273 lines
7.0 KiB
C
273 lines
7.0 KiB
C
/*-
|
|
* Copyright (c) 2010 The FreeBSD Foundation
|
|
* All rights reserved.
|
|
*
|
|
* This software was developed by Rui Paulo under sponsorship from the
|
|
* FreeBSD Foundation.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions
|
|
* are met:
|
|
* 1. Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer.
|
|
* 2. Redistributions in binary form must reproduce the above copyright
|
|
* notice, this list of conditions and the following disclaimer in the
|
|
* documentation and/or other materials provided with the distribution.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
|
|
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
|
|
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
|
|
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
|
|
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
|
|
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
|
|
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
|
|
* SUCH DAMAGE.
|
|
*/
|
|
|
|
#include <sys/cdefs.h>
|
|
__FBSDID("$FreeBSD$");
|
|
|
|
#include <sys/types.h>
|
|
#include <sys/ptrace.h>
|
|
#include <sys/wait.h>
|
|
|
|
#include <assert.h>
|
|
#include <err.h>
|
|
#include <errno.h>
|
|
#include <signal.h>
|
|
#include <stdio.h>
|
|
|
|
#include "_libproc.h"
|
|
|
|
#if defined(__aarch64__)
|
|
#define AARCH64_BRK 0xd4200000
|
|
#define AARCH64_BRK_IMM16_SHIFT 5
|
|
#define AARCH64_BRK_IMM16_VAL (0xd << AARCH64_BRK_IMM16_SHIFT)
|
|
#define BREAKPOINT_INSTR (AARCH64_BRK | AARCH64_BRK_IMM16_VAL)
|
|
#define BREAKPOINT_INSTR_SZ 4
|
|
#elif defined(__amd64__) || defined(__i386__)
|
|
#define BREAKPOINT_INSTR 0xcc /* int 0x3 */
|
|
#define BREAKPOINT_INSTR_SZ 1
|
|
#define BREAKPOINT_ADJUST_SZ BREAKPOINT_INSTR_SZ
|
|
#elif defined(__arm__)
|
|
#define BREAKPOINT_INSTR 0xe7ffffff /* bkpt */
|
|
#define BREAKPOINT_INSTR_SZ 4
|
|
#elif defined(__mips__)
|
|
#define BREAKPOINT_INSTR 0xd /* break */
|
|
#define BREAKPOINT_INSTR_SZ 4
|
|
#elif defined(__powerpc__)
|
|
#define BREAKPOINT_INSTR 0x7fe00008 /* trap */
|
|
#define BREAKPOINT_INSTR_SZ 4
|
|
#elif defined(__riscv__)
|
|
#define BREAKPOINT_INSTR 0x00100073 /* sbreak */
|
|
#define BREAKPOINT_INSTR_SZ 4
|
|
#else
|
|
#error "Add support for your architecture"
|
|
#endif
|
|
|
|
/*
|
|
* Use 4-bytes holder for breakpoint instruction on all the platforms.
|
|
* Works for x86 as well until it is endian-little platform.
|
|
* (We are coping one byte only on x86 from this 4-bytes piece of
|
|
* memory).
|
|
*/
|
|
typedef uint32_t instr_t;
|
|
|
|
static int
|
|
proc_stop(struct proc_handle *phdl)
|
|
{
|
|
int status;
|
|
|
|
if (kill(proc_getpid(phdl), SIGSTOP) == -1) {
|
|
DPRINTF("kill %d", proc_getpid(phdl));
|
|
return (-1);
|
|
} else if (waitpid(proc_getpid(phdl), &status, WSTOPPED) == -1) {
|
|
DPRINTF("waitpid %d", proc_getpid(phdl));
|
|
return (-1);
|
|
} else if (!WIFSTOPPED(status)) {
|
|
DPRINTFX("waitpid: unexpected status 0x%x", status);
|
|
return (-1);
|
|
}
|
|
|
|
return (0);
|
|
}
|
|
|
|
int
|
|
proc_bkptset(struct proc_handle *phdl, uintptr_t address,
|
|
unsigned long *saved)
|
|
{
|
|
struct ptrace_io_desc piod;
|
|
unsigned long caddr;
|
|
int ret = 0, stopped;
|
|
instr_t instr;
|
|
|
|
*saved = 0;
|
|
if (phdl->status == PS_DEAD || phdl->status == PS_UNDEAD ||
|
|
phdl->status == PS_IDLE) {
|
|
errno = ENOENT;
|
|
return (-1);
|
|
}
|
|
|
|
DPRINTFX("adding breakpoint at 0x%lx", address);
|
|
|
|
stopped = 0;
|
|
if (phdl->status != PS_STOP) {
|
|
if (proc_stop(phdl) != 0)
|
|
return (-1);
|
|
stopped = 1;
|
|
}
|
|
|
|
/*
|
|
* Read the original instruction.
|
|
*/
|
|
caddr = address;
|
|
instr = 0;
|
|
piod.piod_op = PIOD_READ_I;
|
|
piod.piod_offs = (void *)caddr;
|
|
piod.piod_addr = &instr;
|
|
piod.piod_len = BREAKPOINT_INSTR_SZ;
|
|
if (ptrace(PT_IO, proc_getpid(phdl), (caddr_t)&piod, 0) < 0) {
|
|
DPRINTF("ERROR: couldn't read instruction at address 0x%jx",
|
|
(uintmax_t)address);
|
|
ret = -1;
|
|
goto done;
|
|
}
|
|
*saved = instr;
|
|
/*
|
|
* Write a breakpoint instruction to that address.
