Re: [Feature Request?] Inline compression of process core dumps

Randy Dunlap
2007-04-13T14:57:39Z

Andi Kleen wrote:
> Alan Cox <alan@lxorguk.ukuu.org.uk> writes:
>
>>> I saw that too, and unfortunately I don't know what what that condition
>>> represents, either. It's the only other element in that if statement
>>> that could make it take that path, so I'm assuming that's part of the
>>> problem.
>> Multiple mm's mean multiple threads with a different set of mappings,
>> which would fit for UML. Either way there should be a check for !pipe
>> before appending the pid
>
> Here's a patch. It just doesn't do any formatting for the pipe case.
>
> -Andi
>
> Fix core to pipe for multithreaded processes
>
> I also removed the BKL around format_corename because it seems unneeded.

so either the comment just above lock_kernel() should be removed, or
it's correct and lock_kernel()/unlock_kernel() should stay.

/*
* lock_kernel() because format_corename() is controlled by sysctl, which
* uses lock_kernel()
*/
lock_kernel();
format_corename(corename, core_pattern, signr);
unlock_kernel();

> Signed-off-by: Andi Kleen <ak@suse.de>
>
> Index: linux-2.6.21-rc3-test/fs/exec.c
> ===================================================================
> --- linux-2.6.21-rc3-test.orig/fs/exec.c
> +++ linux-2.6.21-rc3-test/fs/exec.c
> @@ -1501,9 +1501,6 @@ int do_coredump(long signr, int exit_cod
> * lock_kernel() because format_corename() is controlled by sysctl, which
> * uses lock_kernel()
> */
> - lock_kernel();
> - format_corename(corename, core_pattern, signr);
> - unlock_kernel();
> if (corename[0] == '|') {
> /* SIGPIPE can happen, but it's just never processed */
> if(call_usermodehelper_pipe(corename+1, NULL, NULL, &file)) {
> @@ -1512,10 +1509,12 @@ int do_coredump(long signr, int exit_cod
> goto fail_unlock;
> }
> ispipe = 1;
> - } else
> + } else {
> + format_corename(corename, core_pattern, signr);
> file = filp_open(corename,
> O_CREAT | 2 | O_NOFOLLOW | O_LARGEFILE | flag,
> 0600);
> + }
> if (IS_ERR(file))
> goto fail_unlock;
> inode = file->f_path.dentry->d_inode;

--
~Randy
*** Remember to use Documentation/SubmitChecklist when testing your code ***