| Message ID | 1474371259-18783-1-git-send-email-rrichter@cavium.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Tue, Sep 20, 2016 at 01:34:19PM +0200, Robert Richter wrote: > Booting a kernel with DEBUG_PER_CPU_MAPS enabled triggers the follwing > warning: > > WARNING: CPU: 1 PID: 0 at ./include/linux/cpumask.h:121 gic_raise_softirq+0x298/0x308 James posted a patch for this [1], which we were hoping Thomas would pick up [2]. Does that patch work for you? Thanks, Mark. [1] http://lists.infradead.org/pipermail/linux-arm-kernel/2016-September/458087.html [2] http://lists.infradead.org/pipermail/linux-arm-kernel/2016-September/458094.html > Reason for this is the code in for_each_cpu() that modifies cpu in > gic_compute_target_list() which may cause cpu set to nr_cpumask_bits > and cpumask_check() (cpumask_next() of for_each_cpu()) throwing the > warning. > > Change the code to avoid out-of-range access that stops the warning. > > Note: Though cpumask_check() fails, current for_each_cpu() > implementation is save to use cpu out of range. Also, code in > gic_raise_softirq() might be reworked at all in a way that a single > each-cpu loop is used by squashing it with gic_compute_target_list(). > > Signed-off-by: Robert Richter <rrichter@cavium.com> > --- > drivers/irqchip/irq-gic-v3.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/drivers/irqchip/irq-gic-v3.c b/drivers/irqchip/irq-gic-v3.c > index ede5672ab34d..ed46b906cf0a 100644 > --- a/drivers/irqchip/irq-gic-v3.c > +++ b/drivers/irqchip/irq-gic-v3.c > @@ -615,6 +615,8 @@ static void gic_raise_softirq(const struct cpumask *mask, unsigned int irq) > > tlist = gic_compute_target_list(&cpu, mask, cluster_id); > gic_send_sgi(cluster_id, tlist, irq); > + if (cpu >= nr_cpu_ids) > + break; > } > > /* Force the above writes to ICC_SGI1R_EL1 to be executed */ > -- > 2.7.0.rc3 >
On 20/09/16 12:39, Mark Rutland wrote: > On Tue, Sep 20, 2016 at 01:34:19PM +0200, Robert Richter wrote: >> Booting a kernel with DEBUG_PER_CPU_MAPS enabled triggers the follwing >> warning: >> >> WARNING: CPU: 1 PID: 0 at ./include/linux/cpumask.h:121 gic_raise_softirq+0x298/0x308 > > James posted a patch for this [1], which we were hoping Thomas would > pick up [2]. It is already in tip/irq/urgent (727653d). Thanks, M.
diff --git a/drivers/irqchip/irq-gic-v3.c b/drivers/irqchip/irq-gic-v3.c index ede5672ab34d..ed46b906cf0a 100644 --- a/drivers/irqchip/irq-gic-v3.c +++ b/drivers/irqchip/irq-gic-v3.c @@ -615,6 +615,8 @@ static void gic_raise_softirq(const struct cpumask *mask, unsigned int irq) tlist = gic_compute_target_list(&cpu, mask, cluster_id); gic_send_sgi(cluster_id, tlist, irq); + if (cpu >= nr_cpu_ids) + break; } /* Force the above writes to ICC_SGI1R_EL1 to be executed */
Booting a kernel with DEBUG_PER_CPU_MAPS enabled triggers the follwing warning: WARNING: CPU: 1 PID: 0 at ./include/linux/cpumask.h:121 gic_raise_softirq+0x298/0x308 Reason for this is the code in for_each_cpu() that modifies cpu in gic_compute_target_list() which may cause cpu set to nr_cpumask_bits and cpumask_check() (cpumask_next() of for_each_cpu()) throwing the warning. Change the code to avoid out-of-range access that stops the warning. Note: Though cpumask_check() fails, current for_each_cpu() implementation is save to use cpu out of range. Also, code in gic_raise_softirq() might be reworked at all in a way that a single each-cpu loop is used by squashing it with gic_compute_target_list(). Signed-off-by: Robert Richter <rrichter@cavium.com> --- drivers/irqchip/irq-gic-v3.c | 2 ++ 1 file changed, 2 insertions(+)