valgrind-users — General discussion list for Valgrind users

Re: [Valgrind-users] [Fwd: Re: Random failures when calling free()/malloc()]

[Dirk M. <dm...@gm...>]

On Mon, 14 Jul 2003, Dan Kegel wrote:

> Say, could someone look into the problem Martin is
> having?

NPTL is currently not supported. However we have a configure check and try 
to enforce the use of the pthread library instead. Any reason why that is 
broken on Gentoo ?


-- 
Dirk

Re: [Valgrind-users] BerkeleyDB gets bogus errno in Valgrind

[Erik C. <er...@ar...>]

On Sat, Jul 12, 2003 at 07:01:30PM -0700, Dan Kegel wrote:
> Julian Seward wrote:
> > I think I have fixed this problem.  Can you build from cvs and see
> > if the situation has improved?
> 
> Nope, the CVS situation hasn't improved :-)
> 
> I still can't retrieve sources from CVS:
> 
> Logging in to :pserver:ano...@cv...:2401/cvsroot/valgrind
> CVS password:
> cvs [login aborted]: end of file from server (consult above messages if any)

I get that if I have the CVS_RSH environment variable set to ssh
(for other projects).  Unset the variable and it works (for me).

-- 
Erik Corry er...@ar...

[Valgrind-users] [Fwd: Re: Random failures when calling free()/malloc()]

[Dan K. <da...@ke...>]

Say, could someone look into the problem Martin is
having?
- Dan

-------- Original Message --------
Subject: Re: Random failures when calling free()/malloc()
Date: 14 Jul 2003 00:16:15 +0200
From: Martin Schlemmer <az...@ge...>
Reply-To: az...@ge...
To: Petter Reinholdtsen <pe...@hu...>
CC: GLIBC-Alpha Mailing List <lib...@so...>
References: <105...@no...n>	 <105...@no...n>	 <2fl...@sa...>

On Mon, 2003-07-14 at 00:01, Petter Reinholdtsen wrote:
> [Martin Schlemmer]
> > I did try to revert the malloc/* changes in glibc, but still the same
> > thing.
> 
> Did you try to run valgrind on your program?

Sort of, yes.  Latest CVS of valgrind do not compile - lot of
pthread changes.  I did try to fix it, but it will need some
time to get it compiling against nptl it seems.


-- 

Martin Schlemmer





-- 
Dan Kegel
http://www.kegel.com
http://counter.li.org/cgi-bin/runscript/display-person.cgi?user=78045

RE: [Valgrind-users] BerkeleyDB gets bogus errno in Valgrind

[Troels W. H. <tr...@th...>]

For completeness (and because I wanted to upgrade the machine anyway), I
also tested with the latest kernel+glibc, and it worked fine.

$ uname -a
Linux testus 2.4.20-18.8 #1 Thu May 29 07:40:27 EDT 2003 i686 i686 i386
GNU/Linux
$ rpm -q glibc
glibc-2.3.2-4.80.6

Troels

> -----Original Message-----
> From: val...@li... 
> [mailto:val...@li...] On Behalf 
> Of Troels Walsted Hansen
> Sent: 14. juli 2003 10:37
> To: js...@ac...
> Cc: val...@li...
> Subject: RE: [Valgrind-users] BerkeleyDB gets bogus errno in Valgrind
> 
> 
> Summary: it works.
> 
> My original testsystem is using glibc 2.3.2-4.80.6 which contains a
> workaround for the problem. Fortunately I had another RH8 box around
> with stock glibc (2.2.93-5) installed.

RE: [Valgrind-users] BerkeleyDB gets bogus errno in Valgrind

[Troels W. H. <tr...@th...>]

Summary: it works.

My original testsystem is using glibc 2.3.2-4.80.6 which contains a
workaround for the problem. Fortunately I had another RH8 box around
with stock glibc (2.2.93-5) installed.

$ cat /etc/redhat-release
Red Hat Linux release 8.0 (Psyche)
$ uname -a
Linux testus 2.4.18-26.8.0 #1 Mon Feb 24 10:21:42 EST 2003 i686 i686
i386 GNU/Linux
$ rpm -q glibc
glibc-2.2.93-5
$ valgrind --version
valgrind-1.9.6

--> both testcases succeed

$ rpm -q glibc
glibc-2.3.2-4.80

--> both testcases fail

$ valgrind --version
valgrind-cvs-head-2003-07-13

--> both testcases succeed

Troels

> -----Original Message-----
> From: val...@li... 
> [mailto:val...@li...] On Behalf 
> Of Julian Seward
> Sent: 13. juli 2003 03:29
> To: Troels Walsted Hansen
> Cc: val...@li...
> Subject: Re: [Valgrind-users] BerkeleyDB gets bogus errno in Valgrind
> 
> 
> 
> I think I have fixed this problem.  Can you build from cvs and see
> if the situation has improved?

[Valgrind-users] Cry for Assistance

[<ddy...@ne...>]

Dear friend,

You may be surprised to receive this letter from me since
you do not know me personally. I am the first son of the
most popular black farmer in Zimbabwe who was
murdered in the land dispute in my country. I got your
contact through network online hence decided to write
you. Before the death of my father, he had taken me to
Johannesburg to deposit the sum of USD5.Million (Five
million United States dollars), in one of the private
security company, as he foresaw the looming danger in
Zimbabwe. This money was deposited in a box as gem
stones to avoid much demurrage from Security Company.

This amount was meant for the purchase of new machines
and chemicals for the Farms and establishment of new
farms in Swaziland. This land problem came when
Zimbabwean President Mr. Robert Mugabe when he
introduced a new Land Act Reform wholly affecting the
rich white farmers and some few black farmers, and this
resulted to the killing and mob action by Zimbabwean
war veterans and some lunatics in the society. In fact a lot
of people were killed because of this Land reform Act for
which my father was one of the victims. it is against this
background that I and my family fled Zimbabwe to South
Africa for fear of our lives.

After which I traveled to the Netherlands and I am
currently staying in the Netherlands where i am seeking
political asylum and more so have decided to transfer my
father's money to a more reliable foreign account. Since
the law of Europe prohibits a refugee (asylum seeker) to
open any bank account or to be involved in any financial
transaction throughout the territorial zone of European
Union. As the eldest child of my father, I am saddled with
the responsibility of seeking a genuine foreign account
where this money could be transferred without the
knowledge of my government who are bent on taking
everything we have got.

The South African government seems to be playing along
with them. I am faced with the dilemma of moving this
amount of money out of South Africa for fear of going
through the same experience in future. Both countries
have similar political history. I am seeking for a partner
who I have to entrust my future and that of my family in
his hands, I must let you know that this transaction is risk
free. If you accept to assist me and my family, all I want
you to do for me, is to make arrangements with the
security company to clear the Consignment (funds) from
their affiliate office here in the Netherlands as i have
already given directives for the consignment to be brought
to the Netherlands from South Africa.

But before then all modalities will have to be put in place
like change of ownership to the consignment. I have two
options for you. Firstly you can choose to have certain
percentage of the money for nominating your account for
this transaction. Or you can go into partnership with me
for the proper profitable investment of the money in your
country. Whichever the option you want, feel free to
notify me. I have also mapped out 2% of this money for
all kinds of expenses incurred in the process of this
transaction. If you do not prefer a partnership I am willing
to give you 10% of the money while the remaining 88%
will be for my investment in your country. Contact with
me immediately while I implore you to maintain the
absolute secrecy required in this transaction.

Thanks, GOD BLESS YOU

Best regards,

NOTE:
ON YOUR INABILITY TO HANDLE THIS
TRANSACTION RESPOND TO ME AND INFORM
ME SO I CAN LOOK FOR SOMEONE ELSE.

[Valgrind-users] problem debugging mysql code...

