From 29e74f35b2fed0ca3e8b31db157e1d183e9d0819 Mon Sep 17 00:00:00 2001 From: Tony Luck Date: Mon, 25 Sep 2017 16:39:35 -0700 Subject: [PATCH] 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 Signed-off-by: Thomas Gleixner Cc: Fenghua Yu Cc: Steven Rostedt Cc: Vikas Shivappa Cc: Boris Petkov Cc: Reinette Chatre Link: https://lkml.kernel.org/r/f1841cce6a242aed37cb926dee8942727331bf78.1506382469.git.tony.luck@intel.com --- 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 f29b4c21e7d4..30aeb267cbd2 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 68103513130b..d39092eb63bb 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); -- 2.45.2