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Date:   Tue, 28 May 2019 18:32:57 +0200
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Subject: [PATCH 2/3] tools/objtool: add kasan_check_* to uaccess whitelist
From:   Marco Elver <elver@google.com>
To:     peterz@infradead.org, aryabinin@virtuozzo.com, dvyukov@google.com,
        glider@google.com, andreyknvl@google.com
Cc:     corbet@lwn.net, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de,
        hpa@zytor.com, x86@kernel.org, arnd@arndb.de, jpoimboe@redhat.com,
        linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-arch@vger.kernel.org, kasan-dev@googlegroups.com,
        Marco Elver <elver@google.com>
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This is a pre-requisite for enabling bitops instrumentation. Some bitops
may safely be used with instrumentation in uaccess regions.

For example, on x86, `test_bit` is used to test a CPU-feature in a
uaccess region:   arch/x86/ia32/ia32_signal.c:361

Signed-off-by: Marco Elver <elver@google.com>
---
 tools/objtool/check.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 172f99195726..eff0e5209402 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -443,6 +443,8 @@ static void add_ignores(struct objtool_file *file)
 static const char *uaccess_safe_builtin[] = {
 	/* KASAN */
 	"kasan_report",
+	"kasan_check_read",
+	"kasan_check_write",
 	"check_memory_region",
 	/* KASAN out-of-line */
 	"__asan_loadN_noabort",
-- 
2.22.0.rc1.257.g3120a18244-goog