[lttng-dev] [PATCH] disable_channels.c and enable_channels.c
Thibault, Daniel
Daniel.Thibault at drdc-rddc.gc.ca
Tue Jan 31 16:41:21 EST 2012
>From c297ddf1295b316d1133a49bc8d2fa08f115dcdc Tue, 31 Jan 2012 16:32:47 -0500
From: Daniel U. Thibault <daniel.thibault at drdc-rddc.gc.ca>
Date: Tue, 31 Jan 2012 16:32:33 -0500
Subject: [PATCH] disable_channels.c : * Also use the enable_channels.c channel name length filter enable_channels.c : * Improve usage() printout * Document and enforce return values * Send --help to stdout * Return CMD_WARNING for bad channel name(s) * Fix session_name memory leak * Use LTTNG_SYMBOL_NAME_LEN instead of NAME_MAX for chan.name * Replace atol/atoi with strtol (because the former's behaviour is undefined for bad input) (this required including errno.h) * Change private function enable_channel() to enable_channels() to be consistent with disable_channels.c
Signed-off-by: Daniel U. Thibault <daniel.thibault at drdc-rddc.gc.ca>
diff --git a/src/bin/lttng/commands/disable_channels.c b/src/bin/lttng/commands/disable_channels.c
index 4202963..f6929e6 100644
--- a/src/bin/lttng/commands/disable_channels.c
+++ b/src/bin/lttng/commands/disable_channels.c
@@ -94,6 +94,8 @@
{
int warn = 0, ret;
char *channel_name;
+ char chan_name[LTTNG_SYMBOL_NAME_LEN];
+
struct lttng_domain dom;
/* Create lttng domain */
@@ -120,16 +122,20 @@
while (channel_name != NULL) {
DBG("Disabling channel %s", channel_name);
- ret = lttng_disable_channel(handle, channel_name);
+ /* Copy channel name and normalize it */
+ strncpy(chan_name, channel_name, LTTNG_SYMBOL_NAME_LEN - 1);
+ chan_name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
+
+ ret = lttng_disable_channel(handle, chan_name);
if (ret < 0) {
warn = 1;
ERR("%s channel %s unrecognised for session %s",
- opt_kernel ? "Kernel" : "UST", channel_name,
+ opt_kernel ? "Kernel" : "UST", chan_name,
session_name);
} else {
ret = CMD_SUCCESS;
MSG("%s channel %s disabled for session %s",
- opt_kernel ? "Kernel" : "UST", channel_name,
+ opt_kernel ? "Kernel" : "UST", chan_name,
session_name);
}
diff --git a/src/bin/lttng/commands/enable_channels.c b/src/bin/lttng/commands/enable_channels.c
index 03de524..7bebf76 100644
--- a/src/bin/lttng/commands/enable_channels.c
+++ b/src/bin/lttng/commands/enable_channels.c
@@ -21,6 +21,7 @@
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
+#include <errno.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>
@@ -84,15 +85,17 @@
fprintf(ofp, "\n");
fprintf(ofp, " -h, --help Show this help\n");
fprintf(ofp, " --list-options Simple listing of options\n");
- fprintf(ofp, " -s, --session Apply on session name\n");
- fprintf(ofp, " -k, --kernel Apply on the kernel tracer\n");
+ fprintf(ofp, " -s, --session Apply to session name\n");
+ fprintf(ofp, " -k, --kernel Apply to the kernel tracer\n");
#if 0
- fprintf(ofp, " -u, --userspace [CMD] Apply for the user-space tracer\n");
+ fprintf(ofp, " -u, --userspace [CMD] Apply to the user-space tracer\n");
fprintf(ofp, " If no CMD, the domain used is UST global\n");
- fprintf(ofp, " or else the domain is UST EXEC_NAME\n");
+ fprintf(ofp, " otherwise the domain is UST EXEC_NAME\n");
+ fprintf(ofp, " (--kernel preempts --userspace)\n");
fprintf(ofp, " -p, --pid PID If -u, apply to specific PID (domain: UST PID)\n");
#else
- fprintf(ofp, " -u, --userspace Apply for the user-space tracer\n");
+ fprintf(ofp, " -u, --userspace Apply to the user-space tracer\n");
+ fprintf(ofp, " (--kernel preempts --userspace)\n");
#endif
fprintf(ofp, "\n");
fprintf(ofp, "Channel options:\n");
@@ -100,7 +103,7 @@
DEFAULT_CHANNEL_OVERWRITE ? "" : " (default)");
fprintf(ofp, " --overwrite Flight recorder mode%s\n",
DEFAULT_CHANNEL_OVERWRITE ? " (default)" : "");
- fprintf(ofp, " --subbuf-size Subbuffer size in bytes\n");
+ fprintf(ofp, " --subbuf-size Subbuffer size (in bytes)\n");
fprintf(ofp, " (default: %u, kernel default: %u)\n",
DEFAULT_CHANNEL_SUBBUF_SIZE,
DEFAULT_KERNEL_CHANNEL_SUBBUF_SIZE);
@@ -118,14 +121,16 @@
/*
* Set default attributes depending on those already defined from the command
* line.
+ * The domain argument must not be NULL.
*/
static void set_default_attr(struct lttng_domain *dom)
{
struct lttng_channel_attr default_attr;
- /* Set attributes */
+ /* Recover default attributes */
lttng_channel_set_default_attr(dom, &default_attr);
+ /* Set attributes */
if (chan.attr.overwrite == -1) {
chan.attr.overwrite = default_attr.overwrite;
}
@@ -147,11 +152,13 @@
}
/*
- * Adding channel using the lttng API.
