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/*
* This file is part of ltrace.
* Copyright (C) 2010,2012 Petr Machata, Red Hat Inc.
* Copyright (C) 2011 Andreas Schwab
* Copyright (C) 2002,2004,2008,2009 Juan Cespedes
* Copyright (C) 2008 Luis Machado, IBM Corporation
* Copyright (C) 2006 Ian Wienand
*
* 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., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA
*/
#include "config.h"
#include <assert.h>
#include <elf.h>
#include <errno.h>
#include <signal.h>
#include <string.h>
#include <sys/types.h>
#include <sys/wait.h>
#include "backend.h"
#include "breakpoint.h"
#include "common.h"
#include "insn.h"
#include "proc.h"
#include "ptrace.h"
#include "type.h"
#if (!defined(PTRACE_PEEKUSER) && defined(PTRACE_PEEKUSR))
# define PTRACE_PEEKUSER PTRACE_PEEKUSR
#endif
#if (!defined(PTRACE_POKEUSER) && defined(PTRACE_POKEUSR))
# define PTRACE_POKEUSER PTRACE_POKEUSR
#endif
void
get_arch_dep(Process *proc) {
#ifdef __powerpc64__
proc->mask_32bit = (proc->e_machine == EM_PPC);
#endif
}
#define SYSCALL_INSN 0x44000002
/* Returns 1 if syscall, 2 if sysret, 0 otherwise. */
int
syscall_p(Process *proc, int status, int *sysnum) {
if (WIFSTOPPED(status)
&& WSTOPSIG(status) == (SIGTRAP | proc->tracesysgood)) {
long pc = (long)get_instruction_pointer(proc);
int insn =
(int)ptrace(PTRACE_PEEKTEXT, proc->pid, pc - sizeof(long),
0);
if (insn == SYSCALL_INSN) {
*sysnum =
(int)ptrace(PTRACE_PEEKUSER, proc->pid,
sizeof(long) * PT_R0, 0);
if (proc->callstack_depth > 0 &&
proc->callstack[proc->callstack_depth - 1].is_syscall &&
proc->callstack[proc->callstack_depth - 1].c_un.syscall == *sysnum) {
return 2;
}
return 1;
}
}
return 0;
}
/* The atomic skip code is mostly taken from GDB. */
/* In plt.h. XXX make this official interface. */
int read_target_4(struct Process *proc, arch_addr_t addr, uint32_t *lp);
int
arch_atomic_singlestep(struct Process *proc, struct breakpoint *sbp,
int (*add_cb)(void *addr, void *data),
void *add_cb_data)
{
arch_addr_t ip = get_instruction_pointer(proc);
struct breakpoint *other = address2bpstruct(proc->leader, ip);
debug(1, "arch_atomic_singlestep pid=%d addr=%p %s(%p)",
proc->pid, ip, breakpoint_name(sbp), sbp->addr);
/* If the original instruction was lwarx/ldarx, we can't
* single-step over it, instead we have to execute the whole
* atomic block at once. */
union {
uint32_t insn;
char buf[BREAKPOINT_LENGTH];
} u;
if (other != NULL) {
memcpy(u.buf, sbp->orig_value, BREAKPOINT_LENGTH);
} else if (read_target_4(proc, ip, &u.insn) < 0) {
fprintf(stderr, "couldn't read instruction at IP %p\n", ip);
/* Do the normal singlestep. */
return 1;
}
if ((u.insn & LWARX_MASK) != LWARX_INSTRUCTION
&& (u.insn & LWARX_MASK) != LDARX_INSTRUCTION)
return 1;
debug(1, "singlestep over atomic block at %p", ip);
int insn_count;
arch_addr_t addr = ip;
for (insn_count = 0; ; ++insn_count) {
addr += 4;
unsigned long l = ptrace(PTRACE_PEEKTEXT, proc->pid, addr, 0);
if (l == (unsigned long)-1 && errno)
return -1;
uint32_t insn;
#ifdef __powerpc64__
insn = l >> 32;
#else
insn = l;
#endif
/* If a conditional branch is found, put a breakpoint
* in its destination address. */
if ((insn & BRANCH_MASK) == BC_INSN) {
arch_addr_t branch_addr = ppc_branch_dest(addr, insn);
debug(1, "pid=%d, branch in atomic block from %p to %p",
proc->pid, addr, branch_addr);
if (add_cb(branch_addr, add_cb_data) < 0)
return -1;
}
/* Assume that the atomic sequence ends with a
* stwcx/stdcx instruction. */
if ((insn & STWCX_MASK) == STWCX_INSTRUCTION
|| (insn & STWCX_MASK) == STDCX_INSTRUCTION) {
debug(1, "pid=%d, found end of atomic block %p at %p",
proc->pid, ip, addr);
break;
}
/* Arbitrary cut-off. If we didn't find the
* terminating instruction by now, just give up. */
if (insn_count > 16) {
fprintf(stderr, "[%d] couldn't find end of atomic block"
" at %p\n", proc->pid, ip);
return -1;
}
}
/* Put the breakpoint to the next instruction. */
addr += 4;
if (add_cb(addr, add_cb_data) < 0)
return -1;
debug(1, "PTRACE_CONT");
ptrace(PTRACE_CONT, proc->pid, 0, 0);
return 0;
}
size_t
arch_type_sizeof(struct Process *proc, struct arg_type_info *info)
{
if (proc == NULL)
return (size_t)-2;
switch (info->type) {
case ARGTYPE_VOID:
return 0;
case ARGTYPE_CHAR:
return 1;
case ARGTYPE_SHORT:
case ARGTYPE_USHORT:
return 2;
case ARGTYPE_INT:
case ARGTYPE_UINT:
return 4;
case ARGTYPE_LONG:
case ARGTYPE_ULONG:
case ARGTYPE_POINTER:
return proc->e_machine == EM_PPC64 ? 8 : 4;
case ARGTYPE_FLOAT:
return 4;
case ARGTYPE_DOUBLE:
return 8;
case ARGTYPE_ARRAY:
case ARGTYPE_STRUCT:
/* Use default value. */
return (size_t)-2;
default:
assert(info->type != info->type);
abort();
break;
}
}
size_t
arch_type_alignof(struct Process *proc, struct arg_type_info *info)
{
if (proc == NULL)
return (size_t)-2;
switch (info->type) {
default:
assert(info->type != info->type);
abort();
break;
case ARGTYPE_CHAR:
case ARGTYPE_SHORT:
case ARGTYPE_USHORT:
case ARGTYPE_INT:
case ARGTYPE_UINT:
case ARGTYPE_LONG:
case ARGTYPE_ULONG:
case ARGTYPE_POINTER:
case ARGTYPE_FLOAT:
case ARGTYPE_DOUBLE:
/* On both PPC and PPC64, fundamental types have the
* same alignment as size. */
return arch_type_sizeof(proc, info);
case ARGTYPE_ARRAY:
case ARGTYPE_STRUCT:
/* Use default value. */
return (size_t)-2;
}
}
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