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

[Fangrui Song]

Commit 39d114ddc682 ("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: 39d114ddc682 ("arm64: add KASAN support")
Reported-by: Sami Tolvanen <samitolvanen at google.com>
Signed-off-by: Fangrui Song <maskray at google.com>
Cc: <stable at vger.kernel.org>
---
 arch/arm64/lib/memcpy.S  | 3 +--
 arch/arm64/lib/memmove.S | 3 +--
 arch/arm64/lib/memset.S  | 3 +--
 3 files changed, 3 insertions(+), 6 deletions(-)

diff --git a/arch/arm64/lib/memcpy.S b/arch/arm64/lib/memcpy.S
index e0bf83d556f2..dc8d2a216a6e 100644
--- a/arch/arm64/lib/memcpy.S
+++ b/arch/arm64/lib/memcpy.S
@@ -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)
diff --git a/arch/arm64/lib/memmove.S b/arch/arm64/lib/memmove.S
index 02cda2e33bde..1035dce4bdaf 100644
--- a/arch/arm64/lib/memmove.S
+++ b/arch/arm64/lib/memmove.S
@@ -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
diff --git a/arch/arm64/lib/memset.S b/arch/arm64/lib/memset.S
index 77c3c7ba0084..a9c1c9a01ea9 100644
--- a/arch/arm64/lib/memset.S
+++ b/arch/arm64/lib/memset.S
@@ -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
-- 
2.29.1.341.ge80a0c044ae-goog