Date: Tue, 12 Nov 2013 20:42:39 +0800 (SGT) From: Prashanth Kumar <pra_udupi@yahoo.co.in> To: "freebsd-dtrace@freebsd.org" <freebsd-dtrace@freebsd.org> Subject: Fw: your mail Message-ID: <1384260159.73063.YahooMailNeo@web192605.mail.sg3.yahoo.com> In-Reply-To: <1384258564.17896.YahooMailNeo@web192603.mail.sg3.yahoo.com> References: <1384228985.51085.YahooMailNeo@web192604.mail.sg3.yahoo.com> <20131112041805.GA76413@raichu> <1384258564.17896.YahooMailNeo@web192603.mail.sg3.yahoo.com>
next in thread | previous in thread | raw e-mail | index | archive | help
Hi Mark
---------------------------------------
/* scan.c */
#include <stdio.h>
int main()
{
int str[10];
if (scanf("%s", str) > 0)
printf("name %s\n", str);
return 0;
}
-----------------------------
> "dtrace -n 'pid$target:::entry' -c scanf"
if you run the above dtrace command on the program , dtrace will not exit and hung in input.
Regards
Prashanth
On Tuesday, 12 November 2013 8:18 AM, Mark Johnston <markj@freebsd.org> wrote:
On Tue, Nov 12, 2013 at 12:03:05PM +0800, Prashanth Kumar wrote:
> Hello,
>
> I had been doing some work on the pid provider in Dtrace.
Hi Prashanth,
I've been going through your patches and committing them as time permits.
> I have made a few modification
> so that it will list all the functions used in the program as seen in Solaris or MacOSX.
> Presently in FreeBSD, you have to name each functions you have to probe in the program. For
> example "dtrace -n 'pid$target:program::entry' -c ./program" will list all the functions called
> in the
program.This modification was made in libproc library(proc_sym.c).
This has been fixed:
http://svnweb.freebsd.org/base?view=revision&revision=257300
http://svnweb.freebsd.org/base?view=revision&revision=258000
>
> Also while creating probe points for return probe type, any function with more than one return
> path will fail.This is because "fasttrap_probe_spec_t" type variable is not fully copied into the
> kernel in fasttrap_ioctl() function.I have modified in line with Solaris code
where the copying is
> done manually by Dtrace, rather than the kernel.(fasttap.c, fasttrap.h)
I'm working on this one.
> Also in "fasttrap_pid_probe()" (fasttrap_isa.c) for the case of "FASTTRAP_T_PUSHL_EBP", the ebp register
> has to be copied to the stack not esp.
> I had attached the patch files for review.
This has been fixed:
http://svnweb.freebsd.org/base?view=revision&revision=257679
http://svnweb.freebsd.org/base?view=revision&revision=257143
>
> One other issue i noticed is that if the program being traced uses Thread Local Storage than
> for the case of entry probe, it will hang in ___tls_get_addr function in ld-elf.so.
> If you use scanf or fscanf in your program you can notice this behaviour. This i believe is due to
> Dtrace using gs segment register to point to the scratch space, and TLS also loading the thread variable
> from gs register.
I haven't been able to reproduce this one yet. If you can send me a
program and D script that does the trick, that'd be very helpful.
>
> if you change the following code in fasttrap_isa.c
> <code>
> #ifdef __i386__
> addr = USD_GETBASE(&curthread->td_pcb->pcb_gsd);
> #else
> addr = curthread->td_pcb->pcb_gsbase;
> #endif
> addr += sizeof (void *);
> </code>
>
> to
>
> <code>
> #ifdef __i386__
> addr = USD_GETBASE(&curthread->td_pcb->pcb_gsd);
> #else
> addr = curthread->td_pcb->pcb_gsbase;
> #endif
>
addr += sizeof (void *) * 3;
> </code>
>
> the Dtrace will not hang. I am not sure what is happening here and
> whether this is the correct solution.
Neither am I. :)
> This changes were made in FreeBSD 9.2-386-RELEASE. I applied the above patches on
> FreeBSD 10-BETA (with some manual work) and it was still working.
