user/sven/linux.git/kernel/kcsan, branch v6.7.9

mm: delete checks for xor_unlock_is_negative_byte()

2023-10-18T21:34:17Z

Architectures which don't define their own use the one in asm-generic/bitops/lock.h. Get rid of all the ifdefs around "maybe we don't have it". Link: https://lkml.kernel.org/r/20231004165317.1061855-15-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) Acked-by: Geert Uytterhoeven Cc: Albert Ou Cc: Alexander Gordeev Cc: Andreas Dilger Cc: Christian Borntraeger Cc: Christophe Leroy Cc: Heiko Carstens Cc: Ivan Kokshaysky Cc: Matt Turner Cc: Michael Ellerman Cc: Nicholas Piggin Cc: Palmer Dabbelt Cc: Paul Walmsley Cc: Richard Henderson Cc: Sven Schnelle Cc: "Theodore Ts'o" Cc: Thomas Bogendoerfer Cc: Vasily Gorbik Signed-off-by: Andrew Morton

bitops: add xor_unlock_is_negative_byte()

2023-10-18T21:34:16Z

Replace clear_bit_and_unlock_is_negative_byte() with xor_unlock_is_negative_byte(). We have a few places that like to lock a folio, set a flag and unlock it again. Allow for the possibility of combining the latter two operations for efficiency. We are guaranteed that the caller holds the lock, so it is safe to unlock it with the xor. The caller must guarantee that nobody else will set the flag without holding the lock; it is not safe to do this with the PG_dirty flag, for example. Link: https://lkml.kernel.org/r/20231004165317.1061855-8-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) Cc: Albert Ou Cc: Alexander Gordeev Cc: Andreas Dilger Cc: Christian Borntraeger Cc: Christophe Leroy Cc: Geert Uytterhoeven Cc: Heiko Carstens Cc: Ivan Kokshaysky Cc: Matt Turner Cc: Michael Ellerman Cc: Nicholas Piggin Cc: Palmer Dabbelt Cc: Paul Walmsley Cc: Richard Henderson Cc: Sven Schnelle Cc: "Theodore Ts'o" Cc: Thomas Bogendoerfer Cc: Vasily Gorbik Signed-off-by: Andrew Morton

kcsan: Don't expect 64 bits atomic builtins from 32 bits architectures

2023-06-09T13:29:50Z

Activating KCSAN on a 32 bits architecture leads to the following link-time failure: LD .tmp_vmlinux.kallsyms1 powerpc64-linux-ld: kernel/kcsan/core.o: in function `__tsan_atomic64_load': kernel/kcsan/core.c:1273: undefined reference to `__atomic_load_8' powerpc64-linux-ld: kernel/kcsan/core.o: in function `__tsan_atomic64_store': kernel/kcsan/core.c:1273: undefined reference to `__atomic_store_8' powerpc64-linux-ld: kernel/kcsan/core.o: in function `__tsan_atomic64_exchange': kernel/kcsan/core.c:1273: undefined reference to `__atomic_exchange_8' powerpc64-linux-ld: kernel/kcsan/core.o: in function `__tsan_atomic64_fetch_add': kernel/kcsan/core.c:1273: undefined reference to `__atomic_fetch_add_8' powerpc64-linux-ld: kernel/kcsan/core.o: in function `__tsan_atomic64_fetch_sub': kernel/kcsan/core.c:1273: undefined reference to `__atomic_fetch_sub_8' powerpc64-linux-ld: kernel/kcsan/core.o: in function `__tsan_atomic64_fetch_and': kernel/kcsan/core.c:1273: undefined reference to `__atomic_fetch_and_8' powerpc64-linux-ld: kernel/kcsan/core.o: in function `__tsan_atomic64_fetch_or': kernel/kcsan/core.c:1273: undefined reference to `__atomic_fetch_or_8' powerpc64-linux-ld: kernel/kcsan/core.o: in function `__tsan_atomic64_fetch_xor': kernel/kcsan/core.c:1273: undefined reference to `__atomic_fetch_xor_8' powerpc64-linux-ld: kernel/kcsan/core.o: in function `__tsan_atomic64_fetch_nand': kernel/kcsan/core.c:1273: undefined reference to `__atomic_fetch_nand_8' powerpc64-linux-ld: kernel/kcsan/core.o: in function `__tsan_atomic64_compare_exchange_strong': kernel/kcsan/core.c:1273: undefined reference to `__atomic_compare_exchange_8' powerpc64-linux-ld: kernel/kcsan/core.o: in function `__tsan_atomic64_compare_exchange_weak': kernel/kcsan/core.c:1273: undefined reference to `__atomic_compare_exchange_8' powerpc64-linux-ld: kernel/kcsan/core.o: in function `__tsan_atomic64_compare_exchange_val': kernel/kcsan/core.c:1273: undefined reference to `__atomic_compare_exchange_8' 32 bits architectures don't have 64 bits atomic builtins. Only include DEFINE_TSAN_ATOMIC_OPS(64) on 64 bits architectures. Fixes: 0f8ad5f2e934 ("kcsan: Add support for atomic builtins") Suggested-by: Marco Elver Signed-off-by: Christophe Leroy Reviewed-by: Marco Elver Acked-by: Marco Elver Signed-off-by: Michael Ellerman Link: https://msgid.link/d9c6afc28d0855240171a4e0ad9ffcdb9d07fceb.1683892665.git.christophe.leroy@csgroup.eu

