diff options
| author | Peter Zijlstra | 2022-03-08 16:30:22 +0100 |
|---|---|---|
| committer | Peter Zijlstra | 2022-03-15 10:32:34 +0100 |
| commit | 8b87d8cec1b31ea710568ae49ba5f5146318da0d (patch) | |
| tree | d66a56f82b2e643c95e46710bdbe69064ef32178 /arch/x86/entry | |
| parent | 6cf3e4c0d29102c74aca1ce0c1710be9d02e440e (diff) | |
x86/entry,xen: Early rewrite of restore_regs_and_return_to_kernel()
By doing an early rewrite of 'jmp native_iret` in
restore_regs_and_return_to_kernel() we can get rid of the last
INTERRUPT_RETURN user and paravirt_iret.
Suggested-by: Andrew Cooper <Andrew.Cooper3@citrix.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Link: https://lore.kernel.org/r/20220308154317.815039833@infradead.org
Diffstat (limited to 'arch/x86/entry')
| -rw-r--r-- | arch/x86/entry/entry_64.S | 11 |
1 files changed, 8 insertions, 3 deletions
diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S index 22e4e9aafc34..f731393b5af4 100644 --- a/arch/x86/entry/entry_64.S +++ b/arch/x86/entry/entry_64.S @@ -609,7 +609,7 @@ SYM_INNER_LABEL(swapgs_restore_regs_and_return_to_usermode, SYM_L_GLOBAL) /* Restore RDI. */ popq %rdi swapgs - jmp native_iret + jmp .Lnative_iret SYM_INNER_LABEL(restore_regs_and_return_to_kernel, SYM_L_GLOBAL) @@ -626,9 +626,14 @@ SYM_INNER_LABEL(restore_regs_and_return_to_kernel, SYM_L_GLOBAL) * ARCH_HAS_MEMBARRIER_SYNC_CORE rely on IRET core serialization * when returning from IPI handler. */ - INTERRUPT_RETURN +#ifdef CONFIG_XEN_PV +SYM_INNER_LABEL(early_xen_iret_patch, SYM_L_GLOBAL) + ANNOTATE_NOENDBR + .byte 0xe9 + .long .Lnative_iret - (. + 4) +#endif -SYM_INNER_LABEL_ALIGN(native_iret, SYM_L_GLOBAL) +.Lnative_iret: UNWIND_HINT_IRET_REGS /* * Are we returning to a stack segment from the LDT? Note: in |