From: ntfreak Date: Sat, 16 Feb 2008 15:21:13 +0000 (+0000) Subject: - solve lots of problems with stuck GDB connections, making it impossible to connect... X-Git-Tag: v0.1.0~989 X-Git-Url: https://git.sur5r.net/?a=commitdiff_plain;h=e859281eb3cb977cd26588b595f0519fcad605f6;p=openocd - solve lots of problems with stuck GDB connections, making it impossible to connect to GDB, handle timeout of acknowledgement, etc. - "monitor halt/resume" now works correctly - "monitor sleep 10000" no longer makes the GDB protocol lock up. There is an error message and the protocol recovers nicely afterwards. - it's now possible to connect to a target which needs a reset before halt works. - handle failed memory access more gracefully. Connection is now closed instead of OpenOCD quitting. - *much* improved handling of 2 second timeout on memory read packets. Especially important w/mouseover evaluation of variables in Eclipse. - fixed memory leak upon failed memory packet reply. - 'O' packets w/progress info is no longer sent out randomly. - faster packet reply code. - Thanks to Øyvind Harboe for this patch git-svn-id: svn://svn.berlios.de/openocd/trunk@300 b42882b7-edfa-0310-969c-e2dbd0fdcd60 --- diff --git a/src/server/gdb_server.c b/src/server/gdb_server.c index b15c29d3..99c9376d 100644 --- a/src/server/gdb_server.c +++ b/src/server/gdb_server.c @@ -43,11 +43,11 @@ #endif static unsigned short gdb_port; +static const char *DIGITS = "0123456789abcdef"; -static void gdb_log_callback(void *privData, const char *file, int line, +static void gdb_log_callback(void *priv, const char *file, int line, const char *function, const char *format, va_list args); - enum gdb_detach_mode { GDB_DETACH_RESUME, @@ -107,10 +107,38 @@ int gdb_get_char(connection_t *connection, int* next_char) return ERROR_OK; } - while ((gdb_con->buf_cnt = read_socket(connection->fd, gdb_con->buffer, GDB_BUFFER_SIZE)) <= 0) + for (;;) { +#ifndef _WIN32 + /* a non-blocking socket will block if there is 0 bytes available on the socket, + * but return with as many bytes as are available immediately + */ + struct timeval tv; + fd_set read_fds; + + FD_ZERO(&read_fds); + FD_SET(connection->fd, &read_fds); + + tv.tv_sec = 1; + tv.tv_usec = 0; + if (select(connection->fd + 1, &read_fds, NULL, NULL, &tv) == 0) + { + /* This can typically be because a "monitor" command took too long + * before printing any progress messages + */ + return ERROR_GDB_TIMEOUT; + } +#endif + gdb_con->buf_cnt = read_socket(connection->fd, gdb_con->buffer, GDB_BUFFER_SIZE); + if (gdb_con->buf_cnt > 0) + { + break; + } if (gdb_con->buf_cnt == 0) + { + gdb_con->closed = 1; return ERROR_SERVER_REMOTE_CLOSED; + } #ifdef _WIN32 errno = WSAGetLastError(); @@ -140,7 +168,7 @@ int gdb_get_char(connection_t *connection, int* next_char) return ERROR_SERVER_REMOTE_CLOSED; default: ERROR("read: %s", strerror(errno)); - exit(-1); + return ERROR_SERVER_REMOTE_CLOSED; } #endif } @@ -184,11 +212,27 @@ int gdb_putback_char(connection_t *connection, int last_char) return ERROR_OK; } +/* The only way we can detect that the socket is closed is the first time + * we write to it, we will fail. Subsequent write operations will + * succeed. Shudder! */ +int gdb_write(connection_t *connection, void *data, int len) +{ + gdb_connection_t *gdb_con = connection->priv; + if (gdb_con->closed) + return ERROR_SERVER_REMOTE_CLOSED; + + if (write_socket(connection->fd, data, len) == len) + { + return ERROR_OK; + } + gdb_con->closed = 1; + return