[Qemu-devel] [PATCH v9 15/27] gdbstub: Implement file io (F pkt) with new infra

Jon Doron posted 27 patches 6 years, 9 months ago
Maintainers: Paolo Bonzini <pbonzini@redhat.com>
There is a newer version of this series
[Qemu-devel] [PATCH v9 15/27] gdbstub: Implement file io (F pkt) with new infra
Posted by Jon Doron 6 years, 9 months ago
Signed-off-by: Jon Doron <arilou@gmail.com>
---
 gdbstub.c | 62 +++++++++++++++++++++++++++++++++++--------------------
 1 file changed, 40 insertions(+), 22 deletions(-)

diff --git a/gdbstub.c b/gdbstub.c
index 3478ac778d..9fe130f30d 100644
--- a/gdbstub.c
+++ b/gdbstub.c
@@ -1772,6 +1772,39 @@ static void handle_read_all_regs(GdbCmdContext *gdb_ctx, void *user_ctx)
     put_packet(gdb_ctx->s, gdb_ctx->str_buf);
 }
 
+static void handle_file_io(GdbCmdContext *gdb_ctx, void *user_ctx)
+{
+    int num_syscall_params;
+    GdbCmdVariant syscall_params[3] = {};
+
+    if (!gdb_ctx->num_params) {
+        return;
+    }
+
+    if (cmd_parse_params(gdb_ctx->params[0].data, "L,L,o0", syscall_params,
+                         &num_syscall_params)) {
+        return;
+    }
+
+    if (!num_syscall_params) {
+        return;
+    }
+
+    if (gdb_ctx->s->current_syscall_cb) {
+        gdb_ctx->s->current_syscall_cb(gdb_ctx->s->c_cpu,
+                                       (target_ulong)syscall_params[0].val_ull,
+                                       (target_ulong)syscall_params[1].val_ull);
+        gdb_ctx->s->current_syscall_cb = NULL;
+    }
+
+    if (syscall_params[2].opcode == (uint8_t)'C') {
+        put_packet(gdb_ctx->s, "T02");
+        return;
+    }
+
+    gdb_continue(gdb_ctx->s);
+}
+
 static int gdb_handle_packet(GDBState *s, const char *line_buf)
 {
     CPUState *cpu;
@@ -1913,28 +1946,13 @@ static int gdb_handle_packet(GDBState *s, const char *line_buf)
         return RS_IDLE;
     case 'F':
         {
-            target_ulong ret;
-            target_ulong err;
-
-            ret = strtoull(p, (char **)&p, 16);
-            if (*p == ',') {
-                p++;
-                err = strtoull(p, (char **)&p, 16);
-            } else {
-                err = 0;
-            }
-            if (*p == ',')
-                p++;
-            type = *p;
-            if (s->current_syscall_cb) {
-                s->current_syscall_cb(s->c_cpu, ret, err);
-                s->current_syscall_cb = NULL;
-            }
-            if (type == 'C') {
-                put_packet(s, "T02");
-            } else {
-                gdb_continue(s);
-            }
+            static const GdbCmdParseEntry file_io_cmd_desc = {
+                .handler = handle_file_io,
+                .cmd = "F",
+                .cmd_startswith = 1,
+                .schema = "s0"
+            };
+            cmd_parser = &file_io_cmd_desc;
         }
         break;
     case 'g':
-- 
2.20.1


Re: [Qemu-devel] [PATCH v9 15/27] gdbstub: Implement file io (F pkt) with new infra
Posted by Alex Bennée 6 years, 8 months ago
Jon Doron <arilou@gmail.com> writes:

There is a bit more going on here than a simple conversion. I think we
need some additional commentary about the format of the data coming
back.


