GitHub-Mirror/Star64_linux
2
0
Fork 0
mirror of https://github.com/Fishwaldo/Star64_linux.git synced 2025-03-16 12:14:06 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions

x86/entry: Remove skip_r11rcx

Browse source 
commit 1b331eeea7 upstream.

Yes, r11 and rcx have been restored previously, but since they're being
popped anyway (into rsi) might as well pop them into their own regs --
setting them to the value they already are.

Less magical code.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/r/20220506121631.365070674@infradead.org
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Peter Zijlstra 2022-05-06 14:14:35 +02:00 • committed by Justin Hammond
parent dc8bf07914
commit f80e90bfe5
2 changed files with 2 additions and 11 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

10
arch/x86/entry/calling.h
View file

@ -119,27 +119,19 @@ For 32-bit we have the following conventions - kernel is built with
CLEAR_REGS
.endm
.macro POP_REGS pop_rdi=1 skip_r11rcx=0
.macro POP_REGS pop_rdi=1
popq %r15
popq %r14
popq %r13
popq %r12
popq %rbp
popq %rbx
.if \skip_r11rcx
popq %rsi
.else
popq %r11
.endif
popq %r10
popq %r9
popq %r8
popq %rax
.if \skip_r11rcx
popq %rsi
.else
popq %rcx
.endif
popq %rdx
popq %rsi
.if \pop_rdi

3
arch/x86/entry/entry_64.S
View file

@ -189,8 +189,7 @@ SYM_INNER_LABEL(entry_SYSCALL_64_after_hwframe, SYM_L_GLOBAL)
* perf profiles. Nothing jumps here.
*/
syscall_return_via_sysret:
/* rcx and r11 are already restored (see code above) */
POP_REGS pop_rdi=0 skip_r11rcx=1
POP_REGS pop_rdi=0
/*
* Now all regs are restored except RSP and RDI.