2013-04-24 23:24:15

by Stéphane Graber

Subject: [PATCH] coredump: Add new %P variable in core_pattern

This adds a new %P variable to be used in core_pattern. This variable contains
the global PID (PID in the init namespace) as %p contains the PID in the
current namespace which isn't always what we want.

The main use for this is to make it easier to handle crashes that happened
within a container. With that new variables it's possible to have the crashes
dumped into the container or forwarded to the host with the right PID
(from the host's point of view).

Reported-by: Hans Feldt <[email protected]>
Cc: Alexander Viro <[email protected]>
Cc: Eric W. Biederman <[email protected]>
Cc: Serge Hallyn <[email protected]>
Signed-off-by: Stéphane Graber <[email protected]>
---
Documentation/sysctl/kernel.txt | 1 +
fs/coredump.c | 5 +++++
2 files changed, 6 insertions(+)

diff --git a/Documentation/sysctl/kernel.txt b/Documentation/sysctl/kernel.txt
index ccd4258..833026d 100644
--- a/Documentation/sysctl/kernel.txt
+++ b/Documentation/sysctl/kernel.txt
@@ -182,6 +182,7 @@ core_pattern is used to specify a core dumpfile pattern name.
%<NUL> '%' is dropped
%% output one '%'
%p pid
+ %P global pid (init PID namespace)
%u uid
%g gid
%d dump mode, matches PR_SET_DUMPABLE and
diff --git a/fs/coredump.c b/fs/coredump.c
index c647965..528c6fc 100644
--- a/fs/coredump.c
+++ b/fs/coredump.c
@@ -186,6 +186,11 @@ static int format_corename(struct core_name *cn, struct coredump_params *cprm)
err = cn_printf(cn, "%d",
task_tgid_vnr(current));
break;
+ /* global pid */
+ case 'P':
+ err = cn_printf(cn, "%d",
+ task_tgid_nr(current));
+ break;
/* uid */
case 'u':
err = cn_printf(cn, "%d", cred->uid);
--
1.8.1.2

2013-04-24 23:48:20

by Serge Hallyn

Subject: Re: [PATCH] coredump: Add new %P variable in core_pattern

Quoting St?phane Graber ([email protected]):
> This adds a new %P variable to be used in core_pattern. This variable contains
> the global PID (PID in the init namespace) as %p contains the PID in the
> current namespace which isn't always what we want.
>
> The main use for this is to make it easier to handle crashes that happened
> within a container. With that new variables it's possible to have the crashes
> dumped into the container or forwarded to the host with the right PID
> (from the host's point of view).
>
> Reported-by: Hans Feldt <[email protected]>
> Cc: Alexander Viro <[email protected]>
> Cc: Eric W. Biederman <[email protected]>
> Cc: Serge Hallyn <[email protected]>

Thanks, St?phane.

Acked-by: Serge E. Hallyn <[email protected]>

> Signed-off-by: St?phane Graber <[email protected]>
> ---
> Documentation/sysctl/kernel.txt | 1 +
> fs/coredump.c | 5 +++++
> 2 files changed, 6 insertions(+)
>
> diff --git a/Documentation/sysctl/kernel.txt b/Documentation/sysctl/kernel.txt
> index ccd4258..833026d 100644
> --- a/Documentation/sysctl/kernel.txt
> +++ b/Documentation/sysctl/kernel.txt
> @@ -182,6 +182,7 @@ core_pattern is used to specify a core dumpfile pattern name.
> %<NUL> '%' is dropped
> %% output one '%'
> %p pid
> + %P global pid (init PID namespace)
> %u uid
> %g gid
> %d dump mode, matches PR_SET_DUMPABLE and
> diff --git a/fs/coredump.c b/fs/coredump.c
> index c647965..528c6fc 100644
> --- a/fs/coredump.c
> +++ b/fs/coredump.c
> @@ -186,6 +186,11 @@ static int format_corename(struct core_name *cn, struct coredump_params *cprm)
> err = cn_printf(cn, "%d",
> task_tgid_vnr(current));
> break;
> + /* global pid */
> + case 'P':
> + err = cn_printf(cn, "%d",
> + task_tgid_nr(current));
> + break;
> /* uid */
> case 'u':
> err = cn_printf(cn, "%d", cred->uid);
> --
> 1.8.1.2
>