[PATCH 4.9 096/218] powerpc/sysdev: fix incorrect use to determine if list is empty

From: Jakob Koschel jakobkoschel@gmail.com

[ Upstream commit fa1321b11bd01752f5be2415e74a0e1a7c378262 ]

'gtm' will *always* be set by list_for_each_entry(). It is incorrect to assume that the iterator value will be NULL if the list is empty.

Instead of checking the pointer it should be checked if the list is empty.

Fixes: 83ff9dcf375c ("powerpc/sysdev: implement FSL GTM support") Signed-off-by: Jakob Koschel jakobkoschel@gmail.com Signed-off-by: Michael Ellerman mpe@ellerman.id.au Link: https://lore.kernel.org/r/20220228142434.576226-1-jakobkoschel@gmail.com Signed-off-by: Sasha Levin sashal@kernel.org --- arch/powerpc/sysdev/fsl_gtm.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/sysdev/fsl_gtm.c b/arch/powerpc/sysdev/fsl_gtm.c index a6f0b96ce2c9..97dee7c99aa0 100644 --- a/arch/powerpc/sysdev/fsl_gtm.c +++ b/arch/powerpc/sysdev/fsl_gtm.c @@ -90,7 +90,7 @@ static LIST_HEAD(gtms); */ struct gtm_timer *gtm_get_timer16(void) { - struct gtm *gtm = NULL; + struct gtm *gtm; int i;

list_for_each_entry(gtm, &gtms, list_node) { @@ -107,7 +107,7 @@ struct gtm_timer *gtm_get_timer16(void) spin_unlock_irq(&gtm->lock); }

- if (gtm) + if (!list_empty(&gtms)) return ERR_PTR(-EBUSY); return ERR_PTR(-ENODEV); }