On Sat, Jul 31, 2010 at 10:35:28PM +0200, Julia Lawall wrote: > From: Julia Lawall <julia@xxxxxxx> > > Adjust the default case so that it benefits from the call to rcu_read_unlock. > > The semantic match that finds this problem is as follows: > (http://coccinelle.lip6.fr/) > > // <smpl> > @rcu@ > position p1; > @@ > > rcu_read_lock@p1(); > ... > rcu_read_unlock(); > > @@ > position rcu.p1; > @@ > > *rcu_read_lock@p1(); > ... when != rcu_read_unlock(); > // </smpl> I don't claim to understand the SmPL above, but I do like the patch. Reviewed-by: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx> > Signed-off-by: Julia Lawall <julia@xxxxxxx> > > --- > drivers/acpi/atomicio.c | 10 ++++++---- > 1 files changed, 6 insertions(+), 4 deletions(-) > > diff --git a/drivers/acpi/atomicio.c b/drivers/acpi/atomicio.c > index 8f8bd73..f426010 100644 > --- a/drivers/acpi/atomicio.c > +++ b/drivers/acpi/atomicio.c > @@ -267,6 +267,7 @@ EXPORT_SYMBOL_GPL(acpi_post_unmap_gar); > static int acpi_atomic_read_mem(u64 paddr, u64 *val, u32 width) > { > void __iomem *addr; > + int res = 0; > > rcu_read_lock(); > addr = __acpi_ioremap_fast(paddr, width); > @@ -284,16 +285,17 @@ static int acpi_atomic_read_mem(u64 paddr, u64 *val, u32 width) > *val = readq(addr); > break; > default: > - return -EINVAL; > + res = -EINVAL; > } > rcu_read_unlock(); > > - return 0; > + return res; > } > > static int acpi_atomic_write_mem(u64 paddr, u64 val, u32 width) > { > void __iomem *addr; > + int res = 0; > > rcu_read_lock(); > addr = __acpi_ioremap_fast(paddr, width); > @@ -311,11 +313,11 @@ static int acpi_atomic_write_mem(u64 paddr, u64 val, u32 width) > writeq(val, addr); > break; > default: > - return -EINVAL; > + res = -EINVAL; > } > rcu_read_unlock(); > > - return 0; > + return res; > } > > /* GAR accessing in atomic (including NMI) or process context */ > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ -- To unsubscribe from this list: send the line "unsubscribe kernel-janitors" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