[Diego T. <dtg...@te...>]

ehlo!

i've got the following issue when using valgrind. Maybe i'm doing something
wrong or i don't know how to use valgrind. Another point is that maybe this
isn't the correct place to ask about my problem... i'll see :)

the following function:

>----
MYSQL_ROW db_read(const char *q, ...) {
MYSQL_ROW row;
MYSQL_RES * res;

[...]
if ((res = mysql_store_result(&g.mysql_dbh)) != NULL) {
    row = mysql_fetch_row(res);
    mysql_free_result(res);
    return row;
}
[...]
>----

and when debugging with valgrind, i got the following:

==23479== Invalid read of size 1
==23479==    at 0x4028AD24: __strtol_internal (in /lib/libc-2.3.1.so)
==23479==    by 0x40288848: atoi (in /lib/libc-2.3.1.so)
==23479==    by 0x412F874D: mod_load (in
/home/dtorres/prog/develop/rb/mod/db.so)
==23479==    by 0x804CC32: module_init (src/modules.c:43)
==23479==    Address 0x410C8294 is 32 bytes inside a block of size 8164
free'd
==23479==    at 0x4015D6A4: free (vg_clientfuncs.c:185)
==23479==    by 0x40213838: my_no_flags_free (in
/usr/lib/libmysqlclient.so.10.0.0)
==23479==    by 0x402165F4: free_root (in /usr/lib/libmysqlclient.so.10.0.0)
==23479==    by 0x4020F5E8: mysql_free_result (in
/usr/lib/libmysqlclient.so.10.0.0)
==23479==

the atoi is performed over the returned row: atoi(row[0]). So i understand
that when i'm releasing with mysql_free_result, row is contained inside the
res pointer. Checking the documentation from the mysql api doesn't clarify
this situation, it doesn't state if its safe to access rows returned from
mysql_fetch_row. So lets fix it:


MYSQL_ROW db_read(const char *q, ...) {
MYSQL_ROW row;
MYSQL_ROW row2;
MYSQL_RES * res;

[...]
if ((res = mysql_store_result(&g.mysql_dbh)) != NULL) {
    row = mysql_fetch_row(res);
    memcpy(&row2, &row, sizeof(MYSQL_ROW));
    mysql_free_result(res);
    return row2;
}
[...]

now i'm copying the row content to another variable, but got the same
result.

==24120== Invalid read of size 1
==24120==    at 0x4028AA6E: __strtol_internal (in /lib/libc-2.3.1.so)
==24120==    by 0x40288848: atoi (in /lib/libc-2.3.1.so)
==24120==    by 0x412F86F9: mod_load (in
/home/dtorres/prog/develop/rb/mod/db.so)
==24120==    by 0x804CC32: module_init (src/modules.c:43)
==24120==    Address 0x410C18FC is 32 bytes inside a block of size 8164
free'd
==24120==    at 0x4015D6A4: free (vg_clientfuncs.c:185)
==24120==    by 0x40213838: my_no_flags_free (in
/usr/lib/libmysqlclient.so.10.0.0)
==24120==    by 0x402165F4: free_root (in /usr/lib/libmysqlclient.so.10.0.0)
==24120==    by 0x4020F5E8: mysql_free_result (in
/usr/lib/libmysqlclient.so.10.0.0)


The strange thing is that the program is working without problems, and data
from the returned row is always valid. coincidence? If someone has any
idea... please, help! :)

Re: [Valgrind-users] BerkeleyDB gets bogus errno in Valgrind

[Dima B. <di...@cs...>]

I get the following error with the current CVS sources of valgrind:

==20126== Memcheck, a.k.a. Valgrind, a memory error detector for x86-linux.
==20126== Copyright (C) 2002-2003, and GNU GPL'd, by Julian Seward.
==20126== Using valgrind-cvs-head-2003-07-13, a program supervision framework for x86-linux.
==20126== Copyright (C) 2000-2003, and GNU GPL'd, by Julian Seward.
==20126== Estimated CPU clock rate is 266 MHz
==20126== For more details, rerun with: -v
==20126== 
Root = /root/mcoda/root
mam_journalinit:env_open: Function not implemented
mammoth: mam_journal.c:52: mam_journalenvinit: Assertion `0' failed.
Aborted

This is using Redhat 9, gcc 322, glibc 2.3.2, nptl, and BerkeleyDB 1.4.25.

