130 lines
4.3 KiB
C
Executable file
130 lines
4.3 KiB
C
Executable file
/*
|
|
* dwarf-regs.c : Mapping of DWARF debug register numbers into register names.
|
|
* Extracted from probe-finder.c
|
|
*
|
|
* Written by Masami Hiramatsu <mhiramat@redhat.com>
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License as published by
|
|
* the Free Software Foundation; either version 2 of the License, or
|
|
* (at your option) any later version.
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program; if not, write to the Free Software
|
|
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
|
|
*
|
|
*/
|
|
|
|
#include <stddef.h>
|
|
#include <errno.h> /* for EINVAL */
|
|
#include <string.h> /* for strcmp */
|
|
#include <linux/ptrace.h> /* for struct pt_regs */
|
|
#include <linux/kernel.h> /* for offsetof */
|
|
#include <dwarf-regs.h>
|
|
|
|
/*
|
|
* See arch/x86/kernel/ptrace.c.
|
|
* Different from it:
|
|
*
|
|
* - Since struct pt_regs is defined differently for user and kernel,
|
|
* but we want to use 'ax, bx' instead of 'rax, rbx' (which is struct
|
|
* field name of user's pt_regs), we make REG_OFFSET_NAME to accept
|
|
* both string name and reg field name.
|
|
*
|
|
* - Since accessing x86_32's pt_regs from x86_64 building is difficult
|
|
* and vise versa, we simply fill offset with -1, so
|
|
* get_arch_regstr() still works but regs_query_register_offset()
|
|
* returns error.
|
|
* The only inconvenience caused by it now is that we are not allowed
|
|
* to generate BPF prologue for a x86_64 kernel if perf is built for
|
|
* x86_32. This is really a rare usecase.
|
|
*
|
|
* - Order is different from kernel's ptrace.c for get_arch_regstr(). Use
|
|
* the order defined by dwarf.
|
|
*/
|
|
|
|
struct pt_regs_offset {
|
|
const char *name;
|
|
int offset;
|
|
};
|
|
|
|
#define REG_OFFSET_END {.name = NULL, .offset = 0}
|
|
|
|
#ifdef __x86_64__
|
|
# define REG_OFFSET_NAME_64(n, r) {.name = n, .offset = offsetof(struct pt_regs, r)}
|
|
# define REG_OFFSET_NAME_32(n, r) {.name = n, .offset = -1}
|
|
#else
|
|
# define REG_OFFSET_NAME_64(n, r) {.name = n, .offset = -1}
|
|
# define REG_OFFSET_NAME_32(n, r) {.name = n, .offset = offsetof(struct pt_regs, r)}
|
|
#endif
|
|
|
|
/* TODO: switching by dwarf address size */
|
|
#ifndef __x86_64__
|
|
static const struct pt_regs_offset x86_32_regoffset_table[] = {
|
|
REG_OFFSET_NAME_32("%ax", eax),
|
|
REG_OFFSET_NAME_32("%cx", ecx),
|
|
REG_OFFSET_NAME_32("%dx", edx),
|
|
REG_OFFSET_NAME_32("%bx", ebx),
|
|
REG_OFFSET_NAME_32("$stack", esp), /* Stack address instead of %sp */
|
|
REG_OFFSET_NAME_32("%bp", ebp),
|
|
REG_OFFSET_NAME_32("%si", esi),
|
|
REG_OFFSET_NAME_32("%di", edi),
|
|
REG_OFFSET_END,
|
|
};
|
|
|
|
#define regoffset_table x86_32_regoffset_table
|
|
#else
|
|
static const struct pt_regs_offset x86_64_regoffset_table[] = {
|
|
REG_OFFSET_NAME_64("%ax", rax),
|
|
REG_OFFSET_NAME_64("%dx", rdx),
|
|
REG_OFFSET_NAME_64("%cx", rcx),
|
|
REG_OFFSET_NAME_64("%bx", rbx),
|
|
REG_OFFSET_NAME_64("%si", rsi),
|
|
REG_OFFSET_NAME_64("%di", rdi),
|
|
REG_OFFSET_NAME_64("%bp", rbp),
|
|
REG_OFFSET_NAME_64("%sp", rsp),
|
|
REG_OFFSET_NAME_64("%r8", r8),
|
|
REG_OFFSET_NAME_64("%r9", r9),
|
|
REG_OFFSET_NAME_64("%r10", r10),
|
|
REG_OFFSET_NAME_64("%r11", r11),
|
|
REG_OFFSET_NAME_64("%r12", r12),
|
|
REG_OFFSET_NAME_64("%r13", r13),
|
|
REG_OFFSET_NAME_64("%r14", r14),
|
|
REG_OFFSET_NAME_64("%r15", r15),
|
|
REG_OFFSET_END,
|
|
};
|
|
|
|
#define regoffset_table x86_64_regoffset_table
|
|
#endif
|
|
|
|
/* Minus 1 for the ending REG_OFFSET_END */
|
|
#define ARCH_MAX_REGS ((sizeof(regoffset_table) / sizeof(regoffset_table[0])) - 1)
|
|
|
|
/* Return architecture dependent register string (for kprobe-tracer) */
|
|
const char *get_arch_regstr(unsigned int n)
|
|
{
|
|
return (n < ARCH_MAX_REGS) ? regoffset_table[n].name : NULL;
|
|
}
|
|
|
|
/* Reuse code from arch/x86/kernel/ptrace.c */
|
|
/**
|
|
* regs_query_register_offset() - query register offset from its name
|
|
* @name: the name of a register
|
|
*
|
|
* regs_query_register_offset() returns the offset of a register in struct
|
|
* pt_regs from its name. If the name is invalid, this returns -EINVAL;
|
|
*/
|
|
int regs_query_register_offset(const char *name)
|
|
{
|
|
const struct pt_regs_offset *roff;
|
|
for (roff = regoffset_table; roff->name != NULL; roff++)
|
|
if (!strcmp(roff->name, name))
|
|
return roff->offset;
|
|
return -EINVAL;
|
|
}
|