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uapi/linux/prctl: provide macro definitions for the PR_SCHED_CORE type argument

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Commit 7ac592aa35 ("sched: prctl() core-scheduling interface")
made use of enum pid_type in prctl's arg4; this type and the associated
enumeration definitions are not exposed to userspace.  Christian
has suggested to provide additional macro definitions that convey
the meaning of the type argument more in alignment with its actual
usage, and this patch does exactly that.

Link: https://lore.kernel.org/r/20210825170613.GA3884@asgard.redhat.com
Suggested-by: Christian Brauner <christian.brauner@ubuntu.com>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: Eugene Syromiatnikov <esyr@redhat.com>
Complements: 7ac592aa35 ("sched: prctl() core-scheduling interface")
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
This commit is contained in:
Eugene Syromiatnikov 2021-08-25 19:06:13 +02:00 committed by Christian Brauner
parent 5816b3e657
commit 61bc346ce6
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GPG Key ID: 91C61BC06578DCA2
3 changed files with 10 additions and 2 deletions
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5
Documentation/admin-guide/hw-vuln/core-scheduling.rst
View File

@ -61,8 +61,9 @@ arg3:
``pid`` of the task for which the operation applies.
arg4:
``pid_type`` for which the operation applies. It is of type ``enum pid_type``.
For example, if arg4 is ``PIDTYPE_TGID``, then the operation of this command
``pid_type`` for which the operation applies. It is one of
``PR_SCHED_CORE_SCOPE_``-prefixed macro constants. For example, if arg4
is ``PR_SCHED_CORE_SCOPE_THREAD_GROUP``, then the operation of this command
will be performed for all tasks in the task group of ``pid``.
arg5:

3
include/uapi/linux/prctl.h
View File

@ -268,5 +268,8 @@ struct prctl_mm_map {
# define PR_SCHED_CORE_SHARE_TO 2 /* push core_sched cookie to pid */
# define PR_SCHED_CORE_SHARE_FROM 3 /* pull core_sched cookie to pid */
# define PR_SCHED_CORE_MAX 4
# define PR_SCHED_CORE_SCOPE_THREAD 0
# define PR_SCHED_CORE_SCOPE_THREAD_GROUP 1
# define PR_SCHED_CORE_SCOPE_PROCESS_GROUP 2
#endif /* _LINUX_PRCTL_H */

4
kernel/sched/core_sched.c
View File

@ -134,6 +134,10 @@ int sched_core_share_pid(unsigned int cmd, pid_t pid, enum pid_type type,
if (!static_branch_likely(&sched_smt_present))
return -ENODEV;
BUILD_BUG_ON(PR_SCHED_CORE_SCOPE_THREAD != PIDTYPE_PID);
BUILD_BUG_ON(PR_SCHED_CORE_SCOPE_THREAD_GROUP != PIDTYPE_TGID);
BUILD_BUG_ON(PR_SCHED_CORE_SCOPE_PROCESS_GROUP != PIDTYPE_PGID);
if (type > PIDTYPE_PGID || cmd >= PR_SCHED_CORE_MAX || pid < 0 ||
(cmd != PR_SCHED_CORE_GET && uaddr))
return -EINVAL;