Thanks
ttyl
Dima

On Sun, Jul 13, 2003 at 02:28:45AM +0100, Julian Seward wrote:
> 
> I think I have fixed this problem.  Can you build from cvs and see
> if the situation has improved?
> 
> Thanks,
> 
> J
> 
> 
> Building valgrind from the current cvs sources ... is easy.
> Here's how:
> 
> cvs -d:pserver:ano...@cv...:/cvsroot/valgrind login
> 
> When prompted for a password for anonymous, simply press the Enter key.
> 
> cvs -z3 -d:pserver:ano...@cv...:/cvsroot/valgrind co 
> valgrind
> cd valgrind
> ./autogen.sh
> ./configure --prefix=....
> make
> make install
> 
> And you should be in business.
> 
> 8 Dec 2002
> 
> 
> On Wednesday 07 May 2003 10:01, Troels Walsted Hansen wrote:
> > Sorry, I managed to forget to attach the script.
> >
> > Here's the script, as well as two straces, created with the below
> > commands, on a RH8+glibc 2.3.3 machine.
> >
> > strace python dbboguserrno.py 2> strace-normal.txt
> > strace valgrind python dbboguserrno.py 2> strace-valgrind.txt
> >
> > Both traces show the below syscall, but the instance running in Valgrind
> > seems to get EAGAIN instead...
> >
> > open("nosuchfile.db", O_RDONLY|O_NONBLOCK|O_LARGEFILE) = -1 ENOENT (No
> > such file or directory)
> >
> > Troels
> >
> > > -----Original Message-----
> > > From: Nicholas Nethercote [mailto:nj...@he...] On
> > > Behalf Of Nicholas Nethercote
> > > Sent: 7. mai 2003 10:43
> > > To: Troels Walsted Hansen
> > > Cc: val...@li...
> > > Subject: Re: [Valgrind-users] BerkeleyDB gets bogus errno in Valgrind
> > >
> > > On Wed, 7 May 2003, Troels Walsted Hansen wrote:
> > > > This is the expected behavior of the program.
> > > >
> > > > rpmdb._rpmdb.DBNoSuchFileError: (2, 'No such file or directory')
> > > >
> > > > This is what happens in Valgrind. RH8 and RH9 uses
> > >
> > > BerkeleyDB 4.0.14,
> > >
> > > > rpmdb._rpmdb.DBAgainError: (11, 'Resource temporarily unavailable --
> > > > nosuchfile.db: Resource temporarily unavailable')
> > >
> > > It's possible that Valgrind's doing something slightly
> > > different with file
> > > handling that means you get a different behaviour.  Do you have more
> > > information about what exactly is happening to prompt this
> > > error?  Eg. is
> > > it trying to open a file with the open() system call, or
> > > something like
> > > that?  It's very difficult to know what the problem is from your
> > > description so far.
> > >
> > > N
> 
> 
> 
> -------------------------------------------------------
> This SF.Net email sponsored by: Parasoft
> Error proof Web apps, automate testing & more.
> Download & eval WebKing and get a free book.
> www.parasoft.com/bulletproofapps1
> _______________________________________________
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> https://lists.sourceforge.net/lists/listinfo/valgrind-users

-- 
Dima Brodsky                                   di...@cs...
                                               http://www.cs.ubc.ca/~dima
201-2366 Main Mall
Department of Computer Science                 (604) 822-2895 (DSG Lab)
University of British Columbia, Canada         (604) 822-5485 (FAX)

"The price of reliability is the pursuit of the utmost simplicity.
 It is a price which the very rich find the most hard to pay."
						  (Sir Antony Hoare, 1980)

Re: [Valgrind-users] errno + pthread failure with Valgrind 1.9.6

[Dirk M. <dm...@gm...>]

On Son, 13 Jul 2003, Valient Gough wrote:

> Is this a known problem related to operation with pthreads?

No, but with glibc 2.3.2. Its fixed in CVS.


-- 
Dirk

[Valgrind-users] errno + pthread failure with Valgrind 1.9.6

[Valient G. <vg...@po...>]

I was trying to track down a problem using Valgrind 1.9.6 on a program,
but the program behaved much differently when running under valgrind.

The problem is that a call to lstat() on a non-existant file should
retur -1 and sets errno. This is exactly how it behaves normally, but
when running under valgrind it returns -1 but errno is 0!

Attached is a small test program which calls lstat on a bogus filename. 
Results:

native, no pthreads:  as expected (ret -1, errno = 2)
valgrind, no pthreads: as expected ""
native, pthreads: as expected ""
valgrind, pthreads:  lstat returns -1 but errno = 0!

no pthread build:  g++ -o test-lstat test-lstat.cpp
pthread build:  g++ -o test-lstat test-lstat.cpp -lpthread

SuSE 8.2 system, gcc 3.3 (20030226 prerelease)
glibc 2.3.2

Is this a known problem related to operation with pthreads?

regards,
Valient

[Valgrind-users] valgrind 1.9.6 compile problem with gcc 2.95.2 on SuSE 7.1

[Geoff A. <gal...@nc...>]

I'm trying to install valgrind 1.9.6 on SuSE 7.1 and get the following =
error:
  gcc -DHAVE_CONFIG_H -I. -I. -I.. -I./demangle -I../include =
-DVG_LIBDIR=3D"\"/usr/local/valgrind-1.9.6/lib"\" -Winline -Wall =
-Wshadow -O -fomit-frame-pointer -mpreferred-stack-boundary=3D2 -g =
-fno-omit-frame-pointer -c `test -f 'vg_intercept.c' || echo =
'./'`vg_intercept.c
  vg_intercept.c: In function `vgAllRoadsLeadToRome_poll':
  vg_intercept.c:285: sizeof applied to an incomplete type
  vg_intercept.c: In function `vgAllRoadsLeadToRome_select':
  vg_intercept.c:564: sizeof applied to an incomplete type
  vg_intercept.c:575: dereferencing pointer to incomplete type
  vg_intercept.c:575: dereferencing pointer to incomplete type
  vg_intercept.c:595: dereferencing pointer to incomplete type
  vg_intercept.c:596: dereferencing pointer to incomplete type
  make[3]: *** [vg_intercept.o] Error 1
I'm using gcc 2.95.2.  Anyone seen this before?

BTW, I tried to search the valgrind-users mail archive at =
sourceforge.net =
(http://sourceforge.net/mailarchive/forum.php?forum_id=3D32038), but no =
matter what I entered I got "no matches found".  Is it possible to =
search the mail archives?

Thanks,
Geoff Alexander

Re: [Valgrind-users] BerkeleyDB gets bogus errno in Valgrind

[Steve G <lin...@ya...>]

>Does it actually work for you?  I had the impression 
>the cvs server's been down for weeks.

I've had mixed results getting cvs over the last month. I
tried 5 times this week and only got in twice. The times I
got in were slow to start and then seemed OK once it was
underway.

-Steve Grubb

__________________________________
Do you Yahoo!?
SBC Yahoo! DSL - Now only $29.95 per month!
http://sbc.yahoo.com

Re: [Valgrind-users] BerkeleyDB gets bogus errno in Valgrind

[Dan K. <da...@ke...>]

Dan Kegel wrote:
> Julian Seward wrote:
> 
>> I think I have fixed this problem.  Can you build from cvs and see
>> if the situation has improved?
> 
> 
> Nope, the CVS situation hasn't improved :-)
> 
> I still can't retrieve sources from CVS:

Scratch that.  I can now.  Must have been a cosmic ray.
- Dan

-- 
Dan Kegel
http://www.kegel.com
http://counter.li.org/cgi-bin/runscript/display-person.cgi?user=78045

Re: [Valgrind-users] BerkeleyDB gets bogus errno in Valgrind

[Dan K. <da...@ke...>]

Julian Seward wrote:
> I think I have fixed this problem.  Can you build from cvs and see
> if the situation has improved?

