* @filtered_pids: The list of pids to check
* @search_pid: The PID to find in @filtered_pids
*
- * Returns true if @search_pid is fonud in @filtered_pids, and false otherwis.
+ * Returns true if @search_pid is found in @filtered_pids, and false otherwise.
*/
bool
trace_find_filtered_pid(struct trace_pid_list *filtered_pids, pid_t search_pid)
struct task_struct *task)
{
/*
- * If filterd_no_pids is not empty, and the task's pid is listed
+ * If filtered_no_pids is not empty, and the task's pid is listed
* in filtered_no_pids, then return true.
* Otherwise, if filtered_pids is empty, that means we can
* trace all tasks. If it has content, then only trace pids
(*pos)++;
- /* pid already is +1 of the actual prevous bit */
+ /* pid already is +1 of the actual previous bit */
pid = find_next_bit(pid_list->pids, pid_list->pid_max, pid);
/* Return pid + 1 to allow zero to be represented */
* The content of events may become garbage if we allow other process consumes
* these events concurrently:
* A) the page of the consumed events may become a normal page
- * (not reader page) in ring buffer, and this page will be rewrited
+ * (not reader page) in ring buffer, and this page will be rewritten
* by events producer.
* B) The page of the consumed events may become a page for splice_read,
* and this page will be returned to system.
#undef C
#define C(a, b) b
-/* These must match the bit postions in trace_iterator_flags */
+/* These must match the bit positions in trace_iterator_flags */
static const char *trace_options[] = {
TRACE_FLAGS
NULL
unsigned int trace_ctx)
{
struct ring_buffer_event *entry;
+ struct trace_array *tr = trace_file->tr;
int val;
- *current_rb = trace_file->tr->array_buffer.buffer;
+ *current_rb = tr->array_buffer.buffer;
- if (!ring_buffer_time_stamp_abs(*current_rb) && (trace_file->flags &
- (EVENT_FILE_FL_SOFT_DISABLED | EVENT_FILE_FL_FILTERED)) &&
+ if (!tr->no_filter_buffering_ref &&
+ (trace_file->flags & (EVENT_FILE_FL_SOFT_DISABLED | EVENT_FILE_FL_FILTERED)) &&
(entry = this_cpu_read(trace_buffered_event))) {
/* Try to use the per cpu buffer first */
val = this_cpu_inc_return(trace_buffered_event_cnt);
size = nr_entries * sizeof(unsigned long);
event = __trace_buffer_lock_reserve(buffer, TRACE_STACK,
- sizeof(*entry) + size, trace_ctx);
+ (sizeof(*entry) - sizeof(entry->caller)) + size,
+ trace_ctx);
if (!event)
goto out;
entry = ring_buffer_event_data(event);
* buffer (use trace_printk() for that), as writing into the top level
* buffer should only have events that can be individually disabled.
* trace_printk() is only used for debugging a kernel, and should not
- * be ever encorporated in normal use.
+ * be ever incorporated in normal use.
*
* trace_array_printk() can be used, as it will not add noise to the
* top level tracing buffer.
return tmp;
}
+/* Returns true if the string is safe to dereference from an event */
+static bool trace_safe_str(struct trace_iterator *iter, const char *str)
+{
+ unsigned long addr = (unsigned long)str;
+ struct trace_event *trace_event;
+ struct trace_event_call *event;
+
+ /* OK if part of the event data */
+ if ((addr >= (unsigned long)iter->ent) &&
+ (addr < (unsigned long)iter->ent + iter->ent_size))
+ return true;
+
+ /* OK if part of the temp seq buffer */
+ if ((addr >= (unsigned long)iter->tmp_seq.buffer) &&
+ (addr < (unsigned long)iter->tmp_seq.buffer + PAGE_SIZE))
+ return true;
+
+ /* Core rodata can not be freed */
+ if (is_kernel_rodata(addr))
+ return true;
+
+ if (trace_is_tracepoint_string(str))
+ return true;
+
+ /*
+ * Now this could be a module event, referencing core module
+ * data, which is OK.
