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authorMarco Elver <elver@google.com>2019-11-14 19:03:03 +0100
committerPaul E. McKenney <paulmck@kernel.org>2019-11-16 07:23:16 -0800
commit40d04110f87940b6a03bf0aa19cd29e84f465f20 (patch)
tree85a7f42366dc040bad8e13608ce21c01d0a2222f /arch/x86/include/asm/bitops.h
parente75a6795ed132f26f69d08dea958630d5993056d (diff)
x86, kcsan: Enable KCSAN for x86
This patch enables KCSAN for x86, with updates to build rules to not use KCSAN for several incompatible compilation units. Signed-off-by: Marco Elver <elver@google.com> Acked-by: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Diffstat (limited to 'arch/x86/include/asm/bitops.h')
-rw-r--r--arch/x86/include/asm/bitops.h6
1 files changed, 5 insertions, 1 deletions
diff --git a/arch/x86/include/asm/bitops.h b/arch/x86/include/asm/bitops.h
index 7d1f6a49bfae..542b63ddc8aa 100644
--- a/arch/x86/include/asm/bitops.h
+++ b/arch/x86/include/asm/bitops.h
@@ -201,8 +201,12 @@ arch_test_and_change_bit(long nr, volatile unsigned long *addr)
return GEN_BINARY_RMWcc(LOCK_PREFIX __ASM_SIZE(btc), *addr, c, "Ir", nr);
}
-static __always_inline bool constant_test_bit(long nr, const volatile unsigned long *addr)
+static __no_kcsan_or_inline bool constant_test_bit(long nr, const volatile unsigned long *addr)
{
+ /*
+ * Because this is a plain access, we need to disable KCSAN here to
+ * avoid double instrumentation via instrumented bitops.
+ */
return ((1UL << (nr & (BITS_PER_LONG-1))) &
(addr[nr >> _BITOPS_LONG_SHIFT])) != 0;
}

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