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authorJosh Poimboeuf <jpoimboe@redhat.com>2016-12-13 21:25:35 -0600
committerIngo Molnar <mingo@kernel.org>2016-12-14 08:48:05 +0100
commitec2d86a9b646d93f1948569f368e2c6f5449e6c7 (patch)
treece13273c0fac628752f83f8e46137a2839b150e1 /arch/x86/kernel/head_64.S
parent9d85eb9119f4eeeb48e87adfcd71f752655700e9 (diff)
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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 <bp@alien8.de> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/4d8a1952759721d42d1e62ba9e4a7e3ac5df8574.1481685203.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/kernel/head_64.S')
-rw-r--r--arch/x86/kernel/head_64.S2
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/x86/kernel/head_64.S b/arch/x86/kernel/head_64.S
index 90de28841242..1facaf4f2308 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
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