* [PATCH] gdbstub: change GDBState.last_packet to GByteArray
@ 2019-12-06 13:42 Damien Hedde
2019-12-06 14:23 ` Philippe Mathieu-Daudé
2019-12-09 10:15 ` Luc Michel
0 siblings, 2 replies; 4+ messages in thread
From: Damien Hedde @ 2019-12-06 13:42 UTC (permalink / raw)
To: qemu-devel; +Cc: Damien Hedde, philmd, alex.bennee, luc.michel
Remove the packet size upper limit by using a GByteArray
instead of a statically allocated array for last_packet.
Thus we can now send big packets.
Also remove the last_packet_len field and use last_packet->len
instead.
Signed-off-by: Damien Hedde <damien.hedde@greensocs.com>
---
This patch is a follow-up of Alex's series about sve registers
which introduces some GbyteArray/Gstring in the gdbstub.
It removes the remaining barrier to send big packets.
Based-on <20191130084602.10818-1-alex.bennee@linaro.org>
---
gdbstub.c | 39 +++++++++++++++++++++------------------
1 file changed, 21 insertions(+), 18 deletions(-)
diff --git a/gdbstub.c b/gdbstub.c
index 7b695bdebe..022edd6bdb 100644
--- a/gdbstub.c
+++ b/gdbstub.c
@@ -351,8 +351,7 @@ typedef struct GDBState {
int line_buf_index;
int line_sum; /* running checksum */
int line_csum; /* checksum at the end of the packet */
- uint8_t last_packet[MAX_PACKET_LENGTH + 4];
- int last_packet_len;
+ GByteArray *last_packet;
int signal;
#ifdef CONFIG_USER_ONLY
int fd;
@@ -384,6 +383,7 @@ static void init_gdbserver_state(void)
gdbserver_state.init = true;
gdbserver_state.str_buf = g_string_new(NULL);
gdbserver_state.mem_buf = g_byte_array_sized_new(MAX_PACKET_LENGTH);
+ gdbserver_state.last_packet = g_byte_array_sized_new(MAX_PACKET_LENGTH + 4);
}
#ifndef CONFIG_USER_ONLY
@@ -626,28 +626,29 @@ static void hexdump(const char *buf, int len,
static int put_packet_binary(const char *buf, int len, bool dump)
{
int csum, i;
- uint8_t *p;
- uint8_t *ps = &gdbserver_state.last_packet[0];
+ uint8_t footer[3];
if (dump && trace_event_get_state_backends(TRACE_GDBSTUB_IO_BINARYREPLY)) {
hexdump(buf, len, trace_gdbstub_io_binaryreply);
}
for(;;) {
- p = ps;
- *(p++) = '$';
- memcpy(p, buf, len);
- p += len;
+ g_byte_array_set_size(gdbserver_state.last_packet, 0);
+ g_byte_array_append(gdbserver_state.last_packet,
+ (const uint8_t *) "$", 1);
+ g_byte_array_append(gdbserver_state.last_packet,
+ (const uint8_t *) buf, len);
csum = 0;
for(i = 0; i < len; i++) {
csum += buf[i];
}
- *(p++) = '#';
- *(p++) = tohex((csum >> 4) & 0xf);
- *(p++) = tohex((csum) & 0xf);
+ footer[0] = '#';
+ footer[1] = tohex((csum >> 4) & 0xf);
+ footer[2] = tohex((csum) & 0xf);
+ g_byte_array_append(gdbserver_state.last_packet, footer, 3);
- gdbserver_state.last_packet_len = p - ps;
- put_buffer(ps, gdbserver_state.last_packet_len);
+ put_buffer(gdbserver_state.last_packet->data,
+ gdbserver_state.last_packet->len);
#ifdef CONFIG_USER_ONLY
i = get_char();
@@ -2812,20 +2813,22 @@ static void gdb_read_byte(GDBState *s, uint8_t ch)
uint8_t reply;
#ifndef CONFIG_USER_ONLY
- if (gdbserver_state.last_packet_len) {
+ if (gdbserver_state.last_packet->len) {
/* Waiting for a response to the last packet. If we see the start
of a new command then abandon the previous response. */
if (ch == '-') {
trace_gdbstub_err_got_nack();
- put_buffer((uint8_t *)gdbserver_state.last_packet, gdbserver_state.last_packet_len);
+ put_buffer(gdbserver_state.last_packet->data,
+ gdbserver_state.last_packet->len);
} else if (ch == '+') {
trace_gdbstub_io_got_ack();
} else {
trace_gdbstub_io_got_unexpected(ch);
}
- if (ch == '+' || ch == '$')
- gdbserver_state.last_packet_len = 0;
+ if (ch == '+' || ch == '$') {
+ g_byte_array_set_size(gdbserver_state.last_packet, 0);
+ }
if (ch != '$')
return;
}
@@ -3209,7 +3212,7 @@ static int gdb_monitor_write(Chardev *chr, const uint8_t *buf, int len)
const char *p = (const char *)buf;
int max_sz;
- max_sz = (sizeof(gdbserver_state.last_packet) - 2) / 2;
+ max_sz = MAX_PACKET_LENGTH / 2;
for (;;) {
if (len <= max_sz) {
gdb_monitor_output(&gdbserver_state, p, len);
--
2.24.0
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH] gdbstub: change GDBState.last_packet to GByteArray
2019-12-06 13:42 [PATCH] gdbstub: change GDBState.last_packet to GByteArray Damien Hedde
@ 2019-12-06 14:23 ` Philippe Mathieu-Daudé
2019-12-09 10:15 ` Luc Michel
1 sibling, 0 replies; 4+ messages in thread
From: Philippe Mathieu-Daudé @ 2019-12-06 14:23 UTC (permalink / raw)
To: Damien Hedde, qemu-devel; +Cc: alex.bennee, luc.michel
On 12/6/19 2:42 PM, Damien Hedde wrote:
> Remove the packet size upper limit by using a GByteArray
> instead of a statically allocated array for last_packet.
> Thus we can now send big packets.
>
> Also remove the last_packet_len field and use last_packet->len
> instead.
>
> Signed-off-by: Damien Hedde <damien.hedde@greensocs.com>
> ---
>
> This patch is a follow-up of Alex's series about sve registers
> which introduces some GbyteArray/Gstring in the gdbstub.
> It removes the remaining barrier to send big packets.
>
> Based-on <20191130084602.10818-1-alex.bennee@linaro.org>
> ---
> gdbstub.c | 39 +++++++++++++++++++++------------------
> 1 file changed, 21 insertions(+), 18 deletions(-)
>
> diff --git a/gdbstub.c b/gdbstub.c
> index 7b695bdebe..022edd6bdb 100644
> --- a/gdbstub.c
> +++ b/gdbstub.c
> @@ -351,8 +351,7 @@ typedef struct GDBState {
> int line_buf_index;
> int line_sum; /* running checksum */
> int line_csum; /* checksum at the end of the packet */
> - uint8_t last_packet[MAX_PACKET_LENGTH + 4];
> - int last_packet_len;
> + GByteArray *last_packet;
> int signal;
> #ifdef CONFIG_USER_ONLY
> int fd;
> @@ -384,6 +383,7 @@ static void init_gdbserver_state(void)
> gdbserver_state.init = true;
> gdbserver_state.str_buf = g_string_new(NULL);
> gdbserver_state.mem_buf = g_byte_array_sized_new(MAX_PACKET_LENGTH);
> + gdbserver_state.last_packet = g_byte_array_sized_new(MAX_PACKET_LENGTH + 4);
> }
>
> #ifndef CONFIG_USER_ONLY
> @@ -626,28 +626,29 @@ static void hexdump(const char *buf, int len,
> static int put_packet_binary(const char *buf, int len, bool dump)
> {
> int csum, i;
> - uint8_t *p;
> - uint8_t *ps = &gdbserver_state.last_packet[0];
> + uint8_t footer[3];
>
> if (dump && trace_event_get_state_backends(TRACE_GDBSTUB_IO_BINARYREPLY)) {
