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| author | Taehee Yoo <ap420073@gmail.com> | 2019-01-09 02:23:56 +0900 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2019-01-11 18:05:40 -0800 |
| commit | 73ab1cb2de9e3efe7f818d5453de271e5371df1d (patch) | |
| tree | 597da57b75e0bceceea75e1cbf9980068bc5dc54 /include/linux | |
| parent | 2ff33d6637393fe9348357285931811b76e1402f (diff) | |
| download | lwn-73ab1cb2de9e3efe7f818d5453de271e5371df1d.tar.gz lwn-73ab1cb2de9e3efe7f818d5453de271e5371df1d.zip | |
umh: add exit routine for UMH process
A UMH process which is created by the fork_usermode_blob() such as
bpfilter needs to release members of the umh_info when process is
terminated.
But the do_exit() does not release members of the umh_info. hence module
which uses UMH needs own code to detect whether UMH process is
terminated or not.
But this implementation needs extra code for checking the status of
UMH process. it eventually makes the code more complex.
The new PF_UMH flag is added and it is used to identify UMH processes.
The exit_umh() does not release members of the umh_info.
Hence umh_info->cleanup callback should release both members of the
umh_info and the private data.
Suggested-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/sched.h | 9 | ||||
| -rw-r--r-- | include/linux/umh.h | 2 |
2 files changed, 11 insertions, 0 deletions
diff --git a/include/linux/sched.h b/include/linux/sched.h index 89541d248893..e35e35b9fc48 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1406,6 +1406,7 @@ extern struct pid *cad_pid; #define PF_RANDOMIZE 0x00400000 /* Randomize virtual address space */ #define PF_SWAPWRITE 0x00800000 /* Allowed to write to swap */ #define PF_MEMSTALL 0x01000000 /* Stalled due to lack of memory */ +#define PF_UMH 0x02000000 /* I'm an Usermodehelper process */ #define PF_NO_SETAFFINITY 0x04000000 /* Userland is not allowed to meddle with cpus_allowed */ #define PF_MCE_EARLY 0x08000000 /* Early kill for mce process policy */ #define PF_MUTEX_TESTER 0x20000000 /* Thread belongs to the rt mutex tester */ @@ -1904,6 +1905,14 @@ static inline void rseq_execve(struct task_struct *t) #endif +void __exit_umh(struct task_struct *tsk); + +static inline void exit_umh(struct task_struct *tsk) +{ + if (unlikely(tsk->flags & PF_UMH)) + __exit_umh(tsk); +} + #ifdef CONFIG_DEBUG_RSEQ void rseq_syscall(struct pt_regs *regs); diff --git a/include/linux/umh.h b/include/linux/umh.h index 235f51b62c71..0c08de356d0d 100644 --- a/include/linux/umh.h +++ b/include/linux/umh.h @@ -47,6 +47,8 @@ struct umh_info { const char *cmdline; struct file *pipe_to_umh; struct file *pipe_from_umh; + struct list_head list; + void (*cleanup)(struct umh_info *info); pid_t pid; }; int fork_usermode_blob(void *data, size_t len, struct umh_info *info); |