Reg: problem in using High resolution Timer(hrtimer)

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10-29-2007, 08:11 AM
unix

Reg: problem in using High resolution Timer(hrtimer)

Hello,
I have written and compiled a kernel module on Linux Kernel
version 2.6.22.8. The kernel module uses high precision timer to print
after 2 sec continuosly , but as soon as I insert my module using
modprobe ,the kernel goes in panic state.
The kernel module code is as follows:
_____________________________________________________________________________

#include <linux/ktime.h>
#include <linux/init.h>
#include <linux/list.h>
#include <linux/wait.h>
#include<linux/module.h>
#include<linux/slab.h>

enum hrtimer_restart callback(struct hrtimer *); // return enum
hrtimer_restart

enum hrtimer_restart callback(struct hrtimer *timer)
{
printk(KERN_ALERT "TIMER INTERRUPTED\n");
return HRTIMER_RESTART;
}

const long secs=2;
const long nanosecs=0;

struct hrtimer *timer;
static int __init init_timer(void)
{
ktime_t kt;
clockid_t which_clock=CLOCK_MONOTONIC; //CLOCK_REALTIME
printk(KERN_ALERT "HRTTIMER inserted\n");
kt=ktime_set(secs,nanosecs);
timer = (struct hrtimer *)kmalloc(sizeof(struct hrtimer),GFP_KERNEL);
hrtimer_init(timer,which_clock,HRTIMER_MODE_ABS);
timer->function = &callback; // callback
hrtimer_start(timer, kt,HRTIMER_MODE_ABS);
printk(KERN_ALERT "HRTTIMER STARTED\n");
return 0;
}

static void __exit exit_timer(void)
{
hrtimer_cancel(timer); //
return;
}

MODULE_LICENSE("GPL");

module_init(init_timer);
module_exit(exit_timer);

________________________________________________________________________________

To have panic logs I have also run the module on my UML guest
kernel :
The module log on when run on UML kernel are as follows:

[root@localhost 2.6.22.8]# modprobe -f timer
timer: no version magic, tainting kernel.
HRTTIMER inserted

EIP: 0073:[<080a1890>] CPU: 0 Tainted: GF ESP: 007b:0b5edefc
EFLAGS: 00010246
Tainted: GF
EAX: 00000000 EBX: 0c00705a ECX: 0000001d EDX: 483e313c
ESI: 0805e0e8 EDI: 00000001 EBP: 0b5edf0c DS: 007b ES: 007b
081eabbc: [<08068098>] show_regs+0xb4/0xb9
081eabe8: [<08058807>] segv+0x12d/0x272
081eac8c: [<080586d5>] segv_handler+0x55/0x5a
081eacac: [<08065cb8>] sig_handler_common_skas+0xd4/0xfc
081eacd4: [<08062d1c>] sig_handler+0x34/0x44
081eacec: [<08062eac>] handle_signal+0x4a/0x7a
081ead0c: [<08064a7f>] hard_handler+0xf/0x14
081ead1c: [<00e2d420>] 0xe2d420

Kernel panic - not syncing: Kernel mode fault at addr 0x483e313c, ip
0x80a1890

EIP: 0073:[<400eee2e>] CPU: 0 Tainted: GF ESP: 007b:bfa62e40
EFLAGS: 00000246
Tainted: GF
EAX: ffffffda EBX: 08066a88 ECX: 000054c1 EDX: 0805e0e8
ESI: 0805e0e8 EDI: 0805e0e8 EBP: bfa62ec8 DS: 007b ES: 007b
081eab24: [<08068098>] show_regs+0xb4/0xb9
081eab50: [<08058b90>] panic_exit+0x25/0x3f
081eab64: [<08077a08>] notifier_call_chain+0x21/0x46
081eab84: [<08077aa3>] __atomic_notifier_call_chain+0x17/0x19
081eaba0: [<08077aba>] atomic_notifier_call_chain+0x15/0x17
081eabbc: [<0806c976>] panic+0x52/0xdd

_____________________________________________________________________________

Can somebody help me solving the problem?.

regards
bsahai
10-30-2007, 02:32 AM
unix

Re: Reg: problem in using High resolution Timer(hrtimer)

On Oct 29, 7:11 pm, bsahai <bhagwan.sa...@gmail.com> wrote:[color=blue]
> Hello,
> I have written and compiled a kernel module on Linux Kernel
> version 2.6.22.8. The kernel module uses high precision timer to print
> after 2 sec continuosly , but as soon as I insert my module using
> modprobe ,the kernel goes in panic state.
> The kernel module code is as follows:
> _____________________________________________________________________________
>
> #include <linux/ktime.h>
> #include <linux/init.h>
> #include <linux/list.h>
> #include <linux/wait.h>
> #include<linux/module.h>
> #include<linux/slab.h>
>
> enum hrtimer_restart callback(struct hrtimer *); // return enum
> hrtimer_restart
>
> enum hrtimer_restart callback(struct hrtimer *timer)
> {
> printk(KERN_ALERT "TIMER INTERRUPTED\n");
> return HRTIMER_RESTART;
>
> }
>
> const long secs=2;
> const long nanosecs=0;
>
> struct hrtimer *timer;
> static int __init init_timer(void)
> {
> ktime_t kt;
> clockid_t which_clock=CLOCK_MONOTONIC; //CLOCK_REALTIME
> printk(KERN_ALERT "HRTTIMER inserted\n");
> kt=ktime_set(secs,nanosecs);
> timer = (struct hrtimer *)kmalloc(sizeof(struct hrtimer),GFP_KERNEL);
> hrtimer_init(timer,which_clock,HRTIMER_MODE_ABS);
> timer->function = &callback; // callback
> hrtimer_start(timer, kt,HRTIMER_MODE_ABS);
> printk(KERN_ALERT "HRTTIMER STARTED\n");
> return 0;
>
> }
>
> static void __exit exit_timer(void)
> {
> hrtimer_cancel(timer); //
> return;
>
> }
>
> MODULE_LICENSE("GPL");
>
> module_init(init_timer);
> module_exit(exit_timer);
>
> ________________________________________________________________________________
>
> To have panic logs I have also run the module on my UML guest
> kernel :
> The module log on when run on UML kernel are as follows:
>
> [root@localhost 2.6.22.8]# modprobe -f timer
> timer: no version magic, tainting kernel.
> HRTTIMER inserted
>
> EIP: 0073:[<080a1890>] CPU: 0 Tainted: GF ESP: 007b:0b5edefc
> EFLAGS: 00010246
> Tainted: GF
> EAX: 00000000 EBX: 0c00705a ECX: 0000001d EDX: 483e313c
> ESI: 0805e0e8 EDI: 00000001 EBP: 0b5edf0c DS: 007b ES: 007b
> 081eabbc: [<08068098>] show_regs+0xb4/0xb9
> 081eabe8: [<08058807>] segv+0x12d/0x272
> 081eac8c: [<080586d5>] segv_handler+0x55/0x5a
> 081eacac: [<08065cb8>] sig_handler_common_skas+0xd4/0xfc
> 081eacd4: [<08062d1c>] sig_handler+0x34/0x44
> 081eacec: [<08062eac>] handle_signal+0x4a/0x7a
> 081ead0c: [<08064a7f>] hard_handler+0xf/0x14
> 081ead1c: [<00e2d420>] 0xe2d420
>
> Kernel panic - not syncing: Kernel mode fault at addr 0x483e313c, ip
> 0x80a1890
>
> EIP: 0073:[<400eee2e>] CPU: 0 Tainted: GF ESP: 007b:bfa62e40
> EFLAGS: 00000246
> Tainted: GF
> EAX: ffffffda EBX: 08066a88 ECX: 000054c1 EDX: 0805e0e8
> ESI: 0805e0e8 EDI: 0805e0e8 EBP: bfa62ec8 DS: 007b ES: 007b
> 081eab24: [<08068098>] show_regs+0xb4/0xb9
> 081eab50: [<08058b90>] panic_exit+0x25/0x3f
> 081eab64: [<08077a08>] notifier_call_chain+0x21/0x46
> 081eab84: [<08077aa3>] __atomic_notifier_call_chain+0x17/0x19
> 081eaba0: [<08077aba>] atomic_notifier_call_chain+0x15/0x17
> 081eabbc: [<0806c976>] panic+0x52/0xdd
>
> _____________________________________________________________________________
>
> Can somebody help me solving the problem?.
>
> regards
> bsahai[/color]
[color=blue]
>From my quick reading, you seems to have segment violation problem.[/color]
What architecture are you running (Intel, PPC, ARM ...)?
10-31-2007, 07:24 AM
unix

Re: Reg: problem in using High resolution Timer(hrtimer)

bsahai <bhagwan.sahai@gmail.com> wrote:[color=blue]
>
> I have written and compiled a kernel module on Linux Kernel
>version 2.6.22.8. The kernel module uses high precision timer to print
>after 2 sec continuosly , but as soon as I insert my module using
>modprobe ,the kernel goes in panic state.
>...
>
>struct hrtimer *timer;
>static int __init init_timer(void)
>{
>ktime_t kt;
>clockid_t which_clock=CLOCK_MONOTONIC; //CLOCK_REALTIME
>printk(KERN_ALERT "HRTTIMER inserted\n");
>kt=ktime_set(secs,nanosecs);
>timer = (struct hrtimer *)kmalloc(sizeof(struct hrtimer),GFP_KERNEL);
>hrtimer_init(timer,which_clock,HRTIMER_MODE_ABS);
>timer->function = &callback; // callback
>hrtimer_start(timer, kt,HRTIMER_MODE_ABS);
>printk(KERN_ALERT "HRTTIMER STARTED\n");
>return 0;
>}[/color]

Maybe I'm misunderstanding this, but I would have guessed that you wanted
HRTIMER_MODE_REL. By using CLOCK_MONOTONIC with an absolute time of 2
seconds, you're asking for the timer to fire 2 seconds after the last boot,
which has already expired.
--
Tim Roberts, [email]timr@probo.com[/email]
Providenza & Boekelheide, Inc.
10-31-2007, 01:20 PM
unix

Re: Reg: problem in using High resolution Timer(hrtimer)

On Oct 31, 12:24 pm, Tim Roberts <t...@probo.com> wrote:[color=blue]
> bsahai <bhagwan.sa...@gmail.com> wrote:
>[color=green]
> > I have written and compiled a kernel module on Linux Kernel
> >version 2.6.22.8. The kernel module uses high precision timer to print
> >after 2 sec continuosly , but as soon as I insert my module using
> >modprobe ,the kernel goes in panic state.
> >...[/color]
>[color=green]
> >struct hrtimer *timer;
> >static int __init init_timer(void)
> >{
> >ktime_t kt;
> >clockid_t which_clock=CLOCK_MONOTONIC; //CLOCK_REALTIME
> >printk(KERN_ALERT "HRTTIMER inserted\n");
> >kt=ktime_set(secs,nanosecs);
> >timer = (struct hrtimer *)kmalloc(sizeof(struct hrtimer),GFP_KERNEL);
> >hrtimer_init(timer,which_clock,HRTIMER_MODE_ABS);
> >timer->function = &callback; // callback
> >hrtimer_start(timer, kt,HRTIMER_MODE_ABS);
> >printk(KERN_ALERT "HRTTIMER STARTED\n");
> >return 0;
> >}[/color]
>
> Maybe I'm misunderstanding this, but I would have guessed that you wanted
> HRTIMER_MODE_REL. By using CLOCK_MONOTONIC with an absolute time of 2
> seconds, you're asking for the timer to fire 2 seconds after the last boot,
> which has already expired.
> --
> Tim Roberts, t...@probo.com
> Providenza & Boekelheide, Inc.- Hide quoted text -
>
> - Show quoted text -[/color]

Yes you right it should be HRTTIMER_MOD_REL instead of
HRTIMER_MOD_ABS ,but even after changing this the same problem is
repeating ..I am again pasting the code and log (when run over UML
kernel).

PS: I am using Linux kernel 2.6.22.8 (i386)

/
********************************code***************************************************
#include<linux/hrtimer.h>
#include<linux/ktime.h>
#include<linux/module.h>

struct hrtimer *timer1;
enum hrtimer_restart callback(struct hrtimer *); // return enum
hrtimer_restart

enum hrtimer_restart callback(struct hrtimer *timer)
{
printk(KERN_ALERT "\nTIME INTERRUPTED\n");
return HRTIMER_RESTART;
}

const long secs=2;
const long nanosecs=50;

static int init_timer(void)
{

ktime_t kt;
clockid_t which_clock=CLOCK_MONOTONIC; //CLOCK_REALTIME
timer1=(struct hrtimer *)kmalloc(sizeof(struct hrtimer),GFP_ATOMIC);
printk(KERN_ALERT "\ntimer:after malloc\n");

kt=ktime_set(secs,nanosecs);
printk(KERN_ALERT "\nBefore timer_init\n");
hrtimer_init(timer1,which_clock,HRTIMER_MODE_REL);
printk(KERN_ALERT "\nAfter Timer init\n");
timer1->function = &callback;

hrtimer_start(timer1, kt,HRTIMER_MODE_REL);
printk(KERN_ALERT "\nAfter timer start\n");
return 0;

}

static void exit_timer(void)
{
//hrtimer_cancel(timer);
return;
}
MODULE_LICENSE("GPL");

/*********Code ends here
***************************************************************

/*************************Log
begins*************************************************************

[root@localhost 2.6.22.8]# modprobe -f timer
timer: no version magic, tainting kernel.

EIP: 0073:[<080a1890>] CPU: 0 Tainted: GF ESP: 007b:0ad6aefc
EFLAGS: 000102
46
Tainted: GF
EAX: 00000000 EBX: 0b807480 ECX: 0b807480 EDX: 00000001
ESI: 0805e0e8 EDI: 00000001 EBP: 0ad6af0c DS: 007b ES: 007b
081eabbc: [<08068098>] show_regs+0xb4/0xb9
081eabe8: [<08058807>] segv+0x12d/0x272
081eac8c: [<080586d5>] segv_handler+0x55/0x5a
081eacac: [<08065cb8>] sig_handler_common_skas+0xd4/0xfc
081eacd4: [<08062d1c>] sig_handler+0x34/0x44
081eacec: [<08062eac>] handle_signal+0x4a/0x7a
081ead0c: [<08064a7f>] hard_handler+0xf/0x14
081ead1c: [<00bdd420>] 0xbdd420

Kernel panic - not syncing: Kernel mode fault at addr 0x1, ip
0x80a1890

EIP: 0073:[<400eee2e>] CPU: 0 Tainted: GF ESP: 007b:bf5ec9c0
EFLAGS: 000002
46
Tainted: GF
EAX: ffffffda EBX: 08066a88 ECX: 00005323 EDX: 0805e0e8
ESI: 0805e0e8 EDI: 0805e0e8 EBP: bf5eca48 DS: 007b ES: 007b
081eab24: [<08068098>] show_regs+0xb4/0xb9
081eab50: [<08058b90>] panic_exit+0x25/0x3f
081eab64: [<08077a08>] notifier_call_chain+0x21/0x46
081eab84: [<08077aa3>] __atomic_notifier_call_chain+0x17/0x19
081eaba0: [<08077aba>] atomic_notifier_call_chain+0x15/0x17
081eabbc: [<0806c976>] panic+0x52/0xdd
I?l?I?#?Jp??K`@?Lpk|M`"?NpM\O`?Pp/
<Q`?uRpS`?UTp??T`?5V??V??X???X???Y? Z???[???\?
d`/
GepZ?e`'gp<?g`?ip?i`??j?:?k???l?vm? n??Uo p??5q??or??s?yOtp??t`?8vp??v`x xp??
x`Z?yp??z`<?{pg~|`?}pI^~`????????????????n_skas+0xd4/0xfc
081eacd4: [<08062d1c>] sig_handler+0x34/EDTESTEWTEPTI
Program terminated with signal SIGSEGV, Segmentation fault.
The program no longer exists.handler+0xf/0x14
(gdb) 1c: [<00bdd420>] 0xbdd420
(gdb)

/*************************log
ends**************************************************************

regards
Bhagwan Sahai