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| author | Christian Brauner <brauner@kernel.org> | 2025-06-24 15:48:42 +0200 |
|---|---|---|
| committer | Christian Brauner <brauner@kernel.org> | 2025-06-24 15:50:06 +0200 |
| commit | a4c746f06853f91d3759ae8aca514d135b6aa56d (patch) | |
| tree | 584246a08af3e90d868bdd91a1839f3657210650 /include/uapi | |
| parent | fhandle: reflow get_path_anchor() (diff) | |
| download | linux-a4c746f06853f91d3759ae8aca514d135b6aa56d.tar.gz linux-a4c746f06853f91d3759ae8aca514d135b6aa56d.zip | |
uapi/fcntl: mark range as reserved
Mark the range from -10000 to -40000 as a range reserved for special
in-kernel values. Move the PIDFD_SELF_*/PIDFD_THREAD_* sentinels over so
all the special values are in one place.
Link: https://lore.kernel.org/20250624-work-pidfs-fhandle-v2-6-d02a04858fe3@kernel.org
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Diffstat (limited to 'include/uapi')
| -rw-r--r-- | include/uapi/linux/fcntl.h | 16 | ||||
| -rw-r--r-- | include/uapi/linux/pidfd.h | 15 |
2 files changed, 16 insertions, 15 deletions
diff --git a/include/uapi/linux/fcntl.h b/include/uapi/linux/fcntl.h index a15ac2fa4b20..ed02d8ae0667 100644 --- a/include/uapi/linux/fcntl.h +++ b/include/uapi/linux/fcntl.h @@ -90,10 +90,26 @@ #define DN_ATTRIB 0x00000020 /* File changed attibutes */ #define DN_MULTISHOT 0x80000000 /* Don't remove notifier */ +/* Reserved kernel ranges [-100], [-10000, -40000]. */ #define AT_FDCWD -100 /* Special value for dirfd used to indicate openat should use the current working directory. */ +/* + * 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. */ + /* Generic flags for the *at(2) family of syscalls. */ diff --git a/include/uapi/linux/pidfd.h b/include/uapi/linux/pidfd.h index c27a4e238e4b..957db425d459 100644 --- a/include/uapi/linux/pidfd.h +++ b/include/uapi/linux/pidfd.h @@ -43,21 +43,6 @@ #define PIDFD_COREDUMP_ROOT (1U << 3) /* coredump was done as root. */ /* - * 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. * |