From: Shawn Wang shawnwang@linux.alibaba.com
[ Upstream commit 2997d94b5dd0e8b10076f5e0b6f18410c73e28bd ]
When writing a task id to the "tasks" file in an rdtgroup, rdtgroup_tasks_write() treats the pid as a number in the current pid namespace. But when reading the "tasks" file, rdtgroup_tasks_show() shows the list of global pids from the init namespace, which is confusing and incorrect.
To be more robust, let the "tasks" file only show pids in the current pid namespace.
Fixes: e02737d5b826 ("x86/intel_rdt: Add tasks files") Signed-off-by: Shawn Wang shawnwang@linux.alibaba.com Signed-off-by: Borislav Petkov (AMD) bp@alien8.de Acked-by: Reinette Chatre reinette.chatre@intel.com Acked-by: Fenghua Yu fenghua.yu@intel.com Tested-by: Reinette Chatre reinette.chatre@intel.com Link: https://lore.kernel.org/all/20230116071246.97717-1-shawnwang@linux.alibaba.c... Signed-off-by: Sasha Levin sashal@kernel.org --- arch/x86/kernel/cpu/resctrl/rdtgroup.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c index 421d31718fbd8..2ec16477eb3e1 100644 --- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c +++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c @@ -731,11 +731,15 @@ static ssize_t rdtgroup_tasks_write(struct kernfs_open_file *of, static void show_rdt_tasks(struct rdtgroup *r, struct seq_file *s) { struct task_struct *p, *t; + pid_t pid;
rcu_read_lock(); for_each_process_thread(p, t) { - if (is_closid_match(t, r) || is_rmid_match(t, r)) - seq_printf(s, "%d\n", t->pid); + if (is_closid_match(t, r) || is_rmid_match(t, r)) { + pid = task_pid_vnr(t); + if (pid) + seq_printf(s, "%d\n", pid); + } } rcu_read_unlock(); }