talos-op-linux/mm/kasan, branch master

Merge tag 'riscv-for-linus-5.6-mw0' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux

2020-01-31T19:23:29+00:00

Pull RISC-V updates from Palmer Dabbelt: "This contains a handful of patches for this merge window: - Support for kasan - 32-bit physical addresses on rv32i-based systems - Support for CONFIG_DEBUG_VIRTUAL - DT entry for the FU540 GPIO controller, which has recently had a device driver merged These boot a buildroot-based system on QEMU's virt board for me" * tag 'riscv-for-linus-5.6-mw0' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: riscv: dts: Add DT support for SiFive FU540 GPIO driver riscv: mm: add support for CONFIG_DEBUG_VIRTUAL riscv: keep 32-bit kernel to 32-bit phys_addr_t kasan: Add riscv to KASAN documentation. riscv: Add KASAN support kasan: No KASAN's memmove check if archs don't have it.

kasan: No KASAN's memmove check if archs don't have it.

2020-01-22T21:09:41+00:00

If archs don't have memmove then the C implementation from lib/string.c is used, and then it's instrumented by compiler. So there is no need to add KASAN's memmove to manual checks. Signed-off-by: Nick Hu Acked-by: Dmitry Vyukov Acked-by: Andrey Ryabinin Signed-off-by: Palmer Dabbelt

x86/kasan: Print original address on #GP

2019-12-31T12:15:38+00:00

Make #GP exceptions caused by out-of-bounds KASAN shadow accesses easier to understand by computing the address of the original access and printing that. More details are in the comments in the patch. This turns an error like this: kasan: CONFIG_KASAN_INLINE enabled kasan: GPF could be caused by NULL-ptr deref or user memory access general protection fault, probably for non-canonical address 0xe017577ddf75b7dd: 0000 [#1] PREEMPT SMP KASAN PTI into this: general protection fault, probably for non-canonical address 0xe017577ddf75b7dd: 0000 [#1] PREEMPT SMP KASAN PTI KASAN: maybe wild-memory-access in range [0x00badbeefbadbee8-0x00badbeefbadbeef] The hook is placed in architecture-independent code, but is currently only wired up to the X86 exception handler because I'm not sufficiently familiar with the address space layout and exception handling mechanisms on other architectures. Signed-off-by: Jann Horn Signed-off-by: Borislav Petkov Reviewed-by: Dmitry Vyukov Cc: Alexander Potapenko Cc: Andrew Morton Cc: Andrey Konovalov Cc: Andrey Ryabinin Cc: Andy Lutomirski Cc: Dave Hansen Cc: "H. Peter Anvin" Cc: Ingo Molnar Cc: kasan-dev@googlegroups.com Cc: linux-mm Cc: Peter Zijlstra Cc: Sean Christopherson Cc: Thomas Gleixner Cc: x86-ml Link: https://lkml.kernel.org/r/20191218231150.12139-4-jannh@google.com