> hexdump(buf, len, trace_gdbstub_io_binaryreply);
> }
>
> for(;;) {
> - p = ps;
> - *(p++) = '$';
> - memcpy(p, buf, len);
> - p += len;
> + g_byte_array_set_size(gdbserver_state.last_packet, 0);
> + g_byte_array_append(gdbserver_state.last_packet,
> + (const uint8_t *) "$", 1);
> + g_byte_array_append(gdbserver_state.last_packet,
> + (const uint8_t *) buf, len);
> csum = 0;
> for(i = 0; i < len; i++) {
> csum += buf[i];
> }
> - *(p++) = '#';
> - *(p++) = tohex((csum >> 4) & 0xf);
> - *(p++) = tohex((csum) & 0xf);
> + footer[0] = '#';
> + footer[1] = tohex((csum >> 4) & 0xf);
> + footer[2] = tohex((csum) & 0xf);
> + g_byte_array_append(gdbserver_state.last_packet, footer, 3);
>
> - gdbserver_state.last_packet_len = p - ps;
> - put_buffer(ps, gdbserver_state.last_packet_len);
> + put_buffer(gdbserver_state.last_packet->data,
> + gdbserver_state.last_packet->len);
>
> #ifdef CONFIG_USER_ONLY
> i = get_char();
> @@ -2812,20 +2813,22 @@ static void gdb_read_byte(GDBState *s, uint8_t ch)
> uint8_t reply;
>
> #ifndef CONFIG_USER_ONLY
> - if (gdbserver_state.last_packet_len) {
> + if (gdbserver_state.last_packet->len) {
> /* Waiting for a response to the last packet. If we see the start
> of a new command then abandon the previous response. */
> if (ch == '-') {
> trace_gdbstub_err_got_nack();
> - put_buffer((uint8_t *)gdbserver_state.last_packet, gdbserver_state.last_packet_len);
> + put_buffer(gdbserver_state.last_packet->data,
> + gdbserver_state.last_packet->len);
> } else if (ch == '+') {
> trace_gdbstub_io_got_ack();
> } else {
> trace_gdbstub_io_got_unexpected(ch);
> }
>
> - if (ch == '+' || ch == '$')
> - gdbserver_state.last_packet_len = 0;
> + if (ch == '+' || ch == '$') {
> + g_byte_array_set_size(gdbserver_state.last_packet, 0);
> + }
> if (ch != '$')
> return;
> }
> @@ -3209,7 +3212,7 @@ static int gdb_monitor_write(Chardev *chr, const uint8_t *buf, int len)
> const char *p = (const char *)buf;
> int max_sz;
>
> - max_sz = (sizeof(gdbserver_state.last_packet) - 2) / 2;
> + max_sz = MAX_PACKET_LENGTH / 2;
> for (;;) {
> if (len <= max_sz) {
> gdb_monitor_output(&gdbserver_state, p, len);
>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] gdbstub: change GDBState.last_packet to GByteArray
2019-12-06 13:42 [PATCH] gdbstub: change GDBState.last_packet to GByteArray Damien Hedde
2019-12-06 14:23 ` Philippe Mathieu-Daudé
@ 2019-12-09 10:15 ` Luc Michel
2019-12-11 14:11 ` Damien Hedde
1 sibling, 1 reply; 4+ messages in thread
From: Luc Michel @ 2019-12-09 10:15 UTC (permalink / raw)
To: Damien Hedde, qemu-devel; +Cc: philmd, alex.bennee
On 12/6/19 2:42 PM, Damien Hedde wrote:
> Remove the packet size upper limit by using a GByteArray
> instead of a statically allocated array for last_packet.
> Thus we can now send big packets.
>
> Also remove the last_packet_len field and use last_packet->len
> instead.
>
> Signed-off-by: Damien Hedde <damien.hedde@greensocs.com>
> ---
>
> This patch is a follow-up of Alex's series about sve registers
> which introduces some GbyteArray/Gstring in the gdbstub.
> It removes the remaining barrier to send big packets.
