Commit-ID: 0ca7d5baa1787e5f2a7abd6bfca3303b1bbb48ac Gitweb: https://git.kernel.org/tip/0ca7d5baa1787e5f2a7abd6bfca3303b1bbb48ac Author: Josh Poimboeuf <jpoim...@redhat.com> AuthorDate: Tue, 20 Feb 2018 20:42:14 -0600 Committer: Ingo Molnar <mi...@kernel.org> 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 <torva...@linux-foundation.org> Signed-off-by: Josh Poimboeuf <jpoim...@redhat.com> Cc: Andrew Lutomirski <l...@kernel.org> Cc: Brian Gerst <brge...@gmail.com> Cc: Dan Williams <dan.j.willi...@intel.com> Cc: Dominik Brodowski <li...@dominikbrodowski.net> Cc: Peter Zijlstra <pet...@infradead.org> Cc: Thomas Gleixner <t...@linutronix.de> Link: http://lkml.kernel.org/r/20180221024214.lhl5jfgw33c4vz3m@treble Signed-off-by: Ingo Molnar <mi...@kernel.org> --- 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