kasan: use apply_to_existing_page_range() for releasing vmalloc shadow

2019-12-18T04:59:59+00:00

kasan_release_vmalloc uses apply_to_page_range to release vmalloc shadow. Unfortunately, apply_to_page_range can allocate memory to fill in page table entries, which is not what we want. Also, kasan_release_vmalloc is called under free_vmap_area_lock, so if apply_to_page_range does allocate memory, we get a sleep in atomic bug: BUG: sleeping function called from invalid context at mm/page_alloc.c:4681 in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 15087, name: Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x199/0x216 lib/dump_stack.c:118 ___might_sleep.cold.97+0x1f5/0x238 kernel/sched/core.c:6800 __might_sleep+0x95/0x190 kernel/sched/core.c:6753 prepare_alloc_pages mm/page_alloc.c:4681 [inline] __alloc_pages_nodemask+0x3cd/0x890 mm/page_alloc.c:4730 alloc_pages_current+0x10c/0x210 mm/mempolicy.c:2211 alloc_pages include/linux/gfp.h:532 [inline] __get_free_pages+0xc/0x40 mm/page_alloc.c:4786 __pte_alloc_one_kernel include/asm-generic/pgalloc.h:21 [inline] pte_alloc_one_kernel include/asm-generic/pgalloc.h:33 [inline] __pte_alloc_kernel+0x1d/0x200 mm/memory.c:459 apply_to_pte_range mm/memory.c:2031 [inline] apply_to_pmd_range mm/memory.c:2068 [inline] apply_to_pud_range mm/memory.c:2088 [inline] apply_to_p4d_range mm/memory.c:2108 [inline] apply_to_page_range+0x77d/0xa00 mm/memory.c:2133 kasan_release_vmalloc+0xa7/0xc0 mm/kasan/common.c:970 __purge_vmap_area_lazy+0xcbb/0x1f30 mm/vmalloc.c:1313 try_purge_vmap_area_lazy mm/vmalloc.c:1332 [inline] free_vmap_area_noflush+0x2ca/0x390 mm/vmalloc.c:1368 free_unmap_vmap_area mm/vmalloc.c:1381 [inline] remove_vm_area+0x1cc/0x230 mm/vmalloc.c:2209 vm_remove_mappings mm/vmalloc.c:2236 [inline] __vunmap+0x223/0xa20 mm/vmalloc.c:2299 __vfree+0x3f/0xd0 mm/vmalloc.c:2356 __vmalloc_area_node mm/vmalloc.c:2507 [inline] __vmalloc_node_range+0x5d5/0x810 mm/vmalloc.c:2547 __vmalloc_node mm/vmalloc.c:2607 [inline] __vmalloc_node_flags mm/vmalloc.c:2621 [inline] vzalloc+0x6f/0x80 mm/vmalloc.c:2666 alloc_one_pg_vec_page net/packet/af_packet.c:4233 [inline] alloc_pg_vec net/packet/af_packet.c:4258 [inline] packet_set_ring+0xbc0/0x1b50 net/packet/af_packet.c:4342 packet_setsockopt+0xed7/0x2d90 net/packet/af_packet.c:3695 __sys_setsockopt+0x29b/0x4d0 net/socket.c:2117 __do_sys_setsockopt net/socket.c:2133 [inline] __se_sys_setsockopt net/socket.c:2130 [inline] __x64_sys_setsockopt+0xbe/0x150 net/socket.c:2130 do_syscall_64+0xfa/0x780 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe Switch to using the apply_to_existing_page_range() helper instead, which won't allocate memory. [akpm@linux-foundation.org: s/apply_to_existing_pages/apply_to_existing_page_range/] Link: http://lkml.kernel.org/r/20191205140407.1874-2-dja@axtens.net Fixes: 3c5c3cfb9ef4 ("kasan: support backing vmalloc space with real shadow memory") Signed-off-by: Daniel Axtens Reported-by: Dmitry Vyukov Reviewed-by: Andrey Ryabinin Cc: Alexander Potapenko Cc: Qian Cai Cc: Uladzislau Rezki (Sony) Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

kasan: fix crashes on access to memory mapped by vm_map_ram()

2019-12-18T04:59:59+00:00

With CONFIG_KASAN_VMALLOC=y any use of memory obtained via vm_map_ram() will crash because there is no shadow backing that memory. Instead of sprinkling additional kasan_populate_vmalloc() calls all over the vmalloc code, move it into alloc_vmap_area(). This will fix vm_map_ram() and simplify the code a bit. [aryabinin@virtuozzo.com: v2] Link: http://lkml.kernel.org/r/20191205095942.1761-1-aryabinin@virtuozzo.comLink: http://lkml.kernel.org/r/20191204204534.32202-1-aryabinin@virtuozzo.com Fixes: 3c5c3cfb9ef4 ("kasan: support backing vmalloc space with real shadow memory") Signed-off-by: Andrey Ryabinin Reported-by: Dmitry Vyukov Reviewed-by: Uladzislau Rezki (Sony) Cc: Daniel Axtens Cc: Alexander Potapenko Cc: Daniel Axtens Cc: Qian Cai Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm/kasan/common.c: fix compile error

2019-12-05T03:44:11+00:00

I hit the following compile error in arch/x86/ mm/kasan/common.c: In function kasan_populate_vmalloc: mm/kasan/common.c:797:2: error: implicit declaration of function flush_cache_vmap; did you mean flush_rcu_work? [-Werror=implicit-function-declaration] flush_cache_vmap(shadow_start, shadow_end); ^~~~~~~~~~~~~~~~ flush_rcu_work cc1: some warnings being treated as errors Link: http://lkml.kernel.org/r/1575363013-43761-1-git-send-email-zhongjiang@huawei.com Fixes: 3c5c3cfb9ef4 ("kasan: support backing vmalloc space with real shadow memory") Signed-off-by: zhong jiang Reviewed-by: Andrew Morton Reviewed-by: Daniel Axtens Cc: Mark Rutland Cc: Mark Rutland Cc: Vasily Gorbik Cc: Andrey Ryabinin Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

