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Diffstat (limited to 'kernