[lttng-dev] [PATCH] enable_events.c : Document and enforce return values, detect strtoul() error, enforce exactly one domain flag, adjust usage() output accordingly, handle event list errors
Thibault, Daniel
Daniel.Thibault at drdc-rddc.gc.ca
Thu Feb 2 14:59:19 EST 2012
>From 77d1ab08ea900802b5dc5c5585d92c09800d768b Thu, 2 Feb 2012 14:56:12 -0500
From: Daniel U. Thibault <daniel.thibault at drdc-rddc.gc.ca>
Date: Thu, 2 Feb 2012 14:55:45 -0500
Subject: [PATCH] enable_events.c : Document and enforce return values, detect strtoul() error, enforce exactly one domain flag, adjust usage() output accordingly, handle event list errors
Signed-off-by: Daniel U. Thibault <daniel.thibault at drdc-rddc.gc.ca>
diff --git a/src/bin/lttng/commands/enable_events.c b/src/bin/lttng/commands/enable_events.c
index db0597d..24cd286 100644
--- a/src/bin/lttng/commands/enable_events.c
+++ b/src/bin/lttng/commands/enable_events.c
@@ -21,6 +21,7 @@
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
+#include <error.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>
@@ -99,6 +100,7 @@
static void usage(FILE *ofp)
{
fprintf(ofp, "usage: lttng enable-event NAME[,NAME2,...] [options] [event_options]\n");
+ fprintf(ofp, "Exactly one domain (-k/--kernel or -u/--userspace) must be specified.\n");
fprintf(ofp, "\n");
fprintf(ofp, " -h, --help Show this help\n");
fprintf(ofp, " --list-options Simple listing of options\n");
@@ -167,6 +169,7 @@
/*
* Parse probe options.
+ * Returns a count of parsed options, or -1 in case of error.
*/
static int parse_probe_opts(struct lttng_event *ev, char *opt)
{
@@ -182,7 +185,7 @@
/* Check for symbol+offset */
ret = sscanf(opt, "%[^'+']+%s", name, s_hex);
if (ret == 2) {
- strncpy(ev->attr.probe.symbol_name, name, LTTNG_SYMBOL_NAME_LEN);
+ strncpy(ev->attr.probe.symbol_name, name, LTTNG_SYMBOL_NAME_LEN-1);
ev->attr.probe.symbol_name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
DBG("probe symbol %s", ev->attr.probe.symbol_name);
if (strlen(s_hex) == 0) {
@@ -190,7 +193,13 @@
ret = -1;
goto end;
}
+ errno = 0;
ev->attr.probe.offset = strtoul(s_hex, NULL, 0);
+ if (errno != 0) {
+ ERR("Invalid probe offset value %s", s_hex);
+ ret = -1;
+ goto end;
+ }
DBG("probe offset %" PRIu64, ev->attr.probe.offset);
ev->attr.probe.addr = 0;
goto end;
@@ -200,7 +209,7 @@
if (isalpha(name[0])) {
ret = sscanf(opt, "%s", name);
if (ret == 1) {
- strncpy(ev->attr.probe.symbol_name, name, LTTNG_SYMBOL_NAME_LEN);
+ strncpy(ev->attr.probe.symbol_name, name, LTTNG_SYMBOL_NAME_LEN-1);
ev->attr.probe.symbol_name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
DBG("probe symbol %s", ev->attr.probe.symbol_name);
ev->attr.probe.offset = 0;
@@ -218,7 +227,13 @@
ret = -1;
goto end;
}
+ errno = 0;
ev->attr.probe.addr = strtoul(s_hex, NULL, 0);
+ if (errno != 0) {
+ ERR("Invalid probe address value %s", s_hex);
+ ret = -1;
+ goto end;
+ }
DBG("probe addr %" PRIu64, ev->attr.probe.addr);
ev->attr.probe.offset = 0;
memset(ev->attr.probe.symbol_name, 0, LTTNG_SYMBOL_NAME_LEN);
@@ -233,7 +248,8 @@
}
/*
- * Maps loglevel from string to value
+ * Maps loglevel from string to value (string must not be NULL).
