| From | Greg Kroah-Hartman <> | Subject | [PATCH 3.12 026/212] genirq: Set the irq thread policy without checking CAP_SYS_NICE | Date | Mon, 2 Dec 2013 11:13:37 -0800 |
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3.12-stable review patch. If anyone has any objections, please let me know.
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From: Thomas Pfaff <tpfaff@pcs.com>
commit bbfe65c219c638e19f1da5adab1005b2d68ca810 upstream.
In commit ee23871389 ("genirq: Set irq thread to RT priority on creation") we moved the assigment of the thread's priority from the thread's function into __setup_irq(). That function may run in user context for instance if the user opens an UART node and then driver calls requests in the ->open() callback. That user may not have CAP_SYS_NICE and so the irq thread won't run with the SCHED_OTHER policy.
This patch uses sched_setscheduler_nocheck() so we omit the CAP_SYS_NICE check which is otherwise required for the SCHED_OTHER policy.
[bigeasy: Rewrite the changelog]
Signed-off-by: Thomas Pfaff <tpfaff@pcs.com> Cc: Ivo Sieben <meltedpianoman@gmail.com> Link: http://lkml.kernel.org/r/1381489240-29626-1-git-send-email-bigeasy@linutronix.de Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- kernel/irq/manage.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/kernel/irq/manage.c +++ b/kernel/irq/manage.c @@ -956,7 +956,7 @@ __setup_irq(unsigned int irq, struct irq goto out_mput; } - sched_setscheduler(t, SCHED_FIFO, ¶m); + sched_setscheduler_nocheck(t, SCHED_FIFO, ¶m); /* * We keep the reference to the task struct even if
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