[tip: x86/urgent] x86/entry/64: Fix unwind hints in rewind_stack_do_exit()

[tip-bot2 for Jann Horn]

The following commit has been merged into the x86/urgent branch of tip:

Commit-ID:     f977df7b7ca45a4ac4b66d30a8931d0434c394b1
Gitweb:        https://git.kernel.org/tip/f977df7b7ca45a4ac4b66d30a8931d0434c394b1
Author:        Jann Horn <jannh@xxxxxxxxxx>
AuthorDate:    Sat, 25 Apr 2020 05:03:04 -05:00
Committer:     Ingo Molnar <mingo@xxxxxxxxxx>
CommitterDate: Sat, 25 Apr 2020 12:22:28 +02:00

x86/entry/64: Fix unwind hints in rewind_stack_do_exit()

The LEAQ instruction in rewind_stack_do_exit() moves the stack pointer
directly below the pt_regs at the top of the task stack before calling
do_exit(). Tell the unwinder to expect pt_regs.

Fixes: 8c1f75587a18 ("x86/entry/64: Add unwind hint annotations")
Reviewed-by: Miroslav Benes <mbenes@xxxxxxx>
Signed-off-by: Jann Horn <jannh@xxxxxxxxxx>
Signed-off-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Andy Lutomirski <luto@xxxxxxxxxx>
Cc: Dave Jones <dsj@xxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Vince Weaver <vincent.weaver@xxxxxxxxx>
Link: https://lore.kernel.org/r/68c33e17ae5963854916a46f522624f8e1d264f2.1587808742.git.jpoimboe@xxxxxxxxxx
---
 arch/x86/entry/entry_64.S | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S
index 34a5889..9fe0d5c 100644
--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -1739,7 +1739,7 @@ SYM_CODE_START(rewind_stack_do_exit)
 
 	movq	PER_CPU_VAR(cpu_current_top_of_stack), %rax
 	leaq	-PTREGS_SIZE(%rax), %rsp
-	UNWIND_HINT_FUNC sp_offset=PTREGS_SIZE
+	UNWIND_HINT_REGS
 
 	call	do_exit
 SYM_CODE_END(rewind_stack_do_exit)