Displaying 20 results from an estimated 4000 matches similar to: "use tracemem to dump content in function read/write"
2008 Feb 26
11
Is there way to trace memory in the dtrace ?
N_conreq:entry {
self->x=1;
calledaddr=(struct xaddrf *)arg3;
callingaddr=(struct xaddrf *)arg4;
trace(calledaddr->link_id);
tracemem(calledaddr->DTE_MAC.lsap_add, 80);
trace(callingaddr->link_id);
tracemem(callingaddr->DTE_MAC.lsap_add, 80);
}
0 -> N_conreq 255
2006 Aug 08
9
Handling userland char ** pointers
I''ve been trying to get access to a userland string that''s behind a
second level pointer using DTrace, but I can''t seem to get it to work.
I started with the example on the Team DTrace Tips and Tricks slides:
trace(copyinstr(*(uintptr_t *)copyin(arg0, curpsinfo->pr_dmodel ==
PR_MODEL_ILP32 ? 4 : 8)));
And when I couldn''t get it to work, I started
2008 May 20
6
Dtrace queries - predicates & func arg tracing
[1] Predicates in one-liners
I would like to list the probe modules in my executable and then
dynamically create a dscript to trace execution of those modules alone
(by excluding the 3rd party and system libraries). I tried the below
script without success. The conditional given in the predicate is not
taking effect. Why is this so ?
$ dtrace -ln ''pid$target:::
2006 Jun 29
2
tracemem() not exactly what I had in mind
I was trying to use tracemem to look at mblk contents. First, I tried to use
mblk->b_wptr - mblk->b_rptr as the size, and was told that it had to be a
constant. Foo. (RFE #1).
Then, I tried to use 8 as the size, and kept getting decimal numbers printed.
Stumbled on #pragma D option rawbytes=true (is the =true necessary, btw?) and
that didn''t help.
Then, in desperation, I
2009 Jul 24
9
getting extra characters with printf(copyin(a, b))
Hi,
I have a situation where a DTrace script is printing out extra characters, despite the copyin() call giving a specific length. Can anyone think of why this might be? It''s fine the first time all of the probes fire, but on a second run of my generating operations, I get junk in there. For example:
set setop length 5, FOUND KEY, STORED
set setop length 5, FOUND KEY, STORED
get
2008 Jul 07
2
copyin having secondary effects.
Dtracing gethostbyname I''m trying to read the h_alias array and all the entries it points to however every time I copyin an entry pointed to by the first entry in teh h_alias array the other entries in the array get corrupted.
So I have ended up with this script:
#!/usr/bin/dtrace -CZs
#include <netdb.h>
pid$target::gethostbyname_r:return
{
self->r = (struct hostent
2005 Aug 12
3
Funny output from write syscall
I have a clause that look like this:
syscall::write:entry
/execname == "ntpd" && self->recspec/
{
speculate(self->recspec);
printf(" fd=%d buf=%d\n%s",arg0,arg2,
stringof(copyin(arg1,arg2-1)));
}
The ntpd program always write a \n trminated string in this
context, so I used the "arg2-1" to drop the \n.
This works
2007 Apr 18
3
dtrace-discuss: cannot get a ''string'' to print...
hi,
I''m using the PID provider to trace a 32-bit app, prtdiag.
I''m trying to print the value of "propname" (arg1) in the
following func:
int
picl_get_propval_by_name(picl_nodehdl_t nodeh, const char *propname,
void *valbuf, size_t nbytes)
...
i''ve tried many versions, but this is a representative one:
53 this string propname;
54
55
2008 Sep 30
12
dtrace missing ''unlinkat''? showing process stack?
everyone,
Just out of curiosity, I did a
dtrace -n ''syscall:::entry { @num[execname, probefunc] = count(); }''
and looked at the entries produced by ''rm''.
I see everything that rm did, *except* the unlinkat - which is unfortunate because I want to trace which processes have deleted which files.
So - does dtrace contain unlinkat as a probe for a system call?
