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authorJosh Poimboeuf <jpoimboe@redhat.com>2018-02-21 03:42:14 +0100
committerIngo Molnar <mingo@kernel.org>2018-02-21 16:54:07 +0100
commit0ca7d5baa1787e5f2a7abd6bfca3303b1bbb48ac (patch)
tree866043b4ad57ddfb6fe60eef21ea1b0381e9f36e /arch/x86
parentextable: Make init_kernel_text() global (diff)
downloadlinux-0ca7d5baa1787e5f2a7abd6bfca3303b1bbb48ac.tar.xz
linux-0ca7d5baa1787e5f2a7abd6bfca3303b1bbb48ac.zip
x86/entry/64: Simplify ENCODE_FRAME_POINTER
On 64-bit, the stack pointer is always aligned on interrupt, so instead of setting the LSB of the pt_regs address, we can just add 1 to it. Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andrew Lutomirski <luto@kernel.org> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dominik Brodowski <linux@dominikbrodowski.net> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/20180221024214.lhl5jfgw33c4vz3m@treble Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86')
-rw-r--r--arch/x86/entry/calling.h7
1 files changed, 1 insertions, 6 deletions
diff --git a/arch/x86/entry/calling.h b/arch/x86/entry/calling.h
index 5d10b7a85cad..be63330c5511 100644
--- a/arch/x86/entry/calling.h
+++ b/arch/x86/entry/calling.h
@@ -181,12 +181,7 @@ For 32-bit we have the following conventions - kernel is built with
*/
.macro ENCODE_FRAME_POINTER ptregs_offset=0
#ifdef CONFIG_FRAME_POINTER
- .if \ptregs_offset
- leaq \ptregs_offset(%rsp), %rbp
- .else
- mov %rsp, %rbp
- .endif
- orq $0x1, %rbp
+ leaq 1+\ptregs_offset(%rsp), %rbp
#endif
.endm