/* noinline to diminish caller stack size */
static
int fill_table(const struct trace_syscall_entry *table, size_t table_len,
struct lttng_event **chan_table, struct lttng_channel *chan, void *filter)
{
const struct lttng_event_desc *desc;
unsigned int i;
/* Allocate events for each syscall, insert into table */
for (i = 0; i < table_len; i++) {
struct lttng_kernel_event ev;
desc = table[i].desc;
if (!desc) {
/* Unknown syscall */
continue;
}
/*
* Skip those already populated by previous failed
* register for this channel.
*/
if (chan_table[i])
continue;
memset(&ev, 0, sizeof(ev));
strncpy(ev.name, desc->name, LTTNG_KERNEL_SYM_NAME_LEN);
ev.name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
ev.instrumentation = LTTNG_KERNEL_NOOP;
chan_table[i] = lttng_event_create(chan, &ev, filter,
desc);
WARN_ON_ONCE(!chan_table[i]);
if (IS_ERR(chan_table[i])) {
/*
* If something goes wrong in event registration
* after the first one, we have no choice but to
* leave the previous events in there, until
* deleted by session teardown.
*/
return PTR_ERR(chan_table[i]);
}
}
return 0;
}
/*
* Enabling event using the lttng API.
* Note: in case of error only the last error code will be return.
*/
static int enable_events(char *session_name)
{
int ret = CMD_SUCCESS, command_ret = CMD_SUCCESS;
int error_holder = CMD_SUCCESS, warn = 0, error = 0, success = 1;
char *event_name, *channel_name = NULL;
struct lttng_event *ev;
struct lttng_domain dom;
char **exclusion_list = NULL;
memset(&dom, 0, sizeof(dom));
ev = lttng_event_create();
if (!ev) {
ret = CMD_ERROR;
goto error;
}
if (opt_kernel) {
if (opt_loglevel) {
WARN("Kernel loglevels are not supported.");
}
}
/* Create lttng domain */
if (opt_kernel) {
dom.type = LTTNG_DOMAIN_KERNEL;
dom.buf_type = LTTNG_BUFFER_GLOBAL;
} else if (opt_userspace) {
dom.type = LTTNG_DOMAIN_UST;
/* Default. */
dom.buf_type = LTTNG_BUFFER_PER_UID;
} else if (opt_jul) {
dom.type = LTTNG_DOMAIN_JUL;
/* Default. */
dom.buf_type = LTTNG_BUFFER_PER_UID;
} else if (opt_log4j) {
dom.type = LTTNG_DOMAIN_LOG4J;
/* Default. */
dom.buf_type = LTTNG_BUFFER_PER_UID;
} else if (opt_python) {
dom.type = LTTNG_DOMAIN_PYTHON;
/* Default. */
dom.buf_type = LTTNG_BUFFER_PER_UID;
} else {
/* Checked by the caller. */
assert(0);
}
if (opt_exclude) {
switch (dom.type) {
case LTTNG_DOMAIN_KERNEL:
case LTTNG_DOMAIN_JUL:
case LTTNG_DOMAIN_LOG4J:
case LTTNG_DOMAIN_PYTHON:
ERR("Event name exclusions are not yet implemented for %s events",
get_domain_str(dom.type));
ret = CMD_ERROR;
goto error;
case LTTNG_DOMAIN_UST:
/* Exclusions supported */
break;
default:
assert(0);
}
}
/*
* Adding a filter to a probe, function or userspace-probe would be
* denied by the kernel tracer as it's not supported at the moment. We
* do an early check here to warn the user.
