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Diffstat (limited to 'arch/powerpc/kernel/process.c')
-rw-r--r--arch/powerpc/kernel/process.c43
1 files changed, 30 insertions, 13 deletions
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index f3d4dd580dd..972b2acbe71 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -818,6 +818,35 @@ out:
return error;
}
+#ifdef CONFIG_IRQSTACKS
+static inline int valid_irq_stack(unsigned long sp, struct task_struct *p,
+ unsigned long nbytes)
+{
+ unsigned long stack_page;
+ unsigned long cpu = task_cpu(p);
+
+ /*
+ * Avoid crashing if the stack has overflowed and corrupted
+ * task_cpu(p), which is in the thread_info struct.
+ */
+ if (cpu < NR_CPUS && cpu_possible(cpu)) {
+ stack_page = (unsigned long) hardirq_ctx[cpu];
+ if (sp >= stack_page + sizeof(struct thread_struct)
+ && sp <= stack_page + THREAD_SIZE - nbytes)
+ return 1;
+
+ stack_page = (unsigned long) softirq_ctx[cpu];
+ if (sp >= stack_page + sizeof(struct thread_struct)
+ && sp <= stack_page + THREAD_SIZE - nbytes)
+ return 1;
+ }
+ return 0;
+}
+
+#else
+#define valid_irq_stack(sp, p, nb) 0
+#endif /* CONFIG_IRQSTACKS */
+
int validate_sp(unsigned long sp, struct task_struct *p,
unsigned long nbytes)
{
@@ -827,19 +856,7 @@ int validate_sp(unsigned long sp, struct task_struct *p,
&& sp <= stack_page + THREAD_SIZE - nbytes)
return 1;
-#ifdef CONFIG_IRQSTACKS
- stack_page = (unsigned long) hardirq_ctx[task_cpu(p)];
- if (sp >= stack_page + sizeof(struct thread_struct)
- && sp <= stack_page + THREAD_SIZE - nbytes)
- return 1;
-
- stack_page = (unsigned long) softirq_ctx[task_cpu(p)];
- if (sp >= stack_page + sizeof(struct thread_struct)
- && sp <= stack_page + THREAD_SIZE - nbytes)
- return 1;
-#endif
-
- return 0;
+ return valid_irq_stack(sp, p, nbytes);
}
#ifdef CONFIG_PPC64