[tip:x86/cache] x86/intel_rdt: Add diagnostics when writing the tasks file

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Commit-ID:  29e74f35b2fed0ca3e8b31db157e1d183e9d0819
Gitweb:     http://git.kernel.org/tip/29e74f35b2fed0ca3e8b31db157e1d183e9d0819
Author:     Tony Luck <tony.luck@xxxxxxxxx>
AuthorDate: Mon, 25 Sep 2017 16:39:35 -0700
Committer:  Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitDate: Wed, 27 Sep 2017 12:10:10 +0200

x86/intel_rdt: Add diagnostics when writing the tasks file

About the only tricky case is trying to move a task into a monitor
group that is a subdirectory of a different control group. But cover
the simple cases too.

Signed-off-by: Tony Luck <tony.luck@xxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Fenghua Yu <fenghua.yu@xxxxxxxxx>
Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
Cc: Vikas Shivappa <vikas.shivappa@xxxxxxxxx>
Cc: Boris Petkov <bp@xxxxxxx>
Cc: Reinette Chatre <reinette.chatre@xxxxxxxxx>
Link: https://lkml.kernel.org/r/f1841cce6a242aed37cb926dee8942727331bf78.1506382469.git.tony.luck@xxxxxxxxx

---
 arch/x86/kernel/cpu/intel_rdt_ctrlmondata.c |  4 +---
 arch/x86/kernel/cpu/intel_rdt_rdtgroup.c    | 13 ++++++++++---
 2 files changed, 11 insertions(+), 6 deletions(-)

diff --git a/arch/x86/kernel/cpu/intel_rdt_ctrlmondata.c b/arch/x86/kernel/cpu/intel_rdt_ctrlmondata.c
index f29b4c2..30aeb26 100644
--- a/arch/x86/kernel/cpu/intel_rdt_ctrlmondata.c
+++ b/arch/x86/kernel/cpu/intel_rdt_ctrlmondata.c
@@ -232,10 +232,8 @@ ssize_t rdtgroup_schemata_write(struct kernfs_open_file *of,
 	int closid, ret = 0;
 
 	/* Valid input requires a trailing newline */
-	if (nbytes == 0 || buf[nbytes - 1] != '\n') {
-		seq_buf_puts(&last_cmd_status, "no trailing newline\n");
+	if (nbytes == 0 || buf[nbytes - 1] != '\n')
 		return -EINVAL;
-	}
 	buf[nbytes - 1] = '\0';
 
 	rdtgrp = rdtgroup_kn_lock_live(of->kn);
diff --git a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
index 6810351..d39092e 100644
--- a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
+++ b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
@@ -478,6 +478,7 @@ static int __rdtgroup_move_task(struct task_struct *tsk,
 		 */
 		atomic_dec(&rdtgrp->waitcount);
 		kfree(callback);
+		rdt_last_cmd_puts("task exited\n");
 	} else {
 		/*
 		 * For ctrl_mon groups move both closid and rmid.
@@ -488,10 +489,12 @@ static int __rdtgroup_move_task(struct task_struct *tsk,
 			tsk->closid = rdtgrp->closid;
 			tsk->rmid = rdtgrp->mon.rmid;
 		} else if (rdtgrp->type == RDTMON_GROUP) {
-			if (rdtgrp->mon.parent->closid == tsk->closid)
+			if (rdtgrp->mon.parent->closid == tsk->closid) {
 				tsk->rmid = rdtgrp->mon.rmid;
-			else
+			} else {
+				rdt_last_cmd_puts("Can't move task to different control group\n");
 				ret = -EINVAL;
+			}
 		}
 	}
 	return ret;
@@ -510,8 +513,10 @@ static int rdtgroup_task_write_permission(struct task_struct *task,
 	 */
 	if (!uid_eq(cred->euid, GLOBAL_ROOT_UID) &&
 	    !uid_eq(cred->euid, tcred->uid) &&
-	    !uid_eq(cred->euid, tcred->suid))
+	    !uid_eq(cred->euid, tcred->suid)) {
+		rdt_last_cmd_printf("No permission to move task %d\n", task->pid);
 		ret = -EPERM;
+	}
 
 	put_cred(tcred);
 	return ret;
@@ -528,6 +533,7 @@ static int rdtgroup_move_task(pid_t pid, struct rdtgroup *rdtgrp,
 		tsk = find_task_by_vpid(pid);
 		if (!tsk) {
 			rcu_read_unlock();
+			rdt_last_cmd_printf("No task %d\n", pid);
 			return -ESRCH;
 		}
 	} else {
@@ -555,6 +561,7 @@ static ssize_t rdtgroup_tasks_write(struct kernfs_open_file *of,
 	if (kstrtoint(strstrip(buf), 0, &pid) || pid < 0)
 		return -EINVAL;
 	rdtgrp = rdtgroup_kn_lock_live(of->kn);
+	rdt_last_cmd_clear();
 
 	if (rdtgrp)
 		ret = rdtgroup_move_task(pid, rdtgrp, of);
--
To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html



[Index of Archives]     [Linux Stable Commits]     [Linux Stable Kernel]     [Linux Kernel]     [Linux USB Devel]     [Linux Video &Media]     [Linux Audio Users]     [Yosemite News]     [Linux SCSI]

  Powered by Linux