> Signed-off-by: Jon Doron <arilou@gmail.com>
> ---
>  gdbstub.c | 62 +++++++++++++++++++++++++++++++++++--------------------
>  1 file changed, 40 insertions(+), 22 deletions(-)
>
> diff --git a/gdbstub.c b/gdbstub.c
> index 3478ac778d..9fe130f30d 100644
> --- a/gdbstub.c
> +++ b/gdbstub.c
> @@ -1772,6 +1772,39 @@ static void handle_read_all_regs(GdbCmdContext *gdb_ctx, void *user_ctx)
>      put_packet(gdb_ctx->s, gdb_ctx->str_buf);
>  }
>
> +static void handle_file_io(GdbCmdContext *gdb_ctx, void *user_ctx)
> +{
> +    int num_syscall_params;
> +    GdbCmdVariant syscall_params[3] = {};
> +
> +    if (!gdb_ctx->num_params) {
> +        return;
> +    }
> +
> +    if (cmd_parse_params(gdb_ctx->params[0].data, "L,L,o0", syscall_params,
> +                         &num_syscall_params)) {
> +        return;
> +    }

What's going on here? I thought the schema was meant to handle the
parsing of data. I see bellow we originally parse the command as a null
terminated string but we actually should handle:

  ‘Fretcode,errno,Ctrl-C flag;call-specific attachment’

I see the argument for dealing with the call-specific attachment here
but shouldn't the generic parsing code be able to split everything
apart?

> +
> +    if (!num_syscall_params) {
> +        return;
> +    }
> +
> +    if (gdb_ctx->s->current_syscall_cb) {
> +        gdb_ctx->s->current_syscall_cb(gdb_ctx->s->c_cpu,
> +                                       (target_ulong)syscall_params[0].val_ull,
> +                                       (target_ulong)syscall_params[1].val_ull);
> +        gdb_ctx->s->current_syscall_cb = NULL;
> +    }



> +
> +    if (syscall_params[2].opcode == (uint8_t)'C') {
> +        put_packet(gdb_ctx->s, "T02");
> +        return;
> +    }
> +
> +    gdb_continue(gdb_ctx->s);
> +}
> +
>  static int gdb_handle_packet(GDBState *s, const char *line_buf)
>  {
>      CPUState *cpu;
> @@ -1913,28 +1946,13 @@ static int gdb_handle_packet(GDBState *s, const char *line_buf)
>          return RS_IDLE;
>      case 'F':
>          {
> -            target_ulong ret;
> -            target_ulong err;
> -
> -            ret = strtoull(p, (char **)&p, 16);
> -            if (*p == ',') {
> -                p++;
> -                err = strtoull(p, (char **)&p, 16);
> -            } else {
> -                err = 0;
> -            }
> -            if (*p == ',')
> -                p++;
> -            type = *p;
> -            if (s->current_syscall_cb) {
> -                s->current_syscall_cb(s->c_cpu, ret, err);
> -                s->current_syscall_cb = NULL;
> -            }
> -            if (type == 'C') {
> -                put_packet(s, "T02");
> -            } else {
> -                gdb_continue(s);
> -            }
> +            static const GdbCmdParseEntry file_io_cmd_desc = {
> +                .handler = handle_file_io,
> +                .cmd = "F",
> +                .cmd_startswith = 1,
> +                .schema = "s0"
> +            };
> +            cmd_parser = &file_io_cmd_desc;
>          }
>          break;
>      case 'g':


--
Alex Bennée

Re: [Qemu-devel] [PATCH v9 15/27] gdbstub: Implement file io (F pkt) with new infra
Posted by Jon Doron 6 years, 8 months ago
Hi Alex, I did have some issues with the 'F' packet as it's not really
well documented, I suggest changing the schema to:
"L,L,o0"
so basically no support for anything after the first C in the Ctrl-C,
if you have a sample or a documentation that really implements
the F packet fully ill take a look at it and see how the schema should
really look like.

-- Jon.