*/
if (opt_filter && opt_kernel) {
switch (opt_event_type) {
case LTTNG_EVENT_ALL:
case LTTNG_EVENT_TRACEPOINT:
case LTTNG_EVENT_SYSCALL:
break;
case LTTNG_EVENT_PROBE:
case LTTNG_EVENT_USERSPACE_PROBE:
case LTTNG_EVENT_FUNCTION:
ERR("Filter expressions are not supported for %s events",
get_event_type_str(opt_event_type));
ret = CMD_ERROR;
goto error;
default:
ret = CMD_UNDEFINED;
goto error;
}
}
channel_name = opt_channel_name;
handle = lttng_create_handle(session_name, &dom);
if (handle == NULL) {
ret = -1;
goto error;
}
/* Prepare Mi */
if (lttng_opt_mi) {
/* Open a events element */
ret = mi_lttng_writer_open_element(writer, config_element_events);
if (ret) {
ret = CMD_ERROR;
goto error;
}
}
if (opt_enable_all) {
/* Default setup for enable all */
if (opt_kernel) {
ev->type = opt_event_type;
strcpy(ev->name, "*");
/* kernel loglevels not implemented */
ev->loglevel_type = LTTNG_EVENT_LOGLEVEL_ALL;
} else {
ev->type = LTTNG_EVENT_TRACEPOINT;
strcpy(ev->name, "*");
ev->loglevel_type = opt_loglevel_type;
if (opt_loglevel) {
assert(opt_userspace || opt_jul || opt_log4j || opt_python);
if (opt_userspace) {
ev->loglevel = loglevel_str_to_value(opt_loglevel);
} else if (opt_jul) {
ev->loglevel = loglevel_jul_str_to_value(opt_loglevel);
} else if (opt_log4j) {
ev->loglevel = loglevel_log4j_str_to_value(opt_loglevel);
} else if (opt_python) {
ev->loglevel = loglevel_python_str_to_value(opt_loglevel);
}
if (ev->loglevel == -1) {
ERR("Unknown loglevel %s", opt_loglevel);
ret = -LTTNG_ERR_INVALID;
goto error;
}
} else {
assert(opt_userspace || opt_jul || opt_log4j || opt_python);
if (opt_userspace) {
ev->loglevel = -1;
} else if (opt_jul) {
ev->loglevel = LTTNG_LOGLEVEL_JUL_ALL;
} else if (opt_log4j) {
ev->loglevel = LTTNG_LOGLEVEL_LOG4J_ALL;
} else if (opt_python) {
ev->loglevel = LTTNG_LOGLEVEL_PYTHON_DEBUG;
}
}
}
if (opt_exclude) {
ret = create_exclusion_list_and_validate("*",
opt_exclude, &exclusion_list);
if (ret) {
ret = CMD_ERROR;
goto error;
}
ev->exclusion = 1;
warn_on_truncated_exclusion_names(exclusion_list,
&warn);
}
if (!opt_filter) {
ret = lttng_enable_event_with_exclusions(handle,
ev, channel_name,
NULL,
exclusion_list ? strutils_array_of_strings_len(exclusion_list) : 0,
exclusion_list);
if (ret < 0) {
switch (-ret) {
case LTTNG_ERR_KERN_EVENT_EXIST:
WARN("Kernel events already enabled (channel %s, session %s)",
print_channel_name(channel_name), session_name);
warn = 1;
break;
case LTTNG_ERR_TRACE_ALREADY_STARTED:
{
const char *msg = "The command tried to enable an event in a new domain for a session that has already been started once.";
ERR("Events: %s (channel %s, session %s)",
msg,
print_channel_name(channel_name),
session_name);
error = 1;
break;
}
default:
ERR("Events: %s (channel %s, session %s)",
lttng_strerror(ret),
ret == -LTTNG_ERR_NEED_CHANNEL_NAME
? print_raw_channel_name(channel_name)
: print_channel_name(channel_name),
session_name);
error = 1;
break;
}
goto end;
}
switch (opt_event_type) {
case LTTNG_EVENT_TRACEPOINT:
if (opt_loglevel && dom.type != LTTNG_DOMAIN_KERNEL) {