>
> Based-on <20191130084602.10818-1-alex.bennee@linaro.org>
> ---
> gdbstub.c | 39 +++++++++++++++++++++------------------
> 1 file changed, 21 insertions(+), 18 deletions(-)
>
> diff --git a/gdbstub.c b/gdbstub.c
> index 7b695bdebe..022edd6bdb 100644
> --- a/gdbstub.c
> +++ b/gdbstub.c
> @@ -351,8 +351,7 @@ typedef struct GDBState {
> int line_buf_index;
> int line_sum; /* running checksum */
> int line_csum; /* checksum at the end of the packet */
> - uint8_t last_packet[MAX_PACKET_LENGTH + 4];
> - int last_packet_len;
> + GByteArray *last_packet;
> int signal;
> #ifdef CONFIG_USER_ONLY
> int fd;
> @@ -384,6 +383,7 @@ static void init_gdbserver_state(void)
> gdbserver_state.init = true;
> gdbserver_state.str_buf = g_string_new(NULL);
> gdbserver_state.mem_buf = g_byte_array_sized_new(MAX_PACKET_LENGTH);
> + gdbserver_state.last_packet = g_byte_array_sized_new(MAX_PACKET_LENGTH + 4);
> }
>
> #ifndef CONFIG_USER_ONLY
> @@ -626,28 +626,29 @@ static void hexdump(const char *buf, int len,
> static int put_packet_binary(const char *buf, int len, bool dump)
> {
> int csum, i;
> - uint8_t *p;
> - uint8_t *ps = &gdbserver_state.last_packet[0];
> + uint8_t footer[3];
>
> if (dump && trace_event_get_state_backends(TRACE_GDBSTUB_IO_BINARYREPLY)) {
> hexdump(buf, len, trace_gdbstub_io_binaryreply);
> }
>
> for(;;) {
> - p = ps;
> - *(p++) = '$';
> - memcpy(p, buf, len);
> - p += len;
> + g_byte_array_set_size(gdbserver_state.last_packet, 0);
> + g_byte_array_append(gdbserver_state.last_packet,
> + (const uint8_t *) "$", 1);
> + g_byte_array_append(gdbserver_state.last_packet,
> + (const uint8_t *) buf, len);
> csum = 0;
> for(i = 0; i < len; i++) {
> csum += buf[i];
> }
> - *(p++) = '#';
> - *(p++) = tohex((csum >> 4) & 0xf);
> - *(p++) = tohex((csum) & 0xf);
> + footer[0] = '#';
> + footer[1] = tohex((csum >> 4) & 0xf);
> + footer[2] = tohex((csum) & 0xf);
> + g_byte_array_append(gdbserver_state.last_packet, footer, 3);
>
> - gdbserver_state.last_packet_len = p - ps;
> - put_buffer(ps, gdbserver_state.last_packet_len);
> + put_buffer(gdbserver_state.last_packet->data,
> + gdbserver_state.last_packet->len);
>
> #ifdef CONFIG_USER_ONLY
> i = get_char();
> @@ -2812,20 +2813,22 @@ static void gdb_read_byte(GDBState *s, uint8_t ch)
> uint8_t reply;
>
> #ifndef CONFIG_USER_ONLY
> - if (gdbserver_state.last_packet_len) {
> + if (gdbserver_state.last_packet->len) {
> /* Waiting for a response to the last packet. If we see the start
> of a new command then abandon the previous response. */
> if (ch == '-') {
> trace_gdbstub_err_got_nack();
> - put_buffer((uint8_t *)gdbserver_state.last_packet, gdbserver_state.last_packet_len);
> + put_buffer(gdbserver_state.last_packet->data,
> + gdbserver_state.last_packet->len);
> } else if (ch == '+') {
> trace_gdbstub_io_got_ack();
> } else {
> trace_gdbstub_io_got_unexpected(ch);
> }
>
> - if (ch == '+' || ch == '$')
> - gdbserver_state.last_packet_len = 0;
> + if (ch == '+' || ch == '$') {
> + g_byte_array_set_size(gdbserver_state.last_packet, 0);
> + }
> if (ch != '$')
> return;
> }
> @@ -3209,7 +3212,7 @@ static int gdb_monitor_write(Chardev *chr, const uint8_t *buf, int len)
> const char *p = (const char *)buf;
> int max_sz;
>
> - max_sz = (sizeof(gdbserver_state.last_packet) - 2) / 2;
> + max_sz = MAX_PACKET_LENGTH / 2;
I think max_sz is not the same as before here.
