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2024-07-03kmsan: do not pass NULL pointers as 0Ilya Leoshkevich2-9/+10
sparse complains about passing NULL pointers as 0. Fix all instances. Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Ilya Leoshkevich <[email protected]> Reported-by: kernel test robot <[email protected]> Closes: https://lore.kernel.org/oe-kbuild-all/[email protected]/ Reviewed-by: Alexander Potapenko <[email protected]> Cc: Dmitry Vyukov <[email protected]> Cc: Marco Elver <[email protected]> Signed-off-by: Andrew Morton <[email protected]>
2024-07-03kmsan: add missing __user tagsIlya Leoshkevich3-6/+6
sparse complains that __user pointers are being passed to functions that expect non-__user ones. In all cases, these functions are in fact working with user pointers, only the tag is missing. Add it. Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Ilya Leoshkevich <[email protected]> Reported-by: kernel test robot <[email protected]> Closes: https://lore.kernel.org/oe-kbuild-all/[email protected]/ Reviewed-by: Alexander Potapenko <[email protected]> Cc: Dmitry Vyukov <[email protected]> Cc: Marco Elver <[email protected]> Signed-off-by: Andrew Morton <[email protected]>
2024-07-03kmsan: accept ranges starting with 0 on s390Ilya Leoshkevich1-1/+4
On s390 the virtual address 0 is valid (current CPU's lowcore is mapped there), therefore KMSAN should not complain about it. Disable the respective check on s390. There doesn't seem to be a Kconfig option to describe this situation, so explicitly check for s390. Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Ilya Leoshkevich <[email protected]> Reviewed-by: Alexander Potapenko <[email protected]> Cc: Alexander Gordeev <[email protected]> Cc: Christian Borntraeger <[email protected]> Cc: Christoph Lameter <[email protected]> Cc: David Rientjes <[email protected]> Cc: Dmitry Vyukov <[email protected]> Cc: Heiko Carstens <[email protected]> Cc: Hyeonggon Yoo <[email protected]> Cc: Joonsoo Kim <[email protected]> Cc: <[email protected]> Cc: Marco Elver <[email protected]> Cc: Mark Rutland <[email protected]> Cc: Masami Hiramatsu (Google) <[email protected]> Cc: Pekka Enberg <[email protected]> Cc: Roman Gushchin <[email protected]> Cc: Steven Rostedt (Google) <[email protected]> Cc: Sven Schnelle <[email protected]> Cc: Vasily Gorbik <[email protected]> Cc: Vlastimil Babka <[email protected]> Signed-off-by: Andrew Morton <[email protected]>
2024-07-03kmsan: expose KMSAN_WARN_ON()Ilya Leoshkevich1-23/+1
KMSAN_WARN_ON() is required for implementing s390-specific KMSAN functions, but right now it's available only to the KMSAN internal functions. Expose it to subsystems through <linux/kmsan.h>. Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Ilya Leoshkevich <[email protected]> Reviewed-by: Alexander Potapenko <[email protected]> Cc: Alexander Gordeev <[email protected]> Cc: Christian Borntraeger <[email protected]> Cc: Christoph Lameter <[email protected]> Cc: David Rientjes <[email protected]> Cc: Dmitry Vyukov <[email protected]> Cc: Heiko Carstens <[email protected]> Cc: Hyeonggon Yoo <[email protected]> Cc: Joonsoo Kim <[email protected]> Cc: <[email protected]> Cc: Marco Elver <[email protected]> Cc: Mark Rutland <[email protected]> Cc: Masami Hiramatsu (Google) <[email protected]> Cc: Pekka Enberg <[email protected]> Cc: Roman Gushchin <[email protected]> Cc: Steven Rostedt (Google) <[email protected]> Cc: Sven Schnelle <[email protected]> Cc: Vasily Gorbik <[email protected]> Cc: Vlastimil Babka <[email protected]> Signed-off-by: Andrew Morton <[email protected]>
2024-07-03kmsan: do not round up pg_data_t sizeIlya Leoshkevich1-1/+1
x86's alloc_node_data() rounds up node data size to PAGE_SIZE. It's not explained why it's needed, but it's most likely for performance reasons, since the padding bytes are not used anywhere. Some other architectures do it as well, e.g., mips rounds it up to the cache line size. kmsan_init_shadow() initializes metadata for each node data and assumes the x86 rounding, which does not match other architectures. This may cause the range end to overshoot the end of available memory, in turn causing virt_to_page_or_null() in kmsan_init_alloc_meta_for_range() to return NULL, which leads to kernel panic shortly after. Since the padding bytes are not used, drop the rounding. Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Ilya Leoshkevich <[email protected]> Reviewed-by: Alexander Potapenko <[email protected]> Cc: Alexander Gordeev <[email protected]> Cc: Christian Borntraeger <[email protected]> Cc: Christoph Lameter <[email protected]> Cc: David Rientjes <[email protected]> Cc: Dmitry Vyukov <[email protected]> Cc: Heiko Carstens <[email protected]> Cc: Hyeonggon Yoo <[email protected]> Cc: Joonsoo Kim <[email protected]> Cc: <[email protected]> Cc: Marco Elver <[email protected]> Cc: Mark Rutland <[email protected]> Cc: Masami Hiramatsu (Google) <[email protected]> Cc: Pekka Enberg <[email protected]> Cc: Roman Gushchin <[email protected]> Cc: Steven Rostedt (Google) <[email protected]> Cc: Sven Schnelle <[email protected]> Cc: Vasily Gorbik <[email protected]> Cc: Vlastimil Babka <[email protected]> Signed-off-by: Andrew Morton <[email protected]>
2024-07-03kmsan: use ALIGN_DOWN() in kmsan_get_metadata()Ilya Leoshkevich1-5/+3
Improve the readability by replacing the custom aligning logic with ALIGN_DOWN(). Unlike other places where a similar sequence is used, there is no size parameter that needs to be adjusted, so the standard macro fits. Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Ilya Leoshkevich <[email protected]> Reviewed-by: Alexander Potapenko <[email protected]> Cc: Alexander Gordeev <[email protected]> Cc: Christian Borntraeger <[email protected]> Cc: Christoph Lameter <[email protected]> Cc: David Rientjes <[email protected]> Cc: Dmitry Vyukov <[email protected]> Cc: Heiko Carstens <[email protected]> Cc: Hyeonggon Yoo <[email protected]> Cc: Joonsoo Kim <[email protected]> Cc: <[email protected]> Cc: Marco Elver <[email protected]> Cc: Mark Rutland <[email protected]> Cc: Masami Hiramatsu (Google) <[email protected]> Cc: Pekka Enberg <[email protected]> Cc: Roman Gushchin <[email protected]> Cc: Steven Rostedt (Google) <[email protected]> Cc: Sven Schnelle <[email protected]> Cc: Vasily Gorbik <[email protected]> Cc: Vlastimil Babka <[email protected]> Signed-off-by: Andrew Morton <[email protected]>