char *exclusion_string = print_exclusions(exclusion_list);
if (!exclusion_string) {
PERROR("Cannot allocate exclusion_string");
error = 1;
goto end;
}
MSG("All %s tracepoints%s are enabled in channel %s for loglevel %s",
get_domain_str(dom.type),
exclusion_string,
print_channel_name(channel_name),
opt_loglevel);
free(exclusion_string);
} else {
char *exclusion_string = print_exclusions(exclusion_list);
if (!exclusion_string) {
PERROR("Cannot allocate exclusion_string");
error = 1;
goto end;
}
MSG("All %s tracepoints%s are enabled in channel %s",
get_domain_str(dom.type),
exclusion_string,
print_channel_name(channel_name));
free(exclusion_string);
}
break;
case LTTNG_EVENT_SYSCALL:
if (opt_kernel) {
MSG("All %s system calls are enabled in channel %s",
get_domain_str(dom.type),
print_channel_name(channel_name));
}
break;
case LTTNG_EVENT_ALL:
if (opt_loglevel && dom.type != LTTNG_DOMAIN_KERNEL) {
char *exclusion_string = print_exclusions(exclusion_list);
if (!exclusion_string) {
PERROR("Cannot allocate exclusion_string");
error = 1;
goto end;
}
MSG("All %s events%s are enabled in channel %s for loglevel %s",
get_domain_str(dom.type),
exclusion_string,
print_channel_name(channel_name),
opt_loglevel);
free(exclusion_string);
} else {
char *exclusion_string = print_exclusions(exclusion_list);
if (!exclusion_string) {
PERROR("Cannot allocate exclusion_string");
error = 1;
goto end;
}
MSG("All %s events%s are enabled in channel %s",
get_domain_str(dom.type),
exclusion_string,
print_channel_name(channel_name));
free(exclusion_string);
}
break;
default:
/*
* We should not be here since lttng_enable_event should have
* failed on the event type.
*/
goto error;
}
}
if (opt_filter) {
command_ret = lttng_enable_event_with_exclusions(handle, ev, channel_name,
opt_filter,
exclusion_list ? strutils_array_of_strings_len(exclusion_list) : 0,
exclusion_list);
if (command_ret < 0) {
switch (-command_ret) {
case LTTNG_ERR_FILTER_EXIST:
WARN("Filter on all events is already enabled"
" (channel %s, session %s)",
print_channel_name(channel_name), session_name);
warn = 1;
break;
case LTTNG_ERR_TRACE_ALREADY_STARTED:
{
const char *msg = "The command tried to enable an event in a new domain for a session that has already been started once.";
ERR("All events: %s (channel %s, session %s, filter \'%s\')",
msg,
print_channel_name(channel_name),
session_name, opt_filter);
error = 1;
break;
}
default:
ERR("All events: %s (channel %s, session %s, filter \'%s\')",
lttng_strerror(command_ret),
command_ret == -LTTNG_ERR_NEED_CHANNEL_NAME
? print_raw_channel_name(channel_name)
: print_channel_name(channel_name),
session_name, opt_filter);
error = 1;
break;
}
error_holder = command_ret;
} else {
ev->filter = 1;
MSG("Filter '%s' successfully set", opt_filter);
}
}
if (lttng_opt_mi) {
/* The wildcard * is used for kernel and ust domain to
* represent ALL. We copy * in event name to force the wildcard use
* for kernel domain
*
* Note: this is strictly for semantic and printing while in
* machine interface mode.