kasan: support backing vmalloc space with real shadow memory

2019-12-01T20:59:05+00:00

Patch series "kasan: support backing vmalloc space with real shadow memory", v11. Currently, vmalloc space is backed by the early shadow page. This means that kasan is incompatible with VMAP_STACK. This series provides a mechanism to back vmalloc space with real, dynamically allocated memory. I have only wired up x86, because that's the only currently supported arch I can work with easily, but it's very easy to wire up other architectures, and it appears that there is some work-in-progress code to do this on arm64 and s390. This has been discussed before in the context of VMAP_STACK: - https://bugzilla.kernel.org/show_bug.cgi?id=202009 - https://lkml.org/lkml/2018/7/22/198 - https://lkml.org/lkml/2019/7/19/822 In terms of implementation details: Most mappings in vmalloc space are small, requiring less than a full page of shadow space. Allocating a full shadow page per mapping would therefore be wasteful. Furthermore, to ensure that different mappings use different shadow pages, mappings would have to be aligned to KASAN_SHADOW_SCALE_SIZE * PAGE_SIZE. Instead, share backing space across multiple mappings. Allocate a backing page when a mapping in vmalloc space uses a particular page of the shadow region. This page can be shared by other vmalloc mappings later on. We hook in to the vmap infrastructure to lazily clean up unused shadow memory. Testing with test_vmalloc.sh on an x86 VM with 2 vCPUs shows that: - Turning on KASAN, inline instrumentation, without vmalloc, introuduces a 4.1x-4.2x slowdown in vmalloc operations. - Turning this on introduces the following slowdowns over KASAN: * ~1.76x slower single-threaded (test_vmalloc.sh performance) * ~2.18x slower when both cpus are performing operations simultaneously (test_vmalloc.sh sequential_test_order=1) This is unfortunate but given that this is a debug feature only, not the end of the world. The benchmarks are also a stress-test for the vmalloc subsystem: they're not indicative of an overall 2x slowdown! This patch (of 4): Hook into vmalloc and vmap, and dynamically allocate real shadow memory to back the mappings. Most mappings in vmalloc space are small, requiring less than a full page of shadow space. Allocating a full shadow page per mapping would therefore be wasteful. Furthermore, to ensure that different mappings use different shadow pages, mappings would have to be aligned to KASAN_SHADOW_SCALE_SIZE * PAGE_SIZE. Instead, share backing space across multiple mappings. Allocate a backing page when a mapping in vmalloc space uses a particular page of the shadow region. This page can be shared by other vmalloc mappings later on. We hook in to the vmap infrastructure to lazily clean up unused shadow memory. To avoid the difficulties around swapping mappings around, this code expects that the part of the shadow region that covers the vmalloc space will not be covered by the early shadow page, but will be left unmapped. This will require changes in arch-specific code. This allows KASAN with VMAP_STACK, and may be helpful for architectures that do not have a separate module space (e.g. powerpc64, which I am currently working on). It also allows relaxing the module alignment back to PAGE_SIZE. Testing with test_vmalloc.sh on an x86 VM with 2 vCPUs shows that: - Turning on KASAN, inline instrumentation, without vmalloc, introuduces a 4.1x-4.2x slowdown in vmalloc operations. - Turning this on introduces the following slowdowns over KASAN: * ~1.76x slower single-threaded (test_vmalloc.sh performance) * ~2.18x slower when both cpus are performing operations simultaneously (test_vmalloc.sh sequential_test_order=3D1) This is unfortunate but given that this is a debug feature only, not the end of the world. The full benchmark results are: Performance No KASAN KASAN original x baseline KASAN vmalloc x baseline x KASAN fix_size_alloc_test 662004 11404956 17.23 19144610 28.92 1.68 full_fit_alloc_test 710950 12029752 16.92 13184651 18.55 1.10 long_busy_list_alloc_test 9431875 43990172 4.66 82970178 8.80 1.89 random_size_alloc_test 5033626 23061762 4.58 47158834 9.37 2.04 fix_align_alloc_test 1252514 15276910 12.20 31266116 24.96 2.05 random_size_align_alloc_te 1648501 14578321 8.84 25560052 15.51 1.75 align_shift_alloc_test 147 830 5.65 5692 38.72 6.86 pcpu_alloc_test 80732 125520 1.55 140864 1.74 1.12 Total Cycles 119240774314 763211341128 6.40 1390338696894 11.66 1.82 Sequential, 2 cpus No KASAN KASAN original x baseline KASAN vmalloc x baseline x KASAN fix_size_alloc_test 1423150 14276550 10.03 27733022 19.49 1.94 full_fit_alloc_test 1754219 14722640 8.39 15030786 8.57 1.02 long_busy_list_alloc_test 11451858 52154973 4.55 107016027 9.34 2.05 random_size_alloc_test 5989020 26735276 4.46 68885923 11.50 2.58 fix_align_alloc_test 2050976 20166900 9.83 50491675 24.62 2.50 random_size_align_alloc_te 2858229 17971700 6.29 38730225 13.55 2.16 align_shift_alloc_test 405 6428 15.87 26253 64.82 4.08 pcpu_alloc_test 127183 151464 1.19 216263 1.70 1.43 Total Cycles 54181269392 308723699764 5.70 650772566394 12.01 2.11 fix_size_alloc_test 1420404 14289308 10.06 27790035 19.56 1.94 full_fit_alloc_test 1736145 14806234 8.53 15274301 8.80 1.03 long_busy_list_alloc_test 11404638 52270785 4.58 107550254 9.43 2.06 random_size_alloc_test 6017006 26650625 4.43 68696127 11.42 2.58 fix_align_alloc_test 2045504 20280985 9.91 50414862 24.65 2.49 random_size_align_alloc_te 2845338 17931018 6.30 38510276 13.53 2.15 align_shift_alloc_test 472 3760 7.97 9656 20.46 2.57 pcpu_alloc_test 118643 132732 1.12 146504 1.23 1.10 Total Cycles 54040011688 309102805492 5.72 651325675652 12.05 2.11 [dja@axtens.net: fixups] Link: http://lkml.kernel.org/r/20191120052719.7201-1-dja@axtens.net Link: https://bugzilla.kernel.org/show_bug.cgi?id=3D202009 Link: http://lkml.kernel.org/r/20191031093909.9228-2-dja@axtens.net Signed-off-by: Mark Rutland [shadow rework] Signed-off-by: Daniel Axtens Co-developed-by: Mark Rutland Acked-by: Vasily Gorbik Reviewed-by: Andrey Ryabinin Cc: Alexander Potapenko Cc: Dmitry Vyukov Cc: Christophe Leroy Cc: Qian Cai Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm: introduce compound_nr()

