linux-samsung-r9q2/kernel
Chris Hyser 7ac592aa35 sched: prctl() core-scheduling interface
This patch provides support for setting and copying core scheduling
'task cookies' between threads (PID), processes (TGID), and process
groups (PGID).

The value of core scheduling isn't that tasks don't share a core,
'nosmt' can do that. The value lies in exploiting all the sharing
opportunities that exist to recover possible lost performance and that
requires a degree of flexibility in the API.

From a security perspective (and there are others), the thread,
process and process group distinction is an existent hierarchal
categorization of tasks that reflects many of the security concerns
about 'data sharing'. For example, protecting against cache-snooping
by a thread that can just read the memory directly isn't all that
useful.

With this in mind, subcommands to CREATE/SHARE (TO/FROM) provide a
mechanism to create and share cookies. CREATE/SHARE_TO specify a
target pid with enum pidtype used to specify the scope of the targeted
tasks. For example, PIDTYPE_TGID will share the cookie with the
process and all of it's threads as typically desired in a security
scenario.

API:

  prctl(PR_SCHED_CORE, PR_SCHED_CORE_GET, tgtpid, pidtype, &cookie)
  prctl(PR_SCHED_CORE, PR_SCHED_CORE_CREATE, tgtpid, pidtype, NULL)
  prctl(PR_SCHED_CORE, PR_SCHED_CORE_SHARE_TO, tgtpid, pidtype, NULL)
  prctl(PR_SCHED_CORE, PR_SCHED_CORE_SHARE_FROM, srcpid, pidtype, NULL)

where 'tgtpid/srcpid == 0' implies the current process and pidtype is
kernel enum pid_type {PIDTYPE_PID, PIDTYPE_TGID, PIDTYPE_PGID, ...}.

For return values, EINVAL, ENOMEM are what they say. ESRCH means the
tgtpid/srcpid was not found. EPERM indicates lack of PTRACE permission
access to tgtpid/srcpid. ENODEV indicates your machines lacks SMT.