*/
strcpy(ev->name, "*");
/* If we reach here the events are enabled */
if (!error && !warn) {
ev->enabled = 1;
} else {
ev->enabled = 0;
success = 0;
}
ret = mi_lttng_event(writer, ev, 1, handle->domain.type);
if (ret) {
ret = CMD_ERROR;
goto error;
}
/* print exclusion */
ret = mi_print_exclusion(exclusion_list);
if (ret) {
ret = CMD_ERROR;
goto error;
}
/* Success ? */
ret = mi_lttng_writer_write_element_bool(writer,
mi_lttng_element_command_success, success);
if (ret) {
ret = CMD_ERROR;
goto error;
}
/* Close event element */
ret = mi_lttng_writer_close_element(writer);
if (ret) {
ret = CMD_ERROR;
goto error;
}
}
goto end;
}
/* Strip event list */
event_name = strtok(opt_event_list, ",");
while (event_name != NULL) {
/* Copy name and type of the event */
strncpy(ev->name, event_name, LTTNG_SYMBOL_NAME_LEN);
ev->name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
ev->type = opt_event_type;
/* Kernel tracer action */
if (opt_kernel) {
DBG("Enabling kernel event %s for channel %s",
event_name,
print_channel_name(channel_name));
switch (opt_event_type) {
case LTTNG_EVENT_ALL: /* Enable tracepoints and syscalls */
/* If event name differs from *, select tracepoint. */
if (strcmp(ev->name, "*")) {
ev->type = LTTNG_EVENT_TRACEPOINT;
}
break;
case LTTNG_EVENT_TRACEPOINT:
break;
case LTTNG_EVENT_PROBE:
ret = parse_probe_opts(ev, opt_probe);
if (ret) {
ERR("Unable to parse probe options");
ret = CMD_ERROR;
goto error;
}
break;
case LTTNG_EVENT_USERSPACE_PROBE:
ret = parse_userspace_probe_opts(ev, opt_userspace_probe);
if (ret) {
switch (ret) {
case CMD_UNSUPPORTED:
/*
* Error message describing
* what is not supported was
* printed in the function.
*/
break;
case CMD_ERROR:
default:
ERR("Unable to parse userspace probe options");
break;
}
goto error;
}
break;
case LTTNG_EVENT_FUNCTION:
ret = parse_probe_opts(ev, opt_function);
if (ret) {
ERR("Unable to parse function probe options");
ret = CMD_ERROR;
goto error;
}
break;
case LTTNG_EVENT_SYSCALL:
ev->type = LTTNG_EVENT_SYSCALL;
break;
default:
ret = CMD_UNDEFINED;
goto error;
}
/* kernel loglevels not implemented */
ev->loglevel_type = LTTNG_EVENT_LOGLEVEL_ALL;
} else if (opt_userspace) { /* User-space tracer action */
DBG("Enabling UST event %s for channel %s, loglevel %s", event_name,
print_channel_name(channel_name), opt_loglevel ? : "<all>");
switch (opt_event_type) {
case LTTNG_EVENT_ALL: /* Default behavior is tracepoint */
/* Fall-through */
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);
ev->name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
break;
case LTTNG_EVENT_PROBE:
case LTTNG_EVENT_FUNCTION:
case LTTNG_EVENT_SYSCALL:
case LTTNG_EVENT_USERSPACE_PROBE:
default:
ERR("Event type not available for user-space tracing");
ret = CMD_UNSUPPORTED;
goto error;
}
if (opt_exclude) {
ev->exclusion = 1;
if (opt_event_type != LTTNG_EVENT_ALL && opt_event_type != LTTNG_EVENT_TRACEPOINT) {
ERR("Exclusion option can only be used with tracepoint events");
ret = CMD_ERROR;
goto error;
}
/* Free previously allocated items */
strutils_free_null_terminated_array_of_strings(
exclusion_list);
exclusion_list = NULL;
ret = create_exclusion_list_and_validate(
event_name, opt_exclude,
