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-rw-r--r--include/linux/pid.h4
-rw-r--r--include/uapi/linux/wait.h1
-rw-r--r--kernel/exit.c33
-rw-r--r--kernel/fork.c8
-rw-r--r--kernel/signal.c7
5 files changed, 48 insertions, 5 deletions
diff --git a/include/linux/pid.h b/include/linux/pid.h
index 2a83e434db9d..9645b1194c98 100644
--- a/include/linux/pid.h
+++ b/include/linux/pid.h
@@ -72,6 +72,10 @@ extern struct pid init_struct_pid;
extern const struct file_operations pidfd_fops;
+struct file;
+
+extern struct pid *pidfd_pid(const struct file *file);
+
static inline struct pid *get_pid(struct pid *pid)
{
if (pid)
diff --git a/include/uapi/linux/wait.h b/include/uapi/linux/wait.h
index ac49a220cf2a..85b809fc9f11 100644
--- a/include/uapi/linux/wait.h
+++ b/include/uapi/linux/wait.h
@@ -17,6 +17,7 @@
#define P_ALL 0
#define P_PID 1
#define P_PGID 2
+#define P_PIDFD 3
#endif /* _UAPI_LINUX_WAIT_H */
diff --git a/kernel/exit.c b/kernel/exit.c
index a75b6a7f458a..64bb6893a37d 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -1552,6 +1552,23 @@ end:
return retval;
}
+static struct pid *pidfd_get_pid(unsigned int fd)
+{
+ struct fd f;
+ struct pid *pid;
+
+ f = fdget(fd);
+ if (!f.file)
+ return ERR_PTR(-EBADF);
+
+ pid = pidfd_pid(f.file);
+ if (!IS_ERR(pid))
+ get_pid(pid);
+
+ fdput(f);
+ return pid;
+}
+
static long kernel_waitid(int which, pid_t upid, struct waitid_info *infop,
int options, struct rusage *ru)
{
@@ -1574,19 +1591,29 @@ static long kernel_waitid(int which, pid_t upid, struct waitid_info *infop,
type = PIDTYPE_PID;
if (upid <= 0)
return -EINVAL;
+
+ pid = find_get_pid(upid);
break;
case P_PGID:
type = PIDTYPE_PGID;
if (upid <= 0)
return -EINVAL;
+
+ pid = find_get_pid(upid);
+ break;
+ case P_PIDFD:
+ type = PIDTYPE_PID;
+ if (upid < 0)
+ return -EINVAL;
+
+ pid = pidfd_get_pid(upid);
+ if (IS_ERR(pid))
+ return PTR_ERR(pid);
break;
default:
return -EINVAL;
}
- if (type < PIDTYPE_MAX)
- pid = find_get_pid(upid);
-
wo.wo_type = type;
wo.wo_pid = pid;
wo.wo_flags = options;
diff --git a/kernel/fork.c b/kernel/fork.c
index d8ae0f1b4148..b169e2ca2d84 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1690,6 +1690,14 @@ static inline void rcu_copy_process(struct task_struct *p)
#endif /* #ifdef CONFIG_TASKS_RCU */
}
+struct pid *pidfd_pid(const struct file *file)
+{
+ if (file->f_op == &pidfd_fops)
+ return file->private_data;
+
+ return ERR_PTR(-EBADF);
+}
+
static int pidfd_release(struct inode *inode, struct file *file)
{
struct pid *pid = file->private_data;
diff --git a/kernel/signal.c b/kernel/signal.c
index 91b789dd6e72..2e567f64812f 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -3672,8 +3672,11 @@ static int copy_siginfo_from_user_any(kernel_siginfo_t *kinfo, siginfo_t *info)
static struct pid *pidfd_to_pid(const struct file *file)
{
- if (file->f_op == &pidfd_fops)
- return file->private_data;
+ struct pid *pid;
+
+ pid = pidfd_pid(file);
+ if (!IS_ERR(pid))
+ return pid;
return tgid_pidfd_to_pid(file);
}