Commit ec9d7807 authored Oct 29, 2020 by Fangrui Song Committed by Will Deacon Oct 30, 2020

arm64: Change .weak to SYM_FUNC_START_WEAK_PI for arch/arm64/lib/mem*.S

Commit 39d114dd ("arm64: add KASAN support") added .weak directives to
arch/arm64/lib/mem*.S instead of changing the existing SYM_FUNC_START_PI
macros. 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.

Use the appropriate SYM_FUNC_START_WEAK_PI instead.

Fixes: 39d114dd ("arm64: add KASAN support")
Reported-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Fangrui Song <maskray@google.com>
Tested-by: Sami Tolvanen <samitolvanen@google.com>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20201029181951.1866093-1-maskray@google.com


Signed-off-by: Will Deacon <will@kernel.org>

parent ce3d31ad

arch/arm64/lib/memcpy.S

+1 −2

Original line number	Diff line number	Diff line
		@@ -56,9 +56,8 @@
		stp \reg1, \reg2, [\ptr], \val
		.endm

		.weak memcpy
		SYM_FUNC_START_ALIAS(__memcpy)
		SYM_FUNC_START_PI(memcpy)
		SYM_FUNC_START_WEAK_PI(memcpy)
		#include "copy_template.S"
		ret
		SYM_FUNC_END_PI(memcpy)

arch/arm64/lib/memmove.S

+1 −2

Original line number	Diff line number	Diff line
		@@ -45,9 +45,8 @@ C_h .req x12
		D_l .req x13
		D_h .req x14

		.weak memmove
		SYM_FUNC_START_ALIAS(__memmove)
		SYM_FUNC_START_PI(memmove)
		SYM_FUNC_START_WEAK_PI(memmove)
		cmp dstin, src
		b.lo __memcpy
		add tmp1, src, count

arch/arm64/lib/memset.S

+1 −2

Original line number	Diff line number	Diff line
		@@ -42,9 +42,8 @@ dst .req x8
		tmp3w .req w9
		tmp3 .req x9

		.weak memset
		SYM_FUNC_START_ALIAS(__memset)
		SYM_FUNC_START_PI(memset)
		SYM_FUNC_START_WEAK_PI(memset)
		mov dst, dstin /* Preserve return value. */
		and A_lw, val, #255
		orr A_lw, A_lw, A_lw, lsl #8

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