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| author | Eric W. Biederman <ebiederm@xmission.com> | 2022-01-03 11:32:36 -0600 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-02-23 11:57:34 +0100 |
| commit | 16926f2a1aec3fcfc5208d727f2b3620d373625a (patch) | |
| tree | d288327c8d19c61e25f70a2e39dd011d4b7b9810 | |
| parent | 45f9a195c112a627aadcdc183b251512437f8dca (diff) | |
| download | linux-rt-16926f2a1aec3fcfc5208d727f2b3620d373625a.tar.gz | |
taskstats: Cleanup the use of task->exit_code
commit 1b5a42d9c85f0e731f01c8d1129001fd8531a8a0 upstream.
In the function bacct_add_task the code reading task->exit_code was
introduced in commit f3cef7a99469 ("[PATCH] csa: basic accounting over
taskstats"), and it is not entirely clear what the taskstats interface
is trying to return as only returning the exit_code of the first task
in a process doesn't make a lot of sense.
As best as I can figure the intent is to return task->exit_code after
a task exits. The field is returned with per task fields, so the
exit_code of the entire process is not wanted. Only the value of the
first task is returned so this is not a useful way to get the per task
ptrace stop code. The ordinary case of returning this value is
returning after a task exits, which also precludes use for getting
a ptrace value.
It is common to for the first task of a process to also be the last
task of a process so this field may have done something reasonable by
accident in testing.
Make ac_exitcode a reliable per task value by always returning it for
every exited task.
Setting ac_exitcode in a sensible mannter makes it possible to continue
to provide this value going forward.
Cc: Balbir Singh <bsingharora@gmail.com>
Fixes: f3cef7a99469 ("[PATCH] csa: basic accounting over taskstats")
Link: https://lkml.kernel.org/r/20220103213312.9144-5-ebiederm@xmission.com
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
[sudip: adjust context]
Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | kernel/tsacct.c | 7 |
1 files changed, 3 insertions, 4 deletions
diff --git a/kernel/tsacct.c b/kernel/tsacct.c index 370724b45391..8d7c6d3f1daa 100644 --- a/kernel/tsacct.c +++ b/kernel/tsacct.c @@ -46,11 +46,10 @@ void bacct_add_tsk(struct user_namespace *user_ns, /* Convert to seconds for btime */ do_div(delta, USEC_PER_SEC); stats->ac_btime = get_seconds() - delta; - if (thread_group_leader(tsk)) { + if (tsk->flags & PF_EXITING) stats->ac_exitcode = tsk->exit_code; - if (tsk->flags & PF_FORKNOEXEC) - stats->ac_flag |= AFORK; - } + if (thread_group_leader(tsk) && (tsk->flags & PF_FORKNOEXEC)) + stats->ac_flag |= AFORK; if (tsk->flags & PF_SUPERPRIV) stats->ac_flag |= ASU; if (tsk->flags & PF_DUMPCORE) |