GNU bug report logs - #18145
memory leak in pwd

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Message #5 received at submit <at> debbugs.gnu.org (full text, mbox):

From: srinivas devaki <mr.eightnoteight <at> gmail.com>
To: bug-coreutils <at> gnu.org
Subject: memory leak in pwd
Date: Tue, 29 Jul 2014 12:32:04 +0530

[Message part 1 (text/plain, inline)]

i think there is a memory leak in pwd.c
I’m extremely sorry if this is wrong. I’m sending the git diff.

[eightnoteight <at> mr coreutils]$ git diff
diff --git a/src/pwd.c b/src/pwd.c
index 4993dfb..13d84cd 100644
--- a/src/pwd.c
+++ b/src/pwd.c
@@ -367,6 +367,7 @@ main (int argc, char **argv)
       if (wd)
         {
           puts (wd);
+          free (wd);
           exit (EXIT_SUCCESS);
         }
     }

and how can i contribute to gnu coreutils. how can i understand the code of
utils. which libraries should i get used to, before contributing to the gnu
coreutils.

Thanks !
​

[Message part 2 (text/html, inline)]

Message #8 received at 18145 <at> debbugs.gnu.org (full text, mbox):

From: Pádraig Brady <P <at> draigBrady.com>
To: srinivas devaki <mr.eightnoteight <at> gmail.com>
Cc: 18145 <at> debbugs.gnu.org
Subject: Re: bug#18145: memory leak in pwd
Date: Tue, 29 Jul 2014 12:55:21 +0100

tag 18145 notabug
close 18145
stop

On 07/29/2014 08:02 AM, srinivas devaki wrote:
> i think there is a memory leak in pwd.c
> I’m extremely sorry if this is wrong. I’m sending the git diff.
> 
> [eightnoteight <at> mr coreutils]$ git diff
> diff --git a/src/pwd.c b/src/pwd.c
> index 4993dfb..13d84cd 100644
> --- a/src/pwd.c
> +++ b/src/pwd.c
> @@ -367,6 +367,7 @@ main (int argc, char **argv)
>        if (wd)
>          {
>            puts (wd);
> +          free (wd);
>            exit (EXIT_SUCCESS);
>          }
>      }
> 
> and how can i contribute to gnu coreutils. how can i understand the code of
> utils. which libraries should i get used to, before contributing to the gnu
> coreutils.

valgrind doesn't concur:

  $ valgrind src/pwd -L
  ==30954== All heap blocks were freed -- no leaks are possible

You can see that logical_getcwd() doesn't allocate,
so no free is necessary.

On the general point of coreutils dev there is:
http://git.sv.gnu.org/gitweb/?p=coreutils.git;a=blob;f=README-hacking;hb=HEAD

thanks,
Pádraig.

Message #15 received at 18145 <at> debbugs.gnu.org (full text, mbox):

From: Bob Proulx <bob <at> proulx.com>
To: srinivas devaki <mr.eightnoteight <at> gmail.com>, 18145 <at> debbugs.gnu.org
Subject: Re: bug#18145: memory leak in pwd
Date: Fri, 1 Aug 2014 11:12:04 -0600

srinivas devaki wrote:
> i think there is a memory leak in pwd.c
> I’m extremely sorry if this is wrong. I’m sending the git diff.

> +          free (wd);
>            exit (EXIT_SUCCESS);

There is never a need to free memory before exiting from a program.
All work being done to free up the memory, coalesce memory blocks,
list memory blocks in a free list, and so forth is completely
unnecessary power that is wasted.  Think of the heat and battery life
wasted by doing this across zillions of devices.  Upon exit all
resources are freed as the program evaporates.

Bob

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