From patchwork Tue Oct 30 10:09:46 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: sparc32, leon: Check for existent irq_map entry in leon_handle_ext_irq From: Andreas Larsson X-Patchwork-Id: 195384 Message-Id: <1351591786-21024-1-git-send-email-andreas@gaisler.com> To: davem@davemloft.net, sparclinux@vger.kernel.org Cc: software@gaisler.com, sam@ravnborg.org Date: Tue, 30 Oct 2012 11:09:46 +0100 If an irq is being unlinked concurrently with leon_handle_ext_irq, irq_map[eirq] might be null in leon_handle_ext_irq. Make sure that this is not dereferenced. Signed-off-by: Andreas Larsson Acked-by: Sam Ravnborg --- arch/sparc/kernel/leon_kernel.c | 6 ++++-- 1 files changed, 4 insertions(+), 2 deletions(-) diff --git a/arch/sparc/kernel/leon_kernel.c b/arch/sparc/kernel/leon_kernel.c index f8b6eee..87f60ee 100644 --- a/arch/sparc/kernel/leon_kernel.c +++ b/arch/sparc/kernel/leon_kernel.c @@ -56,11 +56,13 @@ static inline unsigned int leon_eirq_get(int cpu) static void leon_handle_ext_irq(unsigned int irq, struct irq_desc *desc) { unsigned int eirq; + struct irq_bucket *p; int cpu = sparc_leon3_cpuid(); eirq = leon_eirq_get(cpu); - if ((eirq & 0x10) && irq_map[eirq]->irq) /* bit4 tells if IRQ happened */ - generic_handle_irq(irq_map[eirq]->irq); + p = irq_map[eirq]; + if ((eirq & 0x10) && p && p->irq) /* bit4 tells if IRQ happened */ + generic_handle_irq(p->irq); } /* The extended IRQ controller has been found, this function registers it */