From: "tip-bot2 for Fangrui Song" <tip-bot2@linutronix.de>
To: linux-tip-commits@vger.kernel.org
Cc: Sami Tolvanen <samitolvanen@google.com>,
Fangrui Song <maskray@google.com>, Borislav Petkov <bp@suse.de>,
Nick Desaulniers <ndesaulniers@google.com>,
Nathan Chancellor <natechancellor@gmail.com>,
<stable@vger.kernel.org>, x86 <x86@kernel.org>,
LKML <linux-kernel@vger.kernel.org>
Subject: [tip: x86/urgent] x86/lib: Change .weak to SYM_FUNC_START_WEAK for arch/x86/lib/mem*_64.S
Date: Wed, 04 Nov 2020 11:57:54 -0000 [thread overview]
Message-ID: <160449107432.397.983110962215228376.tip-bot2@tip-bot2> (raw)
In-Reply-To: <20201103012358.168682-1-maskray@google.com>
The following commit has been merged into the x86/urgent branch of tip:
Commit-ID: 4d6ffa27b8e5116c0abb318790fd01d4e12d75e6
Gitweb: https://git.kernel.org/tip/4d6ffa27b8e5116c0abb318790fd01d4e12d75e6
Author: Fangrui Song <maskray@google.com>
AuthorDate: Mon, 02 Nov 2020 17:23:58 -08:00
Committer: Borislav Petkov <bp@suse.de>
CommitterDate: Wed, 04 Nov 2020 12:30:20 +01:00
x86/lib: Change .weak to SYM_FUNC_START_WEAK for arch/x86/lib/mem*_64.S
Commit
393f203f5fd5 ("x86_64: kasan: add interceptors for memset/memmove/memcpy functions")
added .weak directives to arch/x86/lib/mem*_64.S instead of changing the
existing ENTRY macros to WEAK. This can lead to the assembly snippet
.weak memcpy
...
.globl memcpy
which will produce a STB_WEAK memcpy with GNU as but STB_GLOBAL memcpy
with LLVM's integrated assembler before LLVM 12. LLVM 12 (since
https://reviews.llvm.org/D90108) will error on such an overridden symbol
binding.
Commit
ef1e03152cb0 ("x86/asm: Make some functions local")
changed ENTRY in arch/x86/lib/memcpy_64.S to SYM_FUNC_START_LOCAL, which
was ineffective due to the preceding .weak directive.
Use the appropriate SYM_FUNC_START_WEAK instead.
Fixes: 393f203f5fd5 ("x86_64: kasan: add interceptors for memset/memmove/memcpy functions")
Fixes: ef1e03152cb0 ("x86/asm: Make some functions local")
Reported-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Fangrui Song <maskray@google.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Nathan Chancellor <natechancellor@gmail.com>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Cc: <stable@vger.kernel.org>
Link: https://lkml.kernel.org/r/20201103012358.168682-1-maskray@google.com
---
arch/x86/lib/memcpy_64.S | 4 +---
arch/x86/lib/memmove_64.S | 4 +---
arch/x86/lib/memset_64.S | 4 +---
3 files changed, 3 insertions(+), 9 deletions(-)
diff --git a/arch/x86/lib/memcpy_64.S b/arch/x86/lib/memcpy_64.S
index 037faac..1e299ac 100644
--- a/arch/x86/lib/memcpy_64.S
+++ b/arch/x86/lib/memcpy_64.S
@@ -16,8 +16,6 @@
* to a jmp to memcpy_erms which does the REP; MOVSB mem copy.
*/
-.weak memcpy
-
/*
* memcpy - Copy a memory block.
*
@@ -30,7 +28,7 @@
* rax original destination
*/
SYM_FUNC_START_ALIAS(__memcpy)
-SYM_FUNC_START_LOCAL(memcpy)
+SYM_FUNC_START_WEAK(memcpy)
ALTERNATIVE_2 "jmp memcpy_orig", "", X86_FEATURE_REP_GOOD, \
"jmp memcpy_erms", X86_FEATURE_ERMS
diff --git a/arch/x86/lib/memmove_64.S b/arch/x86/lib/memmove_64.S
index 7ff00ea..41902fe 100644
--- a/arch/x86/lib/memmove_64.S
+++ b/arch/x86/lib/memmove_64.S
@@ -24,9 +24,7 @@
* Output:
* rax: dest
*/
-.weak memmove
-
-SYM_FUNC_START_ALIAS(memmove)
+SYM_FUNC_START_WEAK(memmove)
SYM_FUNC_START(__memmove)
mov %rdi, %rax
diff --git a/arch/x86/lib/memset_64.S b/arch/x86/lib/memset_64.S
index 9ff15ee..0bfd26e 100644
--- a/arch/x86/lib/memset_64.S
+++ b/arch/x86/lib/memset_64.S
@@ -6,8 +6,6 @@
#include <asm/alternative-asm.h>
#include <asm/export.h>
-.weak memset
-
/*
* ISO C memset - set a memory block to a byte value. This function uses fast
* string to get better performance than the original function. The code is
@@ -19,7 +17,7 @@
*
* rax original destination
*/
-SYM_FUNC_START_ALIAS(memset)
+SYM_FUNC_START_WEAK(memset)
SYM_FUNC_START(__memset)
/*
* Some CPUs support enhanced REP MOVSB/STOSB feature. It is recommended
prev parent reply other threads:[~2020-11-04 11:59 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-03 1:23 [PATCH v2] x86_64: Change .weak to SYM_FUNC_START_WEAK for arch/x86/lib/mem*_64.S Fangrui Song
2020-11-03 1:46 ` Nathan Chancellor
2020-11-03 22:43 ` Nick Desaulniers
2020-11-04 11:57 ` tip-bot2 for Fangrui Song [this message]
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