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

commit ec9d78070de986ecf581ea204fd322af4d2477ec upstream.

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>
[nd: backport to adjust for missing:
  commit 3ac0f4526dfb ("arm64: lib: Use modern annotations for assembly functions")
  commit 35e61c77ef38 ("arm64: asm: Add new-style position independent function annotations")]
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Change-Id: Ibebbfa15f3337b5a2ac88ba683c5e429758d7a98

diff --git a/arch/arm64/lib/memcpy.S b/arch/arm64/lib/memcpy.S
index 67613937711f10d209b3be73ce6a322f674581b5..dfedd4ab1a766fdf7ed47028cca1913e150b4b1e 100644 (file)
--- a/arch/arm64/lib/memcpy.S
+++ b/arch/arm64/lib/memcpy.S
@@ -68,9 +68,8 @@
        stp \ptr, \regB, [\regC], \val
        .endm
 
-       .weak memcpy
 ENTRY(__memcpy)
-ENTRY(memcpy)
+WEAK(memcpy)
 #include "copy_template.S"
        ret
 ENDPIPROC(memcpy)

diff --git a/arch/arm64/lib/memmove.S b/arch/arm64/lib/memmove.S
index a5a4459013b1a59d5a54b2a70fd1ad8e0f256fd9..e3de8f05c21a81b54fafbaedbcf6cf7d86d7ce36 100644 (file)
--- a/arch/arm64/lib/memmove.S
+++ b/arch/arm64/lib/memmove.S
@@ -57,9 +57,8 @@ C_h   .req    x12
 D_l    .req    x13
 D_h    .req    x14
 
-       .weak memmove
 ENTRY(__memmove)
-ENTRY(memmove)
+WEAK(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 f2670a9f218c919ff68a1ffcfdbce468e693ae60..316263c47c00683546946901106aeed2a80f9c85 100644 (file)
--- a/arch/arm64/lib/memset.S
+++ b/arch/arm64/lib/memset.S
@@ -54,9 +54,8 @@ dst           .req    x8
 tmp3w          .req    w9
 tmp3           .req    x9
 
-       .weak memset
 ENTRY(__memset)
-ENTRY(memset)
+WEAK(memset)
        mov     dst, dstin      /* Preserve return value.  */
        and     A_lw, val, #255
        orr     A_lw, A_lw, A_lw, lsl #8