From: Dan Carpenter dan.carpenter@oracle.com
[ Upstream commit 926ee00ea24320052b46745ef4b00d91c05bd03d ]
The intent with this code was to return negative error codes but instead it returns positives.
The problem is how type promotion works with ternary operations. These functions return long, "ret" is an int and "copied" is a u32. The negative error code is first cast to u32 so it becomes a high positive and then cast to long where it's still a positive.
We could fix this by declaring "ret" as a ssize_t but let's just get rid of the ternaries instead.
Link: https://lkml.kernel.org/r/YIE+/cK1tBzSuQPU@mwanda Fixes: 5bf2b19320ec ("kfifo: add example files to the kernel sample directory") Signed-off-by: Dan Carpenter dan.carpenter@oracle.com Cc: Stefani Seibold stefani@seibold.net Signed-off-by: Andrew Morton akpm@linux-foundation.org Signed-off-by: Linus Torvalds torvalds@linux-foundation.org Signed-off-by: Sasha Levin sashal@kernel.org Signed-off-by: Yang Yingliang yangyingliang@huawei.com --- samples/kfifo/bytestream-example.c | 8 ++++++-- samples/kfifo/inttype-example.c | 8 ++++++-- samples/kfifo/record-example.c | 8 ++++++-- 3 files changed, 18 insertions(+), 6 deletions(-)
diff --git a/samples/kfifo/bytestream-example.c b/samples/kfifo/bytestream-example.c index 2fca916d9edfd..a7f5ee8b6edcf 100644 --- a/samples/kfifo/bytestream-example.c +++ b/samples/kfifo/bytestream-example.c @@ -124,8 +124,10 @@ static ssize_t fifo_write(struct file *file, const char __user *buf, ret = kfifo_from_user(&test, buf, count, &copied);
mutex_unlock(&write_lock); + if (ret) + return ret;
- return ret ? ret : copied; + return copied; }
static ssize_t fifo_read(struct file *file, char __user *buf, @@ -140,8 +142,10 @@ static ssize_t fifo_read(struct file *file, char __user *buf, ret = kfifo_to_user(&test, buf, count, &copied);
mutex_unlock(&read_lock); + if (ret) + return ret;
- return ret ? ret : copied; + return copied; }
static const struct file_operations fifo_fops = { diff --git a/samples/kfifo/inttype-example.c b/samples/kfifo/inttype-example.c index 8dc3c2e7105a0..a326a37e91631 100644 --- a/samples/kfifo/inttype-example.c +++ b/samples/kfifo/inttype-example.c @@ -117,8 +117,10 @@ static ssize_t fifo_write(struct file *file, const char __user *buf, ret = kfifo_from_user(&test, buf, count, &copied);
mutex_unlock(&write_lock); + if (ret) + return ret;
- return ret ? ret : copied; + return copied; }
static ssize_t fifo_read(struct file *file, char __user *buf, @@ -133,8 +135,10 @@ static ssize_t fifo_read(struct file *file, char __user *buf, ret = kfifo_to_user(&test, buf, count, &copied);
mutex_unlock(&read_lock); + if (ret) + return ret;
- return ret ? ret : copied; + return copied; }
static const struct file_operations fifo_fops = { diff --git a/samples/kfifo/record-example.c b/samples/kfifo/record-example.c index 2d7529eeb2940..deb87a2e4e6bc 100644 --- a/samples/kfifo/record-example.c +++ b/samples/kfifo/record-example.c @@ -131,8 +131,10 @@ static ssize_t fifo_write(struct file *file, const char __user *buf, ret = kfifo_from_user(&test, buf, count, &copied);
mutex_unlock(&write_lock); + if (ret) + return ret;
- return ret ? ret : copied; + return copied; }
static ssize_t fifo_read(struct file *file, char __user *buf, @@ -147,8 +149,10 @@ static ssize_t fifo_read(struct file *file, char __user *buf, ret = kfifo_to_user(&test, buf, count, &copied);
mutex_unlock(&read_lock); + if (ret) + return ret;
- return ret ? ret : copied; + return copied; }
static const struct file_operations fifo_fops = {