diff mbox series

[v9,02/27] gdbstub: Implement deatch (D pkt) with new infra

Message ID 20190502081554.5521-3-arilou@gmail.com
State New
Headers show
Series gdbstub: Refactor command packets handler | expand

Commit Message

Jon Doron May 2, 2019, 8:15 a.m. UTC 
Signed-off-by: Jon Doron <arilou@gmail.com>
---
 gdbstub.c | 90 ++++++++++++++++++++++++++++++-------------------------
 1 file changed, 50 insertions(+), 40 deletions(-)

Comments

Alex Bennée May 14, 2019, 6:54 p.m. UTC | #1 
Jon Doron <arilou@gmail.com> writes:

> Signed-off-by: Jon Doron <arilou@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
Jon Doron May 21, 2019, 4:47 a.m. UTC | #2 
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.bennee@linaro.org> wrote:
>
>
> Jon Doron <arilou@gmail.com> writes:
>
> > Signed-off-by: Jon Doron <arilou@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 May 21, 2019, 6:43 a.m. UTC | #3 
Jon Doron <arilou@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.bennee@linaro.org> wrote:
>>
>>
>> Jon Doron <arilou@gmail.com> writes:
>>
>> > Signed-off-by: Jon Doron <arilou@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
diff mbox series

Patch

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, "");
+    }
+
     return RS_IDLE;
 }