Thread (6 messages) 6 messages, 5 authors, 2020-03-25

Re: [PATCH] powerpc/boot: Delete unneeded .globl _zimage_start

From: Joel Stanley <joel@jms.id.au>
Date: 2020-03-25 05:24:21

On Wed, 25 Mar 2020 at 05:19, Fangrui Song [off-list ref] wrote:
quoted hunk ↗ jump to hunk
.globl sets the symbol binding to STB_GLOBAL while .weak sets the
binding to STB_WEAK. They should not be used together. It is accidetal
rather then intentional that GNU as let .weak override .globl while
clang integrated assembler let the last win.

Fixes: cd197ffcf10b "[POWERPC] zImage: Cleanup and improve zImage entry point"
Fixes: ee9d21b3b358 "powerpc/boot: Ensure _zimage_start is a weak symbol"
Link: https://github.com/ClangBuiltLinux/linux/issues/937
Signed-off-by: Fangrui Song <redacted>
Cc: Joel Stanley <joel@jms.id.au>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: clang-built-linux@googlegroups.com
---
 arch/powerpc/boot/crt0.S | 3 ---
 1 file changed, 3 deletions(-)
diff --git a/arch/powerpc/boot/crt0.S b/arch/powerpc/boot/crt0.S
index 92608f34d312..1d83966f5ef6 100644
--- a/arch/powerpc/boot/crt0.S
+++ b/arch/powerpc/boot/crt0.S
@@ -44,9 +44,6 @@ p_end:                .long   _end
 p_pstack:      .long   _platform_stack_top
 #endif

-       .globl  _zimage_start
-       /* Clang appears to require the .weak directive to be after the symbol
-        * is defined. See https://bugs.llvm.org/show_bug.cgi?id=38921  */
        .weak   _zimage_start
 _zimage_start:
Your explanation makes sense to me. I've added Alan to cc for his review.

Reviewed-by: Joel Stanley <joel@jms.id.au>

Thanks for the patch.

Cheers,

Joel
        .globl  _zimage_start_lib
--
2.25.1.696.g5e7596f4ac-goog
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