kgdb: kdmx agent-proxy: add status file feature

Add status file feature so tools that use the slave pty paths can be
automated.

An example of using this feature can be found in the section
'example 2(automate paths of gdb pty and terminal emulator pty)'
at http://elinux.org/Kdmx

Signed-off-by: Frank Rowand <frank.rowand@sonymobile.com>
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>

1 files changed, 108 insertions, 1 deletions

diff --git a/kdmx/kdmx.c b/kdmx/kdmx.c
index 9c5f2bc..edf44d6 100644
--- a/kdmx/kdmx.c
+++ b/kdmx/kdmx.c
@@ -60,6 +60,31 @@
 #define pr_info(fmt, ...) \
 	printf(fmt, ##__VA_ARGS__)
 
+#define pr_stat_gdb(fmt, ...)                                         \
+	do {                                                          \
+		if (status_gdb_fd != -1) {                            \
+			rewind(status_gdb_file);                      \
+			ftruncate(status_gdb_fd, 0);                  \
+			fprintf(status_gdb_file, fmt, ##__VA_ARGS__); \
+			fflush(status_gdb_file);                      \
+		} ;                                                   \
+	} while (0)
+
+#define pr_stat_trm(fmt, ...)                                 \
+	do {                                                          \
+		if (status_trm_fd != -1) {                            \
+			rewind(status_trm_file);                      \
+			ftruncate(status_trm_fd, 0);                  \
+			fprintf(status_trm_file, fmt, ##__VA_ARGS__); \
+			fflush(status_trm_file);                      \
+		} ;                                                   \
+	} while (0)
+
+int status_gdb_fd = -1;
+int status_trm_fd = -1;
+FILE *status_gdb_file;
+FILE *status_trm_file;
+
 int print_g;
 int print_s;
 int print_t;
@@ -394,6 +419,9 @@ usage(void)
 	pr_err("    -h       Print this message\n");
 	pr_err("    -n       Allow terminal emulator to send null (\\0) characters\n");
 	pr_err("    -p port  Serial port path. default: %s\n", DEFAULT_SERIAL);
+	pr_err("    -s spath write pty path to status file:\n");
+	pr_err("               ${spath}_gdb: gdb pty path\n");
+	pr_err("               ${spath}_trm: terminal emulator pty path\n");
 	pr_err("    -v       Print version\n");
 	pr_err("\n");
 	pr_err("  Console multiplexor for kgdb Linux kernel debugger.\n");
@@ -543,6 +571,7 @@ handle_gdb(void)
 			perror("gdb pty ptsname_r() [2]");
 		}
 
+		pr_stat_gdb("%s\n", name);
 		pr_info("%s is slave pty for gdb\n", name);
 
 		if (strcmp(name, old_name))
@@ -602,6 +631,7 @@ reset_term(int ret_errno)
 		perror("terminal emulator pty ptsname_r() [2]");
 	}
 
+	pr_stat_trm("%s\n", name);
 	pr_info("%s is slave pty for terminal emulator\n", name);
 
 	if (strcmp(name, old_name))
@@ -775,10 +805,16 @@ main(int argc, char **argv)
 	int select_nfds;
 	struct termios termios;
 	char serial_port_path[MAXPATHLEN];
+	char status_gdb_path[MAXPATHLEN];
+	char status_trm_path[MAXPATHLEN];
 	char name[MAXPATHLEN];
 	fd_set readfds;
 	int ret;
 
+	/* default status file */
+	status_gdb_path[0] = '\0';
+	status_trm_path[0] = '\0';
+
 	/* default serial port */
 	memset(serial_port_path, 0, sizeof(serial_port_path));
 	strcpy(serial_port_path, DEFAULT_SERIAL);
@@ -789,7 +825,7 @@ main(int argc, char **argv)
 
 		optopt = '?';
 