+ */
+ if (!iter->ent)
+ return false;
+
+ trace_event = ftrace_find_event(iter->ent->type);
+ if (!trace_event)
+ return false;
+
+ event = container_of(trace_event, struct trace_event_call, event);
+ if (!event->mod)
+ return false;
+
+ /* Would rather have rodata, but this will suffice */
+ if (within_module_core(addr, event->mod))
+ return true;
+
+ return false;
+}
+
+static const char *show_buffer(struct trace_seq *s)
+{
+ struct seq_buf *seq = &s->seq;
+
+ seq_buf_terminate(seq);
+
+ return seq->buffer;
+}
+
+static DEFINE_STATIC_KEY_FALSE(trace_no_verify);
+
+static int test_can_verify_check(const char *fmt, ...)
+{
+ char buf[16];
+ va_list ap;
+ int ret;
+
+ /*
+ * The verifier is dependent on vsnprintf() modifies the va_list
+ * passed to it, where it is sent as a reference. Some architectures
+ * (like x86_32) passes it by value, which means that vsnprintf()
+ * does not modify the va_list passed to it, and the verifier
+ * would then need to be able to understand all the values that
+ * vsnprintf can use. If it is passed by value, then the verifier
+ * is disabled.
+ */
+ va_start(ap, fmt);
+ vsnprintf(buf, 16, "%d", ap);
+ ret = va_arg(ap, int);
+ va_end(ap);
+
+ return ret;
+}
+
+static void test_can_verify(void)
+{
+ if (!test_can_verify_check("%d %d", 0, 1)) {
+ pr_info("trace event string verifier disabled\n");
+ static_branch_inc(&trace_no_verify);
+ }
+}
+
+/**
+ * trace_check_vprintf - Check dereferenced strings while writing to the seq buffer
+ * @iter: The iterator that holds the seq buffer and the event being printed
+ * @fmt: The format used to print the event
+ * @ap: The va_list holding the data to print from @fmt.
+ *
+ * This writes the data into the @iter->seq buffer using the data from
+ * @fmt and @ap. If the format has a %s, then the source of the string
+ * is examined to make sure it is safe to print, otherwise it will
+ * warn and print "[UNSAFE MEMORY]" in place of the dereferenced string
+ * pointer.
+ */
+void trace_check_vprintf(struct trace_iterator *iter, const char *fmt,
+ va_list ap)
+{
+ const char *p = fmt;
+ const char *str;
+ int i, j;
+
+ if (WARN_ON_ONCE(!fmt))
+ return;
+
+ if (static_branch_unlikely(&trace_no_verify))
+ goto print;
+
+ /* Don't bother checking when doing a ftrace_dump() */
+ if (iter->fmt == static_fmt_buf)
+ goto print;
+
+ while (*p) {
+ j = 0;
+
+ /* We only care about %s and variants */
+ for (i = 0; p[i]; i++) {
+ if (i + 1 >= iter->fmt_size) {
+ /*
+ * If we can't expand the copy buffer,
+ * just print it.
+ */
+ if (!trace_iter_expand_format(iter))
+ goto print;
+ }
+
+ if (p[i] == '\\' && p[i+1]) {
+ i++;
+ continue;
+ }
+ if (p[i] == '%') {
+ /* Need to test cases like %08.*s */
+ for (j = 1; p[i+j]; j++) {
+ if (isdigit(p[i+j]) ||
+ p[i+j] == '*' ||
+ p[i+j] == '.')
+ continue;
+ break;
+ }
+ if (p[i+j] == 's')
+ break;
+ }
+ j = 0;
+ }
+ /* If no %s found then just print normally */
+ if (!p[i])
+ break;
+
+ /* Copy up to the %s, and print that */
+ strncpy(iter->fmt, p, i);
+ iter->fmt[i] = '\0';
+ trace_seq_vprintf(&iter->seq, iter->fmt, ap);
+
+ /* The ap now points to the string data of the %s */
+ str = va_arg(ap, const char *);
+
+ /*
+ * If you hit this warning, it is likely that the
+ * trace event in question used %s on a string that
+ * was saved at the time of the event, but may not be
+ * around when the trace is read. Use __string(),
+ * __assign_str() and __get_str() helpers in the TRACE_EVENT()
+ * instead. See samples/trace_events/trace-events-sample.h
+ * for reference.
