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authorAlexander Potapenko <glider@google.com>2022-09-15 17:04:14 +0200
committerAndrew Morton <akpm@linux-foundation.org>2022-10-03 14:03:25 -0700
commit6cae637fa26df867449c6bc20ea8bc693abe49b0 (patch)
treec8f3799ca26c5f8724cb90cad7ae102f6d36e2aa /kernel/entry
parent37ad4ee8364255c73026a3c343403b5977fa7e79 (diff)
downloadlwn-6cae637fa26df867449c6bc20ea8bc693abe49b0.tar.gz
lwn-6cae637fa26df867449c6bc20ea8bc693abe49b0.zip
entry: kmsan: introduce kmsan_unpoison_entry_regs()
struct pt_regs passed into IRQ entry code is set up by uninstrumented asm functions, therefore KMSAN may not notice the registers are initialized. kmsan_unpoison_entry_regs() unpoisons the contents of struct pt_regs, preventing potential false positives. Unlike kmsan_unpoison_memory(), it can be called under kmsan_in_runtime(), which is often the case in IRQ entry code. Link: https://lkml.kernel.org/r/20220915150417.722975-41-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>
Diffstat (limited to 'kernel/entry')
-rw-r--r--kernel/entry/common.c5
1 files changed, 5 insertions, 0 deletions
diff --git a/kernel/entry/common.c b/kernel/entry/common.c
index 063068a9ea9b..846add8394c4 100644
--- a/kernel/entry/common.c
+++ b/kernel/entry/common.c
@@ -5,6 +5,7 @@
#include <linux/resume_user_mode.h>
#include <linux/highmem.h>
#include <linux/jump_label.h>
+#include <linux/kmsan.h>
#include <linux/livepatch.h>
#include <linux/audit.h>
#include <linux/tick.h>
@@ -24,6 +25,7 @@ static __always_inline void __enter_from_user_mode(struct pt_regs *regs)
user_exit_irqoff();
instrumentation_begin();
+ kmsan_unpoison_entry_regs(regs);
trace_hardirqs_off_finish();
instrumentation_end();
}
@@ -352,6 +354,7 @@ noinstr irqentry_state_t irqentry_enter(struct pt_regs *regs)
lockdep_hardirqs_off(CALLER_ADDR0);
ct_irq_enter();
instrumentation_begin();
+ kmsan_unpoison_entry_regs(regs);
trace_hardirqs_off_finish();
instrumentation_end();
@@ -367,6 +370,7 @@ noinstr irqentry_state_t irqentry_enter(struct pt_regs *regs)
*/
lockdep_hardirqs_off(CALLER_ADDR0);
instrumentation_begin();
+ kmsan_unpoison_entry_regs(regs);
rcu_irq_enter_check_tick();
trace_hardirqs_off_finish();
instrumentation_end();
@@ -452,6 +456,7 @@ irqentry_state_t noinstr irqentry_nmi_enter(struct pt_regs *regs)
ct_nmi_enter();
instrumentation_begin();
+ kmsan_unpoison_entry_regs(regs);
trace_hardirqs_off_finish();
ftrace_nmi_enter();
instrumentation_end();