linux_dsm_epyc7002/kernel
David Howells c73be61ced pipe: Add general notification queue support
Make it possible to have a general notification queue built on top of a
standard pipe.  Notifications are 'spliced' into the pipe and then read
out.  splice(), vmsplice() and sendfile() are forbidden on pipes used for
notifications as post_one_notification() cannot take pipe->mutex.  This
means that notifications could be posted in between individual pipe
buffers, making iov_iter_revert() difficult to effect.

The way the notification queue is used is:

 (1) An application opens a pipe with a special flag and indicates the
     number of messages it wishes to be able to queue at once (this can
     only be set once):

	pipe2(fds, O_NOTIFICATION_PIPE);
	ioctl(fds[0], IOC_WATCH_QUEUE_SET_SIZE, queue_depth);

 (2) The application then uses poll() and read() as normal to extract data
     from the pipe.  read() will return multiple notifications if the
     buffer is big enough, but it will not split a notification across
     buffers - rather it will return a short read or EMSGSIZE.

     Notification messages include a length in the header so that the
     caller can split them up.

Each message has a header that describes it:

	struct watch_notification {
		__u32	type:24;
		__u32	subtype:8;
		__u32	info;
	};

The type indicates the source (eg. mount tree changes, superblock events,
keyring changes, block layer events) and the subtype indicates the event
type (eg. mount, unmount; EIO, EDQUOT; link, unlink).  The info field
indicates a number of things, including the entry length, an ID assigned to
a watchpoint contributing to this buffer and type-specific flags.

Supplementary data, such as the key ID that generated an event, can be
attached in additional slots.  The maximum message size is 127 bytes.
Messages may not be padded or aligned, so there is no guarantee, for
example, that the notification type will be on a 4-byte bounary.

