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From: Alexander Potapenko <glider@google.com>
To: glider@google.com
Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org,
	 Andrew Morton <akpm@linux-foundation.org>,
	Dmitry Vyukov <dvyukov@google.com>,
	 Marco Elver <elver@google.com>,
	Peter Zijlstra <peterz@infradead.org>
Subject: [PATCH 1/5] kmsan: core: kmsan_in_runtime() should return true in NMI context
Date: Wed,  2 Nov 2022 12:06:07 +0100	[thread overview]
Message-ID: <20221102110611.1085175-1-glider@google.com> (raw)

Without that, every call to __msan_poison_alloca() in NMI may end up
allocating memory, which is NMI-unsafe.

Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Marco Elver <elver@google.com>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/lkml/20221025221755.3810809-1-glider@google.com/
Signed-off-by: Alexander Potapenko <glider@google.com>
---
 mm/kmsan/kmsan.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/mm/kmsan/kmsan.h b/mm/kmsan/kmsan.h
index 961eb658020aa..3cd2050a33e6a 100644
--- a/mm/kmsan/kmsan.h
+++ b/mm/kmsan/kmsan.h
@@ -125,6 +125,8 @@ static __always_inline bool kmsan_in_runtime(void)
 {
 	if ((hardirq_count() >> HARDIRQ_SHIFT) > 1)
 		return true;
+	if (in_nmi())
+		return true;
 	return kmsan_get_context()->kmsan_in_runtime;
 }
 
-- 
2.38.1.273.g43a17bfeac-goog



             reply	other threads:[~2022-11-02 11:06 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-11-02 11:06 Alexander Potapenko [this message]
2022-11-02 11:06 ` [PATCH 2/5] x86/uaccess: instrument copy_from_user_nmi() Alexander Potapenko
2022-11-02 12:52   ` Peter Zijlstra
2022-11-02 11:06 ` [PATCH 3/5] Kconfig.debug: ensure early check for KMSAN in CONFIG_KMSAN_WARN Alexander Potapenko
2022-11-02 11:06 ` [PATCH 4/5] kmsan: make sure PREEMPT_RT is off Alexander Potapenko
2022-11-02 12:53   ` Peter Zijlstra
2022-11-02 11:06 ` [PATCH 5/5] x86/traps: avoid KMSAN bugs originating from handle_bug() Alexander Potapenko
2022-11-02 12:50   ` Peter Zijlstra
2022-11-02 13:37     ` Alexander Potapenko
2022-11-03 11:18       ` Peter Zijlstra
2022-11-03 11:18   ` Peter Zijlstra
2022-11-03 13:37     ` Alexander Potapenko
2022-11-02 12:52 ` [PATCH 1/5] kmsan: core: kmsan_in_runtime() should return true in NMI context Peter Zijlstra

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