[PATCH] x86/entry: add compatibility with IAS

From: Jian Cai
Date: Mon Jul 13 2020 - 18:40:46 EST


Clang's integrated assembler does not allow symbols with non-absolute
values to be reassigned. This patch allows the affected code to be
compatible with IAS.

Link: https://github.com/ClangBuiltLinux/linux/issues/1043
Reported-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>
Reported-by: Sedat Dilek <sedat.dilek@xxxxxxxxx>
Suggested-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>
Suggested-by: Brian Gerst <brgerst@xxxxxxxxx>
Suggested-by: Arvind Sankar <nivedita@xxxxxxxxxxxx>
Tested-by: Sedat Dilek <sedat.dilek@xxxxxxxxx>
Signed-off-by: Jian Cai <caij2003@xxxxxxxxx>
---
arch/x86/include/asm/idtentry.h | 14 ++++++--------
1 file changed, 6 insertions(+), 8 deletions(-)

diff --git a/arch/x86/include/asm/idtentry.h b/arch/x86/include/asm/idtentry.h
index f3d70830bf2a..5efaaed34eda 100644
--- a/arch/x86/include/asm/idtentry.h
+++ b/arch/x86/include/asm/idtentry.h
@@ -469,16 +469,15 @@ __visible noinstr void func(struct pt_regs *regs, \
.align 8
SYM_CODE_START(irq_entries_start)
vector=FIRST_EXTERNAL_VECTOR
- pos = .
.rept (FIRST_SYSTEM_VECTOR - FIRST_EXTERNAL_VECTOR)
UNWIND_HINT_IRET_REGS
+0 :
.byte 0x6a, vector
jmp asm_common_interrupt
nop
/* Ensure that the above is 8 bytes max */
- . = pos + 8
- pos=pos+8
- vector=vector+1
+ . = 0b + 8
+ vector = vector+1
.endr
SYM_CODE_END(irq_entries_start)

@@ -486,16 +485,15 @@ SYM_CODE_END(irq_entries_start)
.align 8
SYM_CODE_START(spurious_entries_start)
vector=FIRST_SYSTEM_VECTOR
- pos = .
.rept (NR_VECTORS - FIRST_SYSTEM_VECTOR)
UNWIND_HINT_IRET_REGS
+0 :
.byte 0x6a, vector
jmp asm_spurious_interrupt
nop
/* Ensure that the above is 8 bytes max */
- . = pos + 8
- pos=pos+8
- vector=vector+1
+ . = 0b + 8
+ vector = vector+1
.endr
SYM_CODE_END(spurious_entries_start)
#endif
--
2.27.0.383.g050319c2ae-goog