Merge tag 'mm-stable-2023-04-27-15-30' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2023-04-28T02:42:02Z

Pull MM updates from Andrew Morton: - Nick Piggin's "shoot lazy tlbs" series, to improve the peformance of switching from a user process to a kernel thread. - More folio conversions from Kefeng Wang, Zhang Peng and Pankaj Raghav. - zsmalloc performance improvements from Sergey Senozhatsky. - Yue Zhao has found and fixed some data race issues around the alteration of memcg userspace tunables. - VFS rationalizations from Christoph Hellwig: - removal of most of the callers of write_one_page() - make __filemap_get_folio()'s return value more useful - Luis Chamberlain has changed tmpfs so it no longer requires swap backing. Use `mount -o noswap'. - Qi Zheng has made the slab shrinkers operate locklessly, providing some scalability benefits. - Keith Busch has improved dmapool's performance, making part of its operations O(1) rather than O(n). - Peter Xu adds the UFFD_FEATURE_WP_UNPOPULATED feature to userfaultd, permitting userspace to wr-protect anon memory unpopulated ptes. - Kirill Shutemov has changed MAX_ORDER's meaning to be inclusive rather than exclusive, and has fixed a bunch of errors which were caused by its unintuitive meaning. - Axel Rasmussen give userfaultfd the UFFDIO_CONTINUE_MODE_WP feature, which causes minor faults to install a write-protected pte. - Vlastimil Babka has done some maintenance work on vma_merge(): cleanups to the kernel code and improvements to our userspace test harness. - Cleanups to do_fault_around() by Lorenzo Stoakes. - Mike Rapoport has moved a lot of initialization code out of various mm/ files and into mm/mm_init.c. - Lorenzo Stoakes removd vmf_insert_mixed_prot(), which was added for DRM, but DRM doesn't use it any more. - Lorenzo has also coverted read_kcore() and vread() to use iterators and has thereby removed the use of bounce buffers in some cases. - Lorenzo has also contributed further cleanups of vma_merge(). - Chaitanya Prakash provides some fixes to the mmap selftesting code. - Matthew Wilcox changes xfs and afs so they no longer take sleeping locks in ->map_page(), a step towards RCUification of pagefaults. - Suren Baghdasaryan has improved mmap_lock scalability by switching to per-VMA locking. - Frederic Weisbecker has reworked the percpu cache draining so that it no longer causes latency glitches on cpu isolated workloads. - Mike Rapoport cleans up and corrects the ARCH_FORCE_MAX_ORDER Kconfig logic. - Liu Shixin has changed zswap's initialization so we no longer waste a chunk of memory if zswap is not being used. - Yosry Ahmed has improved the performance of memcg statistics flushing. - David Stevens has fixed several issues involving khugepaged, userfaultfd and shmem. - Christoph Hellwig has provided some cleanup work to zram's IO-related code paths. - David Hildenbrand has fixed up some issues in the selftest code's testing of our pte state changing. - Pankaj Raghav has made page_endio() unneeded and has removed it. - Peter Xu contributed some rationalizations of the userfaultfd selftests. - Yosry Ahmed has fixed an issue around memcg's page recalim accounting. - Chaitanya Prakash has fixed some arm-related issues in the selftests/mm code. - Longlong Xia has improved the way in which KSM handles hwpoisoned pages. - Peter Xu fixes a few issues with uffd-wp at fork() time. - Stefan Roesch has changed KSM so that it may now be used on a per-process and per-cgroup basis. * tag 'mm-stable-2023-04-27-15-30' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (369 commits) mm,unmap: avoid flushing TLB in batch if PTE is inaccessible shmem: restrict noswap option to initial user namespace mm/khugepaged: fix conflicting mods to collapse_file() sparse: remove unnecessary 0 values from rc mm: move 'mmap_min_addr' logic from callers into vm_unmapped_area() hugetlb: pte_alloc_huge() to replace huge pte_alloc_map() maple_tree: fix allocation in mas_sparse_area() mm: do not increment pgfault stats when page fault handler retries zsmalloc: allow only one active pool compaction context selftests/mm: add new selftests for KSM mm: add new KSM process and sysfs knobs mm: add new api to enable ksm per process mm: shrinkers: fix debugfs file permissions mm: don't check VMA write permissions if the PTE/PMD indicates write permissions migrate_pages_batch: fix statistics for longterm pin retry userfaultfd: use helper function range_in_vma() lib/show_mem.c: use for_each_populated_zone() simplify code mm: correct arg in reclaim_pages()/reclaim_clean_pages_from_list() fs/buffer: convert create_page_buffers to folio_create_buffers fs/buffer: add folio_create_empty_buffers helper ...