Nope, the CVS situation hasn't improved :-)

I still can't retrieve sources from CVS:

Logging in to :pserver:ano...@cv...:2401/cvsroot/valgrind
CVS password:
cvs [login aborted]: end of file from server (consult above messages if any)

Does it actually work for you?  I had the impression the cvs
server's been down for weeks.
- Dan

-- 
Dan Kegel
http://www.kegel.com
http://counter.li.org/cgi-bin/runscript/display-person.cgi?user=78045

Re: [Valgrind-users] BerkeleyDB gets bogus errno in Valgrind

[Julian S. <js...@ac...>]

I think I have fixed this problem.  Can you build from cvs and see
if the situation has improved?

Thanks,

J


Building valgrind from the current cvs sources ... is easy.
Here's how:

cvs -d:pserver:ano...@cv...:/cvsroot/valgrind login

When prompted for a password for anonymous, simply press the Enter key.

cvs -z3 -d:pserver:ano...@cv...:/cvsroot/valgrind co 
valgrind
cd valgrind
./autogen.sh
./configure --prefix=....
make
make install

And you should be in business.

8 Dec 2002


On Wednesday 07 May 2003 10:01, Troels Walsted Hansen wrote:
> Sorry, I managed to forget to attach the script.
>
> Here's the script, as well as two straces, created with the below
> commands, on a RH8+glibc 2.3.3 machine.
>
> strace python dbboguserrno.py 2> strace-normal.txt
> strace valgrind python dbboguserrno.py 2> strace-valgrind.txt
>
> Both traces show the below syscall, but the instance running in Valgrind
> seems to get EAGAIN instead...
>
> open("nosuchfile.db", O_RDONLY|O_NONBLOCK|O_LARGEFILE) = -1 ENOENT (No
> such file or directory)
>
> Troels
>
> > -----Original Message-----
> > From: Nicholas Nethercote [mailto:nj...@he...] On
> > Behalf Of Nicholas Nethercote
> > Sent: 7. mai 2003 10:43
> > To: Troels Walsted Hansen
> > Cc: val...@li...
> > Subject: Re: [Valgrind-users] BerkeleyDB gets bogus errno in Valgrind
> >
> > On Wed, 7 May 2003, Troels Walsted Hansen wrote:
> > > This is the expected behavior of the program.
> > >
> > > rpmdb._rpmdb.DBNoSuchFileError: (2, 'No such file or directory')
> > >
> > > This is what happens in Valgrind. RH8 and RH9 uses
> >
> > BerkeleyDB 4.0.14,
> >
> > > rpmdb._rpmdb.DBAgainError: (11, 'Resource temporarily unavailable --
> > > nosuchfile.db: Resource temporarily unavailable')
> >
> > It's possible that Valgrind's doing something slightly
> > different with file
> > handling that means you get a different behaviour.  Do you have more
> > information about what exactly is happening to prompt this
> > error?  Eg. is
> > it trying to open a file with the open() system call, or
> > something like
> > that?  It's very difficult to know what the problem is from your
> > description so far.
> >
> > N

[Valgrind-users] Re: from Joe alt

[Sherman W. <in7...@fo...>]

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Re: [Valgrind-users] float cast

[ragnar s. <rag...@po...>]

Thanks for all replys, and so quickly!

I now understand using floats/doubles
together with gcc optimization can
give cosmetical errors in binaries, that valgrind detects.

I also apologize for not including the
original code, where the optimizer shouldn't remove so much code. Also sorry for not telling the gcc version (2.96.4) right away.

Thanks for your help!

cheers
Ragnar


___________________________________________________ 
Where in the body can you find your metacarpal bones? 
Find out at postmaster.co.uk

http://www.postmaster.co.uk/cgi-bin/meme/quiz.pl?id=201

Re: [Valgrind-users] float cast

[Dirk M. <dm...@gm...>]

On Don, 10 Jul 2003, ragnar sjoberg wrote:

> .LC0:
>         .long 0x3f333333
> .text
>         .align 4
> <snip>
>         flds .LC0

>         .long 0x66666666,0x3fe66666
> .text
>         .align 4
> <snip>
>         fldl .LC0


> My guess is the first assembler output
> is using single-precision, and the second
> defaults to double ?

