FAILED: patch "[PATCH] arm64: Change .weak to SYM_FUNC_START_WEAK_PI for" failed to apply to 4.9-stable tree

The patch below does not apply to the 4.9-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From ec9d78070de986ecf581ea204fd322af4d2477ec Mon Sep 17 00:00:00 2001
From: Fangrui Song <[email protected]>
Date: Thu, 29 Oct 2020 11:19:51 -0700
Subject: [PATCH] arm64: Change .weak to SYM_FUNC_START_WEAK_PI for
arch/arm64/lib/mem*.S

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.

index e0bf83d556f2..dc8d2a216a6e 100644
@@ -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)

index 02cda2e33bde..1035dce4bdaf 100644
@@ -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

index 77c3c7ba0084..a9c1c9a01ea9 100644
@@ -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