+ */
+ if (WARN_ONCE(!trace_safe_str(iter, str),
+ "fmt: '%s' current_buffer: '%s'",
+ fmt, show_buffer(&iter->seq))) {
+ int ret;
+
+ /* Try to safely read the string */
+ ret = strncpy_from_kernel_nofault(iter->fmt, str,
+ iter->fmt_size);
+ if (ret < 0)
+ trace_seq_printf(&iter->seq, "(0x%px)", str);
+ else
+ trace_seq_printf(&iter->seq, "(0x%px:%s)",
+ str, iter->fmt);
+ str = "[UNSAFE-MEMORY]";
+ strcpy(iter->fmt, "%s");
+ } else {
+ strncpy(iter->fmt, p + i, j + 1);
+ iter->fmt[j+1] = '\0';
+ }
+ trace_seq_printf(&iter->seq, iter->fmt, str);
+
+ p += i + j + 1;
+ }
+ print:
+ if (*p)
+ trace_seq_vprintf(&iter->seq, p, ap);
+}
+
const char *trace_event_format(struct trace_iterator *iter, const char *fmt)
{
const char *p, *new_fmt;
if (tr->trace_marker_file && !list_empty(&tr->trace_marker_file->triggers)) {
/* do not add \n before testing triggers, but add \0 */
entry->buf[cnt] = '\0';
- tt = event_triggers_call(tr->trace_marker_file, entry, event);
+ tt = event_triggers_call(tr->trace_marker_file, buffer, entry, event);
}
if (entry->buf[cnt - 1] != '\n') {
return ret;
}
-int tracing_set_time_stamp_abs(struct trace_array *tr, bool abs)
+u64 tracing_event_time_stamp(struct trace_buffer *buffer, struct ring_buffer_event *rbe)
+{
+ if (rbe == this_cpu_read(trace_buffered_event))
+ return ring_buffer_time_stamp(buffer, smp_processor_id());
+
+ return ring_buffer_event_time_stamp(buffer, rbe);
+}
+
+/*
+ * Set or disable using the per CPU trace_buffer_event when possible.
+ */
+int tracing_set_filter_buffering(struct trace_array *tr, bool set)
{
int ret = 0;
mutex_lock(&trace_types_lock);
- if (abs && tr->time_stamp_abs_ref++)
+ if (set && tr->no_filter_buffering_ref++)
goto out;
- if (!abs) {
- if (WARN_ON_ONCE(!tr->time_stamp_abs_ref)) {
+ if (!set) {
+ if (WARN_ON_ONCE(!tr->no_filter_buffering_ref)) {
ret = -EINVAL;
goto out;
}
- if (--tr->time_stamp_abs_ref)
- goto out;
+ --tr->no_filter_buffering_ref;
}
-
- ring_buffer_set_time_stamp_abs(tr->array_buffer.buffer, abs);
-
-#ifdef CONFIG_TRACER_MAX_TRACE
- if (tr->max_buffer.buffer)
- ring_buffer_set_time_stamp_abs(tr->max_buffer.buffer, abs);
-#endif
out:
mutex_unlock(&trace_types_lock);
* @cmd: The tracing command that caused the error
* @str: The string to position the caret at within @cmd
*
- * Finds the position of the first occurence of @str within @cmd. The
+ * Finds the position of the first occurrence of @str within @cmd. The
* return value can be passed to tracing_log_err() for caret placement
* within @cmd.
*
- * Returns the index within @cmd of the first occurence of @str or 0
+ * Returns the index within @cmd of the first occurrence of @str or 0
* if @str was not found.
*/
unsigned int err_pos(char *cmd, const char *str)
* As there may still be users that expect the tracing
* files to exist in debugfs/tracing, we must automount
* the tracefs file system there, so older tools still
- * work with the newer kerenl.
+ * work with the newer kernel.
*/
tr->dir = debugfs_create_automount("tracing", NULL,
trace_automount, NULL);
register_snapshot_cmd();
+ test_can_verify();
+
return 0;
out_free_savedcmd:
projects / linux-2.6-microblaze.git / blobdiff