* hwclock --compare segfaults when run as normal user
@ 2014-07-26 12:40 Benno Schulenberg
2014-07-26 14:48 ` Sami Kerola
0 siblings, 1 reply; 6+ messages in thread
From: Benno Schulenberg @ 2014-07-26 12:40 UTC (permalink / raw)
To: Util-Linux; +Cc: Ondrej Oprala
Hi,
On my system there is no /etc/adjtime file, and then:
$ ./hwclock --compare
Segmentation fault
When run as root, it runs fine.
$ ./hwclock --version
hwclock from util-linux 2.25
Benno
--
http://www.fastmail.fm - mmm... Fastmail...
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: hwclock --compare segfaults when run as normal user
2014-07-26 12:40 hwclock --compare segfaults when run as normal user Benno Schulenberg
@ 2014-07-26 14:48 ` Sami Kerola
2014-07-26 16:05 ` Benno Schulenberg
0 siblings, 1 reply; 6+ messages in thread
From: Sami Kerola @ 2014-07-26 14:48 UTC (permalink / raw)
To: Benno Schulenberg; +Cc: Util-Linux, Ondrej Oprala
On 26 July 2014 13:40, Benno Schulenberg <bensberg@justemail.net> wrote:
> On my system there is no /etc/adjtime file, and then:
>
> $ ./hwclock --compare
> Segmentation fault
>
> When run as root, it runs fine.
>
>
> $ ./hwclock --version
> hwclock from util-linux 2.25
Hi Benno,
I tried to reproduce the issue without success. If you have core file
could you try to gdb backtrace it?
--
Sami Kerola
http://www.iki.fi/kerolasa/
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: hwclock --compare segfaults when run as normal user
2014-07-26 14:48 ` Sami Kerola
@ 2014-07-26 16:05 ` Benno Schulenberg
2014-07-28 11:12 ` Karel Zak
0 siblings, 1 reply; 6+ messages in thread
From: Benno Schulenberg @ 2014-07-26 16:05 UTC (permalink / raw)
To: kerolasa; +Cc: Util-Linux, Ondrej Oprala
On Sat, Jul 26, 2014, at 16:48, Sami Kerola wrote:
> On 26 July 2014 13:40, Benno Schulenberg <bensberg@justemail.net> wrote:
> > On my system there is no /etc/adjtime file, and then:
> >
> > $ ./hwclock --compare
> > Segmentation fault
>
> I tried to reproduce the issue without success. If you have core file
> could you try to gdb backtrace it?
(gdb) run --compare
Starting program: /home/ben/util-linux-2.25/hwclock --compare
Program received signal SIGSEGV, Segmentation fault.
0x0804cf71 in outb () at /usr/include/sys/io.h:99
99 __asm__ __volatile__ ("outb %b0,%w1": :"a" (__value), "Nd" (__port));
(gdb) bt
#0 0x0804cf71 in outb () at /usr/include/sys/io.h:99
#1 cmos_read () at sys-utils/hwclock-cmos.c:348
#2 atomic () at sys-utils/hwclock-cmos.c:307
#3 hclock_read () at sys-utils/hwclock-cmos.c:456
#4 cmos_clock_busy () at sys-utils/hwclock-cmos.c:472
#5 synchronize_to_clock_tick_cmos () at sys-utils/hwclock-cmos.c:484
#6 0x08049919 in synchronize_to_clock_tick () at sys-utils/hwclock.c:348
#7 0x0804c578 in compare_clock (argc=<value optimized out>, argv=0xbffff414) at sys-utils/hwclock.c:1502
#8 main (argc=<value optimized out>, argv=0xbffff414) at sys-utils/hwclock.c:1941
Benno
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^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: hwclock --compare segfaults when run as normal user
2014-07-26 16:05 ` Benno Schulenberg
@ 2014-07-28 11:12 ` Karel Zak
2014-07-28 18:50 ` Benno Schulenberg
0 siblings, 1 reply; 6+ messages in thread
From: Karel Zak @ 2014-07-28 11:12 UTC (permalink / raw)
To: Benno Schulenberg; +Cc: kerolasa, Util-Linux
On Sat, Jul 26, 2014 at 06:05:09PM +0200, Benno Schulenberg wrote:
>
> On Sat, Jul 26, 2014, at 16:48, Sami Kerola wrote:
> > On 26 July 2014 13:40, Benno Schulenberg <bensberg@justemail.net> wrote:
> > > On my system there is no /etc/adjtime file, and then:
> > >
> > > $ ./hwclock --compare
> > > Segmentation fault
> >
> > I tried to reproduce the issue without success. If you have core file
because you have RTC and Benno has cmos I guess
> > could you try to gdb backtrace it?
>
> (gdb) run --compare
> Starting program: /home/ben/util-linux-2.25/hwclock --compare
>
> Program received signal SIGSEGV, Segmentation fault.
> 0x0804cf71 in outb () at /usr/include/sys/io.h:99
> 99 __asm__ __volatile__ ("outb %b0,%w1": :"a" (__value), "Nd" (__port));
>
> (gdb) bt
> #0 0x0804cf71 in outb () at /usr/include/sys/io.h:99
> #1 cmos_read () at sys-utils/hwclock-cmos.c:348
> #2 atomic () at sys-utils/hwclock-cmos.c:307
> #3 hclock_read () at sys-utils/hwclock-cmos.c:456
I have no way how to to test it, but can you try the patch below?
Karel
>From 8fe55779b04e961d9e99bba7e1df382b71b63095 Mon Sep 17 00:00:00 2001
From: Karel Zak <kzak@redhat.com>
Date: Mon, 28 Jul 2014 13:00:54 +0200
Subject: [PATCH] hwclock: check for permissions before use clock interface
Reported-by: Benno Schulenberg <bensberg@justemail.net>
Signed-off-by: Karel Zak <kzak@redhat.com>
---
sys-utils/hwclock.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/sys-utils/hwclock.c b/sys-utils/hwclock.c
index a934ace..474e04f 100644
--- a/sys-utils/hwclock.c
+++ b/sys-utils/hwclock.c
@@ -1495,6 +1495,9 @@ static int compare_clock (const bool utc, const bool local_opt)
bool hclock_valid = FALSE, universal, first_pass = TRUE;
int rc;
+ if (ur->get_permissions())
+ return EX_NOPERM;
+
/* dummy call for increased precision */
gettimeofday(&tv, NULL);
@@ -1893,7 +1896,7 @@ int main(int argc, char **argv)
}
if (!(show | set | systohc | hctosys | systz | adjust | getepoch
- | setepoch | predict))
+ | setepoch | predict | compare))
show = 1; /* default to show */
if (getuid() == 0)
--
1.9.3
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: hwclock --compare segfaults when run as normal user
2014-07-28 11:12 ` Karel Zak
@ 2014-07-28 18:50 ` Benno Schulenberg
2014-07-29 6:27 ` Karel Zak
0 siblings, 1 reply; 6+ messages in thread
From: Benno Schulenberg @ 2014-07-28 18:50 UTC (permalink / raw)
To: Karel Zak; +Cc: kerolasa, Util-Linux
On Mon, Jul 28, 2014, at 13:12, Karel Zak wrote:
> I have no way how to to test it, but can you try the patch below?
> [...]
>
> + if (ur->get_permissions())
> + return EX_NOPERM;
> +
Yes, looks better now:
$ ./hwclock --compare
hwclock: unable to get I/O port access: the iopl(3) call failed.: Operation not permitted
hwclock: Probably you need root privileges.
Benno
--
http://www.fastmail.fm - Email service worth paying for. Try it for free
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: hwclock --compare segfaults when run as normal user
2014-07-28 18:50 ` Benno Schulenberg
@ 2014-07-29 6:27 ` Karel Zak
0 siblings, 0 replies; 6+ messages in thread
From: Karel Zak @ 2014-07-29 6:27 UTC (permalink / raw)
To: Benno Schulenberg; +Cc: kerolasa, Util-Linux
On Mon, Jul 28, 2014 at 08:50:48PM +0200, Benno Schulenberg wrote:
>
> On Mon, Jul 28, 2014, at 13:12, Karel Zak wrote:
> > I have no way how to to test it, but can you try the patch below?
> > [...]
> >
> > + if (ur->get_permissions())
> > + return EX_NOPERM;
> > +
>
> Yes, looks better now:
>
> $ ./hwclock --compare
> hwclock: unable to get I/O port access: the iopl(3) call failed.: Operation not permitted
> hwclock: Probably you need root privileges.
Applied, thanks.
Karel
--
Karel Zak <kzak@redhat.com>
http://karelzak.blogspot.com
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2014-07-29 6:27 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
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2014-07-26 12:40 hwclock --compare segfaults when run as normal user Benno Schulenberg
2014-07-26 14:48 ` Sami Kerola
2014-07-26 16:05 ` Benno Schulenberg
2014-07-28 11:12 ` Karel Zak
2014-07-28 18:50 ` Benno Schulenberg
2014-07-29 6:27 ` Karel Zak
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