Messages in this thread | | | Date | Fri, 7 Nov 2008 14:46:51 +0000 | From | andy <> | Subject | Re: accessing file operations directly in the kernel |
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I agree with you! But there are cases where standards are followed from certain developers. I have to deal with a very "peculiar" arrangement of a set of requirements to access a serial device driver. The type of code below gives me what I need, I think.
filp = filp_open("/dev/device1", O_WRONLY, 0);
if (filp->f_op->ioctl(filp->f_dentry->d_inode, filp, CMD, (unsigned long) &args) != 0) { goto failed; }
Regards Andy
On 11/7/08, Robert Hancock <hancockr@shaw.ca> wrote: > andy wrote: > > > Hi, > > > > I am dealing with an interesting situation, which I have to access a > > serial device driver > > from the kernel space. I tried to use sys_open, sys_ioctl ... but > > there is a problem > > with the file descriptors. Now, I started using direct calls to the > > drivers functions > > driver_open, driver_ioctl... passing the *inode from user_path_walk(), > > but it doesn't > > seem that works right. This serial device is going to be used only > > from the other > > module that runs in the kernel. > > > > For some reason this kind of question (using file operations inside the > kernel) gets asked a lot. The short answer is that if you're asking it, you > likely have a wrong design. It's just not the right thing to do. For one > thing, file descriptors belong to a process, so just stealing the FD space > from some random process is unlikely to do the right thing. > > If you really need to do this, adding hooks to the serial device driver > would seem a more logical thing to do.. but even that seems a suspicious > design. It would be best if you explained what it is you're actually trying > to accomplish. >
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