diff options
author | Milton Miller <miltonm@bga.com> | 2011-05-24 20:34:18 +0000 |
---|---|---|
committer | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2011-05-26 13:38:59 +1000 |
commit | 2e455257d143f54b44701e947a092d513889d01c (patch) | |
tree | 3ec9c640c1bce6b2ea78accc0b0b962f97595e0c /arch/powerpc | |
parent | 3d1b5e206a4f0ce46f2aa138590738c5d8e118ac (diff) | |
download | linux-2e455257d143f54b44701e947a092d513889d01c.tar.bz2 |
powerpc/irq: Check desc in handle_one_irq and expand generic_handle_irq
Look up the descriptor and check that it is found in handle_one_irq
before checking if we are on the irq stack, and call the handler
directly using the descriptor if we are on the stack.
We need check irq_to_desc finds the descriptor to avoid a NULL
pointer dereference. It could have failed because the number from
ppc_md.get_irq was above NR_IRQS, or various exceptional conditions
with sparse irqs (eg race conditions while freeing an irq if its was
not shutdown in the controller).
fe12bc2c99 (genirq: Uninline and sanity check generic_handle_irq())
moved generic_handle_irq out of line to allow its use by interrupt
controllers in modules. However, handle_one_irq is core arch code.
It already knows the details of struct irq_desc and handling irqs in
the nested irq case. This will avoid the extra stack frame to return
the value we don't check.
Signed-off-by: Milton Miller <miltonm@bga.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Diffstat (limited to 'arch/powerpc')
-rw-r--r-- | arch/powerpc/kernel/irq.c | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c index 0df255414836..ac4d29119f3e 100644 --- a/arch/powerpc/kernel/irq.c +++ b/arch/powerpc/kernel/irq.c @@ -295,17 +295,20 @@ static inline void handle_one_irq(unsigned int irq) unsigned long saved_sp_limit; struct irq_desc *desc; + desc = irq_to_desc(irq); + if (!desc) + return; + /* Switch to the irq stack to handle this */ curtp = current_thread_info(); irqtp = hardirq_ctx[smp_processor_id()]; if (curtp == irqtp) { /* We're already on the irq stack, just handle it */ - generic_handle_irq(irq); + desc->handle_irq(irq, desc); return; } - desc = irq_to_desc(irq); saved_sp_limit = current->thread.ksp_limit; irqtp->task = curtp->task; |