Merge tag 'kcsan.2023.04.04a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu

2023-04-24T18:46:53Z

Pull KCSAN updates from Paul McKenney: "Kernel concurrency sanitizer (KCSAN) updates for v6.4 This fixes kernel-doc warnings and also updates instrumentation from READ_ONCE() to volatile in order to avoid unaligned load-acquire instructions on arm64 in kernels built with LTO" * tag 'kcsan.2023.04.04a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu: kcsan: Avoid READ_ONCE() in read_instrumented_memory() instrumented.h: Fix all kernel-doc format warnings

printk: export console trace point for kcsan/kasan/kfence/kmsan

2023-04-18T23:30:11Z

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 Cc: Alexander Potapenko Cc: Andrey Konovalov Cc: Andrey Ryabinin Cc: Dmitry Vyukov Cc: John Ogness Cc: Marco Elver Cc: Petr Mladek Cc: Sergey Senozhatsky Cc: Steven Rostedt Cc: Vincenzo Frascino Signed-off-by: Andrew Morton

kcsan: avoid passing -g for test

2023-03-24T00:18:35Z

Nathan reported that when building with GNU as and a version of clang that defaults to DWARF5, the assembler will complain with: Error: non-constant .uleb128 is not supported This is because `-g` defaults to the compiler debug info default. If the assembler does not support some of the directives used, the above errors occur. To fix, remove the explicit passing of `-g`. All the test wants is that stack traces print valid function names, and debug info is not required for that. (I currently cannot recall why I added the explicit `-g`.) Link: https://lkml.kernel.org/r/20230316224705.709984-2-elver@google.com Fixes: 1fe84fd4a402 ("kcsan: Add test suite") Signed-off-by: Marco Elver Reported-by: Nathan Chancellor Cc: Alexander Potapenko Cc: Dmitry Vyukov Cc: Signed-off-by: Andrew Morton

kcsan: Avoid READ_ONCE() in read_instrumented_memory()

