On Wed, 2008-05-21 at 16:24 +1000, Stephen Rothwell wrote:
> 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 <[EMAIL PROTECTED]>
Acked-by: Benjamin Herrenschmidt <[EMAIL PROTECTED]>
> ---
> arch/powerpc/sysdev/mpic.c | 20 +++-----------------
> include/asm-powerpc/mpic.h | 3 +--
> 2 files changed, 4 insertions(+), 19 deletions(-)
>
> 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 @@ void mpic_irq_set_priority(unsigned int irq, unsigned
> int pri)
> 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 @@ void mpic_irq_set_priority(unsigned int irq, unsigned
> int pri)
> 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
> diff --git a/include/asm-powerpc/mpic.h b/include/asm-powerpc/mpic.h
> index 943c5a3..a4d0f87 100644
> --- a/include/asm-powerpc/mpic.h
> +++ b/include/asm-powerpc/mpic.h
> @@ -428,12 +428,11 @@ extern void mpic_init(struct mpic *mpic);
> */
>
>
> -/* Change/Read the priority of an interrupt. Default is 8 for irqs and
> +/* Change the priority of an interrupt. Default is 8 for irqs and
> * 10 for IPIs. You can call this on both IPIs and IRQ numbers, but the
> * IPI number is then the offset'ed (linux irq number mapped to the IPI)
> */
> extern void mpic_irq_set_priority(unsigned int irq, unsigned int pri);
> -extern unsigned int mpic_irq_get_priority(unsigned int irq);
>
> /* Setup a non-boot CPU */
> extern void mpic_setup_this_cpu(void);
> --
> 1.5.5.1
>
_______________________________________________
Linuxppc-dev mailing list
Linuxppc-dev@ozlabs.org
https://ozlabs.org/mailman/listinfo/linuxppc-dev