&exclusion_list);
if (ret) {
ret = CMD_ERROR;
goto error;
}
warn_on_truncated_exclusion_names(
exclusion_list, &warn);
}
ev->loglevel_type = opt_loglevel_type;
if (opt_loglevel) {
ev->loglevel = loglevel_str_to_value(opt_loglevel);
if (ev->loglevel == -1) {
ERR("Unknown loglevel %s", opt_loglevel);
ret = -LTTNG_ERR_INVALID;
goto error;
}
} else {
ev->loglevel = -1;
}
} else if (opt_jul || opt_log4j || opt_python) {
if (opt_event_type != LTTNG_EVENT_ALL &&
opt_event_type != LTTNG_EVENT_TRACEPOINT) {
ERR("Event type not supported for domain.");
ret = CMD_UNSUPPORTED;
goto error;
}
ev->loglevel_type = opt_loglevel_type;
if (opt_loglevel) {
if (opt_jul) {
ev->loglevel = loglevel_jul_str_to_value(opt_loglevel);
} else if (opt_log4j) {
ev->loglevel = loglevel_log4j_str_to_value(opt_loglevel);
} else if (opt_python) {
ev->loglevel = loglevel_python_str_to_value(opt_loglevel);
}
if (ev->loglevel == -1) {
ERR("Unknown loglevel %s", opt_loglevel);
ret = -LTTNG_ERR_INVALID;
goto error;
}
} else {
if (opt_jul) {
ev->loglevel = LTTNG_LOGLEVEL_JUL_ALL;
} else if (opt_log4j) {
ev->loglevel = LTTNG_LOGLEVEL_LOG4J_ALL;
} else if (opt_python) {
ev->loglevel = LTTNG_LOGLEVEL_PYTHON_DEBUG;
}
}
ev->type = LTTNG_EVENT_TRACEPOINT;
strncpy(ev->name, event_name, LTTNG_SYMBOL_NAME_LEN);
ev->name[LTTNG_SYMBOL_NAME_LEN - 1] = '\0';
} else {
assert(0);
}
if (!opt_filter) {
char *exclusion_string;
command_ret = lttng_enable_event_with_exclusions(handle,
ev, channel_name,
NULL,
exclusion_list ? strutils_array_of_strings_len(exclusion_list) : 0,
exclusion_list);
exclusion_string = print_exclusions(exclusion_list);
if (!exclusion_string) {
PERROR("Cannot allocate exclusion_string");
error = 1;
goto end;
}
if (command_ret < 0) {
/* Turn ret to positive value to handle the positive error code */
switch (-command_ret) {
case LTTNG_ERR_KERN_EVENT_EXIST:
WARN("Kernel event %s%s already enabled (channel %s, session %s)",
event_name,
exclusion_string,
print_channel_name(channel_name), session_name);
warn = 1;
break;
case LTTNG_ERR_TRACE_ALREADY_STARTED:
{
const char *msg = "The command tried to enable an event in a new domain for a session that has already been started once.";
ERR("Event %s%s: %s (channel %s, session %s)", event_name,
exclusion_string,
msg,
print_channel_name(channel_name),
session_name);
error = 1;
break;
}
case LTTNG_ERR_SDT_PROBE_SEMAPHORE:
ERR("SDT probes %s guarded by semaphores are not supported (channel %s, session %s)",
event_name, print_channel_name(channel_name),
session_name);
error = 1;
break;
default:
ERR("Event %s%s: %s (channel %s, session %s)", event_name,
exclusion_string,
lttng_strerror(command_ret),
command_ret == -LTTNG_ERR_NEED_CHANNEL_NAME
? print_raw_channel_name(channel_name)
: print_channel_name(channel_name),
session_name);
error = 1;
break;
}
error_holder = command_ret;
} else {
switch (dom.type) {
case LTTNG_DOMAIN_KERNEL:
case LTTNG_DOMAIN_UST:
MSG("%s event %s%s created in channel %s",
get_domain_str(dom.type),
event_name,
exclusion_string,
print_channel_name(channel_name));
break;
case LTTNG_DOMAIN_JUL:
case LTTNG_DOMAIN_LOG4J:
case LTTNG_DOMAIN_PYTHON:
/*
* Don't print the default channel
* name for agent domains.
