4.4-rc0: 5 W+X pages found

Pavel Machek
2015-11-15T07:00:27Z

Hi!

Kernel complains:

[ 5.256044] ------------[ cut here ]------------
[ 5.259267] WARNING: CPU: 0 PID: 1 at
arch/x86/mm/dump_pagetables.c:225 note_page+0x5ec/0x790()
[ 5.262668] x86/mm: Found insecure W+X mapping at address
ffe69000/0xffe69000
[ 5.267109] Modules linked in:
[ 5.271403] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.3.0+ #122
[ 5.275679] Hardware name: LENOVO 17097HU/17097HU, BIOS 7BETD8WW
(2.19 ) 03/31/2011
[ 5.279957] 00000000 00000000 f5cffeac c42b9f18 f5cffed8 f5cffec8
c404062b 000000e1
[ 5.284387] c403ca9c f5cfff50 00000163 00000000 f5cffee0 c4040686
00000009 f5cffed8
[ 5.288815] c4d268ac f5cffef4 f5cfff1c c403ca9c c4d1f494 000000e1
c4d268ac ffe69000
[ 5.293314] Call Trace:
[ 5.297602] [<c42b9f18>] dump_stack+0x41/0x59
[ 5.301864] [<c404062b>] warn_slowpath_common+0x6b/0xa0
[ 5.306054] [<c403ca9c>] ? note_page+0x5ec/0x790
[ 5.310209] [<c4040686>] warn_slowpath_fmt+0x26/0x30
[ 5.314358] [<c403ca9c>] note_page+0x5ec/0x790
[ 5.318440] [<c403cd8f>] ptdump_walk_pgd_level_core+0x14f/0x230
[ 5.322578] [<c403ce91>] ptdump_walk_pgd_level_checkwx+0x11/0x20
[ 5.326632] [<c4034ead>] mark_rodata_ro+0xcd/0xf0
[ 5.330625] [<c4a4aab7>] kernel_init+0x17/0xc0
[ 5.334585] [<c4a511c9>] ret_from_kernel_thread+0x21/0x38
[ 5.338585] [<c4a4aaa0>] ? rest_init+0xa0/0xa0
[ 5.342583] ---[ end trace bc9ac0874ad9a058 ]---
[ 5.346630] x86/mm: Checked W+X mappings: FAILED, 5 W+X pages
found.

...I'm not quite sure why it does backtrace, or how to debug this
one...

Pavel
--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html