dtrace discuss - Sep 2005 - How to print a buffer allocated using alloca ?

Hi,

I need to print the contents of the memory which are passed to uiomove().
I decided to allocate a buffer using alloca() and have copied the 
contents using bcopy().
Now, I need to print the conents of the buffer and haven''t found a way.

Any pointers/suggestions would be of great help !
Thanks in advance !!

Regards,
Sanjeev.

-- snip --
#!/usr/sbin/dtrace -s
fbt:pxfs:*pxreg*read_cache*:entry
{
        self->flag = 1
}

fbt::uiomove:entry
/self->flag = 1/
{
        buf = alloca(1024);
        bcopy((void *)arg1, buf, 1024);
        printf("buffer = %s", stringof(buf));  <-- ** This needs to
be
fixed ***
        self->flag = 0;
}

Hi Sanjeev,

You can use the tracemem() action to trace an arbitrary memory block. Does
that solve your problem? There isn''t (currently) a printf() format
character
that allows for an arbitrary chunk of memory.

Adam

On Thu, Sep 22, 2005 at 05:56:48PM +0530, Sanjeev Bagewadi
wrote:
> Hi,
> 
> I need to print the contents of the memory which are passed to uiomove().
> I decided to allocate a buffer using alloca() and have copied the 
> contents using bcopy().
> Now, I need to print the conents of the buffer and haven''t found a
way.
> 
> Any pointers/suggestions would be of great help !
> Thanks in advance !!
> 
> Regards,
> Sanjeev.
> 
> -- snip --
> #!/usr/sbin/dtrace -s
> fbt:pxfs:*pxreg*read_cache*:entry
> {
>        self->flag = 1
> }
> 
> fbt::uiomove:entry
> /self->flag = 1/
> {
>        buf = alloca(1024);
>        bcopy((void *)arg1, buf, 1024);
>        printf("buffer = %s", stringof(buf));  <-- ** This
needs to be
> fixed ***
>        self->flag = 0;
> }
> 
> _______________________________________________
> dtrace-discuss mailing list
> dtrace-discuss at opensolaris.org
-- 
Adam Leventhal, Solaris Kernel Development       http://blogs.sun.com/ahl

Thanks Adam ! I shall try that...

Regards,
Sanjeev
Adam Leventhal wrote:
>Hi Sanjeev,
>
>You can use the tracemem() action to trace an arbitrary memory block. Does
>that solve your problem? There isn''t (currently) a printf() format
character
>that allows for an arbitrary chunk of memory.
>
>Adam
>
>On Thu, Sep 22, 2005 at 05:56:48PM +0530, Sanjeev Bagewadi wrote:
>  
>
>>Hi,
>>
>>I need to print the contents of the memory which are passed to
uiomove().
>>I decided to allocate a buffer using alloca() and have copied the 
>>contents using bcopy().
>>Now, I need to print the conents of the buffer and haven''t
found a way.
>>
>>Any pointers/suggestions would be of great help !
>>Thanks in advance !!
>>
>>Regards,
>>Sanjeev.
>>
>>-- snip --
>>#!/usr/sbin/dtrace -s
>>fbt:pxfs:*pxreg*read_cache*:entry
>>{
>>       self->flag = 1
>>}
>>
>>fbt::uiomove:entry
>>/self->flag = 1/
>>{
>>       buf = alloca(1024);
>>       bcopy((void *)arg1, buf, 1024);
>>       printf("buffer = %s", stringof(buf));  <-- ** This
needs to be
>>fixed ***
>>       self->flag = 0;
>>}
>>
>>_______________________________________________
>>dtrace-discuss mailing list
>>dtrace-discuss at opensolaris.org
>>    
>>
>
>  
>