On Thu, Jun 24, 2021 at 02:01:40PM -0500, Eric W. Biederman wrote:
Make thread exiting uniform by causing all threads to pass through
get_signal when they are exiting. This simplifies the analysis
of sychronization during exit and guarantees that all full set
of registers will be available for ptrace to examine for
threads that stop at PTRACE_EVENT_EXIT.
Yeah, cool. I do like making the process lifetime more sensible here. It
always threw me that do_exit*() just stopped execution. :)
For future me, can you add a comment on start_group_exit() that mentions
where final process death happens?
Signed-off-by: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx>
---
kernel/exit.c | 4 ++--
kernel/seccomp.c | 2 +-
2 files changed, 3 insertions(+), 3 deletions(-)
diff --git a/kernel/exit.c b/kernel/exit.c
index fd1c04193e18..921519d80b56 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -931,8 +931,8 @@ do_group_exit(int exit_code)
*/
SYSCALL_DEFINE1(exit_group, int, error_code)
{
- do_group_exit((error_code & 0xff) << 8);
- /* NOTREACHED */
+ start_group_exit((error_code & 0xff) << 8);
+ /* get_signal will call do_exit */
return 0;
"0" feels weird here, but I can't think of any better "fail closed"
error code here.
}
diff --git a/kernel/seccomp.c b/kernel/seccomp.c
index 5301eca670a0..b1c06fd1b205 100644
--- a/kernel/seccomp.c
+++ b/kernel/seccomp.c
@@ -1250,7 +1250,7 @@ static int __seccomp_filter(int this_syscall, const struct seccomp_data *sd,
if (action == SECCOMP_RET_KILL_THREAD)
do_exit(SIGSYS);
else
- do_group_exit(SIGSYS);
+ start_group_exit(SIGSYS);
This could use a similar comment to the syscall's comment, just so I
don't panic when I read this code in like 3 years. ;)
Otherwise, yeah, looks good.
-Kees
}
return -1;
}
--
2.20.1
--
Kees Cook
