[Valgrind-users] valgrind with LD_PRELOAD
Greetings, I invoke my program as follows: LD_PRELOAD=./libfakec.so ./my_app –e The LD_PRELOAD environment variable tells the loader that libfakec.so should be loaded BEFORE every other library including the C runtime, libc.so (see http://stackoverflow.com/questions/426230/what-is-the-ld-preload-trick, for example). I am substituting some of my own routines for standard library calls. My app is working like I want, but the question is how to run the app under valgrind? I tried this: valgrind LD_PRELOAD=./libfakec.so ./my_app –e But valgrind gave and error saying that LD_PRELOAD=./libfakec.so ./my_app –e is not a valid path. In theory, I could put the LD_PRELOAD before the valgrind invocation: LD_PRELOAD=./libfakec.so valgrind ./my_app –e But then valgrind would also be using my special library routines and I am pretty sure that will not work. Is there a way around this? I am running on CentOS 6.5. -Sam PS: I tried to figure out how to search the archives of this mailing list for LD_PRELOAD, but I could not see a way. -- CenturyLink Cloud: The Leader in Enterprise Cloud Services. Learn Why More Businesses Are Choosing CenturyLink Cloud For Critical Workloads, Development Environments Everything In Between. Get a Quote or Start a Free Trial Today. http://pubads.g.doubleclick.net/gampad/clk?id=119420431iu=/4140/ostg.clktrk___ Valgrind-users mailing list Valgrind-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/valgrind-users
[Valgrind-users] valgrind with shell scripts
Greetings, Normally I invoke my app using a shell script: ./run.sh –e run log If I invoke this script using valgrind: valgrind ./run.sh –e run log Will valgrind evaluate the shell script or my app or both? -Sam -- CenturyLink Cloud: The Leader in Enterprise Cloud Services. Learn Why More Businesses Are Choosing CenturyLink Cloud For Critical Workloads, Development Environments Everything In Between. Get a Quote or Start a Free Trial Today. http://pubads.g.doubleclick.net/gampad/clk?id=119420431iu=/4140/ostg.clktrk___ Valgrind-users mailing list Valgrind-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/valgrind-users
Re: [Valgrind-users] valgrind with shell scripts
On Tue, Jan 14, 2014 at 7:18 AM, Samuel Quiring samuel_quir...@symantec.com wrote: valgrind ./run.sh –e run log Will valgrind evaluate the shell script or my app or both? Just the shell script. Try --trace-children=yes . -- CenturyLink Cloud: The Leader in Enterprise Cloud Services. Learn Why More Businesses Are Choosing CenturyLink Cloud For Critical Workloads, Development Environments Everything In Between. Get a Quote or Start a Free Trial Today. http://pubads.g.doubleclick.net/gampad/clk?id=119420431iu=/4140/ostg.clktrk ___ Valgrind-users mailing list Valgrind-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/valgrind-users
Re: [Valgrind-users] valgrind with shell scripts
On Tuesday 14 January 2014 07:18:05 Samuel Quiring wrote: Greetings, Normally I invoke my app using a shell script: ./run.sh –e run log [I don't understand the run log part of it, but let's ignore that] If I invoke this script using valgrind: valgrind ./run.sh –e run log Will valgrind evaluate the shell script or my app or both? The shell script. Better modify the shell script itself to call valgrind :) But you can also use the above command with --trace-children=yes and then it will trace all children, including your app. -- David Faure, fa...@kde.org, http://www.davidfaure.fr Working on KDE, in particular KDE Frameworks 5 -- CenturyLink Cloud: The Leader in Enterprise Cloud Services. Learn Why More Businesses Are Choosing CenturyLink Cloud For Critical Workloads, Development Environments Everything In Between. Get a Quote or Start a Free Trial Today. http://pubads.g.doubleclick.net/gampad/clk?id=119420431iu=/4140/ostg.clktrk ___ Valgrind-users mailing list Valgrind-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/valgrind-users
[Valgrind-users] Best valgrind options for finding corrupt memory
