[PATCH AUTOSEL 3.18 15/98] usb: musb: Fix a few off-by-one lengths

Sasha Levin
2018-10-25T14:17:30Z

From: Rasmus Villemoes <linux@rasmusvillemoes.dk>

[ Upstream commit e87c3f80ad0490d26ffe04754b7d094463b40f30 ]

!strncmp(buf, "force host", 9) is true if and only if buf starts with
"force hos". This was obviously not what was intended. The same error
exists for "force full-speed", "force high-speed" and "test
packet". Using strstarts avoids the error-prone hardcoding of the
prefix length.

For consistency, also change the other occurences of the !strncmp
idiom.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/usb/musb/musb_cppi41.c | 4 ++--
drivers/usb/musb/musb_debugfs.c | 16 ++++++++--------
2 files changed, 10 insertions(+), 10 deletions(-)

diff --git a/drivers/usb/musb/musb_cppi41.c b/drivers/usb/musb/musb_cppi41.c
index 2a535b70af21..3d69971156ea 100644
--- a/drivers/usb/musb/musb_cppi41.c
+++ b/drivers/usb/musb/musb_cppi41.c
@@ -629,9 +629,9 @@ static int cppi41_dma_controller_start(struct cppi41_dma_controller *controller)
ret = of_property_read_string_index(np, "dma-names", i, &str);
if (ret)
goto err;
- if (!strncmp(str, "tx", 2))
+ if (strstarts(str, "tx"))
is_tx = 1;
- else if (!strncmp(str, "rx", 2))
+ else if (strstarts(str, "rx"))
is_tx = 0;
else {
dev_err(dev, "Wrong dmatype %s\n", str);
diff --git a/drivers/usb/musb/musb_debugfs.c b/drivers/usb/musb/musb_debugfs.c
index 4c216790e86b..05d1b203f0d0 100644
--- a/drivers/usb/musb/musb_debugfs.c
+++ b/drivers/usb/musb/musb_debugfs.c
@@ -194,30 +194,30 @@ static ssize_t musb_test_mode_write(struct file *file,
if (copy_from_user(&buf, ubuf, min_t(size_t, sizeof(buf) - 1, count)))
return -EFAULT;

- if (!strncmp(buf, "force host", 9))
+ if (strstarts(buf, "force host"))
test = MUSB_TEST_FORCE_HOST;

- if (!strncmp(buf, "fifo access", 11))
+ if (strstarts(buf, "fifo access"))
test = MUSB_TEST_FIFO_ACCESS;

- if (!strncmp(buf, "force full-speed", 15))
+ if (strstarts(buf, "force full-speed"))
test = MUSB_TEST_FORCE_FS;

- if (!strncmp(buf, "force high-speed", 15))
+ if (strstarts(buf, "force high-speed"))
test = MUSB_TEST_FORCE_HS;

- if (!strncmp(buf, "test packet", 10)) {
+ if (strstarts(buf, "test packet")) {
test = MUSB_TEST_PACKET;
musb_load_testpacket(musb);
}

- if (!strncmp(buf, "test K", 6))
+ if (strstarts(buf, "test K"))
test = MUSB_TEST_K;

- if (!strncmp(buf, "test J", 6))
+ if (strstarts(buf, "test J"))
test = MUSB_TEST_J;

- if (!strncmp(buf, "test SE0 NAK", 12))
+ if (strstarts(buf, "test SE0 NAK"))
test = MUSB_TEST_SE0_NAK;

musb_writeb(musb->mregs, MUSB_TESTMODE, test);
--
2.17.1