Commit-ID:  31dcfec11f827e9a5d8720fe4728f1305894884f
Gitweb:     http://git.kernel.org/tip/31dcfec11f827e9a5d8720fe4728f1305894884f
Author:     Josh Poimboeuf <jpoim...@redhat.com>
AuthorDate: Tue, 13 Dec 2016 21:25:36 -0600
Committer:  Ingo Molnar <mi...@kernel.org>
CommitDate: Wed, 14 Dec 2016 08:48:05 +0100

x86/boot/64: Push correct start_cpu() return address

start_cpu() pushes a text address on the stack so that stack traces from
idle tasks will show start_cpu() at the end.  But it currently shows the
wrong function offset.  It's more correct to show the address
immediately after the 'lretq' instruction.

Signed-off-by: Josh Poimboeuf <jpoim...@redhat.com>
Cc: Andy Lutomirski <l...@kernel.org>
Cc: Borislav Petkov <b...@alien8.de>
Cc: Brian Gerst <brge...@gmail.com>
Cc: Denys Vlasenko <dvlas...@redhat.com>
Cc: H. Peter Anvin <h...@zytor.com>
Cc: Linus Torvalds <torva...@linux-foundation.org>
Cc: Peter Zijlstra <pet...@infradead.org>
Cc: Thomas Gleixner <t...@linutronix.de>
Link: 
http://lkml.kernel.org/r/2cadd9f16c77da7ee7957bfc5e1c67928c23ca48.1481685203.git.jpoim...@redhat.com
Signed-off-by: Ingo Molnar <mi...@kernel.org>
---
 arch/x86/kernel/head_64.S | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S
index 1facaf4..b467b14 100644
--- a/arch/x86/kernel/head_64.S
+++ b/arch/x86/kernel/head_64.S
@@ -298,12 +298,13 @@ ENTRY(start_cpu)
         *      REX.W + FF /5 JMP m16:64 Jump far, absolute indirect,
         *              address given in m16:64.
         */
-       pushq   $1f             # put return address on stack for unwinder
-1:     xorq    %rbp, %rbp      # clear frame pointer
+       pushq   $.Lafter_lret   # put return address on stack for unwinder
+       xorq    %rbp, %rbp      # clear frame pointer
        movq    initial_code(%rip), %rax
        pushq   $__KERNEL_CS    # set correct cs
        pushq   %rax            # target address in negative space
        lretq
+.Lafter_lret:
 ENDPROC(start_cpu)
 
 #include "verify_cpu.S"

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