4.4.-rc5: lguest causes ugly warn on: 5 W+X pages found

Pavel Machek
2015-12-15T21:12:36Z

Hi!

> > or similar?
> >
> > The above is entirely untested. Maybe it doesn't compile. Or
> > boot. Or work.
>
> Well, with two extra spaces at each line, it does not apply :-).
>
> I applied it by hand, and the output is:
>
> [ 0.000000] MTRR variable ranges enabled:
...> [ 0.000000] BRK [0x0566c000, 0x0566cfff] PGTABLE
>
> I'll take a look if I can figure out what it means...

Wait, there's more in the log.

[ 1.952146] Bluetooth: HCI UART protocol H4 registered
[ 1.954335] Bluetooth: HCI UART protocol BCSP registered
[ 1.956750] usbcore: registered new interface driver btusb
[ 1.958953] ------------[ cut here ]------------
[ 1.961149] WARNING: CPU: 1 PID: 1 at
./arch/x86/include/asm/pgtable.h:357
vmap_page_range_noflush+0x1f0/0x280()
[ 1.963511] Modules linked in:
[ 1.965849] CPU: 1 PID: 1 Comm: swapper/0 Tainted: G W
4.4.0-rc5+ #137
[ 1.968230] Hardware name: LENOVO 17097HU/17097HU, BIOS 7BETD8WW
(2.19 ) 03/31/2011
[ 1.970593] 00000001 00000000 f5cffe64 c42baaf8 00000000 f5cffe80
c404066b 00000165
[ 1.973103] c40fbe70 00000163 00000000 00000000 f5cffe90 c404070f
00000009 00000000
[ 1.975670] f5cffee0 c40fbe70 c4f88348 00000000 ffe6dfff ffe6e000
c4f8a018 ffe6dfff
[ 1.978304] Call Trace:
[ 1.980882] [<c42baaf8>] dump_stack+0x41/0x59
[ 1.983464] [<c404066b>] warn_slowpath_common+0x6b/0xa0
[ 1.986053] [<c40fbe70>] ? vmap_page_range_noflush+0x1f0/0x280
[ 1.988625] [<c404070f>] warn_slowpath_null+0xf/0x20
[ 1.991154] [<c40fbe70>] vmap_page_range_noflush+0x1f0/0x280
[ 1.993676] [<c40fbf2b>] map_vm_area+0x2b/0x40
[ 1.996153] [<c4f2c795>] init+0xf8/0x1a4
[ 1.998591] [<c4f2c69d>] ? edac_init+0x67/0x67
[ 2.001014] [<c4000442>] do_one_initcall+0xc2/0x1c0
[ 2.003391] [<c4f044e3>] ? initcall_blacklist+0x97/0x97
[ 2.005815] [<c4f044e3>] ? initcall_blacklist+0x97/0x97
[ 2.008161] [<c4051546>] ?
__usermodehelper_set_disable_depth+0x36/0x40
[ 2.010518] [<c407d4a6>] ? up_write+0x16/0x40
[ 2.012817] [<c4f04ba3>] kernel_init_freeable+0xf0/0x16d
[ 2.015078] [<c4f04ba3>] ? kernel_init_freeable+0xf0/0x16d
[ 2.017386] [<c4a4d9c8>] kernel_init+0x8/0xc0
[ 2.019661] [<c4a54149>] ret_from_kernel_thread+0x21/0x38
[ 2.021932] [<c4a4d9c0>] ? rest_init+0xa0/0xa0
[ 2.024168] ---[ end trace e117245cd61feaf2 ]---
[ 2.026383] lguest: mapped switcher at ffe69000
[ 2.028958] sdhci: Secure Digital Host Controller Interface driver

...which I don't understand; did not we say warn on _once_?
... Um. But I think we have a winner: "lguest: mapped switcher at
ffe69000".

Rusty, does the switcher need to be W+X?

And yes, I have lguest enabled, not sure why.

Pavel
--
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