[PATCH v2] media: cx18, ivtv: eliminate unnecessary array index checks

From: Nickolai Zeldovich
Date: Sun Jan 06 2013 - 20:52:24 EST


The idx values passed to cx18_i2c_register() and ivtv_i2c_register()
by cx18_init_subdevs() and ivtv_load_and_init_modules() respectively
are always in-range, based on how the hw_all bitmask is populated.
Previously, the checks were already ineffective because arrays were
being dereferenced using the index before the check.

Signed-off-by: Nickolai Zeldovich <nickolai@xxxxxxxxxxxxx>
---
Thanks to Andy Walls for suggesting that instead of moving the checks
before array dereference, a better fix is to remove the checks altogether,
since they are superfluous.

drivers/media/pci/cx18/cx18-i2c.c | 3 ---
drivers/media/pci/ivtv/ivtv-i2c.c | 2 --
2 files changed, 5 deletions(-)

diff --git a/drivers/media/pci/cx18/cx18-i2c.c b/drivers/media/pci/cx18/cx18-i2c.c
index 4908eb7..ccb1d15 100644
--- a/drivers/media/pci/cx18/cx18-i2c.c
+++ b/drivers/media/pci/cx18/cx18-i2c.c
@@ -116,9 +116,6 @@ int cx18_i2c_register(struct cx18 *cx, unsigned idx)
const char *type = hw_devicenames[idx];
u32 hw = 1 << idx;

- if (idx >= ARRAY_SIZE(hw_addrs))
- return -1;
-
if (hw == CX18_HW_TUNER) {
/* special tuner group handling */
sd = v4l2_i2c_new_subdev(&cx->v4l2_dev,
diff --git a/drivers/media/pci/ivtv/ivtv-i2c.c b/drivers/media/pci/ivtv/ivtv-i2c.c
index 46e262b..bc984af 100644
--- a/drivers/media/pci/ivtv/ivtv-i2c.c
+++ b/drivers/media/pci/ivtv/ivtv-i2c.c
@@ -267,8 +267,6 @@ int ivtv_i2c_register(struct ivtv *itv, unsigned idx)
const char *type = hw_devicenames[idx];
u32 hw = 1 << idx;

- if (idx >= ARRAY_SIZE(hw_addrs))
- return -1;
if (hw == IVTV_HW_TUNER) {
/* special tuner handling */
sd = v4l2_i2c_new_subdev(&itv->v4l2_dev, adap, type, 0,
--
1.7.10.4

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