Before we had (sizeof(gdbserver_state.last_packet) - 2) / 2
-> ((MAX_PACKET_LENGTH + 4) - 2) / 2
-> (MAX_PACKET_LENGTH / 2) + 1
Now we have MAX_PACKET_LENGTH / 2
But looking at the gdb_monitor_output() function, it performs the
following check:
if (len > (MAX_PACKET_LENGTH/2) - 1)
len = (MAX_PACKET_LENGTH/2) - 1;
So both versions seem actually wrong and can lead to characters being
dropped.
However gdb_monitor_output() is still using a MAX_PACKET_LENGTH sized
local buffer. With this patch it can probably be removed entirely so
that last_packet is written directly (with a g_byte_array aware version
of memtohex?).
--
Luc
> for (;;) {
> if (len <= max_sz) {
> gdb_monitor_output(&gdbserver_state, p, len);
>
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] gdbstub: change GDBState.last_packet to GByteArray
2019-12-09 10:15 ` Luc Michel
@ 2019-12-11 14:11 ` Damien Hedde
0 siblings, 0 replies; 4+ messages in thread
From: Damien Hedde @ 2019-12-11 14:11 UTC (permalink / raw)
To: Luc Michel, qemu-devel; +Cc: philmd, alex.bennee
On 12/9/19 11:15 AM, Luc Michel wrote:
>
>
> On 12/6/19 2:42 PM, Damien Hedde wrote:
>> Remove the packet size upper limit by using a GByteArray
>> instead of a statically allocated array for last_packet.
>> Thus we can now send big packets.
>>
>> Also remove the last_packet_len field and use last_packet->len
>> instead.
>>
>> Signed-off-by: Damien Hedde <damien.hedde@greensocs.com>
>> ---
>>
>> This patch is a follow-up of Alex's series about sve registers
>> which introduces some GbyteArray/Gstring in the gdbstub.
>> It removes the remaining barrier to send big packets.
>>
>> Based-on <20191130084602.10818-1-alex.bennee@linaro.org>
>> ---
>> gdbstub.c | 39 +++++++++++++++++++++------------------
>> 1 file changed, 21 insertions(+), 18 deletions(-)
>>
>> diff --git a/gdbstub.c b/gdbstub.c
>> index 7b695bdebe..022edd6bdb 100644
>> --- a/gdbstub.c
>> +++ b/gdbstub.c
>> @@ -351,8 +351,7 @@ typedef struct GDBState {
>> int line_buf_index;
>> int line_sum; /* running checksum */
>> int line_csum; /* checksum at the end of the packet */
>> - uint8_t last_packet[MAX_PACKET_LENGTH + 4];
>> - int last_packet_len;
>> + GByteArray *last_packet;
>> int signal;
>> #ifdef CONFIG_USER_ONLY
>> int fd;
>> @@ -384,6 +383,7 @@ static void init_gdbserver_state(void)
>> gdbserver_state.init = true;
>> gdbserver_state.str_buf = g_string_new(NULL);
>> gdbserver_state.mem_buf = g_byte_array_sized_new(MAX_PACKET_LENGTH);
>> + gdbserver_state.last_packet = g_byte_array_sized_new(MAX_PACKET_LENGTH + 4);
>> }
>>
>> #ifndef CONFIG_USER_ONLY
>> @@ -626,28 +626,29 @@ static void hexdump(const char *buf, int len,
>> static int put_packet_binary(const char *buf, int len, bool dump)
>> {
>> int csum, i;
>> - uint8_t *p;
>> - uint8_t *ps = &gdbserver_state.last_packet[0];
>> + uint8_t footer[3];
>>
>> if (dump && trace_event_get_state_backends(TRACE_GDBSTUB_IO_BINARYREPLY)) {
>> hexdump(buf, len, trace_gdbstub_io_binaryreply);
>> }
>>
>> for(;;) {
>> - p = ps;
>> - *(p++) = '$';
>> - memcpy(p, buf, len);
>> - p += len;
>> + g_byte_array_set_size(gdbserver_state.last_packet, 0);
>> + g_byte_array_append(gdbserver_state.last_packet,