*/
MSG("%s event %s%s enabled",
get_domain_str(dom.type),
event_name,
exclusion_string);
break;
default:
assert(0);
}
}
free(exclusion_string);
}
if (opt_filter) {
char *exclusion_string;
/* Filter present */
ev->filter = 1;
command_ret = lttng_enable_event_with_exclusions(handle, ev, channel_name,
opt_filter,
exclusion_list ? strutils_array_of_strings_len(exclusion_list) : 0,
exclusion_list);
exclusion_string = print_exclusions(exclusion_list);
if (!exclusion_string) {
PERROR("Cannot allocate exclusion_string");
error = 1;
goto end;
}
if (command_ret < 0) {
switch (-command_ret) {
case LTTNG_ERR_FILTER_EXIST:
WARN("Filter on event %s%s is already enabled"
" (channel %s, session %s)",
event_name,
exclusion_string,
print_channel_name(channel_name), session_name);
warn = 1;
break;
case LTTNG_ERR_TRACE_ALREADY_STARTED:
{
const char *msg = "The command tried to enable an event in a new domain for a session that has already been started once.";
ERR("Event %s%s: %s (channel %s, session %s, filter \'%s\')", ev->name,
exclusion_string,
msg,
print_channel_name(channel_name),
session_name, opt_filter);
error = 1;
break;
}
default:
ERR("Event %s%s: %s (channel %s, session %s, filter \'%s\')", ev->name,
exclusion_string,
lttng_strerror(command_ret),
command_ret == -LTTNG_ERR_NEED_CHANNEL_NAME
? print_raw_channel_name(channel_name)
: print_channel_name(channel_name),
session_name, opt_filter);
error = 1;
break;
}
error_holder = command_ret;
} else {
MSG("Event %s%s: Filter '%s' successfully set",
event_name, exclusion_string,
opt_filter);
}
free(exclusion_string);
}
if (lttng_opt_mi) {
if (command_ret) {
success = 0;
ev->enabled = 0;
} else {
ev->enabled = 1;
}
ret = mi_lttng_event(writer, ev, 1, handle->domain.type);
if (ret) {
ret = CMD_ERROR;
goto error;
}
/* print exclusion */
ret = mi_print_exclusion(exclusion_list);
if (ret) {
ret = CMD_ERROR;
goto error;
}
/* Success ? */
ret = mi_lttng_writer_write_element_bool(writer,
mi_lttng_element_command_success, success);
if (ret) {
ret = CMD_ERROR;
goto end;
}
/* Close event element */
ret = mi_lttng_writer_close_element(writer);
if (ret) {
ret = CMD_ERROR;
goto end;
}
}
/* Next event */
event_name = strtok(NULL, ",");
/* Reset warn, error and success */
success = 1;
}
int lttng_syscalls_register(struct lttng_channel *chan, void *filter)
{
struct lttng_kernel_event ev;
int ret;
wrapper_vmalloc_sync_all();
if (!chan->sc_table) {
/* create syscall table mapping syscall to events */
chan->sc_table = kzalloc(sizeof(struct lttng_event *)
* ARRAY_SIZE(sc_table), GFP_KERNEL);
if (!chan->sc_table)
return -ENOMEM;
}
#ifdef CONFIG_COMPAT
if (!chan->compat_sc_table) {
/* create syscall table mapping compat syscall to events */
chan->compat_sc_table = kzalloc(sizeof(struct lttng_event *)
* ARRAY_SIZE(compat_sc_table), GFP_KERNEL);
if (!chan->compat_sc_table)
return -ENOMEM;
}
#endif
if (!chan->sc_unknown) {
const struct lttng_event_desc *desc =
&__event_desc___sys_unknown;
memset(&ev, 0, sizeof(ev));
strncpy(ev.name, desc->name, LTTNG_KERNEL_SYM_NAME_LEN);
ev.name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
ev.instrumentation = LTTNG_KERNEL_NOOP;
chan->sc_unknown = lttng_event_create(chan, &ev, filter,
desc);
WARN_ON_ONCE(!chan->sc_unknown);
if (IS_ERR(chan->sc_unknown)) {
return PTR_ERR(chan->sc_unknown);
}
}
if (!chan->sc_compat_unknown) {
const struct lttng_event_desc *desc =
&__event_desc___compat_sys_unknown;
memset(&ev, 0, sizeof(ev));
strncpy(ev.name, desc->name, LTTNG_KERNEL_SYM_NAME_LEN);
