From: Peter Zijlstra <peterz@infradead.org>
To: x86@kernel.org
Cc: linux-kernel@vger.kernel.org, peterz@infradead.org,
jpoimboe@redhat.com, brgerst@gmail.com, jiangshanlai@gmail.com,
Andrew.Cooper3@citrix.com, mark.rutland@arm.com
Subject: [PATCH 4/6] x86/entry: Remove skip_r11rcx
Date: Fri, 06 May 2022 14:14:35 +0200 [thread overview]
Message-ID: <20220506121631.365070674@infradead.org> (raw)
In-Reply-To: 20220506121431.563656641@infradead.org
Yes, r11 and rcx have been restored previously, but since we're
popping them 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>
---
arch/x86/entry/calling.h | 10 +---------
arch/x86/entry/entry_64.S | 3 +--
2 files changed, 2 insertions(+), 11 deletions(-)
--- a/arch/x86/entry/calling.h
+++ b/arch/x86/entry/calling.h
@@ -120,27 +120,19 @@ For 32-bit we have the following convent
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
--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -191,8 +191,7 @@ SYM_INNER_LABEL(entry_SYSCALL_64_after_h
* 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.
next prev parent reply other threads:[~2022-05-06 12:21 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-05-06 12:14 [PATCH 0/6] x86: Various cleanups and fixes Peter Zijlstra
2022-05-06 12:14 ` [PATCH 1/6] x86/mm: Simplify RESERVE_BRK() Peter Zijlstra
2022-05-06 15:09 ` [tip: x86/asm] " tip-bot2 for Josh Poimboeuf
2022-05-06 12:14 ` [PATCH 2/6] x86/entry: Simplify entry_INT80_compat() Peter Zijlstra
2022-05-06 15:09 ` [tip: x86/asm] " tip-bot2 for Linus Torvalds
2022-05-06 12:14 ` [PATCH 3/6] x86/entry: Use PUSH_AND_CLEAR_REGS for compat Peter Zijlstra
2022-05-06 15:09 ` [tip: x86/asm] " tip-bot2 for Peter Zijlstra
2022-05-07 2:54 ` [PATCH 3/6] " Lai Jiangshan
2022-05-19 16:24 ` Guenter Roeck
2022-05-19 17:00 ` Peter Zijlstra
2022-05-19 17:11 ` Josh Poimboeuf
2022-05-19 17:35 ` Josh Poimboeuf
2022-05-20 1:11 ` Lai Jiangshan
2022-05-20 2:46 ` Guenter Roeck
2022-05-20 15:55 ` Josh Poimboeuf
2022-05-06 12:14 ` Peter Zijlstra [this message]
2022-05-06 15:09 ` [tip: x86/asm] x86/entry: Remove skip_r11rcx tip-bot2 for Peter Zijlstra
2022-05-07 2:52 ` [PATCH 4/6] " Lai Jiangshan
2022-05-06 12:14 ` [PATCH 5/6] linkage: Fix issue with missing symbol size Peter Zijlstra
2022-05-06 15:08 ` [tip: x86/asm] " tip-bot2 for Peter Zijlstra
2022-05-06 12:14 ` [PATCH 6/6] objtool: Fix STACK_FRAME_NON_STANDARD reloc type Peter Zijlstra
2022-05-06 15:08 ` [tip: x86/asm] " tip-bot2 for Peter Zijlstra
2022-05-06 16:05 ` [PATCH 6/6] " Josh Poimboeuf
2022-05-06 20:26 ` [tip: x86/asm] " tip-bot2 for Peter Zijlstra
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