+ * Enables channel(s) using the lttng API.
+ * Channel names which are too long will be truncated.
+ * Returns one of the CMD_* result values.
*/
-static int enable_channel(char *session_name)
+static int enable_channels(char *session_name)
{
- int ret = CMD_SUCCESS;
+ int warn = 0, ret;
char *channel_name;
struct lttng_domain dom;
@@ -170,23 +177,29 @@
handle = lttng_create_handle(session_name, &dom);
if (handle == NULL) {
- ret = -1;
+ ret = CMD_FATAL;
goto error;
}
/* Strip channel list (format: chan1,chan2,...) */
channel_name = strtok(opt_channels, ",");
+ /* Default to a warning in case opt_channels is empty */
+ ret = CMD_WARNING;
while (channel_name != NULL) {
- /* Copy channel name and normalize it */
- strncpy(chan.name, channel_name, NAME_MAX);
- chan.name[NAME_MAX - 1] = '\0';
-
DBG("Enabling channel %s", channel_name);
+
+ /* Copy channel name and normalize it */
+ strncpy(chan.name, channel_name, LTTNG_SYMBOL_NAME_LEN - 1);
+ chan.name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
ret = lttng_enable_channel(handle, &chan);
if (ret < 0) {
- goto error;
+ warn = 1;
+ ERR("%s channel %s unrecognised for session %s",
+ opt_kernel ? "Kernel" : "UST", channel_name,
+ session_name);
} else {
+ ret = CMD_SUCCESS;
MSG("%s channel %s enabled for session %s",
opt_kernel ? "Kernel" : "UST", channel_name,
session_name);
@@ -194,6 +207,13 @@
/* Next event */
channel_name = strtok(NULL, ",");
+ }
+ if (ret == CMD_WARNING) {
+ ERR("No %s channel specified for session %s",
+ opt_kernel ? "kernel" : "UST", session_name);
+ }
+ if (warn) {
+ ret = CMD_WARNING;
}
error:
@@ -215,7 +235,8 @@
}
/*
- * Add channel to trace session
+ * Add channel(s) to trace session
+ * Returns one of the CMD_* result values.
*/
int cmd_enable_channels(int argc, const char **argv)
{
@@ -231,7 +252,7 @@
while ((opt = poptGetNextOpt(pc)) != -1) {
switch (opt) {
case OPT_HELP:
- usage(stderr);
+ usage(stdout);
ret = CMD_SUCCESS;
goto end;
case OPT_DISCARD:
@@ -243,20 +264,44 @@
DBG("Channel set to overwrite");
break;
case OPT_SUBBUF_SIZE:
- chan.attr.subbuf_size = atol(poptGetOptArg(pc));
+ errno = 0;
+ chan.attr.subbuf_size = strtol(poptGetOptArg(pc), (char **)NULL, 10);
+ if (errno != 0) {
+ ERR("Subbuffer size not a number");
+ ret = CMD_ERROR;
+ goto end;
+ }
DBG("Channel subbuf size set to %" PRIu64, chan.attr.subbuf_size);
break;
case OPT_NUM_SUBBUF:
- chan.attr.num_subbuf = atoi(poptGetOptArg(pc));
+ errno = 0;
+ chan.attr.num_subbuf = strtol(poptGetOptArg(pc), (char **)NULL, 10);
+ if (errno != 0) {
+ ERR("Number of subbuffers not a number");
+ ret = CMD_ERROR;
+ goto end;
+ }
DBG("Channel subbuf num set to %" PRIu64, chan.attr.num_subbuf);
break;
case OPT_SWITCH_TIMER:
- chan.attr.switch_timer_interval = atoi(poptGetOptArg(pc));
- DBG("Channel switch timer interval set to %d", chan.attr.switch_timer_interval);
+ errno = 0;
+ chan.attr.switch_timer_interval = strtol(poptGetOptArg(pc), (char **)NULL, 10);
+ if (errno != 0) {
+ ERR("Switch timer interval not a number");
+ ret = CMD_ERROR;
+ goto end;
+ }
+ DBG("Channel switch timer interval set to %d usec", chan.attr.switch_timer_interval);
break;
case OPT_READ_TIMER:
- chan.attr.read_timer_interval = atoi(poptGetOptArg(pc));
- DBG("Channel read timer interval set to %d", chan.attr.read_timer_interval);
+ errno = 0;
+ chan.attr.read_timer_interval = strtol(poptGetOptArg(pc), (char **)NULL, 10);
+ if (errno != 0) {
+ ERR("Read timer interval not a number");
+ ret = CMD_ERROR;
+ goto end;
+ }
+ DBG("Channel read timer interval set to %d usec", chan.attr.read_timer_interval);
break;
case OPT_USERSPACE:
opt_userspace = 1;
@@ -274,24 +319,26 @@
opt_channels = (char*) poptGetArg(pc);
if (opt_channels == NULL) {
- ERR("Missing channel name.\n");
+ ERR("Missing channel name(s).\n");
usage(stderr);
- ret = CMD_SUCCESS;
+ ret = CMD_ERROR;
goto end;
}
- if (!opt_session_name) {
- session_name = get_session_name();
- if (session_name == NULL) {
- ret = -1;
- 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 cleanup;
}
- ret = enable_channel(session_name);
+ ret = enable_channels(session_name);
+
+cleanup:
+ if (opt_session_name == NULL) {
+ free(session_name);
+ }
end:
poptFreeContext(pc);
------------------------------
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/>
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