Greetings, I suspect my program is corrupting (overwriting) memory, e.g., malloc'ing 16 bytes for a string that is 17 bytes when you count the nul, then copying 17 bytes into the 16 byte area. What are the best valgrind options for detecting memory corruption? -Sam -- CenturyLink Cloud: The Leader in Enterprise Cloud Services. Learn Why More Businesses Are Choosing CenturyLink Cloud For Critical Workloads, Development Environments Everything In Between. Get a Quote or Start a Free Trial Today. http://pubads.g.doubleclick.net/gampad/clk?id=119420431iu=/4140/ostg.clktrk___ Valgrind-users mailing list Valgrind-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/valgrind-users
Re: [Valgrind-users] Best valgrind options for finding corrupt memory
On Tuesday 14 January 2014 08:03:14 Samuel Quiring wrote: Greetings, I suspect my program is corrupting (overwriting) memory, e.g., malloc'ing 16 bytes for a string that is 17 bytes when you count the nul, then copying 17 bytes into the 16 byte area. What are the best valgrind options for detecting memory corruption? The default options :-) (memcheck tool) -- David Faure, fa...@kde.org, http://www.davidfaure.fr Working on KDE, in particular KDE Frameworks 5 -- CenturyLink Cloud: The Leader in Enterprise Cloud Services. Learn Why More Businesses Are Choosing CenturyLink Cloud For Critical Workloads, Development Environments Everything In Between. Get a Quote or Start a Free Trial Today. http://pubads.g.doubleclick.net/gampad/clk?id=119420431iu=/4140/ostg.clktrk ___ Valgrind-users mailing list Valgrind-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/valgrind-users
Re: [Valgrind-users] valgrind with shell scripts
Or modify the shellscript to add valgrind and its args to the statement that invokes your final program. Fred Smith Senior Applications Programmer/Analyst Computrition, Inc. 175 Middlesex Turnpike Bedford, MA 01730 ph: 781-275-4488 x5013 fax: 781-357-4100 -Original Message- From: Dan Kegel [mailto:d...@kegel.com] Sent: Tuesday, January 14, 2014 10:36 AM To: Samuel Quiring Cc: valgrind-users@lists.sourceforge.net Subject: Re: [Valgrind-users] valgrind with shell scripts On Tue, Jan 14, 2014 at 7:18 AM, Samuel Quiring samuel_quir...@symantec.com wrote: valgrind ./run.sh -e run log Will valgrind evaluate the shell script or my app or both? Just the shell script. Try --trace-children=yes . -- CenturyLink Cloud: The Leader in Enterprise Cloud Services. Learn Why More Businesses Are Choosing CenturyLink Cloud For Critical Workloads, Development Environments Everything In Between. Get a Quote or Start a Free Trial Today. http://pubads.g.doubleclick.net/gampad/clk?id=119420431iu=/4140/ostg.clktrk ___ Valgrind-users mailing list Valgrind-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/valgrind-users This email and any files transmitted with it are confidential and intended solely for the use of the individual or entity to which they are addressed. If you have received this email in error please notify the system manager. Please note that any views or opinions presented in this email are solely those of the author and do not necessarily represent those of the company. Finally, the recipient should check this email and any attachments for the presence of viruses. The company accepts no liability for any damage caused by any virus transmitted by this email -- CenturyLink Cloud: The Leader in Enterprise Cloud Services. Learn Why More Businesses Are Choosing CenturyLink Cloud For Critical Workloads, Development Environments Everything In Between. Get a Quote or Start a Free Trial Today. http://pubads.g.doubleclick.net/gampad/clk?id=119420431iu=/4140/ostg.clktrk ___ Valgrind-users mailing list Valgrind-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/valgrind-users
Re: [Valgrind-users] valgrind with shell scripts
On Tue, Jan 14, 2014 at 7:18 AM, Samuel Quiring samuel_quir...@symantec.com wrote: Will valgrind evaluate the shell script or my app or both? The script, and as others have said, --trace-children=yes will do what you want. However... ...you can also change your script to exec your app. That is better style anyway (fewer processes, allows parent process to retrieve proper exit status, etc.), if your script does not have any work to do after your app terminates. - Pat -- CenturyLink Cloud: The Leader in Enterprise Cloud Services. Learn Why More Businesses Are Choosing CenturyLink Cloud For Critical Workloads, Development Environments Everything In Between. Get a Quote or Start a Free Trial Today. http://pubads.g.doubleclick.net/gampad/clk?id=119420431iu=/4140/ostg.clktrk ___ Valgrind-users mailing list Valgrind-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/valgrind-users
