Another mmap / jffs2 problem (was RE: 2.5.59-rmk1: unmap_vmas: VMA list is not sorted correctly!)

[ch@murgatroid.com (Christopher Hoover)]

> I'm getting "unmap_vmas: VMA list is not sorted
> correctly!" with 2.5.59-rmk1 on a badgepad4 
> (SA-1110).  I take it that this is bad.  :-)

I tracked this down to the use of mmap within pppd
(ppp-2.4.1/pppd/tdb.c) on a file in jffs2.  That last part -*- the
mmap'ed file is in jffs2 -*- is key.

I don't always get the "VMA list is not sorted message", but pppd always
segfaults when it starts mucking with the mmap'ed file data.

If I place the file in /tmp, which is a ramfs file system in my setup,
pppd behaves.

Here's the segfault:

pppd-with-mmap: unhandled page fault at 0x000001e3, code 0xc334f007
pgd = c334c000
[000001e3] *pgd=c238b011, *pte=00000000, *ppte=00000000
pc : [<40057f7c>]    lr : [<00026ad4>]    Not tainted
sp : befffd14  ip : befffd28  fp : 00000000
r10: 933f4b6e  r9 : 00000007  r8 : 000438c8
r7 : befffd28  r6 : 0004df80  r5 : 00000004  r4 : 000001e4
r3 : ffffffff  r2 : 00000004  r1 : 000001e3  r0 : befffd28
Flags: nzCv  IRQs on  FIQs on  Mode USER_32  Segment user
Control: C334F17F  Table: C334F17F  DAC: 00000015



Details: 2.5.59-rmk1, uClibc-0.9.19, ppp-2.4.1, gcc-3.2.2

-ch
mailto:ch-at-murgatroid.com