Yes, see flds vs fldl. So the assembly is correct, valgrinds warning is 
wrong as far as I can see. 

However, I cannot reproduce it with the current CVS HEAD version. perhaps it 
depends on the compiler / glibc ? which versions do you use? 


-- 
Dirk

Re: [Valgrind-users] float cast

[Paul H. <pa...@ha...>]

On Thu, 10 Jul 2003, ragnar sjoberg wrote:

> Thanks for the help, I've upgraded to 1.9.6,
> but valgrind still gives the same result.

It looks like a gcc problem, not a valgrind problem.

I added '#include <stdlib.h>' to prog.c to get the definition for exit().
exit() isn't defined in stdio.h anymore.  How old is your copy of gcc?

Here is your original func.c:
#include <stdio.h>

void
func_one (int len)
{
int c;
float e;

  e = 0;
  c = 0;
  while(c < len)
  {
    e = e * 0.7;
    c++;
  }
}

"e" isn't used for anything except calculating "e".  In your first example
you compiled with -O3.  The compiler should have optimized away all of the
references to "e" and 0.7.

I looked at the assembler output after typing:
gcc -S -O3 func.c
and they were indeed gone. (Still room for improvement, the loop was still
there.)

It looks like your version of gcc only removed some of the dead code.
Leaving some broken dead code.  Valgrind detected that the dead code was
broken.

> Still, is there a error in the func.c/prog.c program, that valgrind thinks ?

I tried a couple different versions of gcc and valgrind didn't see any
problems when I compiled them.

The versions I tried were:
gcc version 3.2.3 20030331 (Debian prerelease)
gcc version 2.96 20000731 (Red Hat Linux 7.3 2.96-113)

Type
gcc -v
to see what compiler you are using.
--
Paul Haas pa...@ha...

RE: [Valgrind-users] float cast

[Vincent Penquerc'h <Vin...@ar...>]

> Gcc treats:
> float e;
>   e = e * 0.7;
> differently from :
> e = e * (float)0.7;

0.7 is a double
0.7f is a float
(float)0.7 is a float (double immediate casted to a float)

-- 
Vincent Penquerc'h 

[Valgrind-users] float cast

[ragnar s. <rag...@po...>]

Thanks for the help, I've upgraded to 1.9.6,
but valgrind still gives the same result.

Considering the following code:
int
main (int argc, char **argv)
{
float e;

  e = 0;
  e = e * (float)0.7;

  return 0;
}


Gcc treats:
float e;
  e = e * 0.7;
differently from :
e = e * (float)0.7;

As is shown in this assembler output,
when toggling first with the (float) cast
then without:
---------------
.section        .rodata
        .align 4
.LC0:
        .long 0x3f333333
.text
        .align 4
<snip>
        flds .LC0
        fmulp %st,%st(1)

--------------

.section        .rodata
        .align 8
.LC0:
        .long 0x66666666,0x3fe66666
.text
        .align 4
<snip>
        fldl .LC0
        fmulp %st,%st(1)
-------

My guess is the first assembler output
is using single-precision, and the second
defaults to double ?

So the func.c/prog.c should use double-precision correctly I assume ?

Still, is there a error in the func.c/prog.c program, that valgrind thinks ?

thanks
Ragnar


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Re: [Valgrind-users] no subject

[Igmar P. <mai...@jd...>]

> So I wonder why I need this cast, and why
> valgrind tell me about an error only if the
> function is kept in a separate file, and
> not shown when the function is brought inside
> the main() file.

Valgrind 1.9.6 doesn't give errors, I suggest you upgrade.



	Igmar

[Valgrind-users] no subject

[ragnar s. <rag...@po...>]

Hello!

