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| author | Andi Kleen <ak@suse.de> | 2005-07-28 21:15:49 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2005-07-28 21:46:02 -0700 |
| commit | ed6b676ca8b50e0b538e61c283d52fd04f007abf (patch) | |
| tree | 753ea613ce334c41f835f6aac21074b137d24713 | |
| parent | 3829ee6b1be03d5aa3005fe7d19f30088b539836 (diff) | |
| download | lwn-ed6b676ca8b50e0b538e61c283d52fd04f007abf.tar.gz lwn-ed6b676ca8b50e0b538e61c283d52fd04f007abf.zip | |
[PATCH] x86_64: Switch to the interrupt stack when running a softirq in local_bh_enable()
This avoids some potential stack overflows with very deep softirq callchains.
i386 does this too.
TOADD CFI annotation
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
| -rw-r--r-- | arch/x86_64/kernel/entry.S | 12 | ||||
| -rw-r--r-- | arch/x86_64/kernel/irq.c | 19 | ||||
| -rw-r--r-- | include/asm-x86_64/irq.h | 2 | ||||
| -rw-r--r-- | kernel/softirq.c | 4 |
4 files changed, 35 insertions, 2 deletions
diff --git a/arch/x86_64/kernel/entry.S b/arch/x86_64/kernel/entry.S index 0696e025dce5..096d470e280f 100644 --- a/arch/x86_64/kernel/entry.S +++ b/arch/x86_64/kernel/entry.S @@ -918,3 +918,15 @@ ENTRY(machine_check) ENTRY(call_debug) zeroentry do_call_debug +ENTRY(call_softirq) + movq %gs:pda_irqstackptr,%rax + pushq %r15 + movq %rsp,%r15 + incl %gs:pda_irqcount + cmove %rax,%rsp + call __do_softirq + movq %r15,%rsp + decl %gs:pda_irqcount + popq %r15 + ret + diff --git a/arch/x86_64/kernel/irq.c b/arch/x86_64/kernel/irq.c index cc3fb85f5145..849a20aec7ca 100644 --- a/arch/x86_64/kernel/irq.c +++ b/arch/x86_64/kernel/irq.c @@ -135,3 +135,22 @@ void fixup_irqs(cpumask_t map) local_irq_disable(); } #endif + +extern void call_softirq(void); + +asmlinkage void do_softirq(void) +{ + __u32 pending; + unsigned long flags; + + if (in_interrupt()) + return; + + local_irq_save(flags); + pending = local_softirq_pending(); + /* Switch to interrupt stack */ + if (pending) + call_softirq(); + local_irq_restore(flags); +} +EXPORT_SYMBOL(do_softirq); diff --git a/include/asm-x86_64/irq.h b/include/asm-x86_64/irq.h index eb3b7aa9eb9f..4482657777bb 100644 --- a/include/asm-x86_64/irq.h +++ b/include/asm-x86_64/irq.h @@ -57,4 +57,6 @@ int handle_IRQ_event(unsigned int, struct pt_regs *, struct irqaction *); extern void fixup_irqs(cpumask_t map); #endif +#define __ARCH_HAS_DO_SOFTIRQ 1 + #endif /* _ASM_IRQ_H */ diff --git a/kernel/softirq.c b/kernel/softirq.c index b4ab6af1dea8..31007d6542cc 100644 --- a/kernel/softirq.c +++ b/kernel/softirq.c @@ -86,7 +86,7 @@ restart: /* Reset the pending bitmask before enabling irqs */ local_softirq_pending() = 0; - local_irq_enable(); + //local_irq_enable(); h = softirq_vec; @@ -99,7 +99,7 @@ restart: pending >>= 1; } while (pending); - local_irq_disable(); + //local_irq_disable(); pending = local_softirq_pending(); if (pending && --max_restart) |