Jon Doron <ari...@gmail.com> writes:
> 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);
OK I see your reasoning. So perhaps:
if (cmd_parser) {
/* helper will respond */
process_string_cmd(s, NULL, line_buf, cmd_parser, 1)
} else {
/* unknown command, empty response */
put_packet(s, "");
}
return RS_IDLE;
>
> -- 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
--
Alex Bennée
