Commit c89191ce authored by Lai Jiangshan's avatar Lai Jiangshan Committed by Borislav Petkov

x86/entry: Convert SWAPGS to swapgs and remove the definition of SWAPGS

XENPV doesn't use swapgs_restore_regs_and_return_to_usermode(),
error_entry() and the code between entry_SYSENTER_compat() and
entry_SYSENTER_compat_after_hwframe.

Change the PV-compatible SWAPGS to the ASM instruction swapgs in these
places.

Also remove the definition of SWAPGS since no more users.
Signed-off-by: default avatarLai Jiangshan <jiangshan.ljs@antgroup.com>
Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
Reviewed-by: default avatarJuergen Gross <jgross@suse.com>
Link: https://lore.kernel.org/r/20220503032107.680190-7-jiangshanlai@gmail.com
parent 64cbd0ac
...@@ -1019,7 +1019,7 @@ SYM_CODE_START_LOCAL(error_entry) ...@@ -1019,7 +1019,7 @@ SYM_CODE_START_LOCAL(error_entry)
* We entered from user mode or we're pretending to have entered * We entered from user mode or we're pretending to have entered
* from user mode due to an IRET fault. * from user mode due to an IRET fault.
*/ */
SWAPGS swapgs
FENCE_SWAPGS_USER_ENTRY FENCE_SWAPGS_USER_ENTRY
/* We have user CR3. Change to kernel CR3. */ /* We have user CR3. Change to kernel CR3. */
SWITCH_TO_KERNEL_CR3 scratch_reg=%rax SWITCH_TO_KERNEL_CR3 scratch_reg=%rax
...@@ -1051,7 +1051,7 @@ SYM_CODE_START_LOCAL(error_entry) ...@@ -1051,7 +1051,7 @@ SYM_CODE_START_LOCAL(error_entry)
* gsbase and proceed. We'll fix up the exception and land in * gsbase and proceed. We'll fix up the exception and land in
* .Lgs_change's error handler with kernel gsbase. * .Lgs_change's error handler with kernel gsbase.
*/ */
SWAPGS swapgs
/* /*
* Issue an LFENCE to prevent GS speculation, regardless of whether it is a * Issue an LFENCE to prevent GS speculation, regardless of whether it is a
...@@ -1072,7 +1072,7 @@ SYM_CODE_START_LOCAL(error_entry) ...@@ -1072,7 +1072,7 @@ SYM_CODE_START_LOCAL(error_entry)
* We came from an IRET to user mode, so we have user * We came from an IRET to user mode, so we have user
* gsbase and CR3. Switch to kernel gsbase and CR3: * gsbase and CR3. Switch to kernel gsbase and CR3:
*/ */
SWAPGS swapgs
FENCE_SWAPGS_USER_ENTRY FENCE_SWAPGS_USER_ENTRY
SWITCH_TO_KERNEL_CR3 scratch_reg=%rax SWITCH_TO_KERNEL_CR3 scratch_reg=%rax
......
...@@ -50,7 +50,7 @@ SYM_CODE_START(entry_SYSENTER_compat) ...@@ -50,7 +50,7 @@ SYM_CODE_START(entry_SYSENTER_compat)
UNWIND_HINT_EMPTY UNWIND_HINT_EMPTY
ENDBR ENDBR
/* Interrupts are off on entry. */ /* Interrupts are off on entry. */
SWAPGS swapgs
pushq %rax pushq %rax
SWITCH_TO_KERNEL_CR3 scratch_reg=%rax SWITCH_TO_KERNEL_CR3 scratch_reg=%rax
......
...@@ -137,14 +137,6 @@ static __always_inline void arch_local_irq_restore(unsigned long flags) ...@@ -137,14 +137,6 @@ static __always_inline void arch_local_irq_restore(unsigned long flags)
if (!arch_irqs_disabled_flags(flags)) if (!arch_irqs_disabled_flags(flags))
arch_local_irq_enable(); 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 /* !__ASSEMBLY__ */
#endif #endif
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