Re: 2.5.55-rmk1: user space lossage

From: David Woodhouse (
Date: Thu Jan 23 2003 - 04:48:23 EST

 < Snip long thread about init segfaulting immediately at boot on 2.5.55 > said:
> I just dropped jffs2 from 2.5.52 into 2.5.55 and it works, too. said:
> Aha! This is the problem:
> - .mmap = generic_file_mmap,
> + .mmap = generic_file_readonly_mmap,
> If you reverese this change, 2.5.55-rmk1 behaves.

Er, yes. generic_file_readonly_mmap() silently removed the VM_MAYWRITE bit
from vma->vm_flags when init made a _PRIVATE_ writable mapping, apparently
on the basis that we have no writepage().

Then we return success anyway.

Then init segfaults when it touches something in that mapping.

/me blames akpm. :)


- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to More majordomo info at Please read the FAQ at

This archive was generated by hypermail 2b29 : Thu Jan 23 2003 - 22:00:31 EST