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| author |   Thomas Gleixner <tglx@linutronix.de> | 2020-02-19 18:30:26 +0100 |
|---|---|---|
| committer |   Boris Ostrovsky <boris.ostrovsky@oracle.com> | 2020-02-20 16:40:38 -0600 |
| commit | 8645e56a4ad6dcbf504872db7f14a2f67db88ef2 (patch) | |
| tree | b94527291919659a3aabfbe7082b040143b85579 /drivers | |
| parent | x86/xen: Distribute switch variables for initialization (diff) | |
| download | linux-dev-8645e56a4ad6dcbf504872db7f14a2f67db88ef2.tar.xz linux-dev-8645e56a4ad6dcbf504872db7f14a2f67db88ef2.zip | |
xen: Enable interrupts when calling _cond_resched()
xen_maybe_preempt_hcall() is called from the exception entry point
xen_do_hypervisor_callback with interrupts disabled.
_cond_resched() evades the might_sleep() check in cond_resched() which
would have caught that and schedule_debug() unfortunately lacks a check
for irqs_disabled().
Enable interrupts around the call and use cond_resched() to catch future
issues.
Fixes: fdfd811ddde3 ("x86/xen: allow privcmd hypercalls to be preempted")
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/878skypjrh.fsf@nanos.tec.linutronix.de
Reviewed-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/xen/preempt.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/drivers/xen/preempt.c b/drivers/xen/preempt.c index 8b9919c26095..456a164364a2 100644 --- a/drivers/xen/preempt.c +++ b/drivers/xen/preempt.c @@ -33,7 +33,9 @@ asmlinkage __visible void xen_maybe_preempt_hcall(void) * cpu. */ __this_cpu_write(xen_in_preemptible_hcall, false); - _cond_resched(); + local_irq_enable(); + cond_resched(); + local_irq_disable(); __this_cpu_write(xen_in_preemptible_hcall, true); } } |