On Fri, Jan 28, 2022 at 7:43 PM Michael Jung wrote:
> specific ioctl command implementation
Creating a kernel thread in an ioctl "lower-half" would probably cause
the file descriptors from the calling task to get copied. Might this
be another case of
https://github.com/apache/incubator-nuttx/iss
I see. Thank you for the feedback. I will rework changes to get back
read permissions.
Best regards,
Petro
пт, 28 січ. 2022 р. о 14:41 Alan Carvalho de Assis пише:
>
> Hi Petro,
>
> The read permission is needed even when you just want to open a file:
>
> $ vim noreadfile
>
> $ chmod noread
Hi Petro,
The read permission is needed even when you just want to open a file:
$ vim noreadfile
$ chmod noreadfile
$ ls -l noreadfile
-- 1 user user 5 jan 28 09:24 noreadfile
$ cat noreadfile
cat: noreadfile: Permission denied
You can even try to create a C program just to open
On Fri, Jan 28, 2022 at 6:05 PM Petro Karashchenko <
petro.karashche...@gmail.com> wrote:
> Hello,
>
> Yes, but how does this relate to "" mode for "register_driver()"?
>
"" means no read/write/execute permission, I can't imagine any real
driver could benefit from it.
> Maybe you can de
In the kernel, you should call file_open(file_close...)
instead open(close...) to avoid the problem you described below.
On Fri, Jan 28, 2022 at 7:43 PM Michael Jung wrote:
> Hello everybody,
>
> I am developing a device driver, which is exposed as a character device
> (i.e. /dev/pcd) and which
Hello everybody,
I am developing a device driver, which is exposed as a character device
(i.e. /dev/pcd) and which mostly uses ioctl for device control. Within a
specific ioctl command implementation I am starting a new kernel thread via
kthread_create_with_stack. Once this thread's main functio
Hello,
Yes, but how does this relate to "" mode for "register_driver()"?
Maybe you can describe some use case so it will become more clear?
Currently ioctl works fine if driver is registered with "" permission mode.
Best regards,
Petro
пт, 28 січ. 2022 р. о 11:39 Xiang Xiao пише:
>
> If
If we want to do the correct permission check, the ioctl handler needs to
check R/W bit by itself based on how the ioctl is implemented.
Or follow up how Linux encode the needed permission into each IOCTL:
https://github.com/torvalds/linux/blob/master/include/uapi/asm-generic/ioctl.h#L85-L91
and le
Hello team,
Recently I have noticed that there are many places in code where
register_driver() is called with non-zero mode with file operation
structures that have neither read nor write APIs implemented. For
example "ret = register_driver(path, &opamp_fops, 0444, dev);" while
opamp_fops has only