Signed-off-by: David Howells <dhowells@redhat.com>
2020-05-19 15:08:24 +01:00
..
bpf bpf: Add bpf_probe_read_{user, kernel}_str() to do_refine_retval_range 2020-05-15 08:10:36 -07:00
cgroup Merge branch 'for-5.7' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup 2020-04-03 11:30:20 -07:00
configs compiler: remove CONFIG_OPTIMIZE_INLINING entirely 2020-04-07 10:43:42 -07:00
debug SPDX patches for 5.7-rc1. 2020-04-03 13:12:26 -07:00
dma dma-debug: fix displaying of dma allocation type 2020-04-08 21:46:57 +02:00
events perf/core: fix parent pid/tid in task exit events 2020-04-22 23:10:14 +02:00
gcov kernel/gcov/fs.c: gcov_seq_next() should increase position index 2020-04-10 15:36:22 -07:00
irq genirq: Remove setup_irq() and remove_irq() 2020-04-14 10:08:50 +02:00
livepatch New tracing features: 2019-11-27 11:42:01 -08:00
locking locking/lockdep: Improve 'invalid wait context' splat 2020-04-08 12:05:07 +02:00
power PM: hibernate: Freeze kernel threads in software_resume() 2020-04-27 10:30:30 +02:00
printk printk: queue wake_up_klogd irq_work only if per-CPU areas are ready 2020-04-10 13:18:57 -07:00
rcu Merge branch 'urgent-for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/urgent 2020-04-14 08:36:41 +02:00
sched sched/core: Fix reset-on-fork from RT with uclamp 2020-04-22 23:10:13 +02:00
time proc, time/namespace: Show clock symbolic names in /proc/pid/timens_offsets 2020-04-16 12:10:54 +02:00
trace Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-05-15 13:10:06 -07:00
.gitignore .gitignore: add SPDX License Identifier 2020-03-25 11:50:48 +01:00
acct.c acct: stop using get_seconds() 2019-12-18 18:07:31 +01:00
async.c
audit_fsnotify.c fsnotify: use helpers to access data by data_type 2020-03-23 18:19:06 +01:00
audit_tree.c
audit_watch.c \n 2020-04-06 08:58:42 -07:00
audit.c audit: check the length of userspace generated audit records 2020-04-20 17:10:58 -04:00
audit.h audit: trigger accompanying records when no rules present 2020-03-12 10:42:51 -04:00
auditfilter.c audit: fix error handling in audit_data_to_entry() 2020-02-22 20:36:47 -05:00
auditsc.c audit: trigger accompanying records when no rules present 2020-03-12 10:42:51 -04:00
backtracetest.c
bounds.c
capability.c
compat.c y2038: remove unused time32 interfaces 2020-02-21 11:22:15 -08:00
configs.c proc: convert everything to "struct proc_ops" 2020-02-04 03:05:26 +00:00
context_tracking.c context-tracking: Introduce CONFIG_HAVE_TIF_NOHZ 2020-02-14 16:05:04 +01:00
cpu_pm.c
cpu.c CPU (hotplug) updates: 2020-03-30 18:06:39 -07:00
crash_core.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 230 2019-06-19 17:09:06 +02:00
crash_dump.c
cred.c kernel: doc: remove outdated comment cred.c 2020-03-25 10:04:01 -05:00
delayacct.c
dma.c
elfcore.c kernel/elfcore.c: include proper prototypes 2019-09-25 17:51:39 -07:00
exec_domain.c
exit.c proc: Put thread_pid in release_task not proc_flush_pid 2020-04-24 15:49:00 -05:00
extable.c kernel/extable.c: use address-of operator on section symbols 2020-04-07 10:43:42 -07:00
fail_function.c
fork.c fork: prevent accidental access to clone3 features 2020-05-08 17:31:50 +02:00
freezer.c Revert "libata, freezer: avoid block device removal while system is frozen" 2019-10-06 09:11:37 -06:00
futex.c Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2020-03-30 16:17:15 -07:00
gen_kheaders.sh kheaders: explain why include/config/autoconf.h is excluded from md5sum 2019-11-11 20:10:01 +09:00
groups.c
hung_task.c
iomem.c mm/nvdimm: add is_ioremap_addr and use that to check ioremap address 2019-07-12 11:05:40 -07:00
irq_work.c lockdep: Annotate irq_work 2020-03-21 16:00:24 +01:00
jump_label.c jump_label: Don't warn on __exit jump entries 2019-08-29 15:10:10 +01:00
kallsyms.c kallsyms: unexport kallsyms_lookup_name() and kallsyms_on_each_symbol() 2020-04-07 10:43:44 -07:00
kcmp.c kernel/kcmp.c: Use new infrastructure to fix deadlocks in execve 2020-03-25 10:04:01 -05:00
Kconfig.freezer
Kconfig.hz
Kconfig.locks sched/rt, locking: Use CONFIG_PREEMPTION 2019-12-08 14:37:36 +01:00
Kconfig.preempt sched/Kconfig: Fix spelling mistake in user-visible help text 2019-11-12 11:35:32 +01:00
kcov.c kernel/kcov.c: fix typos in kcov_remote_start documentation 2020-05-07 19:27:20 -07:00
kexec_core.c kexec: add machine_kexec_post_load() 2020-01-08 16:32:55 +00:00
