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/20240627145754.27333-2-iii@linux.ibm.com
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202406272033.KejtfLkw-lkp@intel.com/
Reviewed-by: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Marco Elver <elver@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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/20240621113706.315500-22-iii@linux.ibm.com
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: <kasan-dev@googlegroups.com>
Cc: Marco Elver <elver@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Steven Rostedt (Google) <rostedt@goodmis.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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/20240621113706.315500-17-iii@linux.ibm.com
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: <kasan-dev@googlegroups.com>
Cc: Marco Elver <elver@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Steven Rostedt (Google) <rostedt@goodmis.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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/20240621113706.315500-16-iii@linux.ibm.com
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: <kasan-dev@googlegroups.com>
Cc: Marco Elver <elver@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Steven Rostedt (Google) <rostedt@goodmis.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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/20240621113706.315500-15-iii@linux.ibm.com
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: <kasan-dev@googlegroups.com>
Cc: Marco Elver <elver@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Steven Rostedt (Google) <rostedt@goodmis.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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/20240621113706.315500-14-iii@linux.ibm.com
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: <kasan-dev@googlegroups.com>
Cc: Marco Elver <elver@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Steven Rostedt (Google) <rostedt@goodmis.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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/20240621113706.315500-12-iii@linux.ibm.com
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: <kasan-dev@googlegroups.com>
Cc: Marco Elver <elver@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Steven Rostedt (Google) <rostedt@goodmis.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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/20240621113706.315500-11-iii@linux.ibm.com
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: <kasan-dev@googlegroups.com>
Cc: Marco Elver <elver@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Steven Rostedt (Google) <rostedt@goodmis.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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/20240621113706.315500-10-iii@linux.ibm.com
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: <kasan-dev@googlegroups.com>
Cc: Marco Elver <elver@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Steven Rostedt (Google) <rostedt@goodmis.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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/20240621113706.315500-9-iii@linux.ibm.com
Fixes: f80be4571b ("kmsan: add KMSAN runtime core")
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Suggested-by: Heiko Carstens <hca@linux.ibm.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: <kasan-dev@googlegroups.com>
Cc: Marco Elver <elver@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Steven Rostedt (Google) <rostedt@goodmis.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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/20240621113706.315500-8-iii@linux.ibm.com
Fixes: b073d7f8ae ("mm: kmsan: maintain KMSAN metadata for page operations")
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Suggested-by: Alexander Gordeev <agordeev@linux.ibm.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: <kasan-dev@googlegroups.com>
Cc: Marco Elver <elver@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Steven Rostedt (Google) <rostedt@goodmis.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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/20240621113706.315500-7-iii@linux.ibm.com
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Reported-by: Alexander Gordeev <agordeev@linux.ibm.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: <kasan-dev@googlegroups.com>
Cc: Marco Elver <elver@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Steven Rostedt (Google) <rostedt@goodmis.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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/20240621113706.315500-6-iii@linux.ibm.com
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: <kasan-dev@googlegroups.com>
Cc: Marco Elver <elver@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Steven Rostedt (Google) <rostedt@goodmis.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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/20240621113706.315500-3-iii@linux.ibm.com
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: <kasan-dev@googlegroups.com>
Cc: Marco Elver <elver@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Steven Rostedt (Google) <rostedt@goodmis.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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/20191024120938.11237-1-david@redhat.com/
[2] https://lkml.kernel.org/r/20240607083711.62833-1-david@redhat.com
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().
[david@redhat.com: add missed CONFIG_DEFERRED_STRUCT_PAGE_INIT]
Link: https://lkml.kernel.org/r/b72e6efd-fb0a-459c-b1a0-88a98e5b19e2@redhat.com
[david@redhat.com: fix up the memblock comment, per Oscar]
Link: https://lkml.kernel.org/r/2ed64218-7f3b-4302-a5dc-27f060654fe2@redhat.com
[david@redhat.com: add the parameter name also in the declaration]
Link: https://lkml.kernel.org/r/ca575956-f0dd-4fb9-a307-6b7621681ed9@redhat.com
Link: https://lkml.kernel.org/r/20240607090939.89524-1-david@redhat.com
Link: https://lkml.kernel.org/r/20240607090939.89524-2-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Dexuan Cui <decui@microsoft.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Eugenio Pérez <eperezma@redhat.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Marco Elver <elver@google.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Stefano Stabellini <sstabellini@kernel.org>
Cc: Wei Liu <wei.liu@kernel.org>
Cc: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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.
