This doesn't affect the kernel but the userspace utilities from http://www.kernel.org/pub/linux/kernel/people/horms/kexec-tools/ Since 2.6.21 the maximum length of the kernel command line is 2048 for x86 and x86_64 but the kexec-tools still assume it's 256 therefore a command line longer than 256 chars is truncated upon kexec-reboot. Steps to reproduce: - Boot kernel with a command line longer than 256 chars - cat /proc/cmdline | wc -c - kexec-reboot - cat /proc/cmdline | wc -c
Created attachment 14194 [details] kexec-tools-command_line_size.patch minimalistic patch
See my patch http://www.mail-archive.com/fastboot@lists.osdl.org/msg03054.html. The problem was that reading out the symbol table is not a very clean way to get the command line size of the kernel. I think we should still make sure that new kexec runs with old kernels properly. However, since the command line size is now in the x86 boot protocol and we must currently use bzImage to load the relocatable kernels anyway, it may be a good start to detect the command line size for bzImage and allow larger values for that. I can make a patch for this, but in the next year.
Can we move this discussion over to kexec@lists.infradead.org?
Can you please update the bugzilla with the highlights, and the conclusion of the discussion. Thanks.
http://lists.infradead.org/pipermail/kexec/2008-January/001214.html You can read the whole thread there
Thanks to Neil Horman the fix for this was included in kexec-tools-testing v20080227 http://www.kernel.org/pub/linux/kernel/people/horms/kexec-tools/ For refrence, the relevant commit is b5c2ed5e02cfe862eded56be7f6c1106e84e6e6c in the horms/kexec-tools-testing tree on git.kernel.org. http://git.kernel.org/?p=linux/kernel/git/horms/kexec-tools-testing.git;a=commit;h=b5c2ed5e02cfe862eded56be7f6c1106e84e6e6c Neil, I think that we can close this bug now.
Copy that, closing