[PATCH] x86/mm: annotate no_context with UNWIND_HINTS

From: Nick Desaulniers
Date: Sun Oct 14 2018 - 20:38:15 EST


Fixes the objtool warning:
arch/x86/mm/fault.o: warning: objtool: no_context()+0x220: unreachable
instruction

Link: https://github.com/ClangBuiltLinux/linux/issues/204
Signed-off-by: Nick Desaulniers <nick.desaulniers@xxxxxxxxx>
---
arch/x86/mm/fault.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index 47bebfe6efa7..057d2178fa19 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -760,9 +760,11 @@ no_context(struct pt_regs *regs, unsigned long error_code,
* and then double-fault, though, because we're likely to
* break the console driver and lose most of the stack dump.
*/
- asm volatile ("movq %[stack], %%rsp\n\t"
+ asm volatile (UNWIND_HINT_SAVE
+ "movq %[stack], %%rsp\n\t"
"call handle_stack_overflow\n\t"
- "1: jmp 1b"
+ "1: jmp 1b\n\t"
+ UNWIND_HINT_RESTORE
: ASM_CALL_CONSTRAINT
: "D" ("kernel stack overflow (page fault)"),
"S" (regs), "d" (address),
--
2.17.1