x86/entry: Add compatibility with IAS

Clang's integrated assembler does not allow symbols with non-absolute
values to be reassigned. Modify the interrupt entry loop macro to be
compatible with IAS by using a label and an offset.

Reported-by: Nick Desaulniers <ndesaulniers@google.com>
Reported-by: Sedat Dilek <sedat.dilek@gmail.com>
Suggested-by: Nick Desaulniers <ndesaulniers@google.com>
Suggested-by: Brian Gerst <brgerst@gmail.com>
Suggested-by: Arvind Sankar <nivedita@alum.mit.edu>
Signed-off-by: Jian Cai <caij2003@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com> #
Link: https://github.com/ClangBuiltLinux/linux/issues/1043
Link: https://lkml.kernel.org/r/20200714233024.1789985-1-caij2003@gmail.com

diff --git a/arch/x86/include/asm/idtentry.h b/arch/x86/include/asm/idtentry.h
index f3d70830bf2a568c67fc17adbb40ca81edf0f33e..5efaaed34edac942f9bc60ddc93a8a60cc729a8e 100644 (file)
--- 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