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arm64: Change .weak to SYM_FUNC_START_WEAK_PI for arch/arm64/lib/mem*.S
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Commit 39d114d ("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: 39d114d ("arm64: add KASAN support")
Reported-by: Sami Tolvanen <[email protected]>
Signed-off-by: Fangrui Song <[email protected]>
Tested-by: Sami Tolvanen <[email protected]>
Tested-by: Nick Desaulniers <[email protected]>
Reviewed-by: Nick Desaulniers <[email protected]>
Cc: <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Will Deacon <[email protected]>
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MaskRay authored and willdeacon committed Oct 30, 2020
1 parent ce3d31a commit ec9d780
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Showing 3 changed files with 3 additions and 6 deletions.
3 changes: 1 addition & 2 deletions arch/arm64/lib/memcpy.S
Original file line number Diff line number Diff line change
Expand Up @@ -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)
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3 changes: 1 addition & 2 deletions arch/arm64/lib/memmove.S
Original file line number Diff line number Diff line change
Expand Up @@ -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
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3 changes: 1 addition & 2 deletions arch/arm64/lib/memset.S
Original file line number Diff line number Diff line change
Expand Up @@ -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
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