mm/ptdump/segment_regs.c

0001 // SPDX-License-Identifier: GPL-2.0+
0002 /*
0003  * Copyright 2018, Christophe Leroy CS S.I.
0004  * <christophe.leroy@c-s.fr>
0005  *
0006  * This dumps the content of Segment Registers
0007  */
0008
0009 #include <linux/debugfs.h>
0010
0011 static void seg_show(struct seq_file *m, int i)
0012 {
0013     u32 val = mfsr(i << 28);
0014
0015     seq_printf(m, "0x%01x0000000-0x%01xfffffff ", i, i);
0016     seq_printf(m, "Kern key %d ", (val >> 30) & 1);
0017     seq_printf(m, "User key %d ", (val >> 29) & 1);
0018     if (val & 0x80000000) {
0019         seq_printf(m, "Device 0x%03x", (val >> 20) & 0x1ff);
0020         seq_printf(m, "-0x%05x", val & 0xfffff);
0021     } else {
0022         if (val & 0x10000000)
0023             seq_puts(m, "No Exec ");
0024         seq_printf(m, "VSID 0x%06x", val & 0xffffff);
0025     }
0026     seq_puts(m, "\n");
0027 }
0028
0029 static int sr_show(struct seq_file *m, void *v)
0030 {
0031     int i;
0032
0033     seq_puts(m, "---[ User Segments ]---\n");
0034     for (i = 0; i < TASK_SIZE >> 28; i++)
0035         seg_show(m, i);
0036
0037     seq_puts(m, "\n---[ Kernel Segments ]---\n");
0038     for (; i < 16; i++)
0039         seg_show(m, i);
0040
0041     return 0;
0042 }
0043
0044 DEFINE_SHOW_ATTRIBUTE(sr);
0045
0046 static int __init sr_init(void)
0047 {
0048     debugfs_create_file("segment_registers", 0400, arch_debugfs_dir,
0049                 NULL, &sr_fops);
0050     return 0;
0051 }
0052 device_initcall(sr_init);