|
|
*/
|
|
caddr = address;
|
|
instr = BREAKPOINT_INSTR;
|
|
piod.piod_op = PIOD_WRITE_I;
|
|
piod.piod_offs = (void *)caddr;
|
|
piod.piod_addr = &instr;
|
|
piod.piod_len = BREAKPOINT_INSTR_SZ;
|
|
if (ptrace(PT_IO, proc_getpid(phdl), (caddr_t)&piod, 0) < 0) {
|
|
DPRINTF("ERROR: couldn't write instruction at address 0x%jx",
|
|
(uintmax_t)address);
|
|
ret = -1;
|
|
goto done;
|
|
}
|
|
|
|
done:
|
|
if (stopped)
|
|
/* Restart the process if we had to stop it. */
|
|
proc_continue(phdl);
|
|
|
|
return (ret);
|
|
}
|
|
|
|
int
|
|
proc_bkptdel(struct proc_handle *phdl, uintptr_t address,
|
|
unsigned long saved)
|
|
{
|
|
struct ptrace_io_desc piod;
|
|
unsigned long caddr;
|
|
int ret = 0, stopped;
|
|
instr_t instr;
|
|
|
|
if (phdl->status == PS_DEAD || phdl->status == PS_UNDEAD ||
|
|
phdl->status == PS_IDLE) {
|
|
errno = ENOENT;
|
|
return (-1);
|
|
}
|
|
|
|
DPRINTFX("removing breakpoint at 0x%lx", address);
|
|
|
|
stopped = 0;
|
|
if (phdl->status != PS_STOP) {
|
|
if (proc_stop(phdl) != 0)
|
|
return (-1);
|
|
stopped = 1;
|
|
}
|
|
|
|
/*
|
|
* Overwrite the breakpoint instruction that we setup previously.
|
|
*/
|
|
caddr = address;
|
|
instr = saved;
|
|
piod.piod_op = PIOD_WRITE_I;
|
|
piod.piod_offs = (void *)caddr;
|
|
piod.piod_addr = &instr;
|
|
piod.piod_len = BREAKPOINT_INSTR_SZ;
|
|
if (ptrace(PT_IO, proc_getpid(phdl), (caddr_t)&piod, 0) < 0) {
|
|
DPRINTF("ERROR: couldn't write instruction at address 0x%jx",
|
|
(uintmax_t)address);
|
|
ret = -1;
|
|
}
|
|
|
|
if (stopped)
|
|
/* Restart the process if we had to stop it. */
|
|
proc_continue(phdl);
|
|
|
|
return (ret);
|
|
}
|
|
|
|
/*
|
|
* Decrement pc so that we delete the breakpoint at the correct
|
|
* address, i.e. at the BREAKPOINT_INSTR address.
|
|
*
|
|
* This is only needed on some architectures where the pc value
|
|
* when reading registers points at the instruction after the
|
|
* breakpoint, e.g. x86.
|
|
*/
|
|
void
|
|
proc_bkptregadj(unsigned long *pc)
|
|
{
|
|
|
|
(void)pc;
|
|
#ifdef BREAKPOINT_ADJUST_SZ
|
|
*pc = *pc - BREAKPOINT_ADJUST_SZ;
|
|
#endif
|
|
}
|
|
|
|
/*
|
|
* Step over the breakpoint.
|
|
*/
|
|
int
|
|
proc_bkptexec(struct proc_handle *phdl, unsigned long saved)
|
|
{
|
|
unsigned long pc;
|
|
unsigned long samesaved;
|
|
int status;
|
|
|
|
if (proc_regget(phdl, REG_PC, &pc) < 0) {
|
|
DPRINTFX("ERROR: couldn't get PC register");
|
|
return (-1);
|
|
}
|
|
proc_bkptregadj(&pc);
|
|
if (proc_bkptdel(phdl, pc, saved) < 0) {
|
|
DPRINTFX("ERROR: couldn't delete breakpoint");
|
|
return (-1);
|
|
}
|
|
/*
|
|
* Go back in time and step over the new instruction just
|
|
* set up by proc_bkptdel().
|
|
*/
|
|
proc_regset(phdl, REG_PC, pc);
|
|
if (ptrace(PT_STEP, proc_getpid(phdl), (caddr_t)1, 0) < 0) {
|
|
DPRINTFX("ERROR: ptrace step failed");
|
|
return (-1);
|
|
}
|
|
proc_wstatus(phdl);
|
|
status = proc_getwstat(phdl);
|
|
if (!WIFSTOPPED(status)) {
|
|
DPRINTFX("ERROR: don't know why process stopped");
|
|
return (-1);
|
|
}
|
|
/*
|
|
* Restore the breakpoint. The saved instruction should be
|
|
* the same as the one that we were passed in.
|
|
*/
|
|
if (proc_bkptset(phdl, pc, &samesaved) < 0) {
|
|
DPRINTFX("ERROR: couldn't restore breakpoint");
|
|
return (-1);
|
|
}
|
|
assert(samesaved == saved);
|
|
|
|
return (0);
|
|
}
|