[glider@google.com: change description, remove comment about failing test case]
Link: https://lkml.kernel.org/r/20240528104807.738758-2-glider@google.com
Signed-off-by: Brian Johannesmeyer <bjohannesmeyer@gmail.com>
Link: https://lore.kernel.org/lkml/20240524232804.1984355-1-bjohannesmeyer@gmail.com/T/
Signed-off-by: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Marco Elver <elver@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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/20240528104807.738758-1-glider@google.com
Fixes: f80be4571b ("kmsan: add KMSAN runtime core")
Signed-off-by: Alexander Potapenko <glider@google.com>
Reported-by: Brian Johannesmeyer <bjohannesmeyer@gmail.com>
Link: https://lore.kernel.org/lkml/20240524232804.1984355-1-bjohannesmeyer@gmail.com/T/
Reviewed-by: Marco Elver <elver@google.com>
Tested-by: Brian Johannesmeyer <bjohannesmeyer@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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/3b7dbd88-0861-4638-b2d2-911c97a4cadf@I-love.SAKURA.ne.jp/
Link: https://lkml.kernel.org/r/20240320101851.2589698-1-glider@google.com
Signed-off-by: Alexander Potapenko <glider@google.com>
Suggested-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Reviewed-by: Marco Elver <elver@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Similarly to what's been done in commit 85716a80c1 ("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/20240124173134.1165747-1-glider@google.com
Fixes: f80be4571b ("kmsan: add KMSAN runtime core")
Signed-off-by: Alexander Potapenko <glider@google.com>
Tested-by: Marco Elver <elver@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Ilya Leoshkevich <iii@linux.ibm.com>
Cc: Nicholas Miehlbradt <nicholas@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
commit 23baf831a3 ("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/20231228144704.14033-2-kirill.shutemov@linux.intel.com
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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.
[kirill.shutemov@linux.intel.com: fixup for kerneldoc warning]
Link: https://lkml.kernel.org/r/20240101111512.7empzyifq7kxtzk3@box
Link: https://lkml.kernel.org/r/20231228144704.14033-1-kirill.shutemov@linux.intel.com
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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 <andreyknvl@google.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Evgenii Stepanov <eugenis@google.com>
Cc: Marco Elver <elver@google.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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/20231016153446.132763-1-pedro.falcato@gmail.com
Signed-off-by: Pedro Falcato <pedro.falcato@gmail.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Marco Elver <elver@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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/20230911145702.2663753-4-glider@google.com
Signed-off-by: Alexander Potapenko <glider@google.com>
Suggested-by: Marco Elver <elver@google.com>
Acked-by: Marco Elver <elver@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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/20230911145702.2663753-3-glider@google.com
Signed-off-by: Alexander Potapenko <glider@google.com>
Acked-by: Marco Elver <elver@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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/20230911145702.2663753-2-glider@google.com
Signed-off-by: Alexander Potapenko <glider@google.com>
Acked-by: Marco Elver <elver@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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/20230911145702.2663753-1-glider@google.com
Fixes: f80be4571b ("kmsan: add KMSAN runtime core")
Signed-off-by: Alexander Potapenko <glider@google.com>
Acked-by: Marco Elver <elver@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Use helper macros PAGE_ALIGN and PAGE_ALIGN_DOWN to improve code
readability. No functional modification involved.