Re: [Valgrind-users] valgrind with LD_PRELOAD
On Tue, 2014-01-14 at 07:14 -0800, Samuel Quiring wrote: LD_PRELOAD=./libfakec.so valgrind ./my_app –e But then valgrind would also be using my special library routines and I am pretty sure that will not work. Is there a way around this? I am running on CentOS 6.5. I guess that your second question, related to running a shell script and its children under Valgrind is related to setting LD_PRELOAD in the run.sh. I am not sure that this will solve the possible problem. Here are some elements: There are 2 stages for starting your program under valgrind. The stage 1 is the valgrind launcher (this is the valgrind executable). This is a normal executable, dynamically linked, and depends on some standard shared libs as shown by ldd valgrind linux-gate.so.1 = (0x007ab000) libc.so.6 = /lib/libc.so.6 (0x00214000) /lib/ld-linux.so.2 (0x001f2000) valgrind (stage 1) will then launch the stage 2, which is the specific tool as requested on the command line (e.g. memcheck) and for the needed platform (e.g. x86). So, it will e.g. launch memcheck-x86-linux, which is not a dynamic executable: ldd memcheck-x86-linux not a dynamic executable As long as your LD_PRELOAD does not change the behaviour of the libraries used by valgrind stage 1, then valgrind stage 1 should work properly. If your LD_PRELOAD replaces things part of e.g. libc, you might have problems in valgrind stage 1. If you cannot make all that work, there might be ways to solve that: * maybe statically link the valgrind stage 1 ? * otherwise, modify the function setup_client_env in coregrind/m_initimg/initimg-linux.c so as to add your specific LD_PRELOAD string only for the client. (but I suspect that will however then not work with --trace-children=yes, as then the LD_PRELOAD will be used by the valgrind stage 1 used to launch the tool on a forked/exec-ed children. Hope this helps, give some feedback about what has worked (or not). We might maybe need to add a valgrind option --client-ld-preload=.. to avoid such problem ? Or alternatively, statically link valgrind (but that means that valgrind can then only be built if all libs for static linking are available). Philippe -- CenturyLink Cloud: The Leader in Enterprise Cloud Services. Learn Why More Businesses Are Choosing CenturyLink Cloud For Critical Workloads, Development Environments Everything In Between. Get a Quote or Start a Free Trial Today. http://pubads.g.doubleclick.net/gampad/clk?id=119420431iu=/4140/ostg.clktrk ___ Valgrind-users mailing list Valgrind-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/valgrind-users
Re: [Valgrind-users] Best valgrind options for finding corrupt memory
Hi, Yes defaults. Starting at 4:52 of this YouTube video you will see this fellow determine that his code also has the strlen problem with malloc: http://www.youtube.com/watch?v=fvTsFjDuag8 Bye, Gene Fortanely | Freescale Semiconductor -Original Message- From: David Faure [mailto:fa...@kde.org] Sent: Tuesday, January 14, 2014 10:05 AM To: valgrind-users@lists.sourceforge.net Cc: Samuel Quiring Subject: Re: [Valgrind-users] Best valgrind options for finding corrupt memory On Tuesday 14 January 2014 08:03:14 Samuel Quiring wrote: Greetings, I suspect my program is corrupting (overwriting) memory, e.g., malloc'ing 16 bytes for a string that is 17 bytes when you count the nul, then copying 17 bytes into the 16 byte area. What are the best valgrind options for detecting memory corruption? The default options :-) (memcheck tool) -- David Faure, fa...@kde.org, http://www.davidfaure.fr Working on KDE, in particular KDE Frameworks 5 -- CenturyLink Cloud: The Leader in Enterprise Cloud Services. Learn Why More Businesses Are Choosing CenturyLink Cloud For Critical Workloads, Development Environments Everything In Between. Get a Quote or Start a Free Trial Today. http://pubads.g.doubleclick.net/gampad/clk?id=119420431iu=/4140/ostg.clktrk ___ Valgrind-users mailing list Valgrind-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/valgrind-users -- CenturyLink Cloud: The Leader in Enterprise Cloud Services. Learn Why More Businesses Are Choosing CenturyLink Cloud For Critical Workloads, Development Environments Everything In Between. Get a Quote or Start a Free Trial Today. http://pubads.g.doubleclick.net/gampad/clk?id=119420431iu=/4140/ostg.clktrk ___ Valgrind-users mailing list Valgrind-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/valgrind-users
