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Message-Id: <20220318143016.124387-7-jiangshanlai@gmail.com>
Date: Fri, 18 Mar 2022 22:30:15 +0800
From: Lai Jiangshan <jiangshanlai@...il.com>
To: linux-kernel@...r.kernel.org
Cc: Borislav Petkov <bp@...en8.de>,
Peter Zijlstra <peterz@...radead.org>,
Josh Poimboeuf <jpoimboe@...hat.com>,
Andy Lutomirski <luto@...nel.org>,
Thomas Gleixner <tglx@...utronix.de>, x86@...nel.org,
Lai Jiangshan <jiangshan.ljs@...group.com>,
Ingo Molnar <mingo@...hat.com>,
Dave Hansen <dave.hansen@...ux.intel.com>,
"H. Peter Anvin" <hpa@...or.com>,
"Kirill A. Shutemov" <kirill@...temov.name>
Subject: [PATCH V4 6/7] x86/entry: Convert SWAPGS to swapgs and remove the definition of SWAPGS
From: Lai Jiangshan <jiangshan.ljs@...group.com>
XENPV doesn't use swapgs_restore_regs_and_return_to_usermode(),
error_entry() and entry_SYSENTER_compat(), so the PV-awared SWAPGS in
them can be changed to swapgs. There is no user of the SWAPGS anymore
after this change.
Signed-off-by: Lai Jiangshan <jiangshan.ljs@...group.com>
---
arch/x86/entry/entry_64.S | 6 +++---
arch/x86/entry/entry_64_compat.S | 2 +-
arch/x86/include/asm/irqflags.h | 8 --------
3 files changed, 4 insertions(+), 12 deletions(-)
diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S
index e9fe9f00d17c..9e8d0e259a7d 100644
--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -1008,7 +1008,7 @@ SYM_CODE_START_LOCAL(error_entry)
* We entered from user mode or we're pretending to have entered
* from user mode due to an IRET fault.
*/
- SWAPGS
+ swapgs
FENCE_SWAPGS_USER_ENTRY
/* We have user CR3. Change to kernel CR3. */
SWITCH_TO_KERNEL_CR3 scratch_reg=%rax
@@ -1040,7 +1040,7 @@ SYM_CODE_START_LOCAL(error_entry)
* gsbase and proceed. We'll fix up the exception and land in
* .Lgs_change's error handler with kernel gsbase.
*/
- SWAPGS
+ swapgs
/*
* Issue an LFENCE to prevent GS speculation, regardless of whether it is a
@@ -1061,7 +1061,7 @@ SYM_CODE_START_LOCAL(error_entry)
* We came from an IRET to user mode, so we have user
* gsbase and CR3. Switch to kernel gsbase and CR3:
*/
- SWAPGS
+ swapgs
FENCE_SWAPGS_USER_ENTRY
SWITCH_TO_KERNEL_CR3 scratch_reg=%rax
diff --git a/arch/x86/entry/entry_64_compat.S b/arch/x86/entry/entry_64_compat.S
index 4fdb007cddbd..c5aeb0819707 100644
--- a/arch/x86/entry/entry_64_compat.S
+++ b/arch/x86/entry/entry_64_compat.S
@@ -50,7 +50,7 @@ SYM_CODE_START(entry_SYSENTER_compat)
UNWIND_HINT_EMPTY
ENDBR
/* Interrupts are off on entry. */
- SWAPGS
+ swapgs
pushq %rax
SWITCH_TO_KERNEL_CR3 scratch_reg=%rax
diff --git a/arch/x86/include/asm/irqflags.h b/arch/x86/include/asm/irqflags.h
index 111104d1c2cd..7793e52d6237 100644
--- a/arch/x86/include/asm/irqflags.h
+++ b/arch/x86/include/asm/irqflags.h
@@ -137,14 +137,6 @@ static __always_inline void arch_local_irq_restore(unsigned long flags)
if (!arch_irqs_disabled_flags(flags))
arch_local_irq_enable();
}
-#else
-#ifdef CONFIG_X86_64
-#ifdef CONFIG_XEN_PV
-#define SWAPGS ALTERNATIVE "swapgs", "", X86_FEATURE_XENPV
-#else
-#define SWAPGS swapgs
-#endif
-#endif
#endif /* !__ASSEMBLY__ */
#endif
--
2.19.1.6.gb485710b
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