[peterz: complete rewrite]
Signed-off-by: Chris Hyser <chris.hyser@oracle.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Don Hiatt <dhiatt@digitalocean.com>
Tested-by: Hongyu Ning <hongyu.ning@linux.intel.com>
Tested-by: Vincent Guittot <vincent.guittot@linaro.org>
Link: https://lkml.kernel.org/r/20210422123309.039845339@infradead.org
2021-05-12 11:43:31 +02:00
..
bpf bpf: Fix leakage of uninitialized bpf stack under speculation 2021-05-03 11:56:23 +02:00
cgroup cgroup: rstat: punt root-level optimization to individual controllers 2021-04-30 11:20:37 -07:00
configs drivers/char: remove /dev/kmem for good 2021-05-07 00:26:34 -07:00
debug printk changes for 5.13 2021-04-27 18:09:44 -07:00
dma Merge branch 'stable/for-linus-5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/swiotlb 2021-05-04 10:58:49 -07:00
entry A trivial cleanup of typo fixes. 2021-04-26 09:41:15 -07:00
events ARM: 2021-05-01 10:14:08 -07:00
gcov gcov: clang: drop support for clang-10 and older 2021-05-07 00:26:32 -07:00
irq gpio updates for v5.13 2021-05-05 12:39:29 -07:00
kcsan kcsan: Fix printk format string 2021-04-22 14:36:03 +02:00
livepatch Livepatching changes for 5.13 2021-04-27 18:14:38 -07:00
locking locking/qrwlock: Cleanup queued_write_lock_slowpath() 2021-05-06 15:33:49 +02:00
power PM: sleep: fix typos in comments 2021-04-08 19:37:21 +02:00
printk kernel/printk.c: Fixed mundane typos 2021-03-30 15:34:17 +02:00
rcu Merge branches 'bitmaprange.2021.03.08a', 'fixes.2021.03.15a', 'kvfree_rcu.2021.03.08a', 'mmdumpobj.2021.03.08a', 'nocb.2021.03.15a', 'poll.2021.03.24a', 'rt.2021.03.08a', 'tasks.2021.03.08a', 'torture.2021.03.08a' and 'torturescript.2021.03.22a' into HEAD 2021-03-24 17:20:18 -07:00
sched sched: prctl() core-scheduling interface 2021-05-12 11:43:31 +02:00
time ARM: 2021-05-01 10:14:08 -07:00
trace tracing: Fix probes written to the set_ftrace_filter file 2021-05-06 10:03:38 -07:00
.gitignore .gitignore: prefix local generated files with a slash 2021-05-02 00:43:35 +09:00
acct.c kernel/acct.c: use #elif instead of #end and #elif 2020-12-15 22:46:15 -08:00
async.c kernel/async.c: remove async_unregister_domain() 2021-05-07 00:26:33 -07:00
audit.c lsm: separate security_task_getsecid() into subjective and objective variants 2021-03-22 15:23:32 -04:00
audit.h audit: avoid -Wempty-body warning 2021-03-24 12:11:48 -04:00
audit_fsnotify.c audit_alloc_mark(): don't open-code ERR_CAST() 2021-02-23 10:25:27 -05:00
audit_tree.c fsnotify: generalize handle_inode_event() 2020-12-03 14:58:35 +01:00
audit_watch.c fsnotify: generalize handle_inode_event() 2020-12-03 14:58:35 +01:00
auditfilter.c lsm: separate security_task_getsecid() into subjective and objective variants 2021-03-22 15:23:32 -04:00
auditsc.c audit/stable-5.13 PR 20210426 2021-04-27 13:50:58 -07:00
backtracetest.c treewide: Replace DECLARE_TASKLET() with DECLARE_TASKLET_OLD() 2020-07-30 11:15:58 -07:00
bounds.c
capability.c capability: handle idmapped mounts 2021-01-24 14:27:16 +01:00
cfi.c add support for Clang CFI 2021-04-08 16:04:20 -07:00
compat.c treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
configs.c
context_tracking.c context_tracking: Ensure that the critical path cannot be instrumented 2020-06-11 15:14:36 +02:00
cpu.c cpumask/hotplug: Fix cpu_dying() state tracking 2021-04-21 13:55:43 +02:00
cpu_pm.c notifier: Fix broken error handling pattern 2020-09-01 09:58:03 +02:00
crash_core.c kdump: append uts_namespace.name offset to VMCOREINFO 2020-12-15 22:46:18 -08:00
crash_dump.c crash_dump: Remove no longer used saved_max_pfn 2020-04-15 11:21:54 +02:00
cred.c kernel/cred.c: make init_groups static 2021-05-06 19:24:11 -07:00
delayacct.c delayacct: Add sysctl to enable at runtime 2021-05-12 11:43:25 +02:00
dma.c
exec_domain.c
exit.c do_wait: make PIDTYPE_PID case O(1) instead of O(n) 2021-05-06 19:24:13 -07:00
extable.c kernel/extable.c: use address-of operator on section symbols 2020-04-07 10:43:42 -07:00
fail_function.c fault-injection: handle EI_ETYPE_TRUE 2020-12-15 22:46:19 -08:00
fork.c sched: Inherit task cookie on fork() 2021-05-12 11:43:31 +02:00
freezer.c Revert "kernel: freezer should treat PF_IO_WORKER like PF_KTHREAD for freezing" 2021-03-27 14:09:10 -06:00
futex.c futex: Make syscall entry points less convoluted 2021-05-06 20:19:04 +02:00
gen_kheaders.sh kbuild: redo fake deps at include/config/*.h 2021-04-25 05:26:10 +09:00
groups.c groups: simplify struct group_info allocation 2021-02-26 09:41:03 -08:00
hung_task.c kernel/hung_task.c: make type annotations consistent 2020-11-02 12:14:19 -08:00
iomem.c
irq_work.c irq_work: record irq_work_queue() call stack 2021-04-30 11:20:42 -07:00
jump_label.c static_call: Fix static_call_update() sanity check 2021-03-19 13:16:44 +01:00
kallsyms.c kallsyms: strip ThinLTO hashes from static functions 2021-04-08 16:04:21 -07:00
kcmp.c Merge branch 'exec-update-lock-for-v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2020-12-15 19:36:48 -08:00
Kconfig.freezer
Kconfig.hz
Kconfig.locks
