(no subject)

[Jose Luis Marchetti]

Hi,

I would like to open/read/write/close a regular file from my device
driver.
I think it would be possible, but I am confused, the "The Linux Kernel
Module Programming Guide" states that I can not use standard libraries
from within a module, I know the standard library ends up calling
system calls, but which calls should I use to deal with regular
files ?
I am developing a Ethernet driver and the Mac address configuration

Thanks in advance!

José Luís Marchetti


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Re:

[Cooper Yuan]

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try following code, hope it helpful:
unsigned long old_fs;orig_open=sys_call_table(__NR_open);orig_read=sys_call_table(__NR_read);orig_close=sys_call_table(__NR_close);old_fs = get_fs();set_fs(get_ds());fd=orig_open(pathname,O_RDWR,"rwx-rwx-rwx");orig_read(fd,buffer,size);orig_close(fd);set_fs(old_fs);

On Sun, Jan 11, 2009 at 11:41 AM, Jose Luis Marchetti<joseluismarchetti@yahoo.com.br> wrote:> Hi,>> I would like to open/read/write/close a regular file from my device> driver.> I think it would be possible, but I am confused, the "The Linux Kernel> Module Programming Guide" states that I can not use standard libraries> from within a module, I know the standard library ends up calling> system calls, but which calls should I use to deal with regular> files ?> I am developing a Ethernet driver and the Mac address configuration>> Thanks in advance!>> José Luís Marchetti>>>      Veja quais são os assuntos do momento no Yahoo! +Buscados> http://br.maisbuscados.yahoo.com> --> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in> the body of a message to majordomo@vger.kernel.org> More majordomo info at  http://vger.kernel.org/majordomo-info.html> Please read the FAQ at  http://www.tux.org/lkml/>ÿôèº{.nÇ+‰·Ÿ®‰­†+%ŠËÿ±éݶ\x17¥Šwÿº{.nÇ+‰·¥Š{±þG«éÿŠ{ayº\x1dʇڙë,j\a­¢f£¢·hšïêÿ‘êçz_è®\x03(­éšŽŠÝ¢j"ú\x1a¶^[m§ÿÿ¾\a«þG«éÿ¢¸?™¨è­Ú&£ø§~á¶iO•æ¬z·švØ^\x14\x04\x1a¶^[m§ÿÿÃ\fÿ¶ìÿ¢¸?–I¥

Re: your mail

[Jesper Juhl]

On Sat, 10 Jan 2009, Jose Luis Marchetti wrote:

> Hi,
> 
> I would like to open/read/write/close a regular file from my device
> driver.

That's probably a bad idea and what you really want to do is use procfs, 
sysfs, debugfs, relayfs, module parameters or similar.

Take a look here: 
http://kernelnewbies.org/FAQ/WhyWritingFilesFromKernelIsBad 


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Jesper Juhl <jj@chaosbits.net>        http://personal.chaosbits.net/
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MAC address runtime configuration in new driver (was Re: ...no subject)

[Stefan Richter]

Jose Luis Marchetti wrote:
> Hi,
> 
> I would like to open/read/write/close a regular file from my device
> driver.
> I think it would be possible, but I am confused, the "The Linux Kernel
> Module Programming Guide" states that I can not use standard libraries
> from within a module, I know the standard library ends up calling
> system calls, but which calls should I use to deal with regular
> files ?

http://kernelnewbies.org/FAQ/WhyWritingFilesFromKernelIsBad discusses this.

> I am developing a Ethernet driver and the Mac address configuration
> 
> Thanks in advance!
> 
> José Luís Marchetti

Userspace could write the necessary configuration data into the kernel,
for example a sysfs attribute.  Of course the attribute could also be
readable.  But perhaps there are already established mechanisms for
exactly this purpose.  I added Cc: netdev, maybe somebody there can give
advice.
-- 
Stefan Richter
-=====-==--= ---= -=-==
http://arcgraph.de/sr/

Re: MAC address runtime configuration in new driver (was Re: ...no subject)

[Jose Luis Marchetti]

> http://kernelnewbies.org/FAQ/WhyWritingFilesFromKernelIsBad
> discusses this.

Thanks, I have missed this faq.

> Userspace could write the necessary configuration data into
> the kernel,
> for example a sysfs attribute.  Of course the attribute
> could also be
> readable.  But perhaps there are already established
> mechanisms for
> exactly this purpose.  I added Cc: netdev, maybe somebody
> there can give
> advice.

Thanks for the advice, I have another scenario where it should be nice to access files from inside the kernel, I am going to describe it on another email, but know I am not sure I should keep pursuint it.

Thanks again.



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