Re: [Valgrind-users] Best valgrind options for finding corrupt memory
On Tue, 2014-01-14 at 17:04 +0100, David Faure wrote: On Tuesday 14 January 2014 08:03:14 Samuel Quiring wrote: Greetings, I suspect my program is corrupting (overwriting) memory, e.g., malloc'ing 16 bytes for a string that is 17 bytes when you count the nul, then copying 17 bytes into the 16 byte area. What are the best valgrind options for detecting memory corruption? The default options :-) (memcheck tool) memcheck default options are effectively ok by default. But there are some options that you can change if you want to increase the probability to find a memory corruption or get more info about such a bug. Typically, you might use one or more of the following: --redzone-size=number set minimum size of redzones added before/after heap blocks (in bytes). [16] --read-var-info=yes|noread debug info on stack and global variables and use it to print better error messages in tools that make use of it (Memcheck, Helgrind, DRD) [no] --freelist-vol=number volume of freed blocks queue [2000] --freelist-big-blocks=number releases first blocks with size= [100] --keep-stacktraces=alloc|free|alloc-and-free|alloc-then-free|none stack trace(s) to keep for malloc'd/free'd areas [alloc-then-free] The above will impact (increase or decrease) memory and/or cpu used by valgrind. Philippe -- CenturyLink Cloud: The Leader in Enterprise Cloud Services. Learn Why More Businesses Are Choosing CenturyLink Cloud For Critical Workloads, Development Environments Everything In Between. Get a Quote or Start a Free Trial Today. http://pubads.g.doubleclick.net/gampad/clk?id=119420431iu=/4140/ostg.clktrk ___ Valgrind-users mailing list Valgrind-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/valgrind-users
Re: [Valgrind-users] valgrind with LD_PRELOAD
On Tue, Jan 14, 2014 at 10:14 AM, Samuel Quiring samuel_quir...@symantec.com wrote: Greetings, I invoke my program as follows: LD_PRELOAD=./libfakec.so ./my_app –e The LD_PRELOAD environment variable tells the loader that libfakec.so should be loaded BEFORE every other library including the C runtime, libc.so (see http://stackoverflow.com/questions/426230/what-is-the-ld-preload-trick, for example). I am substituting some of my own routines for standard library calls. My app is working like I want, but the question is how to run the app under valgrind? I tried this: valgrind LD_PRELOAD=./libfakec.so ./my_app –e But valgrind gave and error saying that LD_PRELOAD=./libfakec.so ./my_app –e is not a valid path. In theory, I could put the LD_PRELOAD before the valgrind invocation: LD_PRELOAD=./libfakec.so valgrind ./my_app –e But then valgrind would also be using my special library routines and I am pretty sure that will not work. Maybe you can do it with a shell-script wrapper? Eg: run-me.sh: #! /bin/sh LD_PRELOAD=./libfakec.so ./myapp -e Then run: valgrind --trace-children=yes ./run-me.sh -Mike -- CenturyLink Cloud: The Leader in Enterprise Cloud Services. Learn Why More Businesses Are Choosing CenturyLink Cloud For Critical Workloads, Development Environments Everything In Between. Get a Quote or Start a Free Trial Today. http://pubads.g.doubleclick.net/gampad/clk?id=119420431iu=/4140/ostg.clktrk___ Valgrind-users mailing list Valgrind-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/valgrind-users
Re: [Valgrind-users] valgrind with LD_PRELOAD
On Tue, 2014-01-14 at 11:29 -0500, Mike Shal wrote: O Maybe you can do it with a shell-script wrapper? Eg: run-me.sh: #! /bin/sh LD_PRELOAD=./libfakec.so ./myapp -e Then run: valgrind --trace-children=yes ./run-me.sh I do not think so, as the trace-children=yes will cause the valgrind launcher to be relaunched to launch myapp. And this valgrind child will then use the problematic LD_PRELOAD library. Philippe -- CenturyLink Cloud: The Leader in Enterprise Cloud Services. Learn Why More Businesses Are Choosing CenturyLink Cloud For Critical Workloads, Development Environments Everything In Between. Get a Quote or Start a Free Trial Today. http://pubads.g.doubleclick.net/gampad/clk?id=119420431iu=/4140/ostg.clktrk ___ Valgrind-users mailing list Valgrind-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/valgrind-users