ERROR_SERVER_REMOTE_CLOSED; +} + int gdb_put_packet_inner(connection_t *connection, char *buffer, int len) { int i; unsigned char my_checksum = 0; - char checksum[3]; #ifdef _DEBUG_GDB_IO_ char *debug_buffer; #endif @@ -208,22 +252,55 @@ int gdb_put_packet_inner(connection_t *connection, char *buffer, int len) DEBUG("sending packet '$%s#%2.2x'", debug_buffer, my_checksum); free(debug_buffer); #endif - write_socket(connection->fd, "$", 1); +#if 0 + char checksum[3]; + gdb_write(connection, "$", 1); if (len > 0) - write_socket(connection->fd, buffer, len); - write_socket(connection->fd, "#", 1); - + gdb_write(connection, buffer, len); + gdb_write(connection, "#", 1); + snprintf(checksum, 3, "%2.2x", my_checksum); - - write_socket(connection->fd, checksum, 2); - + + gdb_write(connection, checksum, 2); +#else + void *allocated = NULL; + char stackAlloc[1024]; + char *t = stackAlloc; + int totalLen = 1 + len + 1 + 2; + if (totalLen > sizeof(stackAlloc)) + { + allocated = malloc(totalLen); + t = allocated; + if (allocated == NULL) + { + ERROR("Ran out of memory trying to reply packet %d\n", totalLen); + exit(-1); + } + } + t[0] = '$'; + memcpy(t + 1, buffer, len); + t[1 + len] = '#'; + t[1 + len + 1] = DIGITS[(my_checksum >> 4) & 0xf]; + t[1 + len + 2] = DIGITS[my_checksum & 0xf]; + + gdb_write(connection, t, totalLen); + + if (allocated) + { + free(allocated); + } +#endif if ((retval = gdb_get_char(connection, &reply)) != ERROR_OK) return retval; if (reply == '+') break; else if (reply == '-') + { + /* Stop sending output packets for now */ + log_setCallback(NULL, NULL); WARNING("negative reply, retrying"); + } else if (reply == 0x3) { gdb_con->ctrl_c = 1; @@ -232,7 +309,11 @@ int gdb_put_packet_inner(connection_t *connection, char *buffer, int len) if (reply == '+') break; else if (reply == '-') + { + /* Stop sending output packets for now */ + log_setCallback(NULL, NULL); WARNING("negative reply, retrying"); + } else { ERROR("unknown character 0x%2.2x in reply, dropping connection", reply); @@ -245,16 +326,18 @@ int gdb_put_packet_inner(connection_t *connection, char *buffer, int len) return ERROR_SERVER_REMOTE_CLOSED; } } + if (gdb_con->closed) + return ERROR_SERVER_REMOTE_CLOSED; return ERROR_OK; } int gdb_put_packet(connection_t *connection, char *buffer, int len) { - gdb_connection_t *gdb_connection = connection->priv; - gdb_connection->output_disable=1; - int retval=gdb_put_packet_inner(connection, buffer, len); - gdb_connection->output_disable=0; + gdb_connection_t *gdb_con = connection->priv; + gdb_con->busy = 1; + int retval = gdb_put_packet_inner(connection, buffer, len); + gdb_con->busy = 0; return retval; } @@ -300,7 +383,7 @@ int gdb_get_packet_inner(connection_t *connection, char *buffer, int *len) my_checksum = 0; - count=0; + count = 0; gdb_connection_t *gdb_con = connection->priv; for (;;) { @@ -394,38 +477,33 @@ int gdb_get_packet_inner(connection_t *connection, char *buffer, int *len) if (my_checksum == strtoul(checksum, NULL, 16)) { - write_socket(connection->fd, "+", 1); + gdb_write(connection, "+", 1); break; } WARNING("checksum error, requesting retransmission"); - write_socket(connection->fd, "-", 1); + gdb_write(connection, "-", 1); } + if (gdb_con->closed) + return ERROR_SERVER_REMOTE_CLOSED; return ERROR_OK; } int gdb_get_packet(connection_t *connection, char *buffer, int *len) { - gdb_connection_t *gdb_connection = connection->priv; - gdb_connection->output_disable=1; - int retval=gdb_get_packet_inner(connection, buffer, len); - gdb_connection->output_disable=0; + gdb_connection_t *gdb_con = connection->priv; + gdb_con->busy = 1; + int retval = gdb_get_packet_inner(connection, buffer, len); + gdb_con->busy = 0; return retval; } int gdb_output_con(connection_t *connection, char* line) { - gdb_connection_t *gdb_connection = connection->priv; char *hex_buffer; int i, bin_size; - /* check if output is enabled */ - if (gdb_connection->output_disable) - { - return ERROR_OK; - } - bin_size = strlen(line); hex_buffer = malloc(bin_size*2 + 4); @@ -445,8 +523,9 @@ int gdb_output_con(connection_t *connection, char* line) int gdb_output(struct command_context_s *context, char* line) { - connection_t *connection = context->output_handler_priv; - return gdb_output_con(connection, line); + /* this will be dumped to the log and also sent as an O packet if possible */ + ERROR(line); + return ERROR_OK; } int gdb_program_handler(struct target_s *target, enum target_event event, void *priv) @@ -483,9 +562,18 @@ int gdb_target_callback_event_handler(struct target_s *target, enum target_event switch (event) { case TARGET_EVENT_HALTED: + /* In the GDB protocol when we are stepping or coninuing execution, + * we have a lingering reply. Upon receiving a halted event + * when we have that lingering packet, we reply to the original + * step or continue packet. + * + * Executing monitor commands can bring the target in and + * out of the running state so we'll see lots of TARGET_EVENT_XXX + * that are to be ignored. + */ if (gdb_connection->frontend_state == TARGET_RUNNING) { - // stop forwarding log packets! + /* stop forwarding log packets! */ log_setCallback(NULL, NULL); if (gdb_connection->ctrl_c) @@ -503,12 +591,6 @@ int gdb_target_callback_event_handler(struct target_s *target, enum target_event gdb_connection->frontend_state = TARGET_HALTED; } break; - case TARGET_EVENT_RESUMED: - if (gdb_connection->frontend_state == TARGET_HALTED) - { - gdb_connection->frontend_state = TARGET_RUNNING; - } - break; case TARGET_EVENT_GDB_PROGRAM: gdb_program_handler(target, event, connection->cmd_ctx); break; @@ -534,7 +616,8 @@ int gdb_new_connection(connection_t *connection) gdb_connection->ctrl_c = 0; gdb_connection->frontend_state = TARGET_HALTED; gdb_connection->vflash_image = NULL; - gdb_connection->output_disable = 0; + gdb_connection->closed = 0; + gdb_connection->busy = 0; /* output goes through gdb connection */ command_set_output_handler(connection->cmd_ctx, gdb_output, connection); @@ -546,14 +629,12 @@ int gdb_new_connection(connection_t *connection) if (((retval = gdb_service->target->type->halt(gdb_service->target)) != ERROR_OK) && (retval != ERROR_TARGET_ALREADY_HALTED)) { - ERROR("error when trying to halt target"); - exit(-1); + ERROR("error(%d) when trying to halt target, falling back to \"reset halt\"", retval); + command_run_line(connection->cmd_ctx, "reset halt"); } - while (gdb_service->target->state != TARGET_HALTED) - { - gdb_service->target->type->poll(gdb_service->target); - } + /* This will time out after 1 second */ + command_run_line(connection->cmd_ctx, "wait_halt 1"); /* remove the initial ACK from the incoming buffer */ if ((retval = gdb_get_char(connection, &initial_ack)) != ERROR_OK) @@ -621,7 +702,6 @@ int gdb_last_signal_packet(connection_t *connection, target_t *target, char* pac * case an entire byte is shown. */ void gdb_str_to_target(target_t *target, char *tstr, reg_t *reg) { - static const char *DIGITS = "0123456789abcdef"; int i; u8 *buf; @@ -935,13 +1015,19 @@ int