Commit 2997d94b authored by Shawn Wang's avatar Shawn Wang Committed by Borislav Petkov (AMD)
Browse files

x86/resctrl: Only show tasks' pid in current pid namespace 



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: e02737d5 ("x86/intel_rdt: Add tasks files")
Signed-off-by: default avatarShawn Wang <shawnwang@linux.alibaba.com>
Signed-off-by: default avatarBorislav Petkov (AMD) <bp@alien8.de>
Acked-by: default avatarReinette Chatre <reinette.chatre@intel.com>
Acked-by: default avatarFenghua Yu <fenghua.yu@intel.com>
Tested-by: default avatarReinette Chatre <reinette.chatre@intel.com>
Link: https://lore.kernel.org/all/20230116071246.97717-1-shawnwang@linux.alibaba.com/
parent 7877cb91

arch/x86/kernel/cpu/resctrl/rdtgroup.c

+6 −2
Original line number Diff line number Diff line
@@ -726,11 +726,15 @@ 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();

}