to clean up the way callers fetch random integers. The current rules for doing this right are: - If you want a secure or an insecure random u64, use get_random_u64() - If you want a secure or an insecure random u32, use get_random_u32() The old function prandom_u32() has been deprecated for a while now and is just a wrapper around get_random_u32(). Same for get_random_int(). - If you want a secure or an insecure random u16, use get_random_u16() - If you want a secure or an insecure random u8, use get_random_u8() - If you want secure or insecure random bytes, use get_random_bytes(). The old function prandom_bytes() has been deprecated for a while now and has long been a wrapper around get_random_bytes() - If you want a non-uniform random u32, u16, or u8 bounded by a certain open interval maximum, use prandom_u32_max() I say "non-uniform", because it doesn't do any rejection sampling or divisions. Hence, it stays within the prandom_*() namespace, not the get_random_*() namespace. I'm currently investigating a "uniform" function for 6.2. We'll see what comes of that. By applying these rules uniformly, we get several benefits: - By using prandom_u32_max() with an upper-bound that the compiler can prove at compile-time is ≤65536 or ≤256, internally get_random_u16() or get_random_u8() is used, which wastes fewer batched random bytes, and hence has higher throughput. - By using prandom_u32_max() instead of %, when the upper-bound is not a constant, division is still avoided, because prandom_u32_max() uses a faster multiplication-based trick instead. - By using get_random_u16() or get_random_u8() in cases where the return value is intended to indeed be a u16 or a u8, we waste fewer batched random bytes, and hence have higher throughput. This series was originally done by hand while I was on an airplane without Internet. Later, Kees and I worked on retroactively figuring out what could be done with Coccinelle and what had to be done manually, and then we split things up based on that. So while this touches a lot of files, the actual amount of code that's hand fiddled is comfortably small" * tag 'random-6.1-rc1-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/crng/random: prandom: remove unused functions treewide: use get_random_bytes() when possible treewide: use get_random_u32() when possible treewide: use get_random_{u8,u16}() when possible, part 2 treewide: use get_random_{u8,u16}() when possible, part 1 treewide: use prandom_u32_max() when possible, part 2 treewide: use prandom_u32_max() when possible, part 1