Ralf Baechle wrote:
On Thu, Oct 04, 2007 at 02:49:13PM +0200, Giuseppe Sacco wrote:
Hi, while testing the latest kernel on SGI O2 I got may kernel bugs like
this:
Kernel bug detected[#9]:
Cpu 0
$ 0 : 0000000000000000 ffffffff9001fce0 0000000000000001 0000000000000f18
$ 4 : 980000000111b4b8 000000007f955f18 ffffffff80400000 0000000000003fff
$ 8 : 00000000000050f1 000000007f955f18 9800000006073d68 9800000006073d60
$12 : 0000000000000010 ffffffff80000008 ffffffff80091680 0000000000000000
$16 : 980000000111b4b8 980000000768ddd0 000000000000000e 000000007f955f18
$20 : 9800000000581908 9800000007898080 9800000006073d68 9800000006073d60
$24 : 0000000000478284 000000002ac30580
$28 : 9800000006070000 9800000006073cd0 0000000000000000 ffffffff8001b390
Hi : 000000000000f2d3
Lo : 00000000000050f1
epc : ffffffff8001c800 kmap_coherent+0x10/0x118 Tainted: G D
ra : ffffffff8001b390 __flush_anon_page+0x70/0x90
Very interesting. Can you describe me your setup or maybe even come up
with a test case for this?
Perhaps: 'cat /proc/self/cmdline'
As we were hacking O_DIRECT support into 2.6.15, I found what seems like
a very similar situation.
It seems that all users of get_user_pages() *except*
/proc/*/[cmdline|environ] call get_user_pages() with addresses aligned
on page boundaries. I am not sure if that is the problem here, but it
seems similar.
David Daney.
