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| author |   Juergen Gross <jgross@suse.com> | 2021-01-20 14:55:44 +0100 |
|---|---|---|
| committer |   Borislav Petkov <bp@suse.de> | 2021-02-10 12:25:49 +0100 |
| commit | 53c9d9240944088274aadbbbafc6138ca462db4f (patch) | |
| tree | 240f2116356d20534a96f21db21b469abcd64978 /arch/x86/entry/entry_64.S | |
| parent | x86/xen: Use specific Xen pv interrupt entry for DF (diff) | |
| download | wireguard-linux-53c9d9240944088274aadbbbafc6138ca462db4f.tar.xz wireguard-linux-53c9d9240944088274aadbbbafc6138ca462db4f.zip | |
x86/pv: Switch SWAPGS to ALTERNATIVE
SWAPGS is used only for interrupts coming from user mode or for
returning to user mode. So there is no reason to use the PARAVIRT
framework, as it can easily be replaced by an ALTERNATIVE depending
on X86_FEATURE_XENPV.
There are several instances using the PV-aware SWAPGS macro in paths
which are never executed in a Xen PV guest. Replace those with the
plain swapgs instruction. For SWAPGS_UNSAFE_STACK the same applies.
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Andy Lutomirski <luto@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20210120135555.32594-5-jgross@suse.com
Diffstat (limited to 'arch/x86/entry/entry_64.S')
| -rw-r--r-- | arch/x86/entry/entry_64.S | 10 |
1 files changed, 5 insertions, 5 deletions
diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S index cad08703c4ad..a876204a73e0 100644 --- a/arch/x86/entry/entry_64.S +++ b/arch/x86/entry/entry_64.S @@ -669,7 +669,7 @@ native_irq_return_ldt: */ pushq %rdi /* Stash user RDI */ - SWAPGS /* to kernel GS */ + swapgs /* to kernel GS */ SWITCH_TO_KERNEL_CR3 scratch_reg=%rdi /* to kernel CR3 */ movq PER_CPU_VAR(espfix_waddr), %rdi @@ -699,7 +699,7 @@ native_irq_return_ldt: orq PER_CPU_VAR(espfix_stack), %rax SWITCH_TO_USER_CR3_STACK scratch_reg=%rdi - SWAPGS /* to user GS */ + swapgs /* to user GS */ popq %rdi /* Restore user RDI */ movq %rax, %rsp @@ -943,7 +943,7 @@ SYM_CODE_START_LOCAL(paranoid_entry) ret .Lparanoid_entry_swapgs: - SWAPGS + swapgs /* * The above SAVE_AND_SWITCH_TO_KERNEL_CR3 macro doesn't do an @@ -1001,7 +1001,7 @@ SYM_CODE_START_LOCAL(paranoid_exit) jnz restore_regs_and_return_to_kernel /* We are returning to a context with user GSBASE */ - SWAPGS_UNSAFE_STACK + swapgs jmp restore_regs_and_return_to_kernel SYM_CODE_END(paranoid_exit) @@ -1426,7 +1426,7 @@ nmi_no_fsgsbase: jnz nmi_restore nmi_swapgs: - SWAPGS_UNSAFE_STACK + swapgs nmi_restore: POP_REGS |