2024-07-03kmsan: support SLAB_POISONIlya Leoshkevich1-1/+1
Avoid false KMSAN negatives with SLUB_DEBUG by allowing kmsan_slab_free() to poison the freed memory, and by preventing init_object() from unpoisoning new allocations by using __memset(). There are two alternatives to this approach. First, init_object() can be marked with __no_sanitize_memory. This annotation should be used with great care, because it drops all instrumentation from the function, and any shadow writes will be lost. Even though this is not a concern with the current init_object() implementation, this may change in the future. Second, kmsan_poison_memory() calls may be added after memset() calls. The downside is that init_object() is called from free_debug_processing(), in which case poisoning will erase the distinction between simply uninitialized memory and UAF. Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Ilya Leoshkevich <[email protected]> Reviewed-by: Alexander Potapenko <[email protected]> Cc: Alexander Gordeev <[email protected]> Cc: Christian Borntraeger <[email protected]> Cc: Christoph Lameter <[email protected]> Cc: David Rientjes <[email protected]> Cc: Dmitry Vyukov <[email protected]> Cc: Heiko Carstens <[email protected]> Cc: Hyeonggon Yoo <[email protected]> Cc: Joonsoo Kim <[email protected]> Cc: <[email protected]> Cc: Marco Elver <[email protected]> Cc: Mark Rutland <[email protected]> Cc: Masami Hiramatsu (Google) <[email protected]> Cc: Pekka Enberg <[email protected]> Cc: Roman Gushchin <[email protected]> Cc: Steven Rostedt (Google) <[email protected]> Cc: Sven Schnelle <[email protected]> Cc: Vasily Gorbik <[email protected]> Cc: Vlastimil Babka <[email protected]> Signed-off-by: Andrew Morton <[email protected]>
2024-07-03kmsan: allow disabling KMSAN checks for the current taskIlya Leoshkevich3-7/+19
Like for KASAN, it's useful to temporarily disable KMSAN checks around, e.g., redzone accesses. Introduce kmsan_disable_current() and kmsan_enable_current(), which are similar to their KASAN counterparts. Make them reentrant in order to handle memory allocations in interrupt context. Repurpose the allow_reporting field for this. Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Ilya Leoshkevich <[email protected]> Reviewed-by: Alexander Potapenko <[email protected]> Cc: Alexander Gordeev <[email protected]> Cc: Christian Borntraeger <[email protected]> Cc: Christoph Lameter <[email protected]> Cc: David Rientjes <[email protected]> Cc: Dmitry Vyukov <[email protected]> Cc: Heiko Carstens <[email protected]> Cc: Hyeonggon Yoo <[email protected]> Cc: Joonsoo Kim <[email protected]> Cc: <[email protected]> Cc: Marco Elver <[email protected]> Cc: Mark Rutland <[email protected]> Cc: Masami Hiramatsu (Google) <[email protected]> Cc: Pekka Enberg <[email protected]> Cc: Roman Gushchin <[email protected]> Cc: Steven Rostedt (Google) <[email protected]> Cc: Sven Schnelle <[email protected]> Cc: Vasily Gorbik <[email protected]> Cc: Vlastimil Babka <[email protected]> Signed-off-by: Andrew Morton <[email protected]>
2024-07-03kmsan: export panic_on_kmsanIlya Leoshkevich1-0/+1
When building the kmsan test as a module, modpost fails with the following error message: ERROR: modpost: "panic_on_kmsan" [mm/kmsan/kmsan_test.ko] undefined! Export panic_on_kmsan in order to improve the KMSAN usability for modules. Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Ilya Leoshkevich <[email protected]> Reviewed-by: Alexander Potapenko <[email protected]> Cc: Alexander Gordeev <[email protected]> Cc: Christian Borntraeger <[email protected]> Cc: Christoph Lameter <[email protected]> Cc: David Rientjes <[email protected]> Cc: Dmitry Vyukov <[email protected]> Cc: Heiko Carstens <[email protected]> Cc: Hyeonggon Yoo <[email protected]> Cc: Joonsoo Kim <[email protected]> Cc: <[email protected]> Cc: Marco Elver <[email protected]> Cc: Mark Rutland <[email protected]> Cc: Masami Hiramatsu (Google) <[email protected]> Cc: Pekka Enberg <[email protected]> Cc: Roman Gushchin <[email protected]> Cc: Steven Rostedt (Google) <[email protected]> Cc: Sven Schnelle <[email protected]> Cc: Vasily Gorbik <[email protected]> Cc: Vlastimil Babka <[email protected]> Signed-off-by: Andrew Morton <[email protected]>
2024-07-03kmsan: expose kmsan_get_metadata()Ilya Leoshkevich2-1/+1
Each s390 CPU has lowcore pages associated with it. Each CPU sees its own lowcore at virtual address 0 through a hardware mechanism called prefixing. Additionally, all lowcores are mapped to non-0 virtual addresses stored in the lowcore_ptr[] array. When lowcore is accessed through virtual address 0, one needs to resolve metadata for lowcore_ptr[raw_smp_processor_id()]. Expose kmsan_get_metadata() to make it possible to do this from the arch code. Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Ilya Leoshkevich <[email protected]> Reviewed-by: Alexander Potapenko <[email protected]> Cc: Alexander Gordeev <[email protected]> Cc: Christian Borntraeger <[email protected]> Cc: Christoph Lameter <[email protected]> Cc: David Rientjes <[email protected]> Cc: Dmitry Vyukov <[email protected]> Cc: Heiko Carstens <[email protected]> Cc: Hyeonggon Yoo <[email protected]> Cc: Joonsoo Kim <[email protected]> Cc: <[email protected]> Cc: Marco Elver <[email protected]> Cc: Mark Rutland <[email protected]> Cc: Masami Hiramatsu (Google) <[email protected]> Cc: Pekka Enberg <[email protected]> Cc: Roman Gushchin <[email protected]> Cc: Steven Rostedt (Google) <[email protected]> Cc: Sven Schnelle <[email protected]> Cc: Vasily Gorbik <[email protected]> Cc: Vlastimil Babka <[email protected]> Signed-off-by: Andrew Morton <[email protected]>
2024-07-03kmsan: remove an x86-specific #include from kmsan.hIlya Leoshkevich1-4/+4
