[POWERPC] mpic: Fix use of uninitialized variable
Compiling ppc64_defconfig with gcc 4.3 gives thes warnings:
arch/powerpc/sysdev/mpic.c: In function 'mpic_irq_get_priority':
arch/powerpc/sysdev/mpic.c:1351: warning: 'is_ipi' may be used uninitialized in this function
arch/powerpc/sysdev/mpic.c: In function 'mpic_irq_set_priority':
arch/powerpc/sysdev/mpic.c:1328: warning: 'is_ipi' may be used uninitialized in this function
It turns out that in the cases where is_ipi is uninitialized, another
variable (mpic) will be NULL and it is dereferenced. Protect against
this by returning if mpic is NULL in mpic_irq_set_priority, and removing
mpic_irq_get_priority completely as it has no in tree callers.
This has the nice side effect of making the warning go away.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/arch/powerpc/sysdev/mpic.c b/arch/powerpc/sysdev/mpic.c
index 8619f2a..7680001 100644
--- a/arch/powerpc/sysdev/mpic.c
+++ b/arch/powerpc/sysdev/mpic.c
@@ -1331,6 +1331,9 @@
unsigned long flags;
u32 reg;
+ if (!mpic)
+ return;
+
spin_lock_irqsave(&mpic_lock, flags);
if (is_ipi) {
reg = mpic_ipi_read(src - mpic->ipi_vecs[0]) &
@@ -1346,23 +1349,6 @@
spin_unlock_irqrestore(&mpic_lock, flags);
}
-unsigned int mpic_irq_get_priority(unsigned int irq)
-{
- unsigned int is_ipi;
- struct mpic *mpic = mpic_find(irq, &is_ipi);
- unsigned int src = mpic_irq_to_hw(irq);
- unsigned long flags;
- u32 reg;
-
- spin_lock_irqsave(&mpic_lock, flags);
- if (is_ipi)
- reg = mpic_ipi_read(src = mpic->ipi_vecs[0]);
- else
- reg = mpic_irq_read(src, MPIC_INFO(IRQ_VECTOR_PRI));
- spin_unlock_irqrestore(&mpic_lock, flags);
- return (reg & MPIC_VECPRI_PRIORITY_MASK) >> MPIC_VECPRI_PRIORITY_SHIFT;
-}
-
void mpic_setup_this_cpu(void)
{
#ifdef CONFIG_SMP