Link: https://lkml.kernel.org/r/20230727011612.2721843-4-zhangpeng362@huawei.com
Signed-off-by: ZhangPeng <zhangpeng362@huawei.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Marco Elver <elver@google.com>
Cc: Nanyong Sun <sunnanyong@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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/20230727011612.2721843-1-zhangpeng362@huawei.com
Link: https://lkml.kernel.org/r/20230727011612.2721843-2-zhangpeng362@huawei.com
Signed-off-by: ZhangPeng <zhangpeng362@huawei.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Marco Elver <elver@google.com>
Cc: Nanyong Sun <sunnanyong@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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>
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>
After commit 446ec83805 ("mm/page_alloc: use might_alloc()") and commit
84172f4bb7 ("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/20230327034149.942-1-thunder.leizhen@huawei.com
Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Marco Elver <elver@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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/20230413131223.4135168-2-glider@google.com
Fixes: b073d7f8ae ("mm: kmsan: maintain KMSAN metadata for page operations")
Signed-off-by: Alexander Potapenko <glider@google.com>
Reported-by: Dipanjan Das <mail.dipanjan.das@gmail.com>
Link: https://lore.kernel.org/linux-mm/CANX2M5ZRrRA64k0hOif02TjmY9kbbO2aCBPyq79es34RXZ=cAw@mail.gmail.com/
Reviewed-by: Marco Elver <elver@google.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Uladzislau Rezki (Sony) <urezki@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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/20230413131223.4135168-1-glider@google.com
Fixes: b073d7f8ae ("mm: kmsan: maintain KMSAN metadata for page operations")
Signed-off-by: Alexander Potapenko <glider@google.com>
Reported-by: Dipanjan Das <mail.dipanjan.das@gmail.com>
Link: https://lore.kernel.org/linux-mm/CANX2M5ZRrRA64k0hOif02TjmY9kbbO2aCBPyq79es34RXZ=cAw@mail.gmail.com/
Reviewed-by: Marco Elver <elver@google.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Uladzislau Rezki (Sony) <urezki@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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/20230306111322.205724-2-glider@google.com
Signed-off-by: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Marco Elver <elver@google.com>
Cc: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
commit 5478afc55a ("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/20230303141433.3422671-2-glider@google.com
Signed-off-by: Alexander Potapenko <glider@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Helge Deller <deller@gmx.de>
Cc: Kees Cook <keescook@chromium.org>
Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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/20230215130058.3836177-3-arnd@kernel.org
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Fixes: f80be4571b ("kmsan: add KMSAN runtime core")
Acked-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: Josh Poimboeuf <jpoimboe@kernel.org>
Cc: Kuan-Ying Lee <Kuan-Ying.Lee@mediatek.com>
Cc: Marco Elver <elver@google.com>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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>
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/20230112103147.382416-1-glider@google.com
Signed-off-by: Alexander Potapenko <glider@google.com>
Reported-by: Vlastimil Babka <vbabka@suse.cz>
Suggested-by: Marco Elver <elver@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Reported-by: kernel test robot <lkp@intel.com>
Link: https://lore.kernel.org/lkml/202301020356.dFruA4I5-lkp@intel.com/T/
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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/20221215162710.3802378-1-arnd@kernel.org
Fixes: 553a80188a ("kmsan: handle memory sent to/from USB")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Alexander Potapenko <glider@google.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>
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/20221215163046.4079767-1-arnd@kernel.org
Fixes: 8ed691b02a ("kmsan: add tests for KMSAN")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Alexander Potapenko <glider@google.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>
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/20221205145740.694038-1-glider@google.com
Signed-off-by: Alexander Potapenko <glider@google.com>
Suggested-by: Marco Elver <elver@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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/20221128094541.2645890-2-glider@google.com
Signed-off-by: Alexander Potapenko <glider@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Eric Biggers <ebiggers@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Marco Elver <elver@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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/20221102110611.1085175-1-glider@google.com
Link: https://lore.kernel.org/lkml/20221025221755.3810809-1-glider@google.com/
Signed-off-by: Alexander Potapenko <glider@google.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Marco Elver <elver@google.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
