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From: Ilya Leoshkevich <iii@linux.ibm.com>
To: Alexander Gordeev <agordeev@linux.ibm.com>,
        Alexander Potapenko <glider@google.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Christoph Lameter <cl@linux.com>, David Rientjes <rientjes@google.com>,
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        Masami Hiramatsu <mhiramat@kernel.org>,
        Pekka Enberg <penberg@kernel.org>,
        Steven Rostedt <rostedt@goodmis.org>,
        Vasily Gorbik <gor@linux.ibm.com>, Vlastimil Babka <vbabka@suse.cz>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>,
        Dmitry Vyukov <dvyukov@google.com>,
        Hyeonggon Yoo <42.hyeyoo@gmail.com>, kasan-dev@googlegroups.com,
        linux-kernel@vger.kernel.org, linux-mm@kvack.org,
        linux-s390@vger.kernel.org, linux-trace-kernel@vger.kernel.org,
        Mark Rutland <mark.rutland@arm.com>,
        Roman Gushchin <roman.gushchin@linux.dev>,
        Sven Schnelle <svens@linux.ibm.com>,
        Ilya Leoshkevich <iii@linux.ibm.com>
Subject: [PATCH v4 05/35] kmsan: Fix is_bad_asm_addr() on arches with overlapping address spaces
Date: Thu, 13 Jun 2024 17:34:07 +0200
Message-ID: <20240613153924.961511-6-iii@linux.ibm.com>
In-Reply-To: <20240613153924.961511-1-iii@linux.ibm.com>
References: <20240613153924.961511-1-iii@linux.ibm.com>
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Comparing pointers with TASK_SIZE does not make sense when kernel and
userspace overlap. Skip the comparison when this is the case.

Reviewed-by: Alexander Potapenko <glider@google.com>
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
---
 mm/kmsan/instrumentation.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/mm/kmsan/instrumentation.c b/mm/kmsan/instrumentation.c
index 470b0b4afcc4..8a1bbbc723ab 100644
--- a/mm/kmsan/instrumentation.c
+++ b/mm/kmsan/instrumentation.c
@@ -20,7 +20,8 @@
 
 static inline bool is_bad_asm_addr(void *addr, uintptr_t size, bool is_store)
 {
-	if ((u64)addr < TASK_SIZE)
+	if (IS_ENABLED(CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE) &&
+	    (u64)addr < TASK_SIZE)
 		return true;
 	if (!kmsan_get_metadata(addr, KMSAN_META_SHADOW))
 		return true;
-- 
2.45.1