gdb_memory_packet_error(connection_t *connection, int retval) gdb_send_error(connection, EFAULT); break; default: - ERROR("BUG: unexpected error %i", retval); - exit(-1); + /* This could be that the target reset itself. */ + ERROR("unexpected error %i. Dropping connection.", retval); + return ERROR_SERVER_REMOTE_CLOSED; } return ERROR_OK; } +/* We don't have to worry about the default 2 second timeout for GDB packets, + * because GDB breaks up large memory reads into smaller reads. + * + * 8191 bytes by the looks of it. Why 8191 bytes instead of 8192????? + */ int gdb_read_memory_packet(connection_t *connection, target_t *target, char *packet, int packet_size) { char *separator; @@ -951,8 +1037,7 @@ int gdb_read_memory_packet(connection_t *connection, target_t *target, char *pac u8 *buffer; char *hex_buffer; - int i; - int retval; + int retval = ERROR_OK; /* skip command character */ packet++; @@ -985,11 +1070,14 @@ int gdb_read_memory_packet(connection_t *connection, target_t *target, char *pac else retval = target->type->read_memory(target, addr, 1, len, buffer); break; + case 3: + case 1: + retval = target->type->read_memory(target, addr, 1, len, buffer); + break; + /* handle bulk reads */ default: - if (((addr % 4) == 0) && ((len % 4) == 0)) - retval = target->type->read_memory(target, addr, 4, len / 4, buffer); - else - retval = target->type->read_memory(target, addr, 1, len, buffer); + retval = target_read_buffer(target, addr, len, buffer); + break; } #if 0 @@ -1008,8 +1096,13 @@ int gdb_read_memory_packet(connection_t *connection, target_t *target, char *pac { hex_buffer = malloc(len * 2 + 1); - for (i=0; i> 4) & 0xf]; + hex_buffer[2 * i + 1] = DIGITS[t & 0xf]; + } gdb_put_packet(connection, hex_buffer, len * 2); @@ -1017,13 +1110,12 @@ int gdb_read_memory_packet(connection_t *connection, target_t *target, char *pac } else { - if ((retval = gdb_memory_packet_error(connection, retval)) != ERROR_OK) - return retval; + retval = gdb_memory_packet_error(connection, retval); } free(buffer); - return ERROR_OK; + return retval; } int gdb_write_memory_packet(connection_t *connection, target_t *target, char *packet, int packet_size) @@ -1655,9 +1747,6 @@ int gdb_v_packet(connection_t *connection, target_t *target, char *packet, int p return ERROR_SERVER_REMOTE_CLOSED; } - /* disable gdb output while programming */ - gdb_connection->output_disable = 1; - /* assume all sectors need erasing - stops any problems * when flash_write is called multiple times */ flash_set_dirty(); @@ -1677,9 +1766,6 @@ int gdb_v_packet(connection_t *connection, target_t *target, char *packet, int p else gdb_put_packet(connection, "OK", 2); - /* reenable gdb output */ - gdb_connection->output_disable = 0; - return ERROR_OK; } @@ -1702,9 +1788,6 @@ int gdb_v_packet(connection_t *connection, target_t *target, char *packet, int p } length = packet_size - (parse - packet); - /* disable gdb output while programming */ - gdb_connection->output_disable = 1; - /* create a new image if there isn't already one */ if (gdb_connection->vflash_image == NULL) { @@ -1717,9 +1800,6 @@ int gdb_v_packet(connection_t *connection, target_t *target, char *packet, int p gdb_put_packet(connection, "OK", 2); - /* reenable gdb output */ - gdb_connection->output_disable = 0; - return ERROR_OK; } @@ -1728,9 +1808,6 @@ int gdb_v_packet(connection_t *connection, target_t *target, char *packet, int p u32 written; char *error_str; - /* disable gdb output while programming */ - gdb_connection->output_disable = 1; - /* process the flashing buffer. No need to erase as GDB * always issues a vFlashErase first. */ if ((result = flash_write(gdb_service->target, gdb_connection->vflash_image, &written, &error_str, NULL, 0)) != ERROR_OK) @@ -1756,9 +1833,6 @@ int gdb_v_packet(connection_t *connection, target_t *target, char *packet, int p free(gdb_connection->vflash_image); gdb_connection->vflash_image = NULL; - /* reenable gdb output */ - gdb_connection->output_disable = 0; - return ERROR_OK; } @@ -1791,15 +1865,20 @@ int gdb_detach(connection_t *connection, target_t *target) return ERROR_OK; } - - -static void gdb_log_callback(void *privData, const char *file, int line, +static void gdb_log_callback(void *priv, const char *file, int line, const char *function, const char *format, va_list args) { - connection_t *connection=(connection_t *)privData; + connection_t *connection = priv; + gdb_connection_t *gdb_con = connection->priv; - char *t=allocPrintf(format, args); - if (t==NULL) + if (gdb_con->busy) + { + /* do not reply this using the O packet */ + return; + } + + char *t = allocPrintf(format, args); + if (t == NULL) return; gdb_output_con(connection, t); @@ -1807,7 +1886,7 @@ static void gdb_log_callback(void *privData, const char *file, int line, free(t); } -int gdb_input(connection_t *connection) +int gdb_input_inner(connection_t *connection) { gdb_service_t *gdb_service = connection->service->priv; target_t *target = gdb_service->target; @@ -1823,17 +1902,7 @@ int gdb_input(connection_t *connection) packet_size = GDB_BUFFER_SIZE-1; if ((retval = gdb_get_packet(connection, packet, &packet_size)) != ERROR_OK) { - switch (retval) - { - case ERROR_GDB_BUFFER_TOO_SMALL: - ERROR("BUG: buffer supplied for gdb packet was too small"); - exit(-1); - case ERROR_SERVER_REMOTE_CLOSED: - return ERROR_SERVER_REMOTE_CLOSED; - default: - ERROR("BUG: unexpected error"); - exit(-1); - } + return retval; } /* terminate with zero */ @@ -1881,10 +1950,14 @@ int gdb_input(connection_t *connection) break; case 'c': case 's': + { /* We're running/stepping, in which case we can * forward log output until the target is halted */ - log_setCallback(gdb_log_callback, connection); - gdb_step_continue_packet(connection, target, packet, packet_size); + gdb_connection_t *gdb_con = connection->priv; + gdb_con->frontend_state = TARGET_RUNNING; + log_setCallback(gdb_log_callback, connection); + gdb_step_continue_packet(connection, target, packet, packet_size); + } break; case 'v': retval = gdb_v_packet(connection, target, packet, packet_size); @@ -1937,6 +2010,15 @@ int gdb_input(connection_t *connection) return ERROR_OK; } +int gdb_input(connection_t *connection) +{ + int retval = gdb_input_inner(connection); + if (retval == ERROR_SERVER_REMOTE_CLOSED) + return retval; + /* we'll recover from any other errors(e.g. temporary timeouts, etc.) */ + return ERROR_OK; +} + int gdb_init() { gdb_service_t *gdb_service; diff --git a/src/server/gdb_server.h b/src/server/gdb_server.h index c02ad50e..741f96a0 100644 --- a/src/server/gdb_server.h +++ b/src/server/gdb_server.h @@ -34,7 +34,8 @@ typedef struct gdb_connection_s int ctrl_c; enum target_state frontend_state; image_t *vflash_image; - int output_disable; + int closed; + int busy; } gdb_connection_t; typedef struct gdb_service_s @@ -46,5 +47,6 @@ extern int gdb_init(); extern int gdb_register_commands(command_context_t *command_context); #define ERROR_GDB_BUFFER_TOO_SMALL (-800) +#define ERROR_GDB_TIMEOUT (-801) #endif /* GDB_SERVER_H */