Re:[patch] "single step" atomic instruction sequences as a whole.

Re:[patch] "single step" atomic instruction sequences as a whole.

[emin ak]

Hi All;
Is there aynone can succesfully apply or care about this patch. I have
the same problem with my powerpc.
I have checked the latest cvs gdb and I have found this patch did'nt
merge into mainline. Will it commit later?
Thanks. Best Regards.
Emin Ak
>Sorry forgot the logs.
>--------------------test function.
>#include <stdio.h>
>#define __KERNEL__
>#include <asm/atomic.h>
>
>atomic_t i;
>int main(void)
>{
>printf("atomic_step_test\n");
>atomic_set(&i,5);
>printf("i=%d\n",atomic_read(&i));
>atomic_dec(&i);
>printf("i=%d\n",atomic_read(&i));
>
>
>}
>----------- gdb logs-----------
>Breakpoint 2, main () at test.c:8
>8       printf("atomic_step_test\n");
>(gdb) next
>9       atomic_set(&i,5);
>(gdb) next
>10      printf("i=%d\n",atomic_read(&i));
>(gdb) next
>151                     :"=m" (v->counter), "=qm" (c)
>(gdb) next
>Stepping over an atomic sequence of instructions beginning at 0x10000484
>breakpoint.c:7730: internal-error: remove_single_step_breakpoints:
>Assertion `single_step_breakpoints[0] != NULL' failed.
>A problem internal to GDB has been detected,
>further debugging may prove unreliable.
>Quit this debugging session? (y or n)
>--------------------------
>Regards.
>Emre
> Hello Mr Gilliam;
> Firstly thank you very much for your patch about single stepping problem
> on atomic instructions. In my opinion, this bug is very critical for
> powerpc arch (especially while kernel debugging). We have experienced this
> problem  with both with h/w probe (BDI2000) and KGDB while debugging
> kernel. I have applied your patch to latest gdb (20060911 taken from cvs)
> and after correctting some fail warnings and test it on a PPC8540. It can
> successfullt detects 'lwarx' instruction but can't step over the loop and
> a little moment later, it gives an error message like 'breakpoint.c:7730:
> internal-error: remove_single_step_breakpoints: Assertion
> `single_step_breakpoints[0] != NULL' failed.'
> I have corrected some patch error, I dont know, maybe this is the reason
> of the problem. Here is the output of gdb and my test program that include
> atomic_dec function.
> Where can be the problem? And thank alot again, because atomic functions
> are everywhere on kernel waiting to cause infinite loops..
> Regards.
> Emre KARA
>
>
>

Re: [patch] "single step" atomic instruction sequences as a whole.

[emin ak]

Mr Gilliam,

I'am very interested in one of your gdb patches about ""single step"
atomic instruction sequences as a whole". we have experienced serious
problems on atomic functions while debugging linux kernel and we have
found only your approach can solve the problem. I have applied it
againts latest cvs source but it is not working truly, it can detects
atomic inc. successfully but cant step over them and gives this error:
 'breakpoint.c:7730: internal-error: remove_single_step_breakpoints: Assertion
`single_step_breakpoints[0] != NULL' failed.'

Mr Gilliam, if you can kindly guide me (or give a clue) to overcome
this problem, I can reorganize this patch and resend it to community

Thank you very much for your time.

Best Regards.
Emin Ak

2006/9/18, emin ak <eminak71@gmail.com>:
> Hi All;
> Is there aynone can succesfully apply or care about this patch. I have
> the same problem with my powerpc.
> I have checked the latest cvs gdb and I have found this patch did'nt
> merge into mainline. Will it commit later?
> Thanks. Best Regards.
> Emin Ak
> >Sorry forgot the logs.
> >--------------------test function.
> >#include <stdio.h>
> >#define __KERNEL__
> >#include <asm/atomic.h>
> >
> >atomic_t i;
> >int main(void)
> >{
> >printf("atomic_step_test\n");
> >atomic_set(&i,5);
> >printf("i=%d\n",atomic_read(&i));
> >atomic_dec(&i);
> >printf("i=%d\n",atomic_read(&i));
> >
> >
> >}
> >----------- gdb logs-----------
> >Breakpoint 2, main () at test.c:8
> >8       printf("atomic_step_test\n");
> >(gdb) next
> >9       atomic_set(&i,5);
> >(gdb) next
> >10      printf("i=%d\n",atomic_read(&i));
> >(gdb) next
> >151                     :"=m" (v->counter), "=qm" (c)
> >(gdb) next
> >Stepping over an atomic sequence of instructions beginning at 0x10000484
> >breakpoint.c:7730: internal-error: remove_single_step_breakpoints:
> >Assertion `single_step_breakpoints[0] != NULL' failed.
> >A problem internal to GDB has been detected,
> >further debugging may prove unreliable.
> >Quit this debugging session? (y or n)
> >--------------------------
> >Regards.
> >Emre
> > Hello Mr Gilliam;
> > Firstly thank you very much for your patch about single stepping problem
> > on atomic instructions. In my opinion, this bug is very critical for
> > powerpc arch (especially while kernel debugging). We have experienced this
> > problem  with both with h/w probe (BDI2000) and KGDB while debugging
> > kernel. I have applied your patch to latest gdb (20060911 taken from cvs)
> > and after correctting some fail warnings and test it on a PPC8540. It can
> > successfullt detects 'lwarx' instruction but can't step over the loop and
> > a little moment later, it gives an error message like 'breakpoint.c:7730:
> > internal-error: remove_single_step_breakpoints: Assertion
> > `single_step_breakpoints[0] != NULL' failed.'
> > I have corrected some patch error, I dont know, maybe this is the reason
> > of the problem. Here is the output of gdb and my test program that include
> > atomic_dec function.
> > Where can be the problem? And thank alot again, because atomic functions
> > are everywhere on kernel waiting to cause infinite loops..
> > Regards.
> > Emre KARA
> >
> >
> >
>

Re:[patch] "single step" atomic instruction sequences as a whole.

[ekara]

Sorry forgot the logs.
--------------------test function.
#include <stdio.h>
#define __KERNEL__
#include <asm/atomic.h>

atomic_t i;
int main(void)
{
printf("atomic_step_test\n");
atomic_set(&i,5);
printf("i=%d\n",atomic_read(&i));
atomic_dec(&i);
printf("i=%d\n",atomic_read(&i));


}
----------- gdb logs-----------
Breakpoint 2, main () at test.c:8
8       printf("atomic_step_test\n");
(gdb) next
9       atomic_set(&i,5);
(gdb) next
10      printf("i=%d\n",atomic_read(&i));
(gdb) next
151                     :"=m" (v->counter), "=qm" (c)
(gdb) next
Stepping over an atomic sequence of instructions beginning at 0x10000484
breakpoint.c:7730: internal-error: remove_single_step_breakpoints:
Assertion `single_step_breakpoints[0] != NULL' failed.
A problem internal to GDB has been detected,
further debugging may prove unreliable.
Quit this debugging session? (y or n)
--------------------------
Regards.
Emre
> Hello Mr Gilliam;
> Firstly thank you very much for your patch about single stepping problem
> on atomic instructions. In my opinion, this bug is very critical for
> powerpc arch (especially while kernel debugging). We have experienced this
> problem  with both with h/w probe (BDI2000) and KGDB while debugging
> kernel. I have applied your patch to latest gdb (20060911 taken from cvs)
> and after correctting some fail warnings and test it on a PPC8540. It can
> successfullt detects 'lwarx' instruction but can't step over the loop and
> a little moment later, it gives an error message like 'breakpoint.c:7730:
> internal-error: remove_single_step_breakpoints: Assertion
> `single_step_breakpoints[0] != NULL' failed.'
> I have corrected some patch error, I dont know, maybe this is the reason
> of the problem. Here is the output of gdb and my test program that include
> atomic_dec function.
> Where can be the problem? And thank alot again, because atomic functions
> are everywhere on kernel waiting to cause infinite loops..
> Regards.
> Emre KARA
>
>
>