diff options
Diffstat (limited to 'arch/x86_64/kernel/entry.S')
| -rw-r--r-- | arch/x86_64/kernel/entry.S | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/arch/x86_64/kernel/entry.S b/arch/x86_64/kernel/entry.S index 4fcc0ad8bbe..ea32688386f 100644 --- a/arch/x86_64/kernel/entry.S +++ b/arch/x86_64/kernel/entry.S @@ -519,7 +519,12 @@ END(stub_rt_sigreturn) testl $3,CS(%rdi) je 1f swapgs -1: incl %gs:pda_irqcount # RED-PEN should check preempt count + /* irqcount is used to check if a CPU is already on an interrupt + stack or not. While this is essentially redundant with preempt_count + it is a little cheaper to use a separate counter in the PDA + (short of moving irq_enter into assembly, which would be too + much work) */ +1: incl %gs:pda_irqcount cmoveq %gs:pda_irqstackptr,%rsp push %rbp # backlink for old unwinder /* |