> _______________________________________________
> freebsd-dtrace@freebsd.org mailing list
> https://lists.freebsd.org/mailman/listinfo/freebsd-dtrace
> To unsubscribe, send any mail to "freebsd-dtrace-unsubscribe@freebsd.org
"
From owner-freebsd-dtrace@FreeBSD.ORG Tue Nov 12 16:01:19 2013
Return-Path: <owner-freebsd-dtrace@FreeBSD.ORG>
Delivered-To: freebsd-dtrace@freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org
[IPv6:2001:1900:2254:206a::19:1])
(using TLSv1 with cipher ADH-AES256-SHA (256/256 bits))
(No client certificate requested)
by hub.freebsd.org (Postfix) with ESMTPS id B05BB4ED
for <freebsd-dtrace@freebsd.org>; Tue, 12 Nov 2013 16:01:19 +0000 (UTC)
Received: from mail-qe0-x232.google.com (mail-qe0-x232.google.com
[IPv6:2607:f8b0:400d:c02::232])
(using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits))
(No client certificate requested)
by mx1.freebsd.org (Postfix) with ESMTPS id 782282775
for <freebsd-dtrace@freebsd.org>; Tue, 12 Nov 2013 16:01:19 +0000 (UTC)
Received: by mail-qe0-f50.google.com with SMTP id 1so5759453qee.9
for <freebsd-dtrace@freebsd.org>; Tue, 12 Nov 2013 08:01:18 -0800 (PST)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s 120113;
h=mime-version:date:message-id:subject:from:to:content-type;
bh=SQubBQr4FEjiygwLztQqXBTdycovjvRNRTjRECJ1YTM=;
b=ul7PdNmKjHsCUb7oAg1iQnw+O4hN5rJqyYl0NwomP5bRHk4xgLYQ5vqNYeZK3pXNHs
Cen1qIdKjps9heNfgkXzmpRAg1QTFievzpGtQMMfoHQejzfiYXtlzmN8wy/IkdlM6zbD
sQHFB+yz4auWRHrNZu4xG0NaAdqGngUvMo7LoBaRir/i+o2UsoJVMIXi6BH2mChMuZq/
mWYk9/YjursiMROekwZl4lj1kbSHGpHW2K1H3eEmMjZSh24HdMGJFLGh8ZOz5voxyaCv
eDkuf0Jqmak9U7P4V/58WveB7Ttlm0iUfugJXbbpQ0gTna35aW1CJhOMAq3nHx0xQ08I
nFvg=MIME-Version: 1.0
X-Received: by 10.224.103.199 with SMTP id l7mr59542459qao.56.1384272078701;
Tue, 12 Nov 2013 08:01:18 -0800 (PST)
Received: by 10.224.160.77 with HTTP; Tue, 12 Nov 2013 08:01:18 -0800 (PST)
Date: Wed, 13 Nov 2013 00:01:18 +0800
Message-ID: <CAAvnz_pb_6gwx7fF1731qUf4D5Bia9uZKKMRsyJgy_yAhYQg-g@mail.gmail.com>
Subject: bug in dtrace mips fbt
From: Howard Su <howard0su@gmail.com>
To: freebsd-dtrace@freebsd.org
Content-Type: text/plain; charset=ISO-8859-1
X-Content-Filtered-By: Mailman/MimeDel 2.1.16
X-BeenThere: freebsd-dtrace@freebsd.org
X-Mailman-Version: 2.1.16
Precedence: list
List-Id: "A discussion list for developers working on DTrace in FreeBSD."
<freebsd-dtrace.freebsd.org>
List-Unsubscribe: <https://lists.freebsd.org/mailman/options/freebsd-dtrace>,
<mailto:freebsd-dtrace-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-dtrace/>;
List-Post: <mailto:freebsd-dtrace@freebsd.org>
List-Help: <mailto:freebsd-dtrace-request@freebsd.org?subject=help>
List-Subscribe: <https://lists.freebsd.org/mailman/listinfo/freebsd-dtrace>,
<mailto:freebsd-dtrace-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Tue, 12 Nov 2013 16:01:19 -0000
I notice a small error in fbt provider of mips.
In file: cddl/dev/fbt/powerpc.c
222: limit = (u_int32_t *) symval->value + symval->size;
this should be limit = (u_int32_t *) ((u_int8_t*)symval->value +
symval->size);
I don't have powerpc to test. anyone can test this and fix it?
-Howard
--
-Howard
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?1384260159.73063.YahooMailNeo>