Crash (ext3 ) during 2.6.29-rc6 boot

[Geert Uytterhoeven]

On Mon, 23 Feb 2009, Paul Mackerras wrote:
> Andrew Morton writes:
> > It looks like we died in ext3_xattr_block_get():
> > 
> > 		memcpy(buffer, bh->b_data + le16_to_cpu(entry->e_value_offs),
> > 		       size);
> > 
> > Perhaps entry->e_value_offs is no good.  I wonder if the filesystem is
> > corrupted and this snuck through the defenses.
> > 
> > I also wonder if there is enough info in that trace for a ppc person to
> > be able to determine whether the faulting address is in the source or
> > destination of the memcpy() (please)?
> 
> It appears to have faulted on a load, implicating the source.  The
> address being referenced (0xc00000003f380000) doesn't look
> outlandish.  I wonder if this kernel has CONFIG_DEBUG_PAGEALLOC turned
> on, and what page size is selected?

I'm seeing a similar thing on PS3, but not in ext3. During early userspace
setup (udevd), it crashes accessing a 0xc00* address in:

| NIP setup+0x20/0x130
| LR copy_user_page+0x18/0x6c
| Call trace:
| do_wp_page+0x5b4/0x89c
| do_page_fault+0x3a8/0x58c
| handle_page_fault+0x20/0x5c

I have CONFIG_DEBUG_PAGEALLOC=y. If I disable it, the system boots fine.

If needed, I can probably bisect this tomorrow. It definitely didn't happen in
2.6.29-rc5.

With kind regards,

Geert Uytterhoeven
Software Architect

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