2005 Sep 08
3
DTrace typewriter
G''Day Folks,
I''ve found another use of dtrace, this makes your console keyboard
sound like a typewriter.
http://www.brendangregg.com/DTrace/typewriter-0.70.tar.gz
I''ve only tested it on an UltraSPARC 5 and a Pentium laptop so far, more
to follow.
Ok, sorry, not actually a practical use of DTrace. :)
Enjoy!
Brendan
[Sydney, Australia]
2012 Jul 12
2
Understanding tracemem
Hi all,
I've been trying to get a better handle on what manipulations lead R
to duplicate a vector, creating small experiments and using tracemem
to observe what happens (all in 2.15.1). That's lead me to a few
questions, illustrated using the snippet below.
x <- 1:10
tracemem(x)
# [1] "<0x1058f8238>"
x[5] <- 5
# tracemem[0x1058f8238 -> 0x105994ab0]:
x[11] <-
2006 Jun 03
8
dtrace causing sigtrap?
Just to let people know what my big picture is, I''m trying to write a script
that will let me run a program, and name a progeny of that program
that I want to debug. My script should find the first occurrence
of that progeny, and run it until it finishes initializing the
runtime linker, but stop it before it runs any shared library startup
routines. (Failing that, I''d be okay
2007 Jul 13
1
how to get scratch buffer in dtrace.
the Subroutines copyinto copies data at user address to scratch buffer, but how can i get the buffer used by the 3rd argument in copyinto;
thanks.
--
This message posted from opensolaris.org
2006 Sep 06
3
Dtrace Snooping
Dear dtrace Experts,
I have seen some dtrace utilities like opensnoop and execsnoop etc.
My interest is to write a simple script that can snoop the files which
uses the 3 syscalls like open,create,unlink.
I have gone through dtrace oneliners that can do the same :
dtrace -n ''syscall::open*:entry { printf("%s %s",execname,copyinstr(arg0));}''
dtrace -n
2007 Jun 11
1
2 iosnoop scripts: different results
I am teaching a DTrace class and a student noticed that 2 iosnoop scripts run in two different windows were producing different results. I was not able to answer why this is. Can anyone explain this. Here are the reults from the two windows:
# io.d
...
sched 0 <none> 1024 dad1 W 0.156
bash 1998
2005 Sep 27
2
Invalid address error message
Hi,
I ran a d-program with syscall::open:entry probe but got the following
error messages sometimes:
dtrace: error on enabled probe ID 1 (ID 14: syscall::open:entry): invalid
address (0xff34e000) in predicate at DIF offset 76
dtrace: error on enabled probe ID 6 (ID 14: syscall::open:entry): invalid
address (0xff34e000) in predicate at DIF offset 28
I don''t know how to interpret these
2007 Jul 30
3
dtrace
hi fnds,
i want to print the filenames on which the stat system
call is acting when a stat system call is invoked. can anyone can help
me this regard.
Thanks
jeevan
2006 May 24
2
Reading external files with dtrace
I''d like to be able to dynamically read external configuration files within a dtrace script. I know dtrace allows inclusion of C header files but only at the preprocessing stage.
What we need to do is dynamically enable/disable probes based on current application settings. I''d rather not have a bunch of independant scripts running and being started and killed whenever the
2006 Jul 17
7
access to errno when using pid provider
I would like to know how to get access to errno when using pid provider to probe calls to
libc functions like fopen(). The built-in errno appears to be only for system calls. What I''d
like to be able to do is investigate where in an application I''m encountering EMFILE and
what the stack looks like at the time.
This message posted from opensolaris.org
2006 Mar 24
3
Triggering on close of a written file.
I have just started my first ''serious'' dtrace script and can use some
advice.
I want to have a probe triggered when close() occurs after a
succesfull write of /etc/hosts ( I want to regenerate the nameserver
zone files
from /etc/hosts after it has changed)
At the moment I have the following code:
syscall::open*:entry,
syscall::creat*:entry
{
self->file=arg0;