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From:   Qian Cai <cai@lca.pw>
To:     akpm@linux-foundation.org
Cc:     elver@google.com, catalin.marinas@arm.com, linux-mm@kvack.org,
        linux-kernel@vger.kernel.org, Qian Cai <cai@lca.pw>
Subject: [PATCH -next 1/2] mm: disable KCSAN for kmemleak
Date:   Tue,  3 Mar 2020 14:28:35 -0500
Message-Id: <1583263716-25150-1-git-send-email-cai@lca.pw>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

Kmemleak could scan task stacks while plain writes happens to those
stack variables which could results in data races. For example, in
sys_rt_sigaction and do_sigaction(), it could have plain writes in
a 32-byte size. Since the kmemleak does not care about the actual values
of a non-pointer and all do_sigaction() call sites only copy to stack
variables, just disable KCSAN for kmemleak to avoid annotating anything
outside Kmemleak just because Kmemleak scans everything.

Suggested-by: Marco Elver <elver@google.com>
Signed-off-by: Qian Cai <cai@lca.pw>
---
 mm/Makefile | 1 +
 1 file changed, 1 insertion(+)

diff --git a/mm/Makefile b/mm/Makefile
index 946754cc66b6..6e263045f0c2 100644
--- a/mm/Makefile
+++ b/mm/Makefile
@@ -14,6 +14,7 @@ KCSAN_SANITIZE_slab_common.o := n
 KCSAN_SANITIZE_slab.o := n
 KCSAN_SANITIZE_slub.o := n
 KCSAN_SANITIZE_page_alloc.o := n
+KCSAN_SANITIZE_kmemleak.o := n
 
 # These files are disabled because they produce non-interesting and/or
 # flaky coverage that is not a function of syscall inputs. E.g. slab is out of
-- 
1.8.3.1