On Wed, May 15, 2019 at 7:54 PM Alex Bennée <alex.bennee@linaro.org> wrote:
>
>
> Jon Doron <arilou@gmail.com> writes:
>
> There is a bit more going on here than a simple conversion. I think we
> need some additional commentary about the format of the data coming
> back.
>
>
> > Signed-off-by: Jon Doron <arilou@gmail.com>
> > ---
> >  gdbstub.c | 62 +++++++++++++++++++++++++++++++++++--------------------
> >  1 file changed, 40 insertions(+), 22 deletions(-)
> >
> > diff --git a/gdbstub.c b/gdbstub.c
> > index 3478ac778d..9fe130f30d 100644
> > --- a/gdbstub.c
> > +++ b/gdbstub.c
> > @@ -1772,6 +1772,39 @@ static void handle_read_all_regs(GdbCmdContext *gdb_ctx, void *user_ctx)
> >      put_packet(gdb_ctx->s, gdb_ctx->str_buf);
> >  }
> >
> > +static void handle_file_io(GdbCmdContext *gdb_ctx, void *user_ctx)
> > +{
> > +    int num_syscall_params;
> > +    GdbCmdVariant syscall_params[3] = {};
> > +
> > +    if (!gdb_ctx->num_params) {
> > +        return;
> > +    }
> > +
> > +    if (cmd_parse_params(gdb_ctx->params[0].data, "L,L,o0", syscall_params,
> > +                         &num_syscall_params)) {
> > +        return;
> > +    }
>
> What's going on here? I thought the schema was meant to handle the
> parsing of data. I see bellow we originally parse the command as a null
> terminated string but we actually should handle:
>
>   ‘Fretcode,errno,Ctrl-C flag;call-specific attachment’
>
> I see the argument for dealing with the call-specific attachment here
> but shouldn't the generic parsing code be able to split everything
> apart?
>
> > +
> > +    if (!num_syscall_params) {
> > +        return;
> > +    }
> > +
> > +    if (gdb_ctx->s->current_syscall_cb) {
> > +        gdb_ctx->s->current_syscall_cb(gdb_ctx->s->c_cpu,
> > +                                       (target_ulong)syscall_params[0].val_ull,
> > +                                       (target_ulong)syscall_params[1].val_ull);
> > +        gdb_ctx->s->current_syscall_cb = NULL;
> > +    }
>
>
>
> > +
> > +    if (syscall_params[2].opcode == (uint8_t)'C') {
> > +        put_packet(gdb_ctx->s, "T02");
> > +        return;
> > +    }
> > +
> > +    gdb_continue(gdb_ctx->s);
> > +}
> > +
> >  static int gdb_handle_packet(GDBState *s, const char *line_buf)
> >  {
> >      CPUState *cpu;
> > @@ -1913,28 +1946,13 @@ static int gdb_handle_packet(GDBState *s, const char *line_buf)
> >          return RS_IDLE;
> >      case 'F':
> >          {
> > -            target_ulong ret;
> > -            target_ulong err;
> > -
> > -            ret = strtoull(p, (char **)&p, 16);
> > -            if (*p == ',') {
> > -                p++;
> > -                err = strtoull(p, (char **)&p, 16);
> > -            } else {
> > -                err = 0;
> > -            }
> > -            if (*p == ',')
> > -                p++;
> > -            type = *p;
> > -            if (s->current_syscall_cb) {
> > -                s->current_syscall_cb(s->c_cpu, ret, err);
> > -                s->current_syscall_cb = NULL;
> > -            }
> > -            if (type == 'C') {
> > -                put_packet(s, "T02");
> > -            } else {
> > -                gdb_continue(s);
> > -            }
> > +            static const GdbCmdParseEntry file_io_cmd_desc = {
> > +                .handler = handle_file_io,
> > +                .cmd = "F",
> > +                .cmd_startswith = 1,
> > +                .schema = "s0"
> > +            };
> > +            cmd_parser = &file_io_cmd_desc;
> >          }
> >          break;
> >      case 'g':
>
>
> --
> Alex Bennée

Re: [Qemu-devel] [PATCH v9 15/27] gdbstub: Implement file io (F pkt) with new infra
Posted by Alex Bennée 6 years, 8 months ago
Jon Doron <arilou@gmail.com> writes:

> Hi Alex, I did have some issues with the 'F' packet as it's not really
> well documented, I suggest changing the schema to:
> "L,L,o0"
> so basically no support for anything after the first C in the Ctrl-C,
> if you have a sample or a documentation that really implements
> the F packet fully ill take a look at it and see how the schema should
> really look like.

