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: Lai Jiangshan <jiangshan.ljs@antgroup.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Juergen Gross <jgross@suse.com>
Link: https://lore.kernel.org/r/20220503032107.680190-7-jiangshanlai@gmail.com

diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S
index 062aa9d..3121866 100644 (file)
--- a/arch/x86/entry/entry_64.S
+++ b/arch/x86/entry/entry_64.S
@@ -1019,7 +1019,7 @@ 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
@@ -1051,7 +1051,7 @@ 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
@@ -1072,7 +1072,7 @@ 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 4fdb007..c5aeb08 100644 (file)
--- 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 111104d..7793e52 100644 (file)
--- 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