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authorThomas Gleixner <tglx@linutronix.de>2020-02-19 20:30:26 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2020-02-28 19:22:28 +0300
commit773dfd2223e30dcbc254e71b123a5b24d8adef7e (patch)
tree8919eee7a03085ea238d590c8f9bdb7fdc629c09 /drivers/xen
parent9724b3f28dabf0644018fcea3f2a46fedcb3d6b1 (diff)
downloadlinux-773dfd2223e30dcbc254e71b123a5b24d8adef7e.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>
Diffstat (limited to 'drivers/xen')
-rw-r--r--drivers/xen/preempt.c4
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);
}
}