2019-09-24T22:54:08+00:00

Replace 1 << compound_order(page) with compound_nr(page). Minor improvements in readability. Link: http://lkml.kernel.org/r/20190721104612.19120-4-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) Reviewed-by: Andrew Morton Reviewed-by: Ira Weiny Acked-by: Kirill A. Shutemov Cc: Michal Hocko Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

mm: introduce page_size()

2019-09-24T22:54:08+00:00

Patch series "Make working with compound pages easier", v2. These three patches add three helpers and convert the appropriate places to use them. This patch (of 3): It's unnecessarily hard to find out the size of a potentially huge page. Replace 'PAGE_SIZE << compound_order(page)' with page_size(page). Link: http://lkml.kernel.org/r/20190721104612.19120-2-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) Acked-by: Michal Hocko Reviewed-by: Andrew Morton Reviewed-by: Ira Weiny Acked-by: Kirill A. Shutemov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

kasan: add memory corruption identification for software tag-based mode

2019-09-24T22:54:07+00:00

Add memory corruption identification at bug report for software tag-based mode. The report shows whether it is "use-after-free" or "out-of-bound" error instead of "invalid-access" error. This will make it easier for programmers to see the memory corruption problem. We extend the slab to store five old free pointer tag and free backtrace, we can check if the tagged address is in the slab record and make a good guess if the object is more like "use-after-free" or "out-of-bound". therefore every slab memory corruption can be identified whether it's "use-after-free" or "out-of-bound". [aryabinin@virtuozzo.com: simplify & clenup code] Link: https://lkml.kernel.org/r/3318f9d7-a760-3cc8-b700-f06108ae745f@virtuozzo.com] Link: http://lkml.kernel.org/r/20190821180332.11450-1-aryabinin@virtuozzo.com Signed-off-by: Walter Wu Signed-off-by: Andrey Ryabinin Acked-by: Andrey Konovalov Cc: Dmitry Vyukov Cc: Alexander Potapenko Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds