functions about dump backtrace function names in mips arch

functions about dump backtrace function names in mips arch

[loody]

?Dear all:
?If i remember correctly, when kernel panic there is a function I can
?use to dump all the names of backtrace functions.
?I have searched arch/mips/traps.c, but I only can see the dump
?functions of cpu registers,

?If my assumption is true, would anyone tell me what the name is or
?what Doc I can looking for?
?appreciate your help,
miloody

functions about dump backtrace function names in mips arch

[loody]

?Dear all:
?If i remember correctly, when kernel panic there is a function I can
?use to dump all the names of backtrace functions.
?I have searched arch/mips/traps.c, but I only can see the dump
?functions of cpu registers,

?If my assumption is true, would anyone tell me what the name is or
?what Doc I can looking for?
?appreciate your help,
miloody

functions about dump backtrace function names in mips arch

[Mulyadi Santosa]

On Sun, Jan 2, 2011 at 15:26, loody <miloody@gmail.com> wrote:
> ?Dear all:
> ?If i remember correctly, when kernel panic there is a function I can
> ?use to dump all the names of backtrace functions.
> ?I have searched arch/mips/traps.c, but I only can see the dump
> ?functions of cpu registers,

In x86, it's dump_stack(). The definition can be read here online:
http://lxr.linux.no/#linux+v2.6.36/arch/x86/kernel/dumpstack.c#L198

-- 
regards,

Mulyadi Santosa
Freelance Linux trainer and consultant

blog: the-hydra.blogspot.com
training: mulyaditraining.blogspot.com

functions about dump backtrace function names in mips arch

[Sowmya Sridharan]

Hi,

I was able to check it in 2.6.36 version of kernel, and it is defined in 
traps.c.
http://lxr.linux.no/linux+v2.6.36/arch/mips/kernel/traps.c#L205

dump_stack() calls show_backtrace function which had been show_trace in 
the earlier kernel versions.
I compared between 2.6.14 and the latest version, and here are the 
differences:
-------------------------------------------------------------------------------
http://lxr.linux.no/linux+v2.6.14/arch/mips/kernel/traps.c#L110
function: show_trace
     while (!kstack_end(stack)) {
                addr = *stack++;
                if (__kernel_text_address(addr)) {
                        printk(" [<%0*lx>] ", field, addr);
                        print_symbol("%s\n", addr);
                }
        }
---------------------------------------------------------------------------------
In the latest kernel, show_backtrace function is used, which does the same 
thing, but through different functions
http://lxr.linux.no/linux+v2.6.36/arch/mips/kernel/traps.c#L126
function: show_backtrace
        printk("Call Trace:\n");
         do {
                 print_ip_sym(pc);
                 pc = unwind_stack(task, &sp, pc, &ra);
         } while (pc);


Regards,
Sowmya

kernelnewbies-bounces at kernelnewbies.org wrote on 01/02/2011 04:31:08 PM:

> [image removed] 
> 
> Re: functions about dump backtrace function names in mips arch
> 
> Mulyadi Santosa 
> 
> to:
> 
> loody
> 
> 01/02/2011 04:33 PM
> 
> Sent by:
> 
> kernelnewbies-bounces at kernelnewbies.org
> 
> Cc:
> 
> Kernel Newbies
> 
> On Sun, Jan 2, 2011 at 15:26, loody <miloody@gmail.com> wrote:
> >  Dear all:
> >  If i remember correctly, when kernel panic there is a function I can
> >  use to dump all the names of backtrace functions.
> >  I have searched arch/mips/traps.c, but I only can see the dump
> >  functions of cpu registers,
> 
> In x86, it's dump_stack(). The definition can be read here online:
> http://lxr.linux.no/#linux+v2.6.36/arch/x86/kernel/dumpstack.c#L198
> 
> -- 
> regards,
> 
> Mulyadi Santosa
> Freelance Linux trainer and consultant
> 
> blog: the-hydra.blogspot.com
> training: mulyaditraining.blogspot.com
> 
> _______________________________________________
> Kernelnewbies mailing list
> Kernelnewbies at kernelnewbies.org
> http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
=====-----=====-----=====
Notice: The information contained in this e-mail
message and/or attachments to it may contain 
confidential or privileged information. If you are 
not the intended recipient, any dissemination, use, 
review, distribution, printing or copying of the 
information contained in this e-mail message 
and/or attachments to it are strictly prohibited. If 
you have received this communication in error, 
please notify us by reply e-mail or telephone and 
immediately and permanently delete the message 
and any attachments. Thank you


-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.kernelnewbies.org/pipermail/kernelnewbies/attachments/20110103/de8495d7/attachment.html 

functions about dump backtrace function names in mips arch

[loody]

hi all:

2011/1/3 Sowmya Sridharan <sowmya.sridharan@tcs.com>:
>
> Hi,
>
> I was able to check it in 2.6.36 version of kernel, and it is defined in
> traps.c.
> http://lxr.linux.no/linux+v2.6.36/arch/mips/kernel/traps.c#L205
>
> dump_stack() calls show_backtrace function which had been show_trace in the
> earlier kernel versions.
> I compared between 2.6.14 and the latest version, and here are the
> differences:
> -------------------------------------------------------------------------------
> http://lxr.linux.no/linux+v2.6.14/arch/mips/kernel/traps.c#L110
> function: show_trace
> ? ? ?while (!kstack_end(stack)) {
> ? ? ? ? ? ? ? ? addr = *stack++;
> ? ? ? ? ? ? ? ? if (__kernel_text_address(addr)) {
> ? ? ? ? ? ? ? ? ? ? ? ? printk(" [<%0*lx>] ", field, addr);
> ? ? ? ? ? ? ? ? ? ? ? ? print_symbol("%s\n", addr);
> ? ? ? ? ? ? ? ? }
> ? ? ? ? }
> ---------------------------------------------------------------------------------
> In the latest kernel, show_backtrace function is used, which does the same
> thing, but through different functions
> http://lxr.linux.no/linux+v2.6.36/arch/mips/kernel/traps.c#L126
> function: show_backtrace
> ? ? ? ? printk("Call Trace:\n");
> ? ? ? ? ?do {
> ? ? ? ? ? ? ? ? ?print_ip_sym(pc);
> ? ? ? ? ? ? ? ? ?pc = unwind_stack(task, &sp, pc, &ra);
> ? ? ? ? ?} while (pc);
>
>
> Regards,
> Sowmya
thanks for your kind help, that is what I want.
previously, I only see the address instead of function name, but after
I select CONFIG_KALLSYMS as Y, I can see the function names also.
BTW, what is the mechanism that kernel take to find out the function name?
Regards,
miloody

functions about dump backtrace function names in mips arch

[loody]

hi:

2011/1/3 loody <miloody@gmail.com>:
> hi all:
>
> 2011/1/3 Sowmya Sridharan <sowmya.sridharan@tcs.com>:
>>
>> Hi,
>>
>> I was able to check it in 2.6.36 version of kernel, and it is defined in
>> traps.c.
>> http://lxr.linux.no/linux+v2.6.36/arch/mips/kernel/traps.c#L205
>>
>> dump_stack() calls show_backtrace function which had been show_trace in the
>> earlier kernel versions.
>> I compared between 2.6.14 and the latest version, and here are the
>> differences:
>> -------------------------------------------------------------------------------
>> http://lxr.linux.no/linux+v2.6.14/arch/mips/kernel/traps.c#L110
>> function: show_trace
>> ? ? ?while (!kstack_end(stack)) {
>> ? ? ? ? ? ? ? ? addr = *stack++;
>> ? ? ? ? ? ? ? ? if (__kernel_text_address(addr)) {
>> ? ? ? ? ? ? ? ? ? ? ? ? printk(" [<%0*lx>] ", field, addr);
>> ? ? ? ? ? ? ? ? ? ? ? ? print_symbol("%s\n", addr);
>> ? ? ? ? ? ? ? ? }
>> ? ? ? ? }
>> ---------------------------------------------------------------------------------
>> In the latest kernel, show_backtrace function is used, which does the same
>> thing, but through different functions
>> http://lxr.linux.no/linux+v2.6.36/arch/mips/kernel/traps.c#L126
>> function: show_backtrace
>> ? ? ? ? printk("Call Trace:\n");
>> ? ? ? ? ?do {
>> ? ? ? ? ? ? ? ? ?print_ip_sym(pc);
>> ? ? ? ? ? ? ? ? ?pc = unwind_stack(task, &sp, pc, &ra);
>> ? ? ? ? ?} while (pc);
>>
>>
>> Regards,
>> Sowmya
> thanks for your kind help, that is what I want.
> previously, I only see the address instead of function name, but after
> I select CONFIG_KALLSYMS as Y, I can see the function names also.
> BTW, what is the mechanism that kernel take to find out the function name?
from log such as:
<80128580>] do_softirq+0x48/0x68
i know 0x48 is the offset of do_softirq, but how can I locate precise
what the offset 0x48 of do_softirq is? "objdump -s"?
Regards,
miloody

functions about dump backtrace function names in mips arch

[nilesh]

On Mon, 2011-01-03 at 22:32 +0800, loody wrote:
> hi all:
> 
> 2011/1/3 Sowmya Sridharan <sowmya.sridharan@tcs.com>:
> >
> > Hi,
> >
> > I was able to check it in 2.6.36 version of kernel, and it is defined in
> > traps.c.
> > http://lxr.linux.no/linux+v2.6.36/arch/mips/kernel/traps.c#L205
> >
> > dump_stack() calls show_backtrace function which had been show_trace in the
> > earlier kernel versions.
[...]
> >
> >
[...]
> > Regards,
> > Sowmya
> thanks for your kind help, that is what I want.
> previously, I only see the address instead of function name, but after
> I select CONFIG_KALLSYMS as Y, I can see the function names also.
> BTW, what is the mechanism that kernel take to find out the function name?

Enabling the config option, it allows to build the symbol table for
kernel. It uses /proc/kallsyms.
Below links could help:
http://tldp.org/HOWTO/Module-HOWTO/x627.html
http://fixunix.com/kernel/134739-proc-kallsyms-symbol-size.html

> Regards,
> miloody

-- 
Thanks,
Nilesh