Fix: Crash on lttng list -j/-l/-p when no events are present

[lttng-tools.git] / src / bin / lttng / commands / list.c

diff --git a/src/bin/lttng/commands/list.c b/src/bin/lttng/commands/list.c
index b8d0046aa50e4491d82fd92c89c5a3a702b516b6..108f76065f907ad8b2dc9606b45b3d28dfdf2369 100644 (file)
--- a/src/bin/lttng/commands/list.c
+++ b/src/bin/lttng/commands/list.c
@@ -25,6 +25,7 @@
 #include <assert.h>
 
 #include <common/mi-lttng.h>
+#include <lttng/constant.h>
 
 #include "../command.h"
 
@@ -37,11 +38,6 @@ static char *opt_channel;
 static int opt_domain;
 static int opt_fields;
 static int opt_syscall;
-#if 0
-/* Not implemented yet */
-static char *opt_cmd_name;
-static pid_t opt_pid;
-#endif
 
 const char *indent4 = "    ";
 const char *indent6 = "      ";
@@ -58,22 +54,16 @@ static struct mi_writer *writer;
 
 static struct poptOption long_options[] = {
        /* longName, shortName, argInfo, argPtr, value, descrip, argDesc */
-       {"help",      'h', POPT_ARG_NONE, 0, OPT_HELP, 0, 0},
-       {"kernel",    'k', POPT_ARG_VAL, &opt_kernel, 1, 0, 0},
-       {"jul",       'j', POPT_ARG_VAL, &opt_jul, 1, 0, 0},
-       {"log4j",     'l', POPT_ARG_VAL, &opt_log4j, 1, 0, 0},
-       {"python",    'p', POPT_ARG_VAL, &opt_python, 1, 0, 0},
-#if 0
-       /* Not implemented yet */
-       {"userspace",      'u', POPT_ARG_STRING | POPT_ARGFLAG_OPTIONAL, &opt_cmd_name, OPT_USERSPACE, 0, 0},
-       {"pid",            'p', POPT_ARG_INT, &opt_pid, 0, 0, 0},
-#else
-       {"userspace",      'u', POPT_ARG_NONE, 0, OPT_USERSPACE, 0, 0},
-#endif
-       {"channel",   'c', POPT_ARG_STRING, &opt_channel, 0, 0, 0},
-       {"domain",    'd', POPT_ARG_VAL, &opt_domain, 1, 0, 0},
-       {"fields",    'f', POPT_ARG_VAL, &opt_fields, 1, 0, 0},
-       {"syscall",   'S', POPT_ARG_VAL, &opt_syscall, 1, 0, 0},
+       {"help",        'h', POPT_ARG_NONE, 0, OPT_HELP, 0, 0},
+       {"kernel",      'k', POPT_ARG_VAL, &opt_kernel, 1, 0, 0},
+       {"jul", 'j', POPT_ARG_VAL, &opt_jul, 1, 0, 0},
+       {"log4j",       'l', POPT_ARG_VAL, &opt_log4j, 1, 0, 0},
+       {"python",      'p', POPT_ARG_VAL, &opt_python, 1, 0, 0},
+       {"userspace",   'u', POPT_ARG_NONE, 0, OPT_USERSPACE, 0, 0},
+       {"channel",     'c', POPT_ARG_STRING, &opt_channel, 0, 0, 0},
+       {"domain",      'd', POPT_ARG_VAL, &opt_domain, 1, 0, 0},
+       {"fields",      'f', POPT_ARG_VAL, &opt_fields, 1, 0, 0},
+       {"syscall",     'S', POPT_ARG_VAL, &opt_syscall, 1, 0, 0},
        {"list-options", 0, POPT_ARG_NONE, NULL, OPT_LIST_OPTIONS, NULL, NULL},
        {0, 0, 0, 0, 0, 0, 0}
 };
@@ -99,9 +89,6 @@ static void usage(FILE *ofp)
        fprintf(ofp, "  -p, --python            Apply for Python application using logging\n");
        fprintf(ofp, "  -f, --fields            List event fields.\n");
        fprintf(ofp, "      --syscall           List available system calls.\n");
-#if 0
-       fprintf(ofp, "  -p, --pid PID           List user-space events by PID\n");
-#endif
        fprintf(ofp, "\n");
        fprintf(ofp, "Session Options:\n");
        fprintf(ofp, "  -c, --channel NAME      List details of a channel\n");
@@ -120,7 +107,8 @@ static char *get_cmdline_by_pid(pid_t pid)
        int ret;
        FILE *fp = NULL;
        char *cmdline = NULL;
-       char path[20];  /* Can't go bigger than /proc/65535/cmdline */
+       /* Can't go bigger than /proc/LTTNG_MAX_PID/cmdline */
+       char path[sizeof("/proc//cmdline") + sizeof(LTTNG_MAX_PID_STR) - 1];
 
        snprintf(path, sizeof(path), "/proc/%d/cmdline", pid);
        fp = fopen(path, "r");
@@ -421,7 +409,7 @@ static int list_agent_events(void)
        int i, size, ret = CMD_SUCCESS;
        struct lttng_domain domain;
        struct lttng_handle *handle;
-       struct lttng_event *event_list;
+       struct lttng_event *event_list = NULL;
        pid_t cur_pid = 0;
        char *cmdline = NULL;
        const char *agent_domain_str;
@@ -1253,16 +1241,16 @@ static int list_tracker_pids(void)
 {
        int enabled, ret;
        int *pids = NULL;
-       size_t nr_pids, i;
+       size_t nr_pids;
 
        ret = lttng_list_tracker_pids(handle,
                &enabled, &pids, &nr_pids);
        if (ret) {
                return ret;
        }
-       _MSG("PID tracker: [%s]", enabled ? "enabled" : "disabled");
        if (enabled) {
-               _MSG(", pids: [");
+               int i;
+               _MSG("PID tracker: [");
 
                for (i = 0; i < nr_pids; i++) {
                        if (i) {
@@ -1270,9 +1258,8 @@ static int list_tracker_pids(void)
                        }
                        _MSG(" %d", pids[i]);
                }
-               _MSG(" ]");
+               _MSG(" ]\n\n");
        }
-       _MSG("\n\n");
        free(pids);
        return 0;
 }
@@ -1409,8 +1396,11 @@ static int list_sessions(const char *session_name)
                                                active_string(sessions[i].enabled),
                                                snapshot_string(sessions[i].snapshot_mode));
                                MSG("%sTrace path: %s", indent4, sessions[i].path);
-                               MSG("%sLive timer interval (usec): %u\n", indent4,
-                                               sessions[i].live_timer_interval);
+                               if (sessions[i].live_timer_interval != 0) {
+                                       MSG("%sLive timer interval (usec): %u", indent4,
+                                                       sessions[i].live_timer_interval);
+                               }
+                               MSG("");
                        }
                }