From: buildroot@browserseal.com (Sasha Sirotkin)
To: linux-arm-kernel@lists.infradead.org
Subject: kernel virtual memory access (from app) does not generate segfault
Date: Tue, 20 Apr 2010 12:14:30 +0300 [thread overview]
Message-ID: <4BCD7076.9030802@browserseal.com> (raw)
More specifically, writing from usermode application to a kernel virtual
memory address on ARM does result in segmentation fault, however
calling a function in this memory region for some reason does not.
For instance, this code generates a segfault allright
int * aa;
aa = 0xc0000000;
*aa=42;
However this code does not, instead the process simply hangs (and can be
killed)
void (*func)(void);
func = 0xc0000000;
func();
I stumbled across this by accident. Just curious to understand why it
happens. Isn't it a bug ?
P.S. My kernel is 2.6.32.7 and the CPU is ARM926EJ-S rev 5 (v5l)
next reply other threads:[~2010-04-20 9:14 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-04-20 9:14 Sasha Sirotkin [this message]
2010-04-20 9:34 ` kernel virtual memory access (from app) does not generate segfault Ben Dooks
2010-04-20 10:27 ` Dave P. Martin
2010-04-20 14:20 ` anfei
2010-04-20 17:09 ` Ben Dooks
2010-04-20 19:28 ` Russell King - ARM Linux
2010-04-20 22:31 ` Jamie Lokier
2010-04-20 22:41 ` Russell King - ARM Linux
2010-04-21 0:33 ` Jamie Lokier
2010-04-21 11:17 ` kernel virtual memory access (from app) does not generatesegfault Dave P. Martin
2010-04-21 12:43 ` anfei
2010-04-21 16:07 ` Dave P. Martin
2010-04-21 19:16 ` Jamie Lokier
2010-04-21 19:40 ` Russell King - ARM Linux
2010-04-21 21:00 ` Jamie Lokier
2010-04-21 19:36 ` Russell King - ARM Linux
2010-04-21 19:35 ` Russell King - ARM Linux
2010-04-21 21:24 ` Nicolas Pitre
2010-04-21 21:44 ` Russell King - ARM Linux
2010-04-21 21:54 ` Russell King - ARM Linux
2010-04-21 22:59 ` Nicolas Pitre
2010-04-22 10:56 ` Dave P. Martin
2010-04-22 12:29 ` anfei
2010-04-22 13:18 ` Dave P. Martin
2010-04-22 15:59 ` Jamie Lokier
2010-04-21 13:11 ` kernel virtual memory access (from app) does not generate segfault anfei
2010-04-21 19:45 ` Jamie Lokier
2010-06-08 13:29 ` anfei
2010-06-08 13:36 ` Russell King - ARM Linux
2010-06-08 14:19 ` anfei
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