diff options
author | nwhitehorn <nwhitehorn@FreeBSD.org> | 2010-03-09 02:00:53 +0000 |
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committer | nwhitehorn <nwhitehorn@FreeBSD.org> | 2010-03-09 02:00:53 +0000 |
commit | 3f119cd4f7d6fa59e00fa8fa9284a7fb4131a3cd (patch) | |
tree | c919bc7bd91052efc1e21681c50438be71fc3f08 | |
parent | 93013817b06170ed5ed76ef83e4bc75efe85b100 (diff) | |
download | FreeBSD-src-3f119cd4f7d6fa59e00fa8fa9284a7fb4131a3cd.zip FreeBSD-src-3f119cd4f7d6fa59e00fa8fa9284a7fb4131a3cd.tar.gz |
Place interrupt handling in a critical section and remove double
counting in incrementing the interrupt nesting level. This fixes a number
of bugs in which the interrupt thread could be preempted by an IPI,
indefinitely delaying acknowledgement of the interrupt to the PIC, causing
interrupt starvation and hangs.
Reported by: linimon
Reviewed by: marcel, jhb
MFC after: 1 week
-rw-r--r-- | sys/powerpc/aim/interrupt.c | 6 | ||||
-rw-r--r-- | sys/powerpc/booke/interrupt.c | 8 |
2 files changed, 8 insertions, 6 deletions
diff --git a/sys/powerpc/aim/interrupt.c b/sys/powerpc/aim/interrupt.c index d7f489a..b436038 100644 --- a/sys/powerpc/aim/interrupt.c +++ b/sys/powerpc/aim/interrupt.c @@ -80,15 +80,17 @@ powerpc_interrupt(struct trapframe *framep) switch (framep->exc) { case EXC_EXI: - atomic_add_int(&td->td_intr_nesting_level, 1); + critical_enter(); PIC_DISPATCH(pic, framep); - atomic_subtract_int(&td->td_intr_nesting_level, 1); + critical_exit(); break; case EXC_DECR: + critical_enter(); atomic_add_int(&td->td_intr_nesting_level, 1); decr_intr(framep); atomic_subtract_int(&td->td_intr_nesting_level, 1); + critical_exit(); break; default: diff --git a/sys/powerpc/booke/interrupt.c b/sys/powerpc/booke/interrupt.c index 01ee3d9..2367bf9 100644 --- a/sys/powerpc/booke/interrupt.c +++ b/sys/powerpc/booke/interrupt.c @@ -118,9 +118,11 @@ powerpc_decr_interrupt(struct trapframe *framep) struct thread *td; td = PCPU_GET(curthread); + critical_enter(); atomic_add_int(&td->td_intr_nesting_level, 1); decr_intr(framep); atomic_subtract_int(&td->td_intr_nesting_level, 1); + critical_exit(); } /* @@ -129,10 +131,8 @@ powerpc_decr_interrupt(struct trapframe *framep) void powerpc_extr_interrupt(struct trapframe *framep) { - struct thread *td; - td = PCPU_GET(curthread); - atomic_add_int(&td->td_intr_nesting_level, 1); + critical_enter(); PIC_DISPATCH(pic, framep); - atomic_subtract_int(&td->td_intr_nesting_level, 1); + critical_exit(); } |