Commit 118e2268 authored by Alex Bennée's avatar Alex Bennée Committed by Paolo Bonzini
Browse files

gdbstub: modernise DEBUG_GDB 



Convert the a gdb_debug helper which compiles away to nothing when not
used but still ensures the format strings are checked. There is some
minor code motion for the incorrect checksum message to report it
before we attempt to send the reply.

Signed-off-by: default avatarAlex Bennée <alex.bennee@linaro.org>
Reviewed-by: default avatarPhilippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: default avatarGreg Kurz <groug@kaod.org>
Message-Id: <20170712105216.747-2-alex.bennee@linaro.org>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent cb58a6d3

gdbstub.c

+33 −44
Original line number Diff line number Diff line
@@ -272,7 +272,20 @@ static int gdb_signal_to_target (int sig) 
        return -1;

}



//#define DEBUG_GDB

/* #define DEBUG_GDB */



#ifdef DEBUG_GDB

# define DEBUG_GDB_GATE 1

#else

# define DEBUG_GDB_GATE 0

#endif



#define gdb_debug(fmt, ...) do { \

    if (DEBUG_GDB_GATE) { \

        fprintf(stderr, "%s: " fmt, __func__, ## __VA_ARGS__); \

    } \

} while (0)





typedef struct GDBRegisterState {

    int base_reg;
@@ -548,9 +561,7 @@ static int put_packet_binary(GDBState *s, const char *buf, int len) 
/* return -1 if error, 0 if OK */

static int put_packet(GDBState *s, const char *buf)

{

#ifdef DEBUG_GDB

    printf("reply='%s'\n", buf);

#endif

    gdb_debug("reply='%s'\n", buf);



    return put_packet_binary(s, buf, strlen(buf));

}
@@ -956,9 +967,9 @@ static int gdb_handle_packet(GDBState *s, const char *line_buf) 
    uint8_t *registers;

    target_ulong addr, len;



#ifdef DEBUG_GDB

    printf("command='%s'\n", line_buf);

#endif



    gdb_debug("command='%s'\n", line_buf);



    p = line_buf;

    ch = *p++;

    switch(ch) {
@@ -1519,17 +1530,14 @@ static void gdb_read_byte(GDBState *s, int ch) 
        /* Waiting for a response to the last packet.  If we see the start

           of a new command then abandon the previous response.  */

        if (ch == '-') {

#ifdef DEBUG_GDB

            printf("Got NACK, retransmitting\n");

#endif

            gdb_debug("Got NACK, retransmitting\n");

            put_buffer(s, (uint8_t *)s->last_packet, s->last_packet_len);

        } else if (ch == '+') {

            gdb_debug("Got ACK\n");

        } else {

            gdb_debug("Got '%c' when expecting ACK/NACK\n", ch);

        }

#ifdef DEBUG_GDB

        else if (ch == '+')

            printf("Got ACK\n");

        else

            printf("Got '%c' when expecting ACK/NACK\n", ch);

#endif



        if (ch == '+' || ch == '$')

            s->last_packet_len = 0;

        if (ch != '$')
@@ -1550,9 +1558,7 @@ static void gdb_read_byte(GDBState *s, int ch) 
                s->line_sum = 0;

                s->state = RS_GETLINE;

            } else {

#ifdef DEBUG_GDB

                printf("gdbstub received garbage between packets: 0x%x\n", ch);

#endif

                gdb_debug("received garbage between packets: 0x%x\n", ch);

            }

            break;

        case RS_GETLINE:
@@ -1568,9 +1574,7 @@ static void gdb_read_byte(GDBState *s, int ch) 
                /* end of command, start of checksum*/

                s->state = RS_CHKSUM1;

            } else if (s->line_buf_index >= sizeof(s->line_buf) - 1) {

#ifdef DEBUG_GDB

                printf("gdbstub command buffer overrun, dropping command\n");

#endif

                gdb_debug("command buffer overrun, dropping command\n");

                s->state = RS_IDLE;

            } else {

                /* unescaped command character */
@@ -1584,9 +1588,7 @@ static void gdb_read_byte(GDBState *s, int ch) 
                s->state = RS_CHKSUM1;

            } else if (s->line_buf_index >= sizeof(s->line_buf) - 1) {

                /* command buffer overrun */

#ifdef DEBUG_GDB

                printf("gdbstub command buffer overrun, dropping command\n");

#endif

                gdb_debug("command buffer overrun, dropping command\n");

                s->state = RS_IDLE;

            } else {

                /* parse escaped character and leave escape state */
@@ -1598,25 +1600,18 @@ static void gdb_read_byte(GDBState *s, int ch) 
        case RS_GETLINE_RLE:

            if (ch < ' ') {

                /* invalid RLE count encoding */

#ifdef DEBUG_GDB

                printf("gdbstub got invalid RLE count: 0x%x\n", ch);

#endif

                gdb_debug("got invalid RLE count: 0x%x\n", ch);

                s->state = RS_GETLINE;

            } else {

                /* decode repeat length */

                int repeat = (unsigned char)ch - ' ' + 3;

                if (s->line_buf_index + repeat >= sizeof(s->line_buf) - 1) {

                    /* that many repeats would overrun the command buffer */

#ifdef DEBUG_GDB

                    printf("gdbstub command buffer overrun,"

                           " dropping command\n");

#endif

                    gdb_debug("command buffer overrun, dropping command\n");

                    s->state = RS_IDLE;

                } else if (s->line_buf_index < 1) {

                    /* got a repeat but we have nothing to repeat */

#ifdef DEBUG_GDB

                    printf("gdbstub got invalid RLE sequence\n");

#endif

                    gdb_debug("got invalid RLE sequence\n");

                    s->state = RS_GETLINE;

                } else {

                    /* repeat the last character */
@@ -1631,9 +1626,7 @@ static void gdb_read_byte(GDBState *s, int ch) 
        case RS_CHKSUM1:

            /* get high hex digit of checksum */

            if (!isxdigit(ch)) {

#ifdef DEBUG_GDB

                printf("gdbstub got invalid command checksum digit\n");

#endif

                gdb_debug("got invalid command checksum digit\n");

                s->state = RS_GETLINE;

                break;

            }
@@ -1644,21 +1637,17 @@ static void gdb_read_byte(GDBState *s, int ch) 
        case RS_CHKSUM2:

            /* get low hex digit of checksum */

            if (!isxdigit(ch)) {

#ifdef DEBUG_GDB

                printf("gdbstub got invalid command checksum digit\n");

#endif

                gdb_debug("got invalid command checksum digit\n");

                s->state = RS_GETLINE;

                break;

            }

            s->line_csum |= fromhex(ch);



            if (s->line_csum != (s->line_sum & 0xff)) {

                gdb_debug("got command packet with incorrect checksum\n");

                /* send NAK reply */

                reply = '-';

                put_buffer(s, &reply, 1);

#ifdef DEBUG_GDB

                printf("gdbstub got command packet with incorrect checksum\n");

#endif

                s->state = RS_IDLE;

            } else {

                /* send ACK reply */