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x86/entry: Make sync_regs() invocation a tail call

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No point in having a call there. Spare the call/ret overhead.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20220915111146.539578813@infradead.org
This commit is contained in:
Peter Zijlstra 2022-09-15 13:11:14 +02:00
parent 5a9c361a41
commit ef79ed20e3
1 changed files with 2 additions and 5 deletions
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7
arch/x86/entry/entry_64.S
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@ -1062,11 +1062,8 @@ SYM_CODE_START_LOCAL(error_entry)
UNTRAIN_RET
leaq 8(%rsp), %rdi /* arg0 = pt_regs pointer */
.Lerror_entry_from_usermode_after_swapgs:
/* Put us onto the real thread stack. */
call sync_regs
RET
jmp sync_regs
/*
* There are two places in the kernel that can potentially fault with
@ -1124,7 +1121,7 @@ SYM_CODE_START_LOCAL(error_entry)
leaq 8(%rsp), %rdi /* arg0 = pt_regs pointer */
call fixup_bad_iret
mov %rax, %rdi
jmp .Lerror_entry_from_usermode_after_swapgs
jmp sync_regs
SYM_CODE_END(error_entry)
SYM_CODE_START_LOCAL(error_return)