kexec_elf.c kexec_elf: support 32 bit ELF files 2019-09-06 23:58:44 +02:00
kexec_file.c kexec: add machine_kexec_post_load() 2020-01-08 16:32:55 +00:00
kexec_internal.h kexec: add machine_kexec_post_load() 2020-01-08 16:32:55 +00:00
kexec.c kexec: add machine_kexec_post_load() 2020-01-08 16:32:55 +00:00
kheaders.c
kmod.c kmod: make request_module() return an error when autoloading is disabled 2020-04-10 15:36:22 -07:00
kprobes.c kprobes: Fix optimize_kprobe()/unoptimize_kprobe() cancellation logic 2020-01-09 12:40:13 +01:00
ksysfs.c
kthread.c kthread: Do not preempt current task if it is going to call schedule() 2020-03-20 13:06:20 +01:00
latencytop.c proc: convert everything to "struct proc_ops" 2020-02-04 03:05:26 +00:00
Makefile pipe: Add general notification queue support 2020-05-19 15:08:24 +01:00
module_signature.c MODSIGN: Export module signature definitions 2019-08-05 18:39:56 -04:00
module_signing.c MODSIGN: Export module signature definitions 2019-08-05 18:39:56 -04:00
module-internal.h
module.c Modules updates for v5.7 2020-04-09 12:52:34 -07:00
notifier.c x86/mm: split vmalloc_sync_all() 2020-03-21 18:56:06 -07:00
nsproxy.c ns: Introduce Time Namespace 2020-01-14 12:20:48 +01:00
padata.c crypto: pcrypt - simplify error handling in pcrypt_create_aead() 2020-03-06 12:28:24 +11:00
panic.c locking/refcount: Remove unused 'refcount_error_report()' function 2019-11-25 09:15:42 +01:00
params.c lockdown: Lock down module params that specify hardware parameters (eg. ioport) 2019-08-19 21:54:16 -07:00
pid_namespace.c pid: Improve the comment about waiting in zap_pid_ns_processes 2020-02-28 16:29:12 -06:00
pid.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2020-04-10 12:59:56 -07:00
profile.c proc: convert everything to "struct proc_ops" 2020-02-04 03:05:26 +00:00
ptrace.c ptrace: reintroduce usage of subjective credentials in ptrace_has_cap() 2020-01-18 13:51:39 +01:00
range.c
reboot.c
relay.c
resource.c mm/memory_hotplug.c: use PFN_UP / PFN_DOWN in walk_system_ram_range() 2019-09-24 15:54:09 -07:00
rseq.c rseq: Reject unknown flags on rseq unregister 2019-12-25 10:41:20 +01:00
seccomp.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next 2020-03-31 17:29:33 -07:00
signal.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2020-04-23 13:30:18 -07:00
smp.c cpu/hotplug: Move bringup of secondary CPUs out of smp_init() 2020-03-25 12:59:37 +01:00
smpboot.c
smpboot.h
softirq.c lockdep: Rename trace_{hard,soft}{irq_context,irqs_enabled}() 2020-03-21 16:03:54 +01:00
stackleak.c
stacktrace.c stacktrace: Get rid of unneeded '!!' pattern 2019-11-11 10:30:59 +01:00
stop_machine.c stop_machine: Make stop_cpus() static 2020-01-17 10:19:21 +01:00
sys_ni.c y2038: allow disabling time32 system calls 2019-11-15 14:38:30 +01:00
sys.c sys/sysinfo: Respect boottime inside time namespace 2020-03-03 19:34:32 +01:00
sysctl_binary.c sysctl: Remove the sysctl system call 2019-11-26 13:03:56 -06:00
sysctl-test.c kunit: allow kunit tests to be loaded as a module 2020-01-09 16:42:29 -07:00
sysctl.c mm/compaction: Disable compact_unevictable_allowed on RT 2020-04-02 09:35:31 -07:00
task_work.c task_work_run: don't take ->pi_lock unconditionally 2020-03-02 14:06:33 -07:00
taskstats.c taskstats: fix data-race 2019-12-04 15:18:39 +01:00
test_kprobes.c
torture.c CPU (hotplug) updates: 2020-03-30 18:06:39 -07:00
tracepoint.c The main changes in this release include: 2019-07-18 11:51:00 -07:00
tsacct.c tsacct: add 64-bit btime field 2019-12-18 18:07:31 +01:00
ucount.c ucount: Make sure ucounts in /proc/sys/user don't regress again 2020-04-07 21:51:27 +02:00
uid16.c
uid16.h
umh.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-05-15 13:10:06 -07:00
up.c smp/up: Make smp_call_function_single() match SMP semantics 2020-02-07 15:34:12 +01:00
user_namespace.c Keyrings namespacing 2019-07-08 19:36:47 -07:00
user-return-notifier.c
user.c Keyrings namespacing 2019-07-08 19:36:47 -07:00
utsname_sysctl.c
utsname.c
watch_queue.c pipe: Add general notification queue support 2020-05-19 15:08:24 +01:00
watchdog_hld.c
watchdog.c watchdog/softlockup: Enforce that timestamp is valid on boot 2020-01-17 11:19:22 +01:00
workqueue_internal.h
workqueue.c workqueue: Remove the warning in wq_worker_sleeping() 2020-04-08 11:35:20 +02:00