I'm only going by whats in the gdbdocs:

  https://sourceware.org/gdb/onlinedocs/gdb/The-F-Request-Packet.html#The-F-Request-Packet

>
> -- Jon.
>
> On Wed, May 15, 2019 at 7:54 PM Alex Bennée <alex.bennee@linaro.org> wrote:
>>
>>
>> Jon Doron <arilou@gmail.com> writes:
>>
>> There is a bit more going on here than a simple conversion. I think we
>> need some additional commentary about the format of the data coming
>> back.
>>
>>
>> > Signed-off-by: Jon Doron <arilou@gmail.com>
>> > ---
>> >  gdbstub.c | 62 +++++++++++++++++++++++++++++++++++--------------------
>> >  1 file changed, 40 insertions(+), 22 deletions(-)
>> >
>> > diff --git a/gdbstub.c b/gdbstub.c
>> > index 3478ac778d..9fe130f30d 100644
>> > --- a/gdbstub.c
>> > +++ b/gdbstub.c
>> > @@ -1772,6 +1772,39 @@ static void handle_read_all_regs(GdbCmdContext *gdb_ctx, void *user_ctx)
>> >      put_packet(gdb_ctx->s, gdb_ctx->str_buf);
>> >  }
>> >
>> > +static void handle_file_io(GdbCmdContext *gdb_ctx, void *user_ctx)
>> > +{
>> > +    int num_syscall_params;
>> > +    GdbCmdVariant syscall_params[3] = {};
>> > +
>> > +    if (!gdb_ctx->num_params) {
>> > +        return;
>> > +    }
>> > +
>> > +    if (cmd_parse_params(gdb_ctx->params[0].data, "L,L,o0", syscall_params,
>> > +                         &num_syscall_params)) {
>> > +        return;
>> > +    }
>>
>> What's going on here? I thought the schema was meant to handle the
>> parsing of data. I see bellow we originally parse the command as a null
>> terminated string but we actually should handle:
>>
>>   ‘Fretcode,errno,Ctrl-C flag;call-specific attachment’
>>
>> I see the argument for dealing with the call-specific attachment here
>> but shouldn't the generic parsing code be able to split everything
>> apart?
>>
>> > +
>> > +    if (!num_syscall_params) {
>> > +        return;
>> > +    }
>> > +
>> > +    if (gdb_ctx->s->current_syscall_cb) {
>> > +        gdb_ctx->s->current_syscall_cb(gdb_ctx->s->c_cpu,
>> > +                                       (target_ulong)syscall_params[0].val_ull,
>> > +                                       (target_ulong)syscall_params[1].val_ull);
>> > +        gdb_ctx->s->current_syscall_cb = NULL;
>> > +    }
>>
>>
>>
>> > +
>> > +    if (syscall_params[2].opcode == (uint8_t)'C') {
>> > +        put_packet(gdb_ctx->s, "T02");
>> > +        return;
>> > +    }
>> > +
>> > +    gdb_continue(gdb_ctx->s);
>> > +}
>> > +
>> >  static int gdb_handle_packet(GDBState *s, const char *line_buf)
>> >  {
>> >      CPUState *cpu;
>> > @@ -1913,28 +1946,13 @@ static int gdb_handle_packet(GDBState *s, const char *line_buf)
>> >          return RS_IDLE;
>> >      case 'F':
>> >          {
>> > -            target_ulong ret;
>> > -            target_ulong err;
>> > -
>> > -            ret = strtoull(p, (char **)&p, 16);
>> > -            if (*p == ',') {
>> > -                p++;
>> > -                err = strtoull(p, (char **)&p, 16);
>> > -            } else {
>> > -                err = 0;
>> > -            }
>> > -            if (*p == ',')
>> > -                p++;
>> > -            type = *p;
>> > -            if (s->current_syscall_cb) {
>> > -                s->current_syscall_cb(s->c_cpu, ret, err);
>> > -                s->current_syscall_cb = NULL;
>> > -            }
>> > -            if (type == 'C') {
>> > -                put_packet(s, "T02");
>> > -            } else {
>> > -                gdb_continue(s);
>> > -            }
>> > +            static const GdbCmdParseEntry file_io_cmd_desc = {
>> > +                .handler = handle_file_io,
>> > +                .cmd = "F",
>> > +                .cmd_startswith = 1,
>> > +                .schema = "s0"
>> > +            };
>> > +            cmd_parser = &file_io_cmd_desc;
>> >          }
>> >          break;
>> >      case 'g':
>>
>>
>> --
>> Alex Bennée


--
Alex Bennée