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From:   andrey.konovalov@linux.dev
To:     Marco Elver <elver@google.com>,
        Alexander Potapenko <glider@google.com>
Cc:     Andrey Konovalov <andreyknvl@gmail.com>,
        Dmitry Vyukov <dvyukov@google.com>,
        Andrey Ryabinin <ryabinin.a.a@gmail.com>,
        kasan-dev@googlegroups.com,
        Andrew Morton <akpm@linux-foundation.org>, linux-mm@kvack.org,
        linux-kernel@vger.kernel.org,
        Andrey Konovalov <andreyknvl@google.com>
Subject: [PATCH mm 06/22] kasan: simplify async check in end_report
Date:   Wed,  2 Mar 2022 17:36:26 +0100
Message-Id: <1c8ce43f97300300e62c941181afa2eb738965c5.1646237226.git.andreyknvl@google.com>
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From: Andrey Konovalov <andreyknvl@google.com>

Currently, end_report() does not call trace_error_report_end() for bugs
detected in either async or asymm mode (when kasan_async_fault_possible()
returns true), as the address of the bad access might be unknown.

However, for asymm mode, the address is known for faults triggered by
read operations.

Instead of using kasan_async_fault_possible(), simply check that
the addr is not NULL when calling trace_error_report_end().

Signed-off-by: Andrey Konovalov <andreyknvl@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 d60ee8b81e2b..2d892ec050be 100644
--- a/mm/kasan/report.c
+++ b/mm/kasan/report.c
@@ -112,7 +112,7 @@ static void start_report(unsigned long *flags)
 
 static void end_report(unsigned long *flags, unsigned long addr)
 {
-	if (!kasan_async_fault_possible())
+	if (addr)
 		trace_error_report_end(ERROR_DETECTOR_KASAN, addr);
 	pr_err("==================================================================\n");
 	add_taint(TAINT_BAD_PAGE, LOCKDEP_NOW_UNRELIABLE);
-- 
2.25.1