ev.name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
ev.instrumentation = LTTNG_KERNEL_NOOP;
chan->sc_compat_unknown = lttng_event_create(chan, &ev, filter,
desc);
WARN_ON_ONCE(!chan->sc_unknown);
if (IS_ERR(chan->sc_compat_unknown)) {
return PTR_ERR(chan->sc_compat_unknown);
}
}
if (!chan->sc_exit) {
const struct lttng_event_desc *desc =
&__event_desc___exit_syscall;
memset(&ev, 0, sizeof(ev));
strncpy(ev.name, desc->name, LTTNG_KERNEL_SYM_NAME_LEN);
ev.name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
ev.instrumentation = LTTNG_KERNEL_NOOP;
chan->sc_exit = lttng_event_create(chan, &ev, filter,
desc);
WARN_ON_ONCE(!chan->sc_exit);
if (IS_ERR(chan->sc_exit)) {
return PTR_ERR(chan->sc_exit);
}
}
ret = fill_table(sc_table, ARRAY_SIZE(sc_table),
chan->sc_table, chan, filter);
if (ret)
return ret;
#ifdef CONFIG_COMPAT
ret = fill_table(compat_sc_table, ARRAY_SIZE(compat_sc_table),
chan->compat_sc_table, chan, filter);
if (ret)
return ret;
#endif
ret = lttng_wrapper_tracepoint_probe_register("sys_enter",
(void *) syscall_entry_probe, chan);
if (ret)
return ret;
/*
* We change the name of sys_exit tracepoint due to namespace
* conflict with sys_exit syscall entry.
*/
ret = lttng_wrapper_tracepoint_probe_register("sys_exit",
(void *) __event_probe__exit_syscall,
chan->sc_exit);
if (ret) {
WARN_ON_ONCE(lttng_wrapper_tracepoint_probe_unregister("sys_enter",
(void *) syscall_entry_probe, chan));
}
return ret;
}
static
int lttng_abi_create_event(struct file *channel_file,
struct lttng_kernel_event *event_param)
{
struct lttng_channel *channel = channel_file->private_data;
int event_fd, ret;
struct file *event_file;
void *priv;
event_param->name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
switch (event_param->instrumentation) {
case LTTNG_KERNEL_KRETPROBE:
event_param->u.kretprobe.symbol_name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
break;
case LTTNG_KERNEL_KPROBE:
event_param->u.kprobe.symbol_name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
break;
case LTTNG_KERNEL_FUNCTION:
event_param->u.ftrace.symbol_name[LTTNG_KERNEL_SYM_NAME_LEN - 1] = '\0';
break;
default:
break;
}
event_fd = lttng_get_unused_fd();
if (event_fd < 0) {
ret = event_fd;
goto fd_error;
}
event_file = anon_inode_getfile("[lttng_event]",
<tng_event_fops,
NULL, O_RDWR);
if (IS_ERR(event_file)) {
ret = PTR_ERR(event_file);
goto file_error;
}
/* The event holds a reference on the channel */
if (atomic_long_add_unless(&channel_file->f_count,
1, INT_MAX) == INT_MAX) {
ret = -EOVERFLOW;
goto refcount_error;
}
if (event_param->instrumentation == LTTNG_KERNEL_TRACEPOINT
|| event_param->instrumentation == LTTNG_KERNEL_SYSCALL) {
struct lttng_enabler *enabler;
if (event_param->name[strlen(event_param->name) - 1] == '*') {
enabler = lttng_enabler_create(LTTNG_ENABLER_WILDCARD,
event_param, channel);
} else {
enabler = lttng_enabler_create(LTTNG_ENABLER_NAME,
event_param, channel);
}
priv = enabler;
} else {
struct lttng_event *event;
/*
* We tolerate no failure path after event creation. It
* will stay invariant for the rest of the session.
*/
event = lttng_event_create(channel, event_param,
NULL, NULL,
event_param->instrumentation);
WARN_ON_ONCE(!event);
if (IS_ERR(event)) {
ret = PTR_ERR(event);
goto event_error;
}
priv = event;
}
event_file->private_data = priv;
fd_install(event_fd, event_file);
return event_fd;
event_error:
atomic_long_dec(&channel_file->f_count);
refcount_error:
fput(event_file);
file_error:
put_unused_fd(event_fd);
fd_error:
return ret;
}
