static void
inf_ptrace_resume (struct target_ops *ops,
ptid_t ptid, int step, enum gdb_signal signal)
{
pid_t pid = ptid_get_pid (ptid);
int request;
if (pid == -1)
/* Resume all threads. Traditionally ptrace() only supports
single-threaded processes, so simply resume the inferior. */
pid = ptid_get_pid (inferior_ptid);
if (catch_syscall_enabled () > 0)
request = PT_SYSCALL;
else
request = PT_CONTINUE;
if (step)
{
/* If this system does not support PT_STEP, a higher level
function will have called single_step() to transmute the step
request into a continue request (by setting breakpoints on
all possible successor instructions), so we don't have to
worry about that here. */
request = PT_STEP;
}
/* An address of (PTRACE_TYPE_ARG3)1 tells ptrace to continue from
where it was. If GDB wanted it to start some other way, we have
already written a new program counter value to the child. */
errno = 0;
ptrace (request, pid, (PTRACE_TYPE_ARG3)1, gdb_signal_to_host (signal));
if (errno != 0)
perror_with_name (("ptrace"));
}
static void
i386fbsd_resume (struct target_ops *ops,
ptid_t ptid, int step, enum gdb_signal signal)
{
pid_t pid = ptid_get_pid (ptid);
int request = PT_STEP;
if (pid == -1)
/* Resume all threads. This only gets used in the non-threaded
case, where "resume all threads" and "resume inferior_ptid" are
the same. */
pid = ptid_get_pid (inferior_ptid);
if (!step)
{
struct regcache *regcache = get_current_regcache ();
ULONGEST eflags;
/* Workaround for a bug in FreeBSD. Make sure that the trace
flag is off when doing a continue. There is a code path
through the kernel which leaves the flag set when it should
have been cleared. If a process has a signal pending (such
as SIGALRM) and we do a PT_STEP, the process never really has
a chance to run because the kernel needs to notify the
debugger that a signal is being sent. Therefore, the process
never goes through the kernel's trap() function which would
normally clear it. */
regcache_cooked_read_unsigned (regcache, I386_EFLAGS_REGNUM,
&eflags);
if (eflags & 0x0100)
regcache_cooked_write_unsigned (regcache, I386_EFLAGS_REGNUM,
eflags & ~0x0100);
request = PT_CONTINUE;
}
/* An addres of (caddr_t) 1 tells ptrace to continue from where it
was. (If GDB wanted it to start some other way, we have already
written a new PC value to the child.) */
if (ptrace (request, pid, (caddr_t) 1,
gdb_signal_to_host (signal)) == -1)
perror_with_name (("ptrace"));
}
ptid_t
mywait (ptid_t ptid, struct target_waitstatus *ourstatus, int options,
int connected_wait)
{
ptid_t ret;
if (connected_wait)
server_waiting = 1;
ret = (*the_target->wait) (ptid, ourstatus, options);
/* We don't expose _LOADED events to gdbserver core. See the
`dlls_changed' global. */
if (ourstatus->kind == TARGET_WAITKIND_LOADED)
ourstatus->kind = TARGET_WAITKIND_STOPPED;
/* If GDB is connected through TCP/serial, then GDBserver will most
probably be running on its own terminal/console, so it's nice to
print there why is GDBserver exiting. If however, GDB is
connected through stdio, then there's no need to spam the GDB
console with this -- the user will already see the exit through
regular GDB output, in that same terminal. */
if (!remote_connection_is_stdio ())
{
if (ourstatus->kind == TARGET_WAITKIND_EXITED)
fprintf (stderr,
"\nChild exited with status %d\n", ourstatus->value.integer);
else if (ourstatus->kind == TARGET_WAITKIND_SIGNALLED)
fprintf (stderr, "\nChild terminated with signal = 0x%x (%s)\n",
gdb_signal_to_host (ourstatus->value.sig),
gdb_signal_to_name (ourstatus->value.sig));
}
if (connected_wait)
server_waiting = 0;
return ret;
}
ptid_t
mywait (ptid_t ptid, struct target_waitstatus *ourstatus, int options,
int connected_wait)
{
ptid_t ret;
if (connected_wait)
server_waiting = 1;
ret = (*the_target->wait) (ptid, ourstatus, options);
if (ourstatus->kind == TARGET_WAITKIND_EXITED)
fprintf (stderr,
"\nChild exited with status %d\n", ourstatus->value.integer);
else if (ourstatus->kind == TARGET_WAITKIND_SIGNALLED)
fprintf (stderr, "\nChild terminated with signal = 0x%x (%s)\n",
gdb_signal_to_host (ourstatus->value.sig),
gdb_signal_to_name (ourstatus->value.sig));
if (connected_wait)
server_waiting = 0;
return ret;
}
static void
i386_linux_resume (struct target_ops *ops,
ptid_t ptid, int step, enum gdb_signal signal)
{
int pid = ptid_get_pid (ptid);
int request;
if (catch_syscall_enabled () > 0)
request = PTRACE_SYSCALL;
else
request = PTRACE_CONT;
if (step)
{
struct regcache *regcache = get_thread_regcache (pid_to_ptid (pid));
struct gdbarch *gdbarch = get_regcache_arch (regcache);
enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
ULONGEST pc;
gdb_byte buf[LINUX_SYSCALL_LEN];
request = PTRACE_SINGLESTEP;
regcache_cooked_read_unsigned (regcache,
gdbarch_pc_regnum (gdbarch), &pc);
/* Returning from a signal trampoline is done by calling a
special system call (sigreturn or rt_sigreturn, see
i386-linux-tdep.c for more information). This system call
restores the registers that were saved when the signal was
raised, including %eflags. That means that single-stepping
won't work. Instead, we'll have to modify the signal context
that's about to be restored, and set the trace flag there. */
/* First check if PC is at a system call. */
if (target_read_memory (pc, buf, LINUX_SYSCALL_LEN) == 0
&& memcmp (buf, linux_syscall, LINUX_SYSCALL_LEN) == 0)
{
ULONGEST syscall;
regcache_cooked_read_unsigned (regcache,
LINUX_SYSCALL_REGNUM, &syscall);
/* Then check the system call number. */
if (syscall == SYS_sigreturn || syscall == SYS_rt_sigreturn)
{
ULONGEST sp, addr;
unsigned long int eflags;
regcache_cooked_read_unsigned (regcache, I386_ESP_REGNUM, &sp);
if (syscall == SYS_rt_sigreturn)
addr = read_memory_unsigned_integer (sp + 8, 4, byte_order)
+ 20;
else
addr = sp;
/* Set the trace flag in the context that's about to be
restored. */
addr += LINUX_SIGCONTEXT_EFLAGS_OFFSET;
read_memory (addr, (gdb_byte *) &eflags, 4);
eflags |= 0x0100;
write_memory (addr, (gdb_byte *) &eflags, 4);
}
}
}
if (ptrace (request, pid, 0, gdb_signal_to_host (signal)) == -1)
perror_with_name (("ptrace"));
}