Re: [Valgrind-users] valgrind with LD_PRELOAD
On Tue, Jan 14, 2014 at 11:37 AM, Philippe Waroquiers philippe.waroqui...@skynet.be wrote: On Tue, 2014-01-14 at 11:29 -0500, Mike Shal wrote: O Maybe you can do it with a shell-script wrapper? Eg: run-me.sh: #! /bin/sh LD_PRELOAD=./libfakec.so ./myapp -e Then run: valgrind --trace-children=yes ./run-me.sh I do not think so, as the trace-children=yes will cause the valgrind launcher to be relaunched to launch myapp. And this valgrind child will then use the problematic LD_PRELOAD library. Oh, hmm. I had just tried a simple LD_PRELOAD test with wrapping fopen() and open(). I added a constructor function to the library to see where it gets initialized, and it does indeed get added to valgrind with --trace-children=yes. So, scratch that. We might maybe need to add a valgrind option --client-ld-preload=.. to avoid such problem ? Or maybe a more general --client-environment? That way it's not specific to LD_PRELOAD. -Mike -- CenturyLink Cloud: The Leader in Enterprise Cloud Services. Learn Why More Businesses Are Choosing CenturyLink Cloud For Critical Workloads, Development Environments Everything In Between. Get a Quote or Start a Free Trial Today. http://pubads.g.doubleclick.net/gampad/clk?id=119420431iu=/4140/ostg.clktrk___ Valgrind-users mailing list Valgrind-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/valgrind-users
Re: [Valgrind-users] valgrind with LD_PRELOAD
| Maybe you can do it with a shell-script wrapper? Eg: | | run-me.sh: | #! /bin/sh | LD_PRELOAD=./libfakec.so ./myapp -e | | Then run: | | valgrind --trace-children=yes ./run-me.sh This has been my approach. Now I am suspicious that - -trace-children=yes is not working like I hoped. I get the EXACT SAME output whether I have - -trace–children=yes or do not have that option. So I think there must be more to getting - -trace-children=yes to behave like I want. Here is the output. Every number is the same whether or not I have - -trace-children=yes. ==13527== HEAP SUMMARY: ==13527== in use at exit: 19,116 bytes in 584 blocks ==13527== total heap usage: 766 allocs, 182 frees, 29,553 bytes allocated ==13527== ==13527== LEAK SUMMARY: ==13527==definitely lost: 0 bytes in 0 blocks ==13527==indirectly lost: 0 bytes in 0 blocks ==13527== possibly lost: 0 bytes in 0 blocks ==13527==still reachable: 19,116 bytes in 584 blocks ==13527== suppressed: 0 bytes in 0 blocks From: Mike Shal mar...@gmail.commailto:mar...@gmail.com Date: Tue, Jan 14 9:29 AM To: Samuel Quiring samuel_quir...@symantec.commailto:samuel_quir...@symantec.com Cc: valgrind-users@lists.sourceforge.netmailto:valgrind-users@lists.sourceforge.net valgrind-users@lists.sourceforge.netmailto:valgrind-users@lists.sourceforge.net Subject: Re: [Valgrind-users] valgrind with LD_PRELOAD On Tue, Jan 14, 2014 at 10:14 AM, Samuel Quiring samuel_quir...@symantec.commailto:samuel_quir...@symantec.com wrote: Greetings, I invoke my program as follows: LD_PRELOAD=./libfakec.so ./my_app –e The LD_PRELOAD environment variable tells the loader that libfakec.so should be loaded BEFORE every other library including the C runtime, libc.so (see http://stackoverflow.com/questions/426230/what-is-the-ld-preload-trick, for example). I am substituting some of my own routines for standard library calls. My app is working like I want, but the question is how to run the app under valgrind? I tried this: valgrind LD_PRELOAD=./libfakec.so ./my_app –e But valgrind gave and error saying that LD_PRELOAD=./libfakec.so ./my_app –e is not a valid path. In theory, I could put the LD_PRELOAD before the valgrind invocation: LD_PRELOAD=./libfakec.so valgrind ./my_app –e But then valgrind would also be using my special library routines and I am pretty sure that will not work. Maybe you can do it with a shell-script wrapper? Eg: run-me.sh: #! /bin/sh LD_PRELOAD=./libfakec.so ./myapp -e Then run: valgrind --trace-children=yes ./run-me.sh -Mike -- CenturyLink Cloud: The Leader in Enterprise Cloud Services. Learn Why More Businesses Are Choosing CenturyLink Cloud For Critical Workloads, Development Environments Everything In Between. Get a Quote or Start a Free Trial Today. http://pubads.g.doubleclick.net/gampad/clk?id=119420431iu=/4140/ostg.clktrk___ Valgrind-users mailing list Valgrind-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/valgrind-users
