tools/perf/arch/s390/util/dwarf-regs.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Mapping of DWARF debug register numbers into register names.
   4  *
   5  * Copyright IBM Corp. 2010, 2017
   6  * Author(s): Heiko Carstens <heiko.carstens@de.ibm.com>,
   7  *            Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
   8  *
   9  */
  10
  11 #include <errno.h>
  12 #include <stddef.h>
  13 #include <stdlib.h>
  14 #include <linux/kernel.h>
  15 #include <asm/ptrace.h>
  16 #include <string.h>
  17 #include <dwarf-regs.h>
  18 #include "dwarf-regs-table.h"
  19
  20 const char *get_arch_regstr(unsigned int n)
  21 {
  22         return (n >= ARRAY_SIZE(s390_dwarf_regs)) ? NULL : s390_dwarf_regs[n];
  23 }
  24
  25 /*
  26  * Convert the register name into an offset to struct pt_regs (kernel).
  27  * This is required by the BPF prologue generator.  The BPF
  28  * program is called in the BPF overflow handler in the perf
  29  * core.
  30  */
  31 int regs_query_register_offset(const char *name)
  32 {
  33         unsigned long gpr;
  34
  35         if (!name || strncmp(name, "%r", 2))
  36                 return -EINVAL;
  37
  38         errno = 0;
  39         gpr = strtoul(name + 2, NULL, 10);
  40         if (errno || gpr >= 16)
  41                 return -EINVAL;
  42
  43         return offsetof(user_pt_regs, gprs) + 8 * gpr;
  44 }