Commit 735e8d93 authored Nov 06, 2020 by Fangrui Song Committed by Russell King Nov 12, 2020

ARM: 9022/1: Change arch/arm/lib/mem*.S to use WEAK instead of .weak

Commit d6d51a96 ("ARM: 9014/2: Replace string mem* functions for
KASan") add .weak directives to memcpy/memmove/memset to avoid collision
with KASAN interceptors.

This does not work with LLVM's integrated assembler (the assembly snippet
`.weak memcpy ... .globl memcpy` produces a STB_GLOBAL memcpy while GNU as
produces a STB_WEAK memcpy). LLVM 12 (since https://reviews.llvm.org/D90108)
will error on such an overridden symbol binding.

Use the appropriate WEAK macro instead.

Link: https://github.com/ClangBuiltLinux/linux/issues/1190


--

Fixes: d6d51a96 ("ARM: 9014/2: Replace string mem* functions for KASan")
Reported-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Fangrui Song <maskray@google.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>

parent fc2933c1

arch/arm/lib/memcpy.S

+1 −2

Original line number	Diff line number	Diff line
		@@ -58,10 +58,9 @@

		/* Prototype: void memcpy(void dest, const void src, size_t n); /

		.weak memcpy
		ENTRY(__memcpy)
		ENTRY(mmiocpy)
		ENTRY(memcpy)
		WEAK(memcpy)

		#include "copy_template.S"

arch/arm/lib/memmove.S

+1 −2

Original line number	Diff line number	Diff line
		@@ -24,9 +24,8 @@
		* occurring in the opposite direction.
		*/

		.weak memmove
		ENTRY(__memmove)
		ENTRY(memmove)
		WEAK(memmove)
		UNWIND( .fnstart )

		subs ip, r0, r1

arch/arm/lib/memset.S

+1 −2

Original line number	Diff line number	Diff line
		@@ -13,10 +13,9 @@
		.text
		.align 5

		.weak memset
		ENTRY(__memset)
		ENTRY(mmioset)
		ENTRY(memset)
		WEAK(memset)
		UNWIND( .fnstart )
		ands r3, r0, #3 @ 1 unaligned?
		mov ip, r0 @ preserve r0 as return value

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