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.

Fixes: 39d114ddc682 ("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>

diff --git a/arch/arm64/lib/memcpy.S b/arch/arm64/lib/memcpy.S
index e0bf83d..dc8d2a2 100644 (file)
--- 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 02cda2e..1035dce 100644 (file)
--- 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 77c3c7b..a9c1c9a 100644 (file)
--- 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