Replace the x86-specific asm/pgtable_64_types.h #include with the linux/pgtable.h one, which all architectures have. While at it, sort the headers alphabetically for the sake of consistency with other KMSAN code. Link: https://lkml.kernel.org/r/[email protected] Fixes: f80be4571b19 ("kmsan: add KMSAN runtime core") Signed-off-by: Ilya Leoshkevich <[email protected]> Suggested-by: Heiko Carstens <[email protected]> Reviewed-by: Alexander Potapenko <[email protected]> Cc: Alexander Gordeev <[email protected]> Cc: Christian Borntraeger <[email protected]> Cc: Christoph Lameter <[email protected]> Cc: David Rientjes <[email protected]> Cc: Dmitry Vyukov <[email protected]> Cc: Hyeonggon Yoo <[email protected]> Cc: Joonsoo Kim <[email protected]> Cc: <[email protected]> Cc: Marco Elver <[email protected]> Cc: Mark Rutland <[email protected]> Cc: Masami Hiramatsu (Google) <[email protected]> Cc: Pekka Enberg <[email protected]> Cc: Roman Gushchin <[email protected]> Cc: Steven Rostedt (Google) <[email protected]> Cc: Sven Schnelle <[email protected]> Cc: Vasily Gorbik <[email protected]> Cc: Vlastimil Babka <[email protected]> Signed-off-by: Andrew Morton <[email protected]>
2024-07-03kmsan: remove a useless assignment from kmsan_vmap_pages_range_noflush()Ilya Leoshkevich1-1/+0
The value assigned to prot is immediately overwritten on the next line with PAGE_KERNEL. The right hand side of the assignment has no side-effects. Link: https://lkml.kernel.org/r/[email protected] Fixes: b073d7f8aee4 ("mm: kmsan: maintain KMSAN metadata for page operations") Signed-off-by: Ilya Leoshkevich <[email protected]> Suggested-by: Alexander Gordeev <[email protected]> Reviewed-by: Alexander Potapenko <[email protected]> Cc: Christian Borntraeger <[email protected]> Cc: Christoph Lameter <[email protected]> Cc: David Rientjes <[email protected]> Cc: Dmitry Vyukov <[email protected]> Cc: Heiko Carstens <[email protected]> Cc: Hyeonggon Yoo <[email protected]> Cc: Joonsoo Kim <[email protected]> Cc: <[email protected]> Cc: Marco Elver <[email protected]> Cc: Mark Rutland <[email protected]> Cc: Masami Hiramatsu (Google) <[email protected]> Cc: Pekka Enberg <[email protected]> Cc: Roman Gushchin <[email protected]> Cc: Steven Rostedt (Google) <[email protected]> Cc: Sven Schnelle <[email protected]> Cc: Vasily Gorbik <[email protected]> Cc: Vlastimil Babka <[email protected]> Signed-off-by: Andrew Morton <[email protected]>
2024-07-03kmsan: fix kmsan_copy_to_user() on arches with overlapping address spacesIlya Leoshkevich1-1/+2
Comparing pointers with TASK_SIZE does not make sense when kernel and userspace overlap. Assume that we are handling user memory access in this case. Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Ilya Leoshkevich <[email protected]> Reported-by: Alexander Gordeev <[email protected]> Reviewed-by: Alexander Potapenko <[email protected]> Cc: Christian Borntraeger <[email protected]> Cc: Christoph Lameter <[email protected]> Cc: David Rientjes <[email protected]> Cc: Dmitry Vyukov <[email protected]> Cc: Heiko Carstens <[email protected]> Cc: Hyeonggon Yoo <[email protected]> Cc: Joonsoo Kim <[email protected]> Cc: <[email protected]> Cc: Marco Elver <[email protected]> Cc: Mark Rutland <[email protected]> Cc: Masami Hiramatsu (Google) <[email protected]> Cc: Pekka Enberg <[email protected]> Cc: Roman Gushchin <[email protected]> Cc: Steven Rostedt (Google) <[email protected]> Cc: Sven Schnelle <[email protected]> Cc: Vasily Gorbik <[email protected]> Cc: Vlastimil Babka <[email protected]> Signed-off-by: Andrew Morton <[email protected]>
2024-07-03kmsan: fix is_bad_asm_addr() on arches with overlapping address spacesIlya Leoshkevich1-1/+2
Comparing pointers with TASK_SIZE does not make sense when kernel and userspace overlap. Skip the comparison when this is the case. Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Ilya Leoshkevich <[email protected]> Reviewed-by: Alexander Potapenko <[email protected]> Cc: Alexander Gordeev <[email protected]> Cc: Christian Borntraeger <[email protected]> Cc: Christoph Lameter <[email protected]> Cc: David Rientjes <[email protected]> Cc: Dmitry Vyukov <[email protected]> Cc: Heiko Carstens <[email protected]> Cc: Hyeonggon Yoo <[email protected]> Cc: Joonsoo Kim <[email protected]> Cc: <[email protected]> Cc: Marco Elver <[email protected]> Cc: Mark Rutland <[email protected]> Cc: Masami Hiramatsu (Google) <[email protected]> Cc: Pekka Enberg <[email protected]> Cc: Roman Gushchin <[email protected]> Cc: Steven Rostedt (Google) <[email protected]> Cc: Sven Schnelle <[email protected]> Cc: Vasily Gorbik <[email protected]> Cc: Vlastimil Babka <[email protected]> Signed-off-by: Andrew Morton <[email protected]>
2024-07-03kmsan: increase the maximum store size to 4096Ilya Leoshkevich1-4/+3
The inline assembly block in s390's chsc() stores that much. Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Ilya Leoshkevich <[email protected]> Reviewed-by: Alexander Potapenko <[email protected]> Cc: Alexander Gordeev <[email protected]> Cc: Christian Borntraeger <[email protected]> Cc: Christoph Lameter <[email protected]> Cc: David Rientjes <[email protected]> Cc: Dmitry Vyukov <[email protected]> Cc: Heiko Carstens <[email protected]> Cc: Hyeonggon Yoo <[email protected]> Cc: Joonsoo Kim <[email protected]> Cc: <[email protected]> Cc: Marco Elver <[email protected]> Cc: Mark Rutland <[email protected]> Cc: Masami Hiramatsu (Google) <[email protected]> Cc: Pekka Enberg <[email protected]> Cc: Roman Gushchin <[email protected]> Cc: Steven Rostedt (Google) <[email protected]> Cc: Sven Schnelle <[email protected]> Cc: Vasily Gorbik <[email protected]> Cc: Vlastimil Babka <[email protected]> Signed-off-by: Andrew Morton <[email protected]>
2024-07-03kmsan: make the tests compatible with kmsan.panic=1Ilya Leoshkevich1-0/+5
It's useful to have both tests and kmsan.panic=1 during development, but right now the warnings, that the tests cause, lead to kernel panics. Temporarily set kmsan.panic=0 for the duration of the KMSAN testing. Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Ilya Leoshkevich <[email protected]> Reviewed-by: Alexander Potapenko <[email protected]> Cc: Alexander Gordeev <[email protected]> Cc: Christian Borntraeger <[email protected]> Cc: Christoph Lameter <[email protected]> Cc: David Rientjes <[email protected]> Cc: Dmitry Vyukov <[email protected]> Cc: Heiko Carstens <[email protected]> Cc: Hyeonggon Yoo <[email protected]> Cc: Joonsoo Kim <[email protected]> Cc: <[email protected]> Cc: Marco Elver <[email protected]> Cc: Mark Rutland <[email protected]> Cc: Masami Hiramatsu (Google) <[email protected]> Cc: Pekka Enberg <[email protected]> Cc: Roman Gushchin <[email protected]> Cc: Steven Rostedt (Google) <[email protected]> Cc: Sven Schnelle <[email protected]> Cc: Vasily Gorbik <[email protected]> Cc: Vlastimil Babka <[email protected]> Signed-off-by: Andrew Morton <[email protected]>
