diff options
Diffstat (limited to 'include/uapi/linux/pidfd.h')
| -rw-r--r-- | include/uapi/linux/pidfd.h | 31 |
1 files changed, 30 insertions, 1 deletions
diff --git a/include/uapi/linux/pidfd.h b/include/uapi/linux/pidfd.h index 4540f6301b8c..2970ef44655a 100644 --- a/include/uapi/linux/pidfd.h +++ b/include/uapi/linux/pidfd.h @@ -10,6 +10,10 @@ /* Flags for pidfd_open(). */ #define PIDFD_NONBLOCK O_NONBLOCK #define PIDFD_THREAD O_EXCL +#ifdef __KERNEL__ +#include <linux/sched.h> +#define PIDFD_CLONE CLONE_PIDFD +#endif /* Flags for pidfd_send_signal(). */ #define PIDFD_SIGNAL_THREAD (1UL << 0) @@ -20,9 +24,34 @@ #define PIDFD_INFO_PID (1UL << 0) /* Always returned, even if not requested */ #define PIDFD_INFO_CREDS (1UL << 1) /* Always returned, even if not requested */ #define PIDFD_INFO_CGROUPID (1UL << 2) /* Always returned if available, even if not requested */ +#define PIDFD_INFO_EXIT (1UL << 3) /* Only returned if requested. */ #define PIDFD_INFO_SIZE_VER0 64 /* sizeof first published struct */ +/* + * The concept of process and threads in userland and the kernel is a confusing + * one - within the kernel every thread is a 'task' with its own individual PID, + * however from userland's point of view threads are grouped by a single PID, + * which is that of the 'thread group leader', typically the first thread + * spawned. + * + * To cut the Gideon knot, for internal kernel usage, we refer to + * PIDFD_SELF_THREAD to refer to the current thread (or task from a kernel + * perspective), and PIDFD_SELF_THREAD_GROUP to refer to the current thread + * group leader... + */ +#define PIDFD_SELF_THREAD -10000 /* Current thread. */ +#define PIDFD_SELF_THREAD_GROUP -20000 /* Current thread group leader. */ + +/* + * ...and for userland we make life simpler - PIDFD_SELF refers to the current + * thread, PIDFD_SELF_PROCESS refers to the process thread group leader. + * + * For nearly all practical uses, a user will want to use PIDFD_SELF. + */ +#define PIDFD_SELF PIDFD_SELF_THREAD +#define PIDFD_SELF_PROCESS PIDFD_SELF_THREAD_GROUP + struct pidfd_info { /* * This mask is similar to the request_mask in statx(2). @@ -62,7 +91,7 @@ struct pidfd_info { __u32 sgid; __u32 fsuid; __u32 fsgid; - __u32 spare0[1]; + __s32 exit_code; }; #define PIDFS_IOCTL_MAGIC 0xFF |