Hi Alex, I implemented this change but i'm having second guesses on
this, basically a NULL packet means the command is not supported (as
far as i understand from the protocol documentation and implementation
of GDB)
That being said I think it's correct to send back a NULL packet if
process_string_cmd fails for any reason, or you would prefer ill just
omit it?
Snippet of the change I did according to your review:
- if (cmd_parser &&
- process_string_cmd(s, NULL, line_buf, cmd_parser, 1)) {
- put_packet(s, "");
+ if (!cmd_parser) {
+ return RS_IDLE;
}
+ process_string_cmd(s, NULL, line_buf, cmd_parser, 1);
-- Jon.
On Tue, May 14, 2019 at 9:54 PM Alex Bennée <alex.ben...@linaro.org> wrote:
>
>
> Jon Doron <ari...@gmail.com> writes:
>
> > Signed-off-by: Jon Doron <ari...@gmail.com>
> > ---
> > gdbstub.c | 90 ++++++++++++++++++++++++++++++-------------------------
> > 1 file changed, 50 insertions(+), 40 deletions(-)
> >
> > diff --git a/gdbstub.c b/gdbstub.c
> > index d5e0f3878a..621d689868 100644
> > --- a/gdbstub.c
> > +++ b/gdbstub.c
> > @@ -1418,11 +1418,6 @@ static inline int startswith(const char *string,
> > const char *pattern)
> > return !strncmp(string, pattern, strlen(pattern));
> > }
> >
> > -static int process_string_cmd(
> > - GDBState *s, void *user_ctx, const char *data,
> > - const GdbCmdParseEntry *cmds, int num_cmds)
> > - __attribute__((unused));
> > -
> > static int process_string_cmd(GDBState *s, void *user_ctx, const char
> > *data,
> > const GdbCmdParseEntry *cmds, int num_cmds)
> > {
> > @@ -1468,6 +1463,41 @@ static int process_string_cmd(GDBState *s, void
> > *user_ctx, const char *data,
> > return -1;
> > }
> >
> > +static void handle_detach(GdbCmdContext *gdb_ctx, void *user_ctx)
> > +{
> > + GDBProcess *process;
> > + GDBState *s = gdb_ctx->s;
> > + uint32_t pid = 1;
> > +
> > + if (s->multiprocess) {
> > + if (!gdb_ctx->num_params) {
> > + put_packet(s, "E22");
> > + return;
> > + }
> > +
> > + pid = gdb_ctx->params[0].val_ul;
> > + }
> > +
> > + process = gdb_get_process(s, pid);
> > + gdb_process_breakpoint_remove_all(s, process);
> > + process->attached = false;
> > +
> > + if (pid == gdb_get_cpu_pid(s, s->c_cpu)) {
> > + s->c_cpu = gdb_first_attached_cpu(s);
> > + }
> > +
> > + if (pid == gdb_get_cpu_pid(s, s->g_cpu)) {
> > + s->g_cpu = gdb_first_attached_cpu(s);
> > + }
> > +
> > + if (!s->c_cpu) {
> > + /* No more process attached */
> > + gdb_syscall_mode = GDB_SYS_DISABLED;
> > + gdb_continue(s);
> > + }
> > + put_packet(s, "OK");
> > +}
> > +
> > static int gdb_handle_packet(GDBState *s, const char *line_buf)
> > {
> > CPUState *cpu;
> > @@ -1482,6 +1512,7 @@ static int gdb_handle_packet(GDBState *s, const char
> > *line_buf)
> > uint8_t *registers;
> > target_ulong addr, len;
> > GDBThreadIdKind thread_kind;
> > + const GdbCmdParseEntry *cmd_parser = NULL;
> >
> > trace_gdbstub_io_command(line_buf);
> >
> > @@ -1582,42 +1613,15 @@ static int gdb_handle_packet(GDBState *s, const
> > char *line_buf)
> > error_report("QEMU: Terminated via GDBstub");
> > exit(0);
> > case 'D':
> > - /* Detach packet */
> > - pid = 1;
> > -
> > - if (s->multiprocess) {
> > - unsigned long lpid;
> > - if (*p != ';') {
> > - put_packet(s, "E22");
> > - break;
> > - }
> > -
> > - if (qemu_strtoul(p + 1, &p, 16, &lpid)) {
> > - put_packet(s, "E22");
> > - break;
> > - }
> > -
> > - pid = lpid;
> > - }
> > -
> > - process = gdb_get_process(s, pid);
> > - gdb_process_breakpoint_remove_all(s, process);
> > - process->attached = false;
> > -
> > - if (pid == gdb_get_cpu_pid(s, s->c_cpu)) {
> > - s->c_cpu = gdb_first_attached_cpu(s);
> > - }
> > -
> > - if (pid == gdb_get_cpu_pid(s, s->g_cpu)) {
> > - s->g_cpu = gdb_first_attached_cpu(s);
> > - }
> > -
> > - if (s->c_cpu == NULL) {
> > - /* No more process attached */
> > - gdb_syscall_mode = GDB_SYS_DISABLED;
> > - gdb_continue(s);
> > + {
> > + static const GdbCmdParseEntry detach_cmd_desc = {
> > + .handler = handle_detach,
> > + .cmd = "D",
> > + .cmd_startswith = 1,
> > + .schema = "?.l0"
> > + };
> > + cmd_parser = &detach_cmd_desc;
> > }
> > - put_packet(s, "OK");
> > break;
> > case 's':
> > if (*p != '\0') {
> > @@ -1990,6 +1994,12 @@ static int gdb_handle_packet(GDBState *s, const char
> > *line_buf)
> > put_packet(s, buf);
> > break;
> > }
> > +
> > + if (cmd_parser &&
> > + process_string_cmd(s, NULL, line_buf, cmd_parser, 1)) {
> > + put_packet(s, "");
>
> Why this null put_packet at the end? You've passed the handling of the
> OK reply back to your handler so this seems superfluous.
>
> --
> Alex Bennée