2024-07-03mm: pass meminit_context to __free_pages_core()David Hildenbrand1-1/+1
Patch series "mm/memory_hotplug: use PageOffline() instead of PageReserved() for !ZONE_DEVICE". This can be a considered a long-overdue follow-up to some parts of [1]. The patches are based on [2], but they are not strictly required -- just makes it clearer why we can use adjust_managed_page_count() for memory hotplug without going into details about highmem. We stop initializing pages with PageReserved() in memory hotplug code -- except when dealing with ZONE_DEVICE for now. Instead, we use PageOffline(): all pages are initialized to PageOffline() when onlining a memory section, and only the ones actually getting exposed to the system/page allocator will get PageOffline cleared. This way, we enlighten memory hotplug more about PageOffline() pages and can cleanup some hacks we have in virtio-mem code. What about ZONE_DEVICE? PageOffline() is wrong, but we might just stop using PageReserved() for them later by simply checking for is_zone_device_page() at suitable places. That will be a separate patch set / proposal. This primarily affects virtio-mem, HV-balloon and XEN balloon. I only briefly tested with virtio-mem, which benefits most from these cleanups. [1] https://lore.kernel.org/all/[email protected]/ [2] https://lkml.kernel.org/r/[email protected] This patch (of 3): In preparation for further changes, let's teach __free_pages_core() about the differences of memory hotplug handling. Move the memory hotplug specific handling from generic_online_page() to __free_pages_core(), use adjust_managed_page_count() on the memory hotplug path, and spell out why memory freed via memblock cannot currently use adjust_managed_page_count(). [[email protected]: add missed CONFIG_DEFERRED_STRUCT_PAGE_INIT] Link: https://lkml.kernel.org/r/[email protected] [[email protected]: fix up the memblock comment, per Oscar] Link: https://lkml.kernel.org/r/[email protected] [[email protected]: add the parameter name also in the declaration] Link: https://lkml.kernel.org/r/[email protected] Link: https://lkml.kernel.org/r/[email protected] Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: David Hildenbrand <[email protected]> Cc: Alexander Potapenko <[email protected]> Cc: Dexuan Cui <[email protected]> Cc: Dmitry Vyukov <[email protected]> Cc: Eugenio Pérez <[email protected]> Cc: Haiyang Zhang <[email protected]> Cc: Jason Wang <[email protected]> Cc: Juergen Gross <[email protected]> Cc: "K. Y. Srinivasan" <[email protected]> Cc: Marco Elver <[email protected]> Cc: Michael S. Tsirkin <[email protected]> Cc: Mike Rapoport (IBM) <[email protected]> Cc: Oleksandr Tyshchenko <[email protected]> Cc: Oscar Salvador <[email protected]> Cc: Stefano Stabellini <[email protected]> Cc: Wei Liu <[email protected]> Cc: Xuan Zhuo <[email protected]> Signed-off-by: Andrew Morton <[email protected]>
2024-07-03kmsan: introduce test_unpoison_memory()Brian Johannesmeyer1-0/+27
Add a regression test to ensure that kmsan_unpoison_memory() works the same as an unpoisoning operation added by the instrumentation. The test has two subtests: one that checks the instrumentation, and one that checks kmsan_unpoison_memory(). Each subtest initializes the first byte of a 4-byte buffer, then checks that the other 3 bytes are uninitialized. [[email protected]: change description, remove comment about failing test case] Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Brian Johannesmeyer <[email protected]> Link: https://lore.kernel.org/lkml/[email protected]/T/ Signed-off-by: Alexander Potapenko <[email protected]> Cc: Dmitry Vyukov <[email protected]> Cc: Kees Cook <[email protected]> Cc: Marco Elver <[email protected]> Signed-off-by: Andrew Morton <[email protected]>
2024-06-05kmsan: do not wipe out origin when doing partial unpoisoningAlexander Potapenko1-4/+11
As noticed by Brian, KMSAN should not be zeroing the origin when unpoisoning parts of a four-byte uninitialized value, e.g.: char a[4]; kmsan_unpoison_memory(a, 1); This led to false negatives, as certain poisoned values could receive zero origins, preventing those values from being reported. To fix the problem, check that kmsan_internal_set_shadow_origin() writes zero origins only to slots which have zero shadow. Link: https://lkml.kernel.org/r/[email protected] Fixes: f80be4571b19 ("kmsan: add KMSAN runtime core") Signed-off-by: Alexander Potapenko <[email protected]> Reported-by: Brian Johannesmeyer <[email protected]> Link: https://lore.kernel.org/lkml/[email protected]/T/ Reviewed-by: Marco Elver <[email protected]> Tested-by: Brian Johannesmeyer <[email protected]> Cc: Dmitry Vyukov <[email protected]> Cc: Kees Cook <[email protected]> Cc: <[email protected]> Signed-off-by: Andrew Morton <[email protected]>
2024-04-25mm: kmsan: implement kmsan_memmove()Alexander Potapenko1-0/+11
Provide a hook that can be used by custom memcpy implementations to tell KMSAN that the metadata needs to be copied. Without that, false positive reports are possible in the cases where KMSAN fails to intercept memory initialization. Link: https://lore.kernel.org/all/[email protected]/ Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Alexander Potapenko <[email protected]> Suggested-by: Tetsuo Handa <[email protected]> Reviewed-by: Marco Elver <[email protected]> Cc: Dmitry Vyukov <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Tetsuo Handa <[email protected]> Cc: Thomas Gleixner <[email protected]> Signed-off-by: Andrew Morton <[email protected]>
2024-02-22mm: kmsan: remove runtime checks from kmsan_unpoison_memory()Alexander Potapenko1-23/+13
Similarly to what's been done in commit 85716a80c16d ("kmsan: allow using __msan_instrument_asm_store() inside runtime"), it should be safe to call kmsan_unpoison_memory() from within the runtime, as it does not allocate memory or take locks. Remove the redundant runtime checks. This should fix false positives seen with CONFIG_DEBUG_LIST=y when the non-instrumented lib/stackdepot.c failed to unpoison the memory chunks later checked by the instrumented lib/list_debug.c Also replace the implementation of kmsan_unpoison_entry_regs() with a call to kmsan_unpoison_memory(). Link: https://lkml.kernel.org/r/[email protected] Fixes: f80be4571b19 ("kmsan: add KMSAN runtime core") Signed-off-by: Alexander Potapenko <[email protected]> Tested-by: Marco Elver <[email protected]> Cc: Dmitry Vyukov <[email protected]> Cc: Ilya Leoshkevich <[email protected]> Cc: Nicholas Miehlbradt <[email protected]> Signed-off-by: Andrew Morton <[email protected]>
