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author | 2019-12-16 15:15:02 +0100 | |
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committer | 2020-01-03 15:46:36 +0100 | |
commit | c8ef1a6076bfb986052ff8fd8f5eb3b3a3f1048e (patch) | |
tree | 5b912870e6d0ecb137ecb25473d855709ca82c1f | |
parent | media: v4l2-core: compat: ignore native command codes (diff) | |
download | linux-c8ef1a6076bfb986052ff8fd8f5eb3b3a3f1048e.tar.gz linux-c8ef1a6076bfb986052ff8fd8f5eb3b3a3f1048e.tar.bz2 linux-c8ef1a6076bfb986052ff8fd8f5eb3b3a3f1048e.zip |
media: v4l2-core: split out data copy from video_usercopy
The copy-in/out portions of video_usercopy() are about to
get more complex, so turn then into separate functions as
a cleanup first.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
-rw-r--r-- | drivers/media/v4l2-core/v4l2-ioctl.c | 108 |
1 files changed, 69 insertions, 39 deletions
diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c index 282ffeef778f..1f22b1355778 100644 --- a/drivers/media/v4l2-core/v4l2-ioctl.c +++ b/drivers/media/v4l2-core/v4l2-ioctl.c @@ -3023,8 +3023,69 @@ static int check_array_args(unsigned int cmd, void *parg, size_t *array_size, return ret; } +static unsigned int video_translate_cmd(unsigned int cmd) +{ + return cmd; +} + +static int video_get_user(void __user *arg, void *parg, unsigned int cmd, + bool *always_copy) +{ + unsigned int n = _IOC_SIZE(cmd); + + if (!(_IOC_DIR(cmd) & _IOC_WRITE)) { + /* read-only ioctl */ + memset(parg, 0, n); + return 0; + } + + switch (cmd) { + default: + /* + * In some cases, only a few fields are used as input, + * i.e. when the app sets "index" and then the driver + * fills in the rest of the structure for the thing + * with that index. We only need to copy up the first + * non-input field. + */ + if (v4l2_is_known_ioctl(cmd)) { + u32 flags = v4l2_ioctls[_IOC_NR(cmd)].flags; + + if (flags & INFO_FL_CLEAR_MASK) + n = (flags & INFO_FL_CLEAR_MASK) >> 16; + *always_copy = flags & INFO_FL_ALWAYS_COPY; + } + + if (copy_from_user(parg, (void __user *)arg, n)) + return -EFAULT; + + /* zero out anything we don't copy from userspace */ + if (n < _IOC_SIZE(cmd)) + memset((u8 *)parg + n, 0, _IOC_SIZE(cmd) - n); + break; + } + + return 0; +} + +static int video_put_user(void __user *arg, void *parg, unsigned int cmd) +{ + if (!(_IOC_DIR(cmd) & _IOC_READ)) + return 0; + + switch (cmd) { + default: + /* Copy results into user buffer */ + if (copy_to_user(arg, parg, _IOC_SIZE(cmd))) + return -EFAULT; + break; + } + + return 0; +} + long -video_usercopy(struct file *file, unsigned int cmd, unsigned long arg, +video_usercopy(struct file *file, unsigned int orig_cmd, unsigned long arg, v4l2_kioctl func) { char sbuf[128]; @@ -3036,6 +3097,7 @@ video_usercopy(struct file *file, unsigned int cmd, unsigned long arg, size_t array_size = 0; void __user *user_ptr = NULL; void **kernel_ptr = NULL; + unsigned int cmd = video_translate_cmd(orig_cmd); const size_t ioc_size = _IOC_SIZE(cmd); /* Copy arguments into temp kernel buffer */ @@ -3050,37 +3112,12 @@ video_usercopy(struct file *file, unsigned int cmd, unsigned long arg, parg = mbuf; } - err = -EFAULT; - if (_IOC_DIR(cmd) & _IOC_WRITE) { - unsigned int n = ioc_size; - - /* - * In some cases, only a few fields are used as input, - * i.e. when the app sets "index" and then the driver - * fills in the rest of the structure for the thing - * with that index. We only need to copy up the first - * non-input field. - */ - if (v4l2_is_known_ioctl(cmd)) { - u32 flags = v4l2_ioctls[_IOC_NR(cmd)].flags; - - if (flags & INFO_FL_CLEAR_MASK) - n = (flags & INFO_FL_CLEAR_MASK) >> 16; - always_copy = flags & INFO_FL_ALWAYS_COPY; - } - - if (copy_from_user(parg, (void __user *)arg, n)) - goto out; - - /* zero out anything we don't copy from userspace */ - if (n < ioc_size) - memset((u8 *)parg + n, 0, ioc_size - n); - } else { - /* read-only ioctl */ - memset(parg, 0, ioc_size); - } } + err = video_get_user((void __user *)arg, parg, orig_cmd, &always_copy); + if (err) + goto out; + err = check_array_args(cmd, parg, &array_size, &user_ptr, &kernel_ptr); if (err < 0) goto out; @@ -3131,15 +3168,8 @@ video_usercopy(struct file *file, unsigned int cmd, unsigned long arg, goto out; out_array_args: - /* Copy results into user buffer */ - switch (_IOC_DIR(cmd)) { - case _IOC_READ: - case (_IOC_WRITE | _IOC_READ): - if (copy_to_user((void __user *)arg, parg, ioc_size)) - err = -EFAULT; - break; - } - + if (video_put_user((void __user *)arg, parg, orig_cmd)) + err = -EFAULT; out: kvfree(mbuf); return err; |