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authorAlexander Potapenko <glider@google.com>2022-09-15 18:04:08 +0300
committerAndrew Morton <akpm@linux-foundation.org>2022-10-04 00:03:24 +0300
commit9245ec01ce848eb5147e2e5030cf33ffbf1befff (patch)
tree3745786e9ae9936828a09b8d585fc127dbc1868b
parentb11671b37f8f4761ff5a3d344553d65238309954 (diff)
downloadlinux-9245ec01ce848eb5147e2e5030cf33ffbf1befff.tar.xz
x86: kmsan: handle open-coded assembly in lib/iomem.c
KMSAN cannot intercept memory accesses within asm() statements. That's why we add kmsan_unpoison_memory() and kmsan_check_memory() to hint it how to handle memory copied from/to I/O memory. Link: https://lkml.kernel.org/r/20220915150417.722975-35-glider@google.com Signed-off-by: Alexander Potapenko <glider@google.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Andrey Konovalov <andreyknvl@google.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Borislav Petkov <bp@alien8.de> Cc: Christoph Hellwig <hch@lst.de> Cc: Christoph Lameter <cl@linux.com> Cc: David Rientjes <rientjes@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Eric Biggers <ebiggers@google.com> Cc: Eric Biggers <ebiggers@kernel.org> Cc: Eric Dumazet <edumazet@google.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Ilya Leoshkevich <iii@linux.ibm.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Kees Cook <keescook@chromium.org> Cc: Marco Elver <elver@google.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Michael S. Tsirkin <mst@redhat.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Petr Mladek <pmladek@suse.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vegard Nossum <vegard.nossum@oracle.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
-rw-r--r--arch/x86/lib/iomem.c5
1 files changed, 5 insertions, 0 deletions
diff --git a/arch/x86/lib/iomem.c b/arch/x86/lib/iomem.c
index 3e2f33fc33de..e0411a3774d4 100644
--- a/arch/x86/lib/iomem.c
+++ b/arch/x86/lib/iomem.c
@@ -1,6 +1,7 @@
#include <linux/string.h>
#include <linux/module.h>
#include <linux/io.h>
+#include <linux/kmsan-checks.h>
#define movs(type,to,from) \
asm volatile("movs" type:"=&D" (to), "=&S" (from):"0" (to), "1" (from):"memory")
@@ -37,6 +38,8 @@ static void string_memcpy_fromio(void *to, const volatile void __iomem *from, si
n-=2;
}
rep_movs(to, (const void *)from, n);
+ /* KMSAN must treat values read from devices as initialized. */
+ kmsan_unpoison_memory(to, n);
}
static void string_memcpy_toio(volatile void __iomem *to, const void *from, size_t n)
@@ -44,6 +47,8 @@ static void string_memcpy_toio(volatile void __iomem *to, const void *from, size
if (unlikely(!n))
return;
+ /* Make sure uninitialized memory isn't copied to devices. */
+ kmsan_check_memory(from, n);
/* Align any unaligned destination IO */
if (unlikely(1 & (unsigned long)to)) {
movs("b", to, from);