2024-01-08mm, treewide: rename MAX_ORDER to MAX_PAGE_ORDERKirill A. Shutemov1-3/+3
commit 23baf831a32c ("mm, treewide: redefine MAX_ORDER sanely") has changed the definition of MAX_ORDER to be inclusive. This has caused issues with code that was not yet upstream and depended on the previous definition. To draw attention to the altered meaning of the define, rename MAX_ORDER to MAX_PAGE_ORDER. Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Kirill A. Shutemov <[email protected]> Cc: Linus Torvalds <[email protected]> Signed-off-by: Andrew Morton <[email protected]>
2024-01-08mm, treewide: introduce NR_PAGE_ORDERSKirill A. Shutemov1-1/+1
NR_PAGE_ORDERS defines the number of page orders supported by the page allocator, ranging from 0 to MAX_ORDER, MAX_ORDER + 1 in total. NR_PAGE_ORDERS assists in defining arrays of page orders and allows for more natural iteration over them. [[email protected]: fixup for kerneldoc warning] Link: https://lkml.kernel.org/r/20240101111512.7empzyifq7kxtzk3@box Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Kirill A. Shutemov <[email protected]> Reviewed-by: Zi Yan <[email protected]> Cc: Linus Torvalds <[email protected]> Signed-off-by: Andrew Morton <[email protected]>
2023-12-10kmsan: use stack_depot_save instead of __stack_depot_saveAndrey Konovalov1-4/+3
Make KMSAN use stack_depot_save instead of __stack_depot_save, as it always passes true to __stack_depot_save as the last argument. Link: https://lkml.kernel.org/r/18092240699efdc6acd78b51e41ea782953e6c8d.1700502145.git.andreyknvl@google.com Signed-off-by: Andrey Konovalov <[email protected]> Reviewed-by: Alexander Potapenko <[email protected]> Cc: Dmitry Vyukov <[email protected]> Cc: Evgenii Stepanov <[email protected]> Cc: Marco Elver <[email protected]> Cc: Oscar Salvador <[email protected]> Cc: Vlastimil Babka <[email protected]> Signed-off-by: Andrew Morton <[email protected]>
2023-10-25mm: kmsan: panic on failure to allocate early boot metadataPedro Falcato1-2/+7
Given large enough allocations and a machine with low enough memory (i.e a default QEMU VM), it's entirely possible that kmsan_init_alloc_meta_for_range's shadow+origin allocation fails. Instead of eating a NULL deref kernel oops, check explicitly for memblock_alloc() failure and panic with a nice error message. Alexander Potapenko said: For posterity, it is generally quite important for the allocated shadow and origin to be contiguous, otherwise an unaligned memory write may result in memory corruption (the corresponding unaligned shadow write will be assuming that shadow pages are adjacent). So instead of panicking we could have split the range into smaller ones until the allocation succeeds, but that would've led to hard-to-debug problems in the future. Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Pedro Falcato <[email protected]> Reviewed-by: Alexander Potapenko <[email protected]> Cc: Dmitry Vyukov <[email protected]> Cc: Marco Elver <[email protected]> Signed-off-by: Andrew Morton <[email protected]>
2023-10-04kmsan: introduce test_memcpy_initialized_gap()Alexander Potapenko1-0/+53
Add a regression test for the special case where memcpy() previously failed to correctly set the origins: if upon memcpy() four aligned initialized bytes with a zero origin value ended up split between two aligned four-byte chunks, one of those chunks could've received the zero origin value even despite it contained uninitialized bytes from other writes. Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Alexander Potapenko <[email protected]> Suggested-by: Marco Elver <[email protected]> Acked-by: Marco Elver <[email protected]> Cc: Dmitry Vyukov <[email protected]> Signed-off-by: Andrew Morton <[email protected]>
2023-10-04kmsan: merge test_memcpy_aligned_to_unaligned{,2}() togetherAlexander Potapenko1-24/+13
Introduce report_reset() that allows checking for more than one KMSAN report per testcase. Fold test_memcpy_aligned_to_unaligned2() into test_memcpy_aligned_to_unaligned(), so that they share the setup phase and check the behavior of a single memcpy() call. Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Alexander Potapenko <[email protected]> Acked-by: Marco Elver <[email protected]> Cc: Dmitry Vyukov <[email protected]> Signed-off-by: Andrew Morton <[email protected]>
2023-10-04kmsan: prevent optimizations in memcpy testsAlexander Potapenko1-25/+16
Clang 18 learned to optimize away memcpy() calls of small uninitialized scalar values. To ensure that memcpy tests in kmsan_test.c still perform calls to memcpy() (which KMSAN replaces with __msan_memcpy()), declare a separate memcpy_noinline() function with volatile parameters, which won't be optimized. Also retire DO_NOT_OPTIMIZE(), as memcpy_noinline() is apparently enough. Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Alexander Potapenko <[email protected]> Acked-by: Marco Elver <[email protected]> Cc: Dmitry Vyukov <[email protected]> Signed-off-by: Andrew Morton <[email protected]>
2023-10-04kmsan: simplify kmsan_internal_memmove_metadata()Alexander Potapenko1-96/+31
