Commit-ID: ec2d86a9b646d93f1948569f368e2c6f5449e6c7 Gitweb: http://git.kernel.org/tip/ec2d86a9b646d93f1948569f368e2c6f5449e6c7 Author: Josh Poimboeuf <jpoim...@redhat.com> AuthorDate: Tue, 13 Dec 2016 21:25:35 -0600 Committer: Ingo Molnar <mi...@kernel.org> CommitDate: Wed, 14 Dec 2016 08:48:05 +0100
x86/boot/64: Use 'push' instead of 'call' in start_cpu() 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 uses a call instruction to do that, which is rather obtuse. Use a straightforward push instead. Suggested-by: Borislav Petkov <b...@alien8.de> Signed-off-by: Josh Poimboeuf <jpoim...@redhat.com> Cc: Andy Lutomirski <l...@kernel.org> 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/4d8a1952759721d42d1e62ba9e4a7e3ac5df8574.1481685203.git.jpoim...@redhat.com Signed-off-by: Ingo Molnar <mi...@kernel.org> --- arch/x86/kernel/head_64.S | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S index 90de288..1facaf4 100644 --- a/arch/x86/kernel/head_64.S +++ b/arch/x86/kernel/head_64.S @@ -298,7 +298,7 @@ ENTRY(start_cpu) * REX.W + FF /5 JMP m16:64 Jump far, absolute indirect, * address given in m16:64. */ - call 1f # put return address on stack for unwinder + pushq $1f # put return address on stack for unwinder 1: xorq %rbp, %rbp # clear frame pointer movq initial_code(%rip), %rax pushq $__KERNEL_CS # set correct cs
