cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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asids-debugfs.c (1464B)


      1/*
      2 * debugfs ops for process ASIDs
      3 *
      4 *  Copyright (C) 2000, 2001  Paolo Alberelli
      5 *  Copyright (C) 2003 - 2008  Paul Mundt
      6 *  Copyright (C) 2003, 2004  Richard Curnow
      7 *
      8 * Provides a debugfs file that lists out the ASIDs currently associated
      9 * with the processes.
     10 *
     11 * In the SH-5 case, if the DM.PC register is examined through the debug
     12 * link, this shows ASID + PC. To make use of this, the PID->ASID
     13 * relationship needs to be known. This is primarily for debugging.
     14 *
     15 * This file is subject to the terms and conditions of the GNU General Public
     16 * License.  See the file "COPYING" in the main directory of this archive
     17 * for more details.
     18 */
     19#include <linux/init.h>
     20#include <linux/debugfs.h>
     21#include <linux/seq_file.h>
     22#include <linux/spinlock.h>
     23#include <linux/sched/signal.h>
     24#include <linux/sched/task.h>
     25
     26#include <asm/processor.h>
     27#include <asm/mmu_context.h>
     28
     29static int asids_debugfs_show(struct seq_file *file, void *iter)
     30{
     31	struct task_struct *p;
     32
     33	read_lock(&tasklist_lock);
     34
     35	for_each_process(p) {
     36		int pid = p->pid;
     37
     38		if (unlikely(!pid))
     39			continue;
     40
     41		if (p->mm)
     42			seq_printf(file, "%5d : %04lx\n", pid,
     43				   cpu_asid(smp_processor_id(), p->mm));
     44	}
     45
     46	read_unlock(&tasklist_lock);
     47
     48	return 0;
     49}
     50
     51DEFINE_SHOW_ATTRIBUTE(asids_debugfs);
     52
     53static int __init asids_debugfs_init(void)
     54{
     55	debugfs_create_file("asids", S_IRUSR, arch_debugfs_dir, NULL,
     56			    &asids_debugfs_fops);
     57	return 0;
     58}
     59device_initcall(asids_debugfs_init);