+ * Returns a TRACE_* enum value (0+), or -1 in case of error.
*/
static
int loglevel_str_to_value(const char *str)
@@ -277,6 +293,7 @@
/*
* Enabling event using the lttng API.
+ * Returns a CMD_* result value.
*/
static int enable_events(char *session_name)
{
@@ -286,14 +303,12 @@
struct lttng_domain dom;
/* Create lttng domain */
+ /* cmd_add_context() enforces the existence of exactly one domain flag */
if (opt_kernel) {
dom.type = LTTNG_DOMAIN_KERNEL;
- } else if (opt_userspace) {
+ } else { /* if (opt_userspace) { */
dom.type = LTTNG_DOMAIN_UST;
- } else {
- ERR("Please specify a tracer (-k/--kernel or -u/--userspace)");
- ret = CMD_ERROR;
- goto error;
+ /* TODO As LTTNG_DOMAIN_* values are added, capture them here */
}
if (opt_channel_name == NULL) {
@@ -306,9 +321,10 @@
channel_name = opt_channel_name;
}
+ handle = NULL;
handle = lttng_create_handle(session_name, &dom);
if (handle == NULL) {
- ret = -1;
+ ret = CMD_FATAL;
goto error;
}
@@ -327,7 +343,7 @@
ev.loglevel = loglevel_str_to_value(opt_loglevel);
if (ev.loglevel == -1) {
ERR("Unknown loglevel %s", opt_loglevel);
- ret = -1;
+ ret = CMD_ERROR;
goto error;
}
}
@@ -335,6 +351,7 @@
ret = lttng_enable_event(handle, &ev, channel_name);
if (ret < 0) {
+ ret = CMD_ERROR;
goto error;
}
@@ -360,6 +377,7 @@
* We should not be here since lttng_enable_event should have
* failed on the event type.
*/
+ ret = CMD_FATAL;
goto error;
}
goto end;
@@ -367,9 +385,11 @@
/* Strip event list */
event_name = strtok(opt_event_list, ",");
+ /* Default to a warning in case opt_event_list is empty */
+ ret = CMD_WARNING;
while (event_name != NULL) {
/* Copy name and type of the event */
- strncpy(ev.name, event_name, LTTNG_SYMBOL_NAME_LEN);
+ strncpy(ev.name, event_name, LTTNG_SYMBOL_NAME_LEN-1);
ev.name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
ev.type = opt_event_type;
@@ -388,7 +408,7 @@
ret = parse_probe_opts(&ev, opt_probe);
if (ret < 0) {
ERR("Unable to parse probe options");
- ret = 0;
+ ret = CMD_ERROR;
goto error;
}
break;
@@ -396,13 +416,13 @@
ret = parse_probe_opts(&ev, opt_function);
if (ret < 0) {
ERR("Unable to parse function probe options");
- ret = 0;
+ ret = CMD_ERROR;
goto error;
}
break;
case LTTNG_EVENT_FUNCTION_ENTRY:
strncpy(ev.attr.ftrace.symbol_name, opt_function_entry_symbol,
- LTTNG_SYMBOL_NAME_LEN);
+ LTTNG_SYMBOL_NAME_LEN-1);
ev.attr.ftrace.symbol_name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
break;
case LTTNG_EVENT_SYSCALL:
@@ -414,7 +434,7 @@
}
if (opt_loglevel) {
- MSG("Kernel loglevels are not supported.");
+ ERR("Kernel loglevels are not supported.");
ret = CMD_UNDEFINED;
goto error;
}
@@ -424,7 +444,7 @@
} else if (opt_userspace) { /* User-space tracer action */
#if 0
if (opt_cmd_name != NULL || opt_pid) {
- MSG("Only supporting tracing all UST processes (-u) for now.");
+ ERR("Only supporting tracing all UST processes (-u) for now.");
ret = CMD_UNDEFINED;