>> + (const uint8_t *) "$", 1);
>> + g_byte_array_append(gdbserver_state.last_packet,
>> + (const uint8_t *) buf, len);
>> csum = 0;
>> for(i = 0; i < len; i++) {
>> csum += buf[i];
>> }
>> - *(p++) = '#';
>> - *(p++) = tohex((csum >> 4) & 0xf);
>> - *(p++) = tohex((csum) & 0xf);
>> + footer[0] = '#';
>> + footer[1] = tohex((csum >> 4) & 0xf);
>> + footer[2] = tohex((csum) & 0xf);
>> + g_byte_array_append(gdbserver_state.last_packet, footer, 3);
>>
>> - gdbserver_state.last_packet_len = p - ps;
>> - put_buffer(ps, gdbserver_state.last_packet_len);
>> + put_buffer(gdbserver_state.last_packet->data,
>> + gdbserver_state.last_packet->len);
>>
>> #ifdef CONFIG_USER_ONLY
>> i = get_char();
>> @@ -2812,20 +2813,22 @@ static void gdb_read_byte(GDBState *s, uint8_t ch)
>> uint8_t reply;
>>
>> #ifndef CONFIG_USER_ONLY
>> - if (gdbserver_state.last_packet_len) {
>> + if (gdbserver_state.last_packet->len) {
>> /* Waiting for a response to the last packet. If we see the start
>> of a new command then abandon the previous response. */
>> if (ch == '-') {
>> trace_gdbstub_err_got_nack();
>> - put_buffer((uint8_t *)gdbserver_state.last_packet, gdbserver_state.last_packet_len);
>> + put_buffer(gdbserver_state.last_packet->data,
>> + gdbserver_state.last_packet->len);
>> } else if (ch == '+') {
>> trace_gdbstub_io_got_ack();
>> } else {
>> trace_gdbstub_io_got_unexpected(ch);
>> }
>>
>> - if (ch == '+' || ch == '$')
>> - gdbserver_state.last_packet_len = 0;
>> + if (ch == '+' || ch == '$') {
>> + g_byte_array_set_size(gdbserver_state.last_packet, 0);
>> + }
>> if (ch != '$')
>> return;
>> }
>> @@ -3209,7 +3212,7 @@ static int gdb_monitor_write(Chardev *chr, const uint8_t *buf, int len)
>> const char *p = (const char *)buf;
>> int max_sz;
>>
>> - max_sz = (sizeof(gdbserver_state.last_packet) - 2) / 2;
>> + max_sz = MAX_PACKET_LENGTH / 2;
> I think max_sz is not the same as before here.
>
> Before we had (sizeof(gdbserver_state.last_packet) - 2) / 2
> -> ((MAX_PACKET_LENGTH + 4) - 2) / 2
> -> (MAX_PACKET_LENGTH / 2) + 1
>
> Now we have MAX_PACKET_LENGTH / 2
Oups... I'll fix that.
>
> But looking at the gdb_monitor_output() function, it performs the
> following check:
> if (len > (MAX_PACKET_LENGTH/2) - 1)
> len = (MAX_PACKET_LENGTH/2) - 1;
>
> So both versions seem actually wrong and can lead to characters being
> dropped.
>
> However gdb_monitor_output() is still using a MAX_PACKET_LENGTH sized
> local buffer. With this patch it can probably be removed entirely so
> that last_packet is written directly (with a g_byte_array aware version
> of memtohex?).
>
Actually, Alex's patches (on which this patch is based) already do the
memtohex aware version. But yes we can simplify this, I'll prepare a v2
with this.
Thanks,
--
Damien
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2019-12-11 14:14 UTC | newest]
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2019-12-06 13:42 [PATCH] gdbstub: change GDBState.last_packet to GByteArray Damien Hedde
2019-12-06 14:23 ` Philippe Mathieu-Daudé
2019-12-09 10:15 ` Luc Michel
2019-12-11 14:11 ` Damien Hedde
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