I have two C files:
---------------------
#include <stdio.h>

void
func_one (int len)
{
int c;
float e;

  e = 0;
  c = 0;
  while(c < len)
  {
    e = e * 0.7;
    c++;
  }
}

--------------------
#include <stdio.h>

void
func_one (int size);

void
func_two (int len)
{
int c;
float e;

  e = 0;
  c = 0;
  while(c < len)
  {
    e = e * 0.7;
    c++;
  }
}

int
main (int argc, char **argv)
{

  func_one (1024);
  func_two (1024);

  exit(0);
}
-------------------

These two I compile with:

gcc -g -O3 -Wall -c func.c -o func.o 
gcc -g -O3 -Wall prog.c -o prog func.o  


Now when I run valgrind I get:
$ valgrind -v --gdb-attach=yes ./prog
==4808== Memcheck, a.k.a. Valgrind, a memory error detector for x86-linux.
==4808== Copyright (C) 2002, and GNU GPL'd, by Julian Seward.
==4808== Using valgrind-1.9.5, a program instrumentation system for x86-linux.
==4808== Copyright (C) 2000-2002, and GNU GPL'd, by Julian Seward.
==4808== Startup, with flags:
==4808==    --suppressions=/usr/local/lib/valgrind/default.supp
==4808==    -v
==4808==    --gdb-attach=yes
==4808== Reading suppressions file: /usr/local/lib/valgrind/default.supp
==4808== Estimated CPU clock rate is 1001 MHz
==4808== 
==4808== Reading syms from /prog
==4808== Reading syms from /lib/ld-2.2.5.so
==4808==    object doesn't have any debug info
==4808== Reading syms from /usr/local/lib/valgrind/vgskin_memcheck.so
==4808== Reading syms from /usr/local/lib/valgrind/valgrind.so
==4808== Reading syms from /lib/libc-2.2.5.so
==4808==    object doesn't have any debug info
==4808== Use of uninitialised value of size 8
==4808==    at 0x804843D: func_one (func.c:11)
==4808==    by 0x804841A: main (prog.c:25)
==4808==    by 0x4023214E: __libc_start_main (in /lib/libc-2.2.5.so)
==4808==    by 0x8048330: (within /prog)
==4808== 
==4808== ---- Attach to GDB ? --- [Return/N/n/Y/y/C/c] ---- 
...

If i remark func_one() inside main,
so only func_two() will be called, then
valgrind will not show any errors.

Also if I change the line in func_one() to:
    e = e * (float)0.7;
valgrind will also not complain about errors.

So I wonder why I need this cast, and why
valgrind tell me about an error only if the
function is kept in a separate file, and
not shown when the function is brought inside
the main() file.

Thanks for any help on this.
Ragnar



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Re: [Valgrind-users] valgrind and dns queries

[Julian S. <js...@ac...>]

Ok, I've just committed to cvs an alternative function-call intercept
scheme which works around this, and causes the res_search test case
associated with this thread, to work properly on my SuSE 8.2
(glibc-2.3.2) box.  So I think it's sorted.

J

On Wednesday 09 July 2003 21:06, Julian Seward wrote:
> On Wednesday 09 July 2003 02:18, Dan Kegel wrote:
> > Julian Seward wrote:
> > > I guess the only advice I can offer is to avoid glibc-2.3.2 based
> > > systems at the moment, and to ask the glibc people to fix this bug
> > > (never do PLT bypassing for calls to __errno_location,
> > > __h_errno_location or __res_state).
> >
> > Did you get no response to your earlier message,
> > http://sources.redhat.com/ml/libc-alpha/2003-05/msg00145.html
> > ?
>
> No, in a word.
>
> J
>
>
>
> -------------------------------------------------------
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Re: [Valgrind-users] valgrind and dns queries

[Julian S. <js...@ac...>]

On Wednesday 09 July 2003 02:18, Dan Kegel wrote:
> Julian Seward wrote:
> > I guess the only advice I can offer is to avoid glibc-2.3.2 based systems
> > at the moment, and to ask the glibc people to fix this bug (never do
> > PLT bypassing for calls to __errno_location, __h_errno_location or
> >  __res_state).
>
> Did you get no response to your earlier message,
> http://sources.redhat.com/ml/libc-alpha/2003-05/msg00145.html
> ?

No, in a word.

J