linux/include
Lorenzo Stoakes f08d0c3a71
pidfd: add PIDFD_SELF* sentinels to refer to own thread/process
It is useful to be able to utilise the pidfd mechanism to reference the
current thread or process (from a userland point of view - thread group
leader from the kernel's point of view).

Therefore introduce PIDFD_SELF_THREAD to refer to the current thread, and
PIDFD_SELF_THREAD_GROUP to refer to the current thread group leader.

For convenience and to avoid confusion from userland's perspective we alias
these:

* PIDFD_SELF is an alias for PIDFD_SELF_THREAD - This is nearly always what
  the user will want to use, as they would find it surprising if for
  instance fd's were unshared()'d and they wanted to invoke pidfd_getfd()
  and that failed.

* PIDFD_SELF_PROCESS is an alias for PIDFD_SELF_THREAD_GROUP - Most users
  have no concept of thread groups or what a thread group leader is, and
  from userland's perspective and nomenclature this is what userland
  considers to be a process.

We adjust pidfd_get_task() and the pidfd_send_signal() system call with
specific handling for this, implementing this functionality for
process_madvise(), process_mrelease() (albeit, using it here wouldn't
really make sense) and pidfd_send_signal().

Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Link: https://lore.kernel.org/r/24315a16a3d01a548dd45c7515f7d51c767e954e.1738268370.git.lorenzo.stoakes@oracle.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-02-05 15:14:37 +01:00
..
acpi LoongArch changes for v6.14 2025-01-28 08:52:01 -08:00
asm-generic The various patchsets are summarized below. Plus of course many 2025-01-26 18:36:23 -08:00
clocksource KVM/arm64 updates for 6.14 2025-01-28 09:01:36 -08:00
crypto crypto: skcipher - document skcipher_walk_done() and rename some vars 2025-01-14 11:38:32 +08:00
cxl cxl/events: Update Memory Module Event Record to CXL spec rev 3.1 2025-01-13 09:33:21 -07:00
drm drm/bridge: fix documentation for the hdmi_audio_prepare() callback 2025-01-15 12:32:47 +02:00
dt-bindings Char/Misc/IIO driver updates for 6.14-rc1 2025-01-27 16:51:51 -08:00
hyperv hyperv: Add new Hyper-V headers in include/hyperv 2025-01-10 00:54:20 +00:00
keys keys: drop shadowing dead prototype 2025-01-21 11:25:23 +02:00
kunit linux_kselftest-kunit-6.14-rc1 2025-01-22 12:32:39 -08:00
kvm Merge branch kvm-arm64/pkvm-memshare-declutter into kvmarm-master/next 2025-01-17 11:05:18 +00:00
linux assorted stuff for this merge window 2025-02-01 15:07:56 -08:00
math-emu
media media: cec: include linux/debugfs.h and linux/seq_file.h where needed 2025-01-07 12:21:38 +01:00
memory
misc
net ipsec-2025-01-27 2025-01-27 15:15:12 -08:00
pcmcia
ras
rdma
rv rv: Reset per-task monitors also for idle tasks 2025-01-23 12:16:04 -05:00
scsi Driver core and debugfs updates 2025-01-28 12:25:12 -08:00
soc soc: driver updates for 6.14 2025-01-24 14:56:59 -08:00
sound sound updates for 6.14-rc1 2025-01-24 07:54:34 -08:00
target
trace f2fs-for-6.14-rc1 2025-01-27 20:58:58 -08:00
uapi pidfd: add PIDFD_SELF* sentinels to refer to own thread/process 2025-02-05 15:14:37 +01:00
ufs scsi: Revert "scsi: ufs: core: Probe for EXT_IID support" 2025-01-10 16:38:21 -05:00
vdso vdso: Correct typo in PAGE_SHIFT comment 2025-01-15 11:07:08 +01:00
video
xen