From: Michael Davidson <md@google.com>
To: "H . Peter Anvin" <hpa@zytor.com>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>
Cc: Alexander Potapenko <glider@google.com>,
Dmitry Vyukov <dvyukov@google.com>,
x86@kernel.org, linux-kernel@vger.kernel.org,
Michael Davidson <md@google.com>
Subject: [PATCH 1/2] x86, boot: #undef memcpy etc in string.c
Date: Wed, 15 Mar 2017 14:48:20 -0700 [thread overview]
Message-ID: <20170315214821.127170-1-md@google.com> (raw)
undef memcpy and friends in boot/string.c so that the functions
defined here will have the correct names, otherwise we end up
up trying to redefine __builtin_memcpy etc.
Surprisingly, gcc allows this (and, helpfully, discards the
--builtin_ prefix from the function name when compiling it),
but clang does not.
Adding these #undef's appears to preserve what I assume was
the original intent of the code.
Signed-off-by: Michael Davidson <md@google.com>
---
arch/x86/boot/string.c | 9 +++++++++
1 file changed, 9 insertions(+)
diff --git a/arch/x86/boot/string.c b/arch/x86/boot/string.c
index 5457b02fc050..b40266850869 100644
--- a/arch/x86/boot/string.c
+++ b/arch/x86/boot/string.c
@@ -16,6 +16,15 @@
#include "ctype.h"
#include "string.h"
+/*
+ * Undef these macros so that the functions that we provide
+ * here will have the correct names regardless of how string.h
+ * may have chosen to #define them.
+ */
+#undef memcpy
+#undef memset
+#undef memcmp
+
int memcmp(const void *s1, const void *s2, size_t len)
{
bool diff;
--
2.12.0.367.g23dc2f6d3c-goog
next reply other threads:[~2017-03-15 21:48 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-03-15 21:48 Michael Davidson [this message]
2017-03-15 21:48 ` [PATCH 2/2] x86, boot: Use regparm=0 for memcpy and memset when using clang Michael Davidson
2017-03-16 7:46 ` Ingo Molnar
2017-03-16 15:21 ` Michael Davidson
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