Commit-ID: 0ca7d5baa1787e5f2a7abd6bfca3303b1bbb48ac Gitweb: https://git.kernel.org/tip/0ca7d5baa1787e5f2a7abd6bfca3303b1bbb48ac Author: Josh Poimboeuf <[email protected]> AuthorDate: Tue, 20 Feb 2018 20:42:14 -0600 Committer: Ingo Molnar <[email protected]> CommitDate: Wed, 21 Feb 2018 16:54:07 +0100
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 <[email protected]> Signed-off-by: Josh Poimboeuf <[email protected]> Cc: Andrew Lutomirski <[email protected]> Cc: Brian Gerst <[email protected]> Cc: Dan Williams <[email protected]> Cc: Dominik Brodowski <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Link: http://lkml.kernel.org/r/20180221024214.lhl5jfgw33c4vz3m@treble Signed-off-by: Ingo Molnar <[email protected]> --- arch/x86/entry/calling.h | 7 +------ 1 file changed, 1 insertion(+), 6 deletions(-) diff --git a/arch/x86/entry/calling.h b/arch/x86/entry/calling.h index 5d10b7a..be63330 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