goto error;
}
@@ -439,13 +459,17 @@
case LTTNG_EVENT_TRACEPOINT:
/* Copy name and type of the event */
ev.type = LTTNG_EVENT_TRACEPOINT;
- strncpy(ev.name, event_name, LTTNG_SYMBOL_NAME_LEN);
+ strncpy(ev.name, event_name, LTTNG_SYMBOL_NAME_LEN-1);
ev.name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
break;
case LTTNG_EVENT_PROBE:
+ /* Fall-through */
case LTTNG_EVENT_FUNCTION:
+ /* Fall-through */
case LTTNG_EVENT_FUNCTION_ENTRY:
+ /* Fall-through */
case LTTNG_EVENT_SYSCALL:
+ /* Fall-through */
default:
ERR("Event type not available for user-space tracing");
ret = CMD_UNDEFINED;
@@ -457,14 +481,10 @@
ev.loglevel = loglevel_str_to_value(opt_loglevel);
if (ev.loglevel == -1) {
ERR("Unknown loglevel %s", opt_loglevel);
- ret = -1;
+ ret = CMD_ERROR;
goto error;
}
}
- } else {
- ERR("Please specify a tracer (-k/--kernel or -u/--userspace)");
- ret = CMD_ERROR;
- goto error;
}
ret = lttng_enable_event(handle, &ev, channel_name);
@@ -475,10 +495,15 @@
} else {
MSG("%s event %s created in channel %s",
opt_kernel ? "kernel": "UST", event_name, channel_name);
+ ret = CMD_SUCCESS;
}
/* Next event */
event_name = strtok(NULL, ",");
+ }
+ if (ret == CMD_WARNING) {
+ ERR("No event specified for %s channel %s",
+ (opt_kernel ? "kernel" : "UST"), channel_name);
}
end:
@@ -496,6 +521,7 @@
/*
* Add event to trace session
+ * Returns a CMD_* result value.
*/
int cmd_enable_events(int argc, const char **argv)
{
@@ -550,6 +576,18 @@
}
}
+ /* Enforce requirement for exactly one domain */
+ /* Five LTTNG_DOMAIN_* values are currently planned */
+ if (!opt_userspace && !opt_kernel) {
+ ERR("No domain specified: Use one of -k/--kernel or -u/--userspace");
+ ret = CMD_ERROR;
+ goto end;
+ } else if (opt_userspace && opt_kernel) {
+ ERR("More than one domain specified");
+ ret = CMD_ERROR;
+ goto end;
+ }
+
opt_event_list = (char*) poptGetArg(pc);
if (opt_event_list == NULL && opt_enable_all == 0) {
ERR("Missing event name(s).\n");
@@ -558,14 +596,10 @@
goto end;
}
- if (!opt_session_name) {
- session_name = get_session_name();
- if (session_name == NULL) {
- ret = CMD_ERROR;
- goto end;
- }
- } else {
- session_name = opt_session_name;
+ session_name = opt_session_name ? opt_session_name : get_session_name();
+ if (session_name == NULL) {
+ ret = CMD_ERROR;
+ goto end;
}
ret = enable_events(session_name);
------------------------------
Daniel U. Thibault
R & D pour la défense Canada - Valcartier (RDDC Valcartier) / Defence R&D Canada - Valcartier (DRDC Valcartier)
Système de systèmes (SdS) / System of Systems (SoS)
Solutions informatiques et expérimentations (SIE) / Computing Solutions and Experimentations (CSE)
2459 Boul. Pie XI Nord
Québec, QC G3J 1X5
CANADA
Vox : (418) 844-4000 x4245
Fax : (418) 844-4538
NAC: 918V QSDJ
Gouvernement du Canada / Government of Canada
<http://www.valcartier.drdc-rddc.gc.ca/>
More information about the lttng-dev
mailing list