-		opt = getopt(argc, argv, "?b:dhl:np:vD:");
+		opt = getopt(argc, argv, "?b:dhl:np:s:vD:");
 
 		if (opt == -1)
 			break;
@@ -822,6 +858,23 @@ main(int argc, char **argv)
 			strcpy(serial_port_path, optarg);
 			break;
 
+		case 's':
+			if ((strlen(optarg) >= (sizeof(status_gdb_path) + strlen("_xxx"))) ||
+			    (strlen(optarg) >= (sizeof(status_trm_path) + strlen("_xxx")))) {
+				pr_err("Path length for status file too long\n");
+				exit(EXIT_FAILURE);
+			}
+
+			/* len of suffix is strlen("_xxx") */
+
+			strcpy(status_gdb_path, optarg);
+			strcpy(status_trm_path, optarg);
+
+			strcat(status_gdb_path, "_gdb");
+			strcat(status_trm_path, "_trm");
+
+			break;
+
 		case 'v':
 			pr_err("kdmx %s\n", VUFX);
 			exit(EXIT_SUCCESS);
@@ -865,6 +918,58 @@ main(int argc, char **argv)
 	if (print_label < 2)
 		print_label = 0;
 
+	if (strlen(status_gdb_path)) {
+		/*
+		 * fopen() creates file with mode == 0666.  use open() to
+		 * create with mode 0640
+		 */
+		status_gdb_fd = open(status_gdb_path,
+				 O_RDWR | O_CREAT | O_TRUNC,
+				 S_IRUSR | S_IWUSR | S_IRGRP);
+		if (status_gdb_fd == -1) {
+			char msg[strlen("open of ") + sizeof(status_gdb_path) + 1];
+
+			memset(msg, 0, sizeof(msg));
+			sprintf(msg, "open of %s", status_gdb_path);
+			die(msg);
+		}
+		status_gdb_file = fdopen(status_gdb_fd, "r+");
+		if (status_gdb_file == NULL) {
+			char msg[strlen("fdopen of ") + sizeof(status_gdb_path) + 1];
+
+			memset(msg, 0, sizeof(msg));
+			sprintf(msg, "fdopen of %s", status_gdb_path);
+			die(msg);
+		}
+		pr_debug("gdb status file: %s\n", status_gdb_path);
+	}
+
+	if (strlen(status_trm_path)) {
+		/*
+		 * fopen() creates file with mode == 0666.  use open() to
+		 * create with mode 0640
+		 */
+		status_trm_fd = open(status_trm_path,
+				 O_RDWR | O_CREAT | O_TRUNC,
+				 S_IRUSR | S_IWUSR | S_IRGRP);
+		if (status_trm_fd == -1) {
+			char msg[strlen("open of ") + sizeof(status_trm_path) + 1];
+
+			memset(msg, 0, sizeof(msg));
+			sprintf(msg, "open of %s", status_trm_path);
+			die(msg);
+		}
+		status_trm_file = fdopen(status_trm_fd, "r+");
+		if (status_trm_file == NULL) {
+			char msg[strlen("fdopen of ") + sizeof(status_trm_path) + 1];
+
+			memset(msg, 0, sizeof(msg));
+			sprintf(msg, "fdopen of %s", status_trm_path);
+			die(msg);
+		}
+		pr_debug("terminal emulator status file: %s\n", status_trm_path);
+	}
+
 	pr_debug("serial port: %s\n", serial_port_path);
 
 	serial_fd = open(serial_port_path, O_RDWR|O_NDELAY|O_NOCTTY);
@@ -935,12 +1040,14 @@ main(int argc, char **argv)
 	if (ret)
 		perror("terminal emulator pty ptsname_r() [3]");
 
+	pr_stat_trm("%s\n", name);
 	pr_info("%s is slave pty for terminal emulator\n", name);
 
 	ret = ptsname_r(gdb_fd, name, sizeof(name));
 	if (ret)
 		perror("gdb pty ptsname_r() [3]");
 
+	pr_stat_gdb("%s\n", name);
 	pr_info("%s is slave pty for gdb\n", name);
 
 	pr_info("\n");