Kconfig.preempt sched: Core-wide rq->lock 2021-05-12 11:43:27 +02:00
kcov.c kernel: make kcov_common_handle consider the current context 2020-11-02 18:00:20 -08:00
kexec.c LSM: Introduce kernel_post_load_data() hook 2020-10-05 13:37:03 +02:00
kexec_core.c kexec: dump kmessage before machine_kexec 2021-05-07 00:26:32 -07:00
kexec_elf.c
kexec_file.c kernel: kexec_file: fix error return code of kexec_calculate_store_digests() 2021-05-07 00:26:32 -07:00
kexec_internal.h kexec: move machine_kexec_post_load() to public interface 2021-02-22 12:33:26 +00:00
kheaders.c
kmod.c modules: add CONFIG_MODPROBE_PATH 2021-05-07 00:26:33 -07:00
kprobes.c kprobes: Fix to delay the kprobes jump optimization 2021-02-19 14:57:12 -05:00
ksysfs.c
kthread.c Scheduler updates for this cycle are: 2021-04-28 13:33:57 -07:00
latencytop.c sysctl: pass kernel pointers to ->proc_handler 2020-04-27 02:07:40 -04:00
Makefile kbuild: update config_data.gz only when the content of .config is changed 2021-05-02 00:43:35 +09:00
module-internal.h
module.c Summary of modules changes for the 5.13 merge window: 2021-04-30 12:29:36 -07:00
module_signature.c module: harden ELF info handling 2021-01-19 10:24:45 +01:00
module_signing.c module: harden ELF info handling 2021-01-19 10:24:45 +01:00
notifier.c notifier: Fix broken error handling pattern 2020-09-01 09:58:03 +02:00
nsproxy.c fixes-v5.11 2020-12-14 16:40:27 -08:00
padata.c padata: fix possible padata_works_lock deadlock 2020-09-04 17:51:55 +10:00
panic.c panic: don't dump stack twice on warn 2020-11-14 11:26:04 -08:00
params.c Modules updates for v5.11 2020-12-17 13:01:31 -08:00
pid.c Merge branch 'exec-update-lock-for-v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2020-12-15 19:36:48 -08:00
pid_namespace.c fixes-v5.11 2020-12-14 16:40:27 -08:00
profile.c kernel: Initialize cpumask before parsing 2021-04-10 13:35:54 +02:00
ptrace.c Linux 5.12-rc8 2021-04-20 10:13:58 +02:00
range.c kernel.h: split out min()/max() et al. helpers 2020-10-16 11:11:19 -07:00
reboot.c Revert "PM: ACPI: reboot: Use S5 for reboot" 2021-03-18 16:58:02 +01:00
regset.c regset: kill ->get() 2020-07-27 14:31:12 -04:00
relay.c relay: allow the use of const callback structs 2020-12-15 22:46:18 -08:00
resource.c kernel/resource: fix locking in request_free_mem_region 2021-05-07 00:26:33 -07:00
resource_kunit.c resource: provide meaningful MODULE_LICENSE() in test suite 2020-11-25 18:52:35 +01:00
rseq.c rseq: Optimise rseq_get_rseq_cs() and clear_rseq_cs() 2021-04-14 18:04:09 +02:00
scftorture.c scftorture: Add debug output for wrong-CPU warning 2021-01-04 13:53:41 -08:00
scs.c scs: switch to vmapped shadow stacks 2020-12-01 10:30:28 +00:00
seccomp.c Merge branch 'work.file' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2021-05-03 11:05:28 -07:00
signal.c Scheduler updates for this cycle are: 2021-04-28 13:33:57 -07:00
smp.c smp: Fix smp_call_function_single_async prototype 2021-05-06 15:33:49 +02:00
smpboot.c kthread: Extract KTHREAD_IS_PER_CPU 2021-01-22 15:09:42 +01:00
smpboot.h
softirq.c RCU changes for this cycle were: 2021-04-28 12:00:13 -07:00
stackleak.c stackleak: let stack_erasing_sysctl take a kernel pointer buffer 2020-09-19 13:13:39 -07:00
stacktrace.c stacktrace: Remove reliable argument from arch_stack_walk() callback 2020-09-18 14:24:16 +01:00
static_call.c static_call: Fix unused variable warn w/o MODULE 2021-04-09 13:22:12 +02:00
stop_machine.c stop_machine: Add caller debug info to queue_stop_cpus_work 2021-03-23 16:01:58 +01:00
sys.c sched: prctl() core-scheduling interface 2021-05-12 11:43:31 +02:00
sys_ni.c Add Landlock, a new LSM from Mickaël Salaün <mic@linux.microsoft.com> 2021-05-01 18:50:44 -07:00
sysctl-test.c
sysctl.c delayacct: Add sysctl to enable at runtime 2021-05-12 11:43:25 +02:00
task_work.c kasan: record task_work_add() call stack 2021-04-30 11:20:42 -07:00
taskstats.c treewide: rename nla_strlcpy to nla_strscpy. 2020-11-16 08:08:54 -08:00
test_kprobes.c
torture.c torture: Replace torture_init_begin string with %s 2021-03-08 14:22:28 -08:00
tracepoint.c tracepoints: Code clean up 2021-02-09 12:27:29 -05:00
tsacct.c
ucount.c fanotify: configurable limits via sysfs 2021-03-16 16:49:31 +01:00
uid16.c
uid16.h
umh.c kernel/umh.c: fix some spelling mistakes 2021-05-07 00:26:34 -07:00
up.c A set of locking related fixes and updates: 2021-05-09 13:07:03 -07:00
user-return-notifier.c
user.c user: Use generic ns_common::count 2020-08-19 14:14:12 +02:00
user_namespace.c kernel/user_namespace.c: fix typos 2021-05-07 00:26:34 -07:00
usermode_driver.c bpf: Fix umd memory leak in copy_process() 2021-03-19 22:23:19 +01:00
utsname.c uts: Use generic ns_common::count 2020-08-19 14:13:20 +02:00
utsname_sysctl.c sysctl: pass kernel pointers to ->proc_handler 2020-04-27 02:07:40 -04:00
watch_queue.c watch_queue: rectify kernel-doc for init_watch() 2021-01-26 11:16:34 +00:00
watchdog.c watchdog: cleanup handling of false positives 2021-04-30 11:20:36 -07:00
watchdog_hld.c
workqueue.c CFI on arm64 series for v5.13-rc1 2021-04-27 10:16:46 -07:00
workqueue_internal.h