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

From: Pavel Machek <pavel@ucw.cz>
To: Linus Torvalds <torvalds@linux-foundation.org>, rusty@rustcorp.com.au
Cc: Andy Lutomirski <luto@amacapital.net>,
	Arjan van de Ven <arjan@linux.intel.com>,
	Borislav Petkov <bp@alien8.de>,
	kernel list <linux-kernel@vger.kernel.org>,
	Stephen Smalley <sds@tycho.nsa.gov>,
	Brian Gerst <brgerst@gmail.com>,
	Denys Vlasenko <dvlasenk@redhat.com>, Peter Anvin <hpa@zytor.com>,
	Mike Galbraith <efault@gmx.de>,
	Peter Zijlstra <peterz@infradead.org>,
	Thomas Gleixner <tglx@linutronix.de>
Subject: 4.4.-rc5: lguest causes ugly warn on: 5 W+X pages found
Date: Tue, 15 Dec 2015 22:12:31 +0100	[thread overview]
Message-ID: <20151215211231.GA6752@amd> (raw)
In-Reply-To: <20151215205835.GA3522@amd>

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
-- 
(english) http://www.livejournal.com/~pavelmachek
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