[Xenomai-git] Gilles Chanteperdrix : nucleus/sched: Fix fallout of f6af9b831
Module: xenomai-head
Branch: master
Commit: 9eb58f13ef476130371cb1bed4248640b05dfad6
URL:
http://git.xenomai.org/?p=xenomai-head.git;a=commit;h=9eb58f13ef476130371cb1bed4248640b05dfad6
Author: Gilles Chanteperdrix gilles.chanteperd...@xenomai.org
Date: Fri Jan 7 23:44:29 2011 +0100
nucleus/sched: Fix fallout of f6af9b831
By re-enabling interrupts in the middle of xnpod_suspend_thread(), f6af9b831
allows an interrupt to happen when running __xnpod_schedule() as a result of
xnshadow_relax(), right between the time xnarch_escalate() is called, and the
time the interrupts are shut off (and the nklock locked).
When this happens, __xnpod_schedule() critical section is run while the current
Adeos domain is Linux, which is precisely what xnarch_escalate() was called to
avoid.
So, we simply shut interrupts off in xnpod_suspend_thread() right after
enabling them for the XNRELAX case, since this is the only place where this
issue may happen.
---
ksrc/nucleus/pod.c | 13 +
1 files changed, 13 insertions(+), 0 deletions(-)
diff --git a/ksrc/nucleus/pod.c b/ksrc/nucleus/pod.c
index 617c34d..d3a3122 100644
--- a/ksrc/nucleus/pod.c
+++ b/ksrc/nucleus/pod.c
@@ -1466,10 +1466,23 @@ void xnpod_suspend_thread(xnthread_t *thread, xnflags_t
mask,
* shortens the uninterruptible code path. This
* particular caller expects us to always return with
* interrupts enabled.
+*
+* We have to shut irqs off around xnpod_schedule()
+* though: if an interrupt could preempt us in
+* __xnpod_schedule right after the call to
+* xnarch_escalate but before we lock the nklock, we
+* would enter the critical section in xnpod_schedule
+* while the current Adeos domain is Linux, which
+* would defeat the purpose of having called
+* xnarch_escalate(). xnpod_schedule() is expected to
+* return with interrupts on.
*/
if (mask XNRELAX) {
xnlock_clear_irqon(nklock);
+
+ splhigh(s);
xnpod_schedule();
+ splexit(s);
return;
}
/*
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[Xenomai-git] Gilles Chanteperdrix : nucleus/sched: Fix fallout of f6af9b831
Module: xenomai-head
Branch: master
Commit: 867bb8e2a7bf51e1f2de33fadd55edefdfc02f51
URL:
http://git.xenomai.org/?p=xenomai-head.git;a=commit;h=867bb8e2a7bf51e1f2de33fadd55edefdfc02f51
Author: Gilles Chanteperdrix gilles.chanteperd...@xenomai.org
Date: Fri Jan 7 23:44:29 2011 +0100
nucleus/sched: Fix fallout of f6af9b831
By re-enabling interrupts in the middle of xnpod_suspend_thread(), f6af9b831
allows an interrupt to happen when running __xnpod_schedule() as a result of
xnshadow_relax(), right between the time xnarch_escalate() is called, and the
time the interrupts are shut off (and the nklock locked).
When this happens, __xnpod_schedule() critical section is run while the current
Adeos domain is Linux, which is precisely what xnarch_escalate() was called to
avoid.
So, we simply shut interrupts off in xnpod_suspend_thread() right after
enabling them for the XNRELAX case, since this is the only place where this
issue may happen.
---
ksrc/nucleus/pod.c | 13 +
1 files changed, 13 insertions(+), 0 deletions(-)
diff --git a/ksrc/nucleus/pod.c b/ksrc/nucleus/pod.c
index 4695fd8..ff21f73 100644
--- a/ksrc/nucleus/pod.c
+++ b/ksrc/nucleus/pod.c
@@ -1466,10 +1466,23 @@ void xnpod_suspend_thread(xnthread_t *thread, xnflags_t
mask,
* shortens the uninterruptible code path. This
* particular caller expects us to always return with
* interrupts enabled.
+*
+* We have to shut irqs off around xnpod_schedule()
+* though: if an interrupt could preempt us in
+* __xnpod_schedule right after the call to
+* xnarch_escalate but before we lock the nklock, we
+* would enter the critical section in xnpod_schedule
+* while the current Adeos domain is Linux, which
+* would defeat the purpose of having called
+* xnarch_escalate(). xnpod_schedule() is expected to
+* return with interrupts on.
*/
if (mask XNRELAX) {
xnlock_clear_irqon(nklock);
+
+ splhigh(s);
xnpod_schedule();
+ splexit(s);
return;
}
/*
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[Xenomai-git] Gilles Chanteperdrix : nucleus/sched: Fix fallout of f6af9b831
Module: xenomai-2.5
Branch: master
Commit: 9eb58f13ef476130371cb1bed4248640b05dfad6
URL:
http://git.xenomai.org/?p=xenomai-2.5.git;a=commit;h=9eb58f13ef476130371cb1bed4248640b05dfad6
Author: Gilles Chanteperdrix gilles.chanteperd...@xenomai.org
Date: Fri Jan 7 23:44:29 2011 +0100
nucleus/sched: Fix fallout of f6af9b831
By re-enabling interrupts in the middle of xnpod_suspend_thread(), f6af9b831
allows an interrupt to happen when running __xnpod_schedule() as a result of
xnshadow_relax(), right between the time xnarch_escalate() is called, and the
time the interrupts are shut off (and the nklock locked).
When this happens, __xnpod_schedule() critical section is run while the current
Adeos domain is Linux, which is precisely what xnarch_escalate() was called to
avoid.
So, we simply shut interrupts off in xnpod_suspend_thread() right after
enabling them for the XNRELAX case, since this is the only place where this
issue may happen.
---
ksrc/nucleus/pod.c | 13 +
1 files changed, 13 insertions(+), 0 deletions(-)
diff --git a/ksrc/nucleus/pod.c b/ksrc/nucleus/pod.c
index 617c34d..d3a3122 100644
--- a/ksrc/nucleus/pod.c
+++ b/ksrc/nucleus/pod.c
@@ -1466,10 +1466,23 @@ void xnpod_suspend_thread(xnthread_t *thread, xnflags_t
mask,
* shortens the uninterruptible code path. This
* particular caller expects us to always return with
* interrupts enabled.
+*
+* We have to shut irqs off around xnpod_schedule()
+* though: if an interrupt could preempt us in
+* __xnpod_schedule right after the call to
+* xnarch_escalate but before we lock the nklock, we
+* would enter the critical section in xnpod_schedule
+* while the current Adeos domain is Linux, which
+* would defeat the purpose of having called
+* xnarch_escalate(). xnpod_schedule() is expected to
+* return with interrupts on.
*/
if (mask XNRELAX) {
xnlock_clear_irqon(nklock);
+
+ splhigh(s);
xnpod_schedule();
+ splexit(s);
return;
}
/*
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