Hi,
We are using Linux 2.6.22.19 in one of our custom board based on AT91SAM9260.Some times Linux crashes with the following error messages.

Starting kernel ...

Uncompressing Linux.............................................................
.............. done, booting the kernel.
INIT: version 2.86 booting
remounting / read-write... done.
mounting /proc... done.
mounting /sys... done.
creating device nodes... Eeek! page_mapcount(page) went negative! (-1)
page pfn = 21f3b
page->flags = 28
page->count = 1
page->mapping = c1cfba44
vma->vm_ops = 0xc0236d88
vma->vm_ops->nopage = filemap_nopage+0x0/0x334
vma->vm_file->f_op->mmap = generic_file_readonly_mmap+0x0/0x38
Unable to handle kernel NULL pointer dereference at virtual address 00000000
pgd = c0004000
[00000000] *pgd=00000000
Internal error: Oops: 817 [#1]
Modules linked in:
CPU: 0 Not tainted (2.6.22.19 #62)
PC is at page_remove_rmap+0xec/0x188
LR is at 0xc02321a0
pc : [] lr : [] psr: 60000013
sp : c1f5be64 ip : c02321a0 fp : c1f5be78
r10: 000be000 r9 : 21f3b101 r8 : 00014000
r7 : 00000000 r6 : c1e31a58 r5 : c1e31a58 r4 : c02b5760
r3 : 00000000 r2 : 00000001 r1 : 00000001 r0 : 00000044
Flags: nZCv IRQs on FIQs on Mode SVC_32 Segment user
Control: 0005317f Table: 21f24000 DAC: 00000015
Process makenodes-2.6 (pid: 187, stack limit = 0xc1f5a258)
Stack: (0xc1f5be64 to 0xc1f5c000)
be60: c02b5760 c1f3a850 c1f5bef0 c1f5be7c c00675b8 c006ea24 00015000
be80: c1f3a854 c03c8b10 00000000 fffffff9 c03c8ac0 000be000 c1f24000 c1f24000
bea0: 000be000 c1f24000 c0247488 00000001 00000000 00000001 ffffffff 00000000
bec0: c1f5bf00 003f8ffa c1f5bf00 00000000 c1e31a58 c03c8ac0 c02330d8 c1f5a000
bee0: 00000000 c1f5bf20 c1f5bef4 c006cb5c c00671e4 c1f5befc 00000000 00000000
bf00: c0247488 c03c8ac0 c03c8b20 c03ddce8 c03ddac0 c1f5bf38 c1f5bf24 c0033458
bf20: c006cb04 c03c8ac0 c03c8af4 c1f5bf58 c1f5bf3c c0037cb4 c0033414 c03ddcf8
bf40: c1e2aca0 c03ddac0 00000001 c1f5bf74 c1f5bf5c c0038278 c0037bf0 c1f395c0
bf60: c1f5bf78 00000719 c1f5bf94 c1f5bf78 c003892c c00380c4 00099b10 00099af0
bf80: 000c8880 000000f8 c1f5bfa4 c1f5bf98 c0038944 c00388b4 00000000 c1f5bfa8
bfa0: c0020dc0 c003893c 00099b10 00099af0 00000000 00000000 00000000 00000000
bfc0: 00099b10 00099af0 000c8880 00000000 00000000 000c5de4 beb6ae94 00000002
bfe0: 401965d0 beb6aa38 000875f0 401965fc 60000010 00000000 00000000 00000000
Backtrace:
[] (page_remove_rmap+0x0/0x188) from [] (unmap_vmas+0x3e4/0x
5d8)
r5:c1f3a850 r4:c02b5760
[] (unmap_vmas+0x0/0x5d8) from [] (exit_mmap+0x68/0x108)
[] (exit_mmap+0x0/0x108) from [] (mmput+0x54/0xec)
r7:c03ddac0 r6:c03ddce8 r5:c03c8b20 r4:c03c8ac0
[] (mmput+0x0/0xec) from [] (exit_mm+0xd4/0xd8)
r5:c03c8af4 r4:c03c8ac0
[] (exit_mm+0x0/0xd8) from [] (do_exit+0x1c4/0x7b8)
r7:00000001 r6:c03ddac0 r5:c1e2aca0 r4:c03ddcf8
[] (do_exit+0x0/0x7b8) from [] (sys_exit_group+0x0/0x1c)
[] (do_group_exit+0x0/0x88) from [] (sys_exit_group+0x18/0x1
c)
r7:000000f8 r6:000c8880 r5:00099af0 r4:00099b10
[] (sys_exit_group+0x0/0x1c) from [] (ret_fast_syscall+0x0/0
x2c)
Code: 1591102c 159f0094 1bff9ec9 e3a03000 (e5833000)
Fixing recursive fault but reboot is needed!

So what can be the problem?

Regards
Tomy