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| author | Thomas Gleixner <tglx@linutronix.de> | 2020-02-19 20:30:26 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-02-28 18:36:16 +0300 |
| commit | f02017e021758c6dc3da591cac78ed512813dbb1 (patch) | |
| tree | dffcf224039975a8e8f904a91ea58f3999f69e86 | |
| parent | 8b6934200c2469c0726a709f93ad108573550c80 (diff) | |
| download | linux-f02017e021758c6dc3da591cac78ed512813dbb1.tar.xz | |
xen: Enable interrupts when calling _cond_resched()
commit 8645e56a4ad6dcbf504872db7f14a2f67db88ef2 upstream.
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -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 08cb419eb4e6..5f6b77ea34fb 100644 --- a/drivers/xen/preempt.c +++ b/drivers/xen/preempt.c @@ -37,7 +37,9 @@ 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); } } |