2023-03-11T20:28:07Z

Haibo Li reported: | Unable to handle kernel paging request at virtual address | ffffff802a0d8d7171 | Mem abort info:o: | ESR = 0x9600002121 | EC = 0x25: DABT (current EL), IL = 32 bitsts | SET = 0, FnV = 0 0 | EA = 0, S1PTW = 0 0 | FSC = 0x21: alignment fault | Data abort info:o: | ISV = 0, ISS = 0x0000002121 | CM = 0, WnR = 0 0 | swapper pgtable: 4k pages, 39-bit VAs, pgdp=000000002835200000 | [ffffff802a0d8d71] pgd=180000005fbf9003, p4d=180000005fbf9003, | pud=180000005fbf9003, pmd=180000005fbe8003, pte=006800002a0d8707 | Internal error: Oops: 96000021 [#1] PREEMPT SMP | Modules linked in: | CPU: 2 PID: 45 Comm: kworker/u8:2 Not tainted | 5.15.78-android13-8-g63561175bbda-dirty #1 | ... | pc : kcsan_setup_watchpoint+0x26c/0x6bc | lr : kcsan_setup_watchpoint+0x88/0x6bc | sp : ffffffc00ab4b7f0 | x29: ffffffc00ab4b800 x28: ffffff80294fe588 x27: 0000000000000001 | x26: 0000000000000019 x25: 0000000000000001 x24: ffffff80294fdb80 | x23: 0000000000000000 x22: ffffffc00a70fb68 x21: ffffff802a0d8d71 | x20: 0000000000000002 x19: 0000000000000000 x18: ffffffc00a9bd060 | x17: 0000000000000001 x16: 0000000000000000 x15: ffffffc00a59f000 | x14: 0000000000000001 x13: 0000000000000000 x12: ffffffc00a70faa0 | x11: 00000000aaaaaaab x10: 0000000000000054 x9 : ffffffc00839adf8 | x8 : ffffffc009b4cf00 x7 : 0000000000000000 x6 : 0000000000000007 | x5 : 0000000000000000 x4 : 0000000000000000 x3 : ffffffc00a70fb70 | x2 : 0005ff802a0d8d71 x1 : 0000000000000000 x0 : 0000000000000000 | Call trace: | kcsan_setup_watchpoint+0x26c/0x6bc | __tsan_read2+0x1f0/0x234 | inflate_fast+0x498/0x750 | zlib_inflate+0x1304/0x2384 | __gunzip+0x3a0/0x45c | gunzip+0x20/0x30 | unpack_to_rootfs+0x2a8/0x3fc | do_populate_rootfs+0xe8/0x11c | async_run_entry_fn+0x58/0x1bc | process_one_work+0x3ec/0x738 | worker_thread+0x4c4/0x838 | kthread+0x20c/0x258 | ret_from_fork+0x10/0x20 | Code: b8bfc2a8 2a0803f7 14000007 d503249f (78bfc2a8) ) | ---[ end trace 613a943cb0a572b6 ]----- The reason for this is that on certain arm64 configuration since e35123d83ee3 ("arm64: lto: Strengthen READ_ONCE() to acquire when CONFIG_LTO=y"), READ_ONCE() may be promoted to a full atomic acquire instruction which cannot be used on unaligned addresses. Fix it by avoiding READ_ONCE() in read_instrumented_memory(), and simply forcing the compiler to do the required access by casting to the appropriate volatile type. In terms of generated code this currently only affects architectures that do not use the default READ_ONCE() implementation. The only downside is that we are not guaranteed atomicity of the access itself, although on most architectures a plain load up to machine word size should still be atomic (a fact the default READ_ONCE() still relies on itself). Reported-by: Haibo Li Tested-by: Haibo Li Cc: # 5.17+ Signed-off-by: Marco Elver Signed-off-by: Paul E. McKenney

kcsan: test: don't put the expect array on the stack

2023-01-02T16:59:33Z

Size of the 'expect' array in the __report_matches is 1536 bytes, which is exactly the default frame size warning limit of the xtensa architecture. As a result allmodconfig xtensa kernel builds with the gcc that does not support the compiler plugins (which otherwise would push the said warning limit to 2K) fail with the following message: kernel/kcsan/kcsan_test.c:257:1: error: the frame size of 1680 bytes is larger than 1536 bytes Fix it by dynamically allocating the 'expect' array. Signed-off-by: Max Filippov Reviewed-by: Marco Elver Tested-by: Marco Elver

Merge tag 'hardening-v6.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

2022-12-14T20:20:00Z

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 ...