Re: [Valgrind-users] valgrind with LD_PRELOAD
On Tue, 2014-01-14 at 08:57 -0800, Samuel Quiring wrote: | Maybe you can do it with a shell-script wrapper? Eg: | | run-me.sh: | #! /bin/sh | LD_PRELOAD=./libfakec.so ./myapp -e | | Then run: | | valgrind --trace-children=yes ./run-me.sh This has been my approach. Now I am suspicious that - As explained in another mail, it is highly suspected that this will not help to solve your problem. -trace-children=yes is not working like I hoped. I get the EXACT SAME output whether I have - -trace–children=yes or do not have that option. So I think there must be more to getting - -trace-children=yes to behave like I want. Here is the output. Every number is the same whether or not I have - -trace-children=yes. ==13527== HEAP SUMMARY: ==13527== in use at exit: 19,116 bytes in 584 blocks ==13527== total heap usage: 766 allocs, 182 frees, 29,553 bytes allocated ==13527== ==13527== LEAK SUMMARY: ==13527==definitely lost: 0 bytes in 0 blocks ==13527==indirectly lost: 0 bytes in 0 blocks ==13527== possibly lost: 0 bytes in 0 blocks ==13527==still reachable: 19,116 bytes in 584 blocks ==13527== suppressed: 0 bytes in 0 blocks The above must be the output of valgrind for the shell. The shell behaviour does not change for --trace-children=yes/no. But when giving --trace-children=yes, you should get additional input before. E.g. this is what I get: ==3589== Command: ./run.sh ... ==3590== Command: /home/philippe/valgrind/trunk_untouched/memcheck/tests/trivialleak ... ==3590== HEAP SUMMARY: ==3590== in use at exit: 1,000 bytes in 1,000 blocks ==3590== total heap usage: 1,000 allocs, 0 frees, 1,000 bytes allocated ... ==3589== HEAP SUMMARY: ==3589== in use at exit: 19,960 bytes in 572 blocks ==3589== total heap usage: 725 allocs, 153 frees, 26,630 bytes allocated ... So, with trace children, you see lines for different pids (and a heap summary result for each process which exits) Philippe -- CenturyLink Cloud: The Leader in Enterprise Cloud Services. Learn Why More Businesses Are Choosing CenturyLink Cloud For Critical Workloads, Development Environments Everything In Between. Get a Quote or Start a Free Trial Today. http://pubads.g.doubleclick.net/gampad/clk?id=119420431iu=/4140/ostg.clktrk ___ Valgrind-users mailing list Valgrind-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/valgrind-users
Re: [Valgrind-users] valgrind with LD_PRELOAD
On 14 January 2014 16:14, Samuel Quiring samuel_quir...@symantec.com wrote: Greetings, I invoke my program as follows: LD_PRELOAD=./libfakec.so ./my_app –e The LD_PRELOAD environment variable tells the loader that libfakec.so should be loaded BEFORE every other library including the C runtime, libc.so (see http://stackoverflow.com/questions/426230/what-is-the-ld-preload-trick, for example). I am substituting some of my own routines for standard library calls. My app is working like I want, but the question is how to run the app under valgrind? What I did when I was in a similar situation was to have an initialization function ( marked __attribute__((constructor)) ) which checked the name of the executable to determine whether to use my versions of the functions or the libc ones. In my functions, I then had an if which either did the special things which was the reason for the LD_PRELOAD, or just delegated to the libc implementation of the function depending on whether the executable was the target one. But yes, the suggestions from Philippe Waroquiers and Mike Shal about passing variables would have made life a lot easier. BR Magnus Reftel -- CenturyLink Cloud: The Leader in Enterprise Cloud Services. Learn Why More Businesses Are Choosing CenturyLink Cloud For Critical Workloads, Development Environments Everything In Between. Get a Quote or Start a Free Trial Today. http://pubads.g.doubleclick.net/gampad/clk?id=119420431iu=/4140/ostg.clktrk ___ Valgrind-users mailing list Valgrind-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/valgrind-users
