From: David Gow <davidgow@google.com>
To: trishalfonso@google.com, brendanhiggins@google.com,
aryabinin@virtuozzo.com, dvyukov@google.com, mingo@redhat.com,
peterz@infradead.org, juri.lelli@redhat.com,
vincent.guittot@linaro.org, andreyknvl@google.com,
shuah@kernel.org, akpm@linux-foundation.org
Cc: David Gow <davidgow@google.com>,
linux-kernel@vger.kernel.org, kasan-dev@googlegroups.com,
kunit-dev@googlegroups.com, linux-kselftest@vger.kernel.org,
linux-mm@kvack.org
Subject: [PATCH v11 6/6] mm: kasan: Do not panic if both panic_on_warn and kasan_multishot set
Date: Tue, 4 Aug 2020 21:29:38 -0700 [thread overview]
Message-ID: <20200805042938.2961494-7-davidgow@google.com> (raw)
In-Reply-To: <20200805042938.2961494-1-davidgow@google.com>
KASAN errors will currently trigger a panic when panic_on_warn is set.
This renders kasan_multishot useless, as further KASAN errors won't be
reported if the kernel has already paniced. By making kasan_multishot
disable this behaviour for KASAN errors, we can still have the benefits
of panic_on_warn for non-KASAN warnings, yet be able to use
kasan_multishot.
This is particularly important when running KASAN tests, which need to
trigger multiple KASAN errors: previously these would panic the system
if panic_on_warn was set, now they can run (and will panic the system
should non-KASAN warnings show up).
Signed-off-by: David Gow <davidgow@google.com>
Reviewed-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
---
mm/kasan/report.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/mm/kasan/report.c b/mm/kasan/report.c
index e2c14b10bc81..00a53f1355ae 100644
--- a/mm/kasan/report.c
+++ b/mm/kasan/report.c
@@ -95,7 +95,7 @@ static void end_report(unsigned long *flags)
pr_err("==================================================================\n");
add_taint(TAINT_BAD_PAGE, LOCKDEP_NOW_UNRELIABLE);
spin_unlock_irqrestore(&report_lock, *flags);
- if (panic_on_warn) {
+ if (panic_on_warn && !test_bit(KASAN_BIT_MULTI_SHOT, &kasan_flags)) {
/*
* This thread may hit another WARN() in the panic path.
* Resetting this prevents additional WARN() from panicking the
--
2.28.0.163.g6104cc2f0b6-goog
next prev parent reply other threads:[~2020-08-05 4:30 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-08-05 4:29 [PATCH v11 0/6] KASAN-KUnit Integration David Gow
2020-08-05 4:29 ` [PATCH v11 1/6] Add KUnit Struct to Current Task David Gow
2020-08-05 4:29 ` [PATCH v11 2/6] KUnit: KASAN Integration David Gow
2020-08-05 4:29 ` [PATCH v11 3/6] KASAN: Port KASAN Tests to KUnit David Gow
2020-08-07 13:10 ` Andrey Konovalov
2020-08-05 4:29 ` [PATCH v11 4/6] kasan: test: Make KASAN KUnit test comply with naming guidelines David Gow
2020-08-05 4:29 ` [PATCH v11 5/6] KASAN: Testing Documentation David Gow
2020-08-05 4:29 ` David Gow [this message]
2020-08-07 13:14 ` [PATCH v11 0/6] KASAN-KUnit Integration Andrey Konovalov
2020-08-08 3:26 ` David Gow
2020-08-10 13:58 ` Andrey Konovalov
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