kmsan_internal_memmove_metadata() is the function that implements copying metadata every time memcpy()/memmove() is called. Because shadow memory stores 1 byte per each byte of kernel memory, copying the shadow is trivial and can be done by a single memmove() call. Origins, on the other hand, are stored as 4-byte values corresponding to every aligned 4 bytes of kernel memory. Therefore, if either the source or the destination of kmsan_internal_memmove_metadata() is unaligned, the number of origin slots corresponding to the source or destination may differ: 1) memcpy(0xffff888080a00000, 0xffff888080900000, 4) copies 1 origin slot into 1 origin slot: src (0xffff888080900000): xxxx src origins: o111 dst (0xffff888080a00000): xxxx dst origins: o111 2) memcpy(0xffff888080a00001, 0xffff888080900000, 4) copies 1 origin slot into 2 origin slots: src (0xffff888080900000): xxxx src origins: o111 dst (0xffff888080a00000): .xxx x... dst origins: o111 o111 3) memcpy(0xffff888080a00000, 0xffff888080900001, 4) copies 2 origin slots into 1 origin slot: src (0xffff888080900000): .xxx x... src origins: o111 o222 dst (0xffff888080a00000): xxxx dst origins: o111 (or o222) Previously, kmsan_internal_memmove_metadata() tried to solve this problem by copying min(src_slots, dst_slots) as is and cloning the missing slot on one of the ends, if needed. This was error-prone even in the simple cases where 4 bytes were copied, and did not account for situations where the total number of nonzero origin slots could have increased by more than one after copying: memcpy(0xffff888080a00000, 0xffff888080900002, 8) src (0xffff888080900002): ..xx .... xx.. src origins: o111 0000 o222 dst (0xffff888080a00000): xx.. ..xx o111 0000 (or 0000 o222) The new implementation simply copies the shadow byte by byte, and updates the corresponding origin slot, if the shadow byte is nonzero. This approach can handle complex cases with mixed initialized and uninitialized bytes. Similarly to KMSAN inline instrumentation, latter writes to bytes sharing the same origin slots take precedence. Link: https://lkml.kernel.org/r/[email protected] Fixes: f80be4571b19 ("kmsan: add KMSAN runtime core") Signed-off-by: Alexander Potapenko <[email protected]> Acked-by: Marco Elver <[email protected]> Cc: Dmitry Vyukov <[email protected]> Signed-off-by: Andrew Morton <[email protected]>
2023-08-21mm: kmsan: use helper macros PAGE_ALIGN and PAGE_ALIGN_DOWNZhangPeng1-2/+2
Use helper macros PAGE_ALIGN and PAGE_ALIGN_DOWN to improve code readability. No functional modification involved. Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: ZhangPeng <[email protected]> Reviewed-by: Alexander Potapenko <[email protected]> Cc: Dmitry Vyukov <[email protected]> Cc: Kefeng Wang <[email protected]> Cc: Marco Elver <[email protected]> Cc: Nanyong Sun <[email protected]> Signed-off-by: Andrew Morton <[email protected]>
2023-08-21mm: kmsan: use helper macro offset_in_page()ZhangPeng2-2/+2
Use helper macro offset_in_page() to improve code readability. No functional modification involved. Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: ZhangPeng <[email protected]> Reviewed-by: Alexander Potapenko <[email protected]> Cc: Dmitry Vyukov <[email protected]> Cc: Kefeng Wang <[email protected]> Cc: Marco Elver <[email protected]> Cc: Nanyong Sun <[email protected]> Signed-off-by: Andrew Morton <[email protected]>
2023-08-21mm: kmsan: use helper function page_size()ZhangPeng2-2/+2
Patch series "minor cleanups for kmsan". Use helper function and macros to improve code readability. No functional modification involved. This patch (of 3): Use function page_size() to improve code readability. No functional modification involved. Link: https://lkml.kernel.org/r/[email protected] Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: ZhangPeng <[email protected]> Reviewed-by: Alexander Potapenko <[email protected]> Cc: Dmitry Vyukov <[email protected]> Cc: Kefeng Wang <[email protected]> Cc: Marco Elver <[email protected]> Cc: Nanyong Sun <[email protected]> Signed-off-by: Andrew Morton <[email protected]>
2023-06-23kasan,kmsan: remove __GFP_KSWAPD_RECLAIM usage from kasan/kmsanTetsuo Handa2-4/+4
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/[email protected] Signed-off-by: Tetsuo Handa <[email protected]> Reported-by: syzbot <[email protected]> Closes: https://syzkaller.appspot.com/bug?extid=ece2915262061d6e0ac1 Reviewed-by: "Huang, Ying" <[email protected]> Reviewed-by: Alexander Potapenko <[email protected]> Cc: Andrey Konovalov <[email protected]> Cc: Andrey Ryabinin <[email protected]> Cc: Dmitry Vyukov <[email protected]> Cc: Marco Elver <[email protected]> Cc: Mel Gorman <[email protected]> Cc: Vincenzo Frascino <[email protected]> Cc: Vlastimil Babka <[email protected]> Signed-off-by: Andrew Morton <[email protected]>
2023-04-18printk: 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/[email protected] Signed-off-by: Pavankumar Kondeti <[email protected]> Cc: Alexander Potapenko <[email protected]> Cc: Andrey Konovalov <[email protected]> Cc: Andrey Ryabinin <[email protected]> Cc: Dmitry Vyukov <[email protected]> Cc: John Ogness <[email protected]> Cc: Marco Elver <[email protected]> Cc: Petr Mladek <[email protected]> Cc: Sergey Senozhatsky <[email protected]> Cc: Steven Rostedt <[email protected]> Cc: Vincenzo Frascino <[email protected]> Signed-off-by: Andrew Morton <[email protected]>
2023-04-18kmsan: fix a stale comment in kmsan_save_stack_with_flags()Zhen Lei1-1/+1
After commit 446ec83805dd ("mm/page_alloc: use might_alloc()") and commit 84172f4bb752 ("mm/page_alloc: combine __alloc_pages and __alloc_pages_nodemask"), the comment is no longer accurate. Flag '__GFP_DIRECT_RECLAIM' is clear enough on its own, so remove the comment rather than update it. Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Zhen Lei <[email protected]> Reviewed-by: Alexander Potapenko <[email protected]> Cc: Dmitry Vyukov <[email protected]> Cc: Marco Elver <[email protected]> Signed-off-by: Andrew Morton <[email protected]>
2023-04-18sync mm-stable with mm-hotfixes-stable to pick up depended-upon upstream changesAndrew Morton2-17/+65
2023-04-18mm: kmsan: handle alloc failures in kmsan_ioremap_page_range()Alexander Potapenko1-8/+47
Similarly to kmsan_vmap_pages_range_noflush(), kmsan_ioremap_page_range() must also properly handle allocation/mapping failures. In the case of such, it must clean up the already created metadata mappings and return an error code, so that the error can be propagated to ioremap_page_range(). Without doing so, KMSAN may silently fail to bring the metadata for the page range into a consistent state, which will result in user-visible crashes when trying to access them. Link: https://lkml.kernel.org/r/[email protected] Fixes: b073d7f8aee4 ("mm: kmsan: maintain KMSAN metadata for page operations") Signed-off-by: Alexander Potapenko <[email protected]> Reported-by: Dipanjan Das <[email protected]> Link: https://lore.kernel.org/linux-mm/CANX2M5ZRrRA64k0hOif02TjmY9kbbO2aCBPyq79es34RXZ=cAw@mail.gmail.com/ Reviewed-by: Marco Elver <[email protected]> Cc: Christoph Hellwig <[email protected]> Cc: Dmitry Vyukov <[email protected]> Cc: Uladzislau Rezki (Sony) <[email protected]> Cc: <[email protected]> Signed-off-by: Andrew Morton <[email protected]>
2023-04-18mm: kmsan: handle alloc failures in kmsan_vmap_pages_range_noflush()Alexander Potapenko1-9/+18
As reported by Dipanjan Das, when KMSAN is used together with kernel fault injection (or, generally, even without the latter), calls to kcalloc() or __vmap_pages_range_noflush() may fail, leaving the metadata mappings for the virtual mapping in an inconsistent state. When these metadata mappings are accessed later, the kernel crashes. To address the problem, we return a non-zero error code from kmsan_vmap_pages_range_noflush() in the case of any allocation/mapping failure inside it, and make vmap_pages_range_noflush() return an error if KMSAN fails to allocate the metadata. This patch also removes KMSAN_WARN_ON() from vmap_pages_range_noflush(), as these allocation failures are not fatal anymore. Link: https://lkml.kernel.org/r/[email protected] Fixes: b073d7f8aee4 ("mm: kmsan: maintain KMSAN metadata for page operations") Signed-off-by: Alexander Potapenko <[email protected]> Reported-by: Dipanjan Das <[email protected]> Link: https://lore.kernel.org/linux-mm/CANX2M5ZRrRA64k0hOif02TjmY9kbbO2aCBPyq79es34RXZ=cAw@mail.gmail.com/ Reviewed-by: Marco Elver <[email protected]> Cc: Christoph Hellwig <[email protected]> Cc: Dmitry Vyukov <[email protected]> Cc: Uladzislau Rezki (Sony) <[email protected]> Cc: <[email protected]> Signed-off-by: Andrew Morton <[email protected]>
2023-04-05mm, treewide: redefine MAX_ORDER sanelyKirill A. Shutemov1-3/+3
MAX_ORDER currently defined as number of orders page allocator supports: user can ask buddy allocator for page order between 0 and MAX_ORDER-1. This definition is counter-intuitive and lead to number of bugs all over the kernel. Change the definition of MAX_ORDER to be inclusive: the range of orders user can ask from buddy allocator is 0..MAX_ORDER now. [[email protected]: fix min() warning] Link: https://lkml.kernel.org/r/20230315153800.32wib3n5rickolvh@box [[email protected]: fix another min_t warning] [[email protected]: fixups per Zi Yan] Link: https://lkml.kernel.org/r/[email protected] [[email protected]: fix underlining in docs] Link: https://lore.kernel.org/oe-kbuild-all/[email protected]/ Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Kirill A. Shutemov <[email protected]> Reviewed-by: Michael Ellerman <[email protected]> [powerpc] Cc: "Kirill A. Shutemov" <[email protected]> Cc: Zi Yan <[email protected]> Signed-off-by: Andrew Morton <[email protected]>
2023-03-28kmsan: add test_stackdepot_roundtripAlexander Potapenko1-0/+31
Ensure that KMSAN does not report false positives in instrumented callers of stack_depot_save(), stack_depot_print(), and stack_depot_fetch(). Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Alexander Potapenko <[email protected]> Cc: Andrey Konovalov <[email protected]> Cc: Dmitry Vyukov <[email protected]> Cc: Marco Elver <[email protected]> Cc: syzbot <[email protected]> Signed-off-by: Andrew Morton <[email protected]>
2023-03-28kmsan: add memsetXX testsAlexander Potapenko1-0/+22
Add tests ensuring that memset16()/memset32()/memset64() are instrumented by KMSAN and correctly initialize the memory. Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Alexander Potapenko <[email protected]> Reviewed-by: Marco Elver <[email protected]> Cc: Daniel Vetter <[email protected]> Cc: Geert Uytterhoeven <[email protected]> Cc: Helge Deller <[email protected]> Cc: Kees Cook <[email protected]> Cc: Tetsuo Handa <[email protected]> Signed-off-by: Andrew Morton <[email protected]>
2023-03-28kmsan: another take at fixing memcpy testsAlexander Potapenko1-6/+38
commit 5478afc55a21 ("kmsan: fix memcpy tests") uses OPTIMIZER_HIDE_VAR() to hide the uninitialized var from the compiler optimizations. However OPTIMIZER_HIDE_VAR(uninit) enforces an immediate check of @uninit, so memcpy tests did not actually check the behavior of memcpy(), because they always contained a KMSAN report. Replace OPTIMIZER_HIDE_VAR() with a file-local macro that just clobbers the memory with a barrier(), and add a test case for memcpy() that does not expect an error report. Also reflow kmsan_test.c with clang-format. Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Alexander Potapenko <[email protected]> Reviewed-by: Marco Elver <[email protected]> Cc: Daniel Vetter <[email protected]> Cc: Geert Uytterhoeven <[email protected]> Cc: Helge Deller <[email protected]> Cc: Kees Cook <[email protected]> Cc: Tetsuo Handa <[email protected]> Signed-off-by: Andrew Morton <[email protected]>
2023-02-20kmsan: disable ftrace in kmsan core codeArnd Bergmann1-1/+7
objtool warns about some suspicous code inside of kmsan: vmlinux.o: warning: objtool: __msan_metadata_ptr_for_load_n+0x4: call to __fentry__() with UACCESS enabled vmlinux.o: warning: objtool: __msan_metadata_ptr_for_store_n+0x4: call to __fentry__() with UACCESS enabled vmlinux.o: warning: objtool: __msan_metadata_ptr_for_load_1+0x4: call to __fentry__() with UACCESS enabled vmlinux.o: warning: objtool: __msan_metadata_ptr_for_store_1+0x4: call to __fentry__() with UACCESS enabled vmlinux.o: warning: objtool: __msan_metadata_ptr_for_load_2+0x4: call to __fentry__() with UACCESS enabled vmlinux.o: warning: objtool: __msan_metadata_ptr_for_store_2+0x4: call to __fentry__() with UACCESS enabled vmlinux.o: warning: objtool: __msan_metadata_ptr_for_load_4+0x4: call to __fentry__() with UACCESS enabled vmlinux.o: warning: objtool: __msan_metadata_ptr_for_store_4+0x4: call to __fentry__() with UACCESS enabled vmlinux.o: warning: objtool: __msan_metadata_ptr_for_load_8+0x4: call to __fentry__() with UACCESS enabled vmlinux.o: warning: objtool: __msan_metadata_ptr_for_store_8+0x4: call to __fentry__() with UACCESS enabled vmlinux.o: warning: objtool: __msan_instrument_asm_store+0x4: call to __fentry__() with UACCESS enabled vmlinux.o: warning: objtool: __msan_chain_origin+0x4: call to __fentry__() with UACCESS enabled vmlinux.o: warning: objtool: __msan_poison_alloca+0x4: call to __fentry__() with UACCESS enabled vmlinux.o: warning: objtool: __msan_warning+0x4: call to __fentry__() with UACCESS enabled vmlinux.o: warning: objtool: __msan_get_context_state+0x4: call to __fentry__() with UACCESS enabled vmlinux.o: warning: objtool: kmsan_copy_to_user+0x4: call to __fentry__() with UACCESS enabled vmlinux.o: warning: objtool: kmsan_unpoison_memory+0x4: call to __fentry__() with UACCESS enabled vmlinux.o: warning: objtool: kmsan_unpoison_entry_regs+0x4: call to __fentry__() with UACCESS enabled vmlinux.o: warning: objtool: kmsan_report+0x4: call to __fentry__() with UACCESS enabled The Makefile contained a line to turn off ftrace for the entire directory, but this does not work. Replace it with individual lines, matching the approach in kasan. Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Arnd Bergmann <[email protected]> Fixes: f80be4571b19 ("kmsan: add KMSAN runtime core") Acked-by: Alexander Potapenko <[email protected]> Cc: Andrey Konovalov <[email protected]> Cc: Andrey Ryabinin <[email protected]> Cc: Dmitry Vyukov <[email protected]> Cc: Josh Poimboeuf <[email protected]> Cc: Kuan-Ying Lee <[email protected]> Cc: Marco Elver <[email protected]> Cc: Peter Zijlstra (Intel) <[email protected]> Cc: Vincenzo Frascino <[email protected]> Signed-off-by: Andrew Morton <[email protected]>
2023-02-16lib/stacktrace, kasan, kmsan: rework extra_bits interfaceAndrey Konovalov1-3/+7
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 <[email protected]> Reviewed-by: Alexander Potapenko <[email protected]> Signed-off-by: Andrew Morton <[email protected]>
2023-02-02kmsan: silence -Wmissing-prototypes warningsAlexander Potapenko1-0/+23
When building the kernel with W=1, the compiler reports numerous warnings about the missing prototypes for KMSAN instrumentation hooks. Because these functions are not supposed to be called explicitly by the kernel code (calls to them are emitted by the compiler), they do not have to be declared in the headers. Instead, we add forward declarations right before the definitions to silence the warnings produced by -Wmissing-prototypes. Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Alexander Potapenko <[email protected]> Reported-by: Vlastimil Babka <[email protected]> Suggested-by: Marco Elver <[email protected]> Reviewed-by: Marco Elver <[email protected]> Reported-by: kernel test robot <[email protected]> Link: https://lore.kernel.org/lkml/[email protected]/T/ Cc: Dmitry Vyukov <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Peter Zijlstra <[email protected]> Signed-off-by: Andrew Morton <[email protected]>
2022-12-21kmsan: export kmsan_handle_urbArnd Bergmann1-0/+1
USB support can be in a loadable module, and this causes a link failure with KMSAN: ERROR: modpost: "kmsan_handle_urb" [drivers/usb/core/usbcore.ko] undefined! Export the symbol so it can be used by this module. Link: https://lkml.kernel.org/r/[email protected] Fixes: 553a80188a5d ("kmsan: handle memory sent to/from USB") Signed-off-by: Arnd Bergmann <[email protected]> Reviewed-by: Alexander Potapenko <[email protected]> Cc: Dmitry Vyukov <[email protected]> Cc: Marco Elver <[email protected]> Cc: <[email protected]> Signed-off-by: Andrew Morton <[email protected]>
2022-12-21kmsan: include linux/vmalloc.hArnd Bergmann1-0/+1
This is needed for the vmap/vunmap declarations: mm/kmsan/kmsan_test.c:316:9: error: implicit declaration of function 'vmap' is invalid in C99 [-Werror,-Wimplicit-function-declaration] vbuf = vmap(pages, npages, VM_MAP, PAGE_KERNEL); ^ mm/kmsan/kmsan_test.c:316:29: error: use of undeclared identifier 'VM_MAP' vbuf = vmap(pages, npages, VM_MAP, PAGE_KERNEL); ^ mm/kmsan/kmsan_test.c:322:3: error: implicit declaration of function 'vunmap' is invalid in C99 [-Werror,-Wimplicit-function-declaration] vunmap(vbuf); ^ Link: https://lkml.kernel.org/r/[email protected] Fixes: 8ed691b02ade ("kmsan: add tests for KMSAN") Signed-off-by: Arnd Bergmann <[email protected]> Reviewed-by: Alexander Potapenko <[email protected]> Cc: Dmitry Vyukov <[email protected]> Cc: Marco Elver <[email protected]> Cc: <[email protected]> Signed-off-by: Andrew Morton <[email protected]>
2022-12-11kmsan: fix memcpy testsAlexander Potapenko1-0/+3
Recent Clang changes may cause it to delete calls of memcpy(), if the source is an uninitialized volatile local. This happens because passing a pointer to a volatile local into memcpy() discards the volatile qualifier, giving the compiler a free hand to optimize the memcpy() call away. Use OPTIMIZER_HIDE_VAR() to hide the uninitialized var from the too-smart compiler. Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Alexander Potapenko <[email protected]> Suggested-by: Marco Elver <[email protected]> Reviewed-by: Marco Elver <[email protected]> Cc: Dmitry Vyukov <[email protected]> Signed-off-by: Andrew Morton <[email protected]>
2022-12-11kmsan: allow using __msan_instrument_asm_store() inside runtimeAlexander Potapenko1-3/+5
In certain cases (e.g. when handling a softirq) __msan_instrument_asm_store(&var, sizeof(var)) may be called with from within KMSAN runtime, but later the value of @var is used with !kmsan_in_runtime(), leading to false positives. Because kmsan_internal_unpoison_memory() doesn't take locks, it should be fine to call it without kmsan_in_runtime() checks, which fixes the mentioned false positives. Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Alexander Potapenko <[email protected]> Cc: Dmitry Vyukov <[email protected]> Cc: Eric Biggers <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Marco Elver <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Will Deacon <[email protected]> Signed-off-by: Andrew Morton <[email protected]>
2022-11-08kmsan: core: kmsan_in_runtime() should return true in NMI contextAlexander Potapenko1-0/+2
Without that, every call to __msan_poison_alloca() in NMI may end up allocating memory, which is NMI-unsafe. Link: https://lkml.kernel.org/r/[email protected] Link: https://lore.kernel.org/lkml/[email protected]/ Signed-off-by: Alexander Potapenko <[email protected]> Acked-by: Peter Zijlstra (Intel) <[email protected]> Cc: Dmitry Vyukov <[email protected]> Cc: Marco Elver <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: Dave Hansen <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Kees Cook <[email protected]> Cc: Masahiro Yamada <[email protected]> Cc: Nick Desaulniers <[email protected]> Cc: Thomas Gleixner <[email protected]> Signed-off-by: Andrew Morton <[email protected]>