Bug 108291 – gentoo-sources /proc/cmdline limited to 256 chars

• Product: Gentoo Linux
• Status: RESOLVED UPSTREAM

[Description georg.lippold 2005-10-06 09:08:38 UTC]

When booting, the content of /proc/cmdline is truncated to 256 chars. Although
this is the vanilla kernel default, for LiveCD's a longer /proc/cmdline would be
helpful.

Reproducible: Always
Steps to Reproduce:
1. boot via syslinux >=3.09 and enter kernel boot options that take up more than
256 chars
2. after booting, execute 'cat /proc/cmdline | wc -c' and see that only 256
chars are left over

Actual Results:  
only 256 chars are transported via /proc/cmdline

Expected Results:  
It would be nice if more characters could be used. A patch for 512 chars is here:

http://syslinux.zytor.com/archives/2005-June/005313.html

The fix could easily included in genpatches. I will attach a patch for it.

[Comment 1 georg.lippold 2005-10-06 09:10:29 UTC]

Created attachment 69999 [details, diff]
Kernel patch suitable for genkernel

Kernel patch for /proc/cmdline with size limit of 512 bytes. Found at
http://syslinux.zytor.com/archives/2005-June/005313.html

[Comment 2 John Mylchreest (RETIRED) 2005-10-06 11:11:04 UTC]

Personally, I would prefer this to be resubmitted to LKML and applied to mainline.
This bug has come up a few times in the past, and although there is no
particular reason to not allocate more space, I would prefer to not have it as a
burden.

Thoughts?

[Comment 3 Daniel Drake (RETIRED) 2005-10-06 12:07:12 UTC]

Please get this accepted upstream first

[Comment 4 georg.lippold 2005-10-06 12:51:27 UTC]

Do you submit it on LKML or do I have to?

[Comment 5 Daniel Drake (RETIRED) 2005-10-06 13:11:28 UTC]

Please do so yourself. Make sure you read
/usr/src/linux/Documentation/SubmittingPatches first :)