diff options
| author | Dmitry Torokhov <dmitry.torokhov@gmail.com> | 2012-03-09 19:55:17 +0100 |
|---|---|---|
| committer | Dmitry Torokhov <dmitry.torokhov@gmail.com> | 2012-03-09 19:55:17 +0100 |
| commit | b675b3667f6729dcd1036a2a129b35445947f905 (patch) | |
| tree | 0d58791e9063d3ca2c352da6f3e7df2bdb876f9d /drivers/oprofile/oprofilefs.c | |
| parent | Input: max8925_onkey - avoid accessing input device too early (diff) | |
| parent | Linux 3.3-rc6 (diff) | |
| download | linux-b675b3667f6729dcd1036a2a129b35445947f905.tar.xz linux-b675b3667f6729dcd1036a2a129b35445947f905.zip | |
Merge commit 'v3.3-rc6' into next
Diffstat (limited to 'drivers/oprofile/oprofilefs.c')
| -rw-r--r-- | drivers/oprofile/oprofilefs.c | 11 |
1 files changed, 9 insertions, 2 deletions
diff --git a/drivers/oprofile/oprofilefs.c b/drivers/oprofile/oprofilefs.c index d0de6cc2d7a5..2f0aa0f700e6 100644 --- a/drivers/oprofile/oprofilefs.c +++ b/drivers/oprofile/oprofilefs.c @@ -60,6 +60,13 @@ ssize_t oprofilefs_ulong_to_user(unsigned long val, char __user *buf, size_t cou } +/* + * Note: If oprofilefs_ulong_from_user() returns 0, then *val remains + * unchanged and might be uninitialized. This follows write syscall + * implementation when count is zero: "If count is zero ... [and if] + * no errors are detected, 0 will be returned without causing any + * other effect." (man 2 write) + */ int oprofilefs_ulong_from_user(unsigned long *val, char const __user *buf, size_t count) { char tmpbuf[TMPBUFSIZE]; @@ -79,7 +86,7 @@ int oprofilefs_ulong_from_user(unsigned long *val, char const __user *buf, size_ raw_spin_lock_irqsave(&oprofilefs_lock, flags); *val = simple_strtoul(tmpbuf, NULL, 0); raw_spin_unlock_irqrestore(&oprofilefs_lock, flags); - return 0; + return count; } @@ -99,7 +106,7 @@ static ssize_t ulong_write_file(struct file *file, char const __user *buf, size_ return -EINVAL; retval = oprofilefs_ulong_from_user(&value, buf, count); - if (retval) + if (retval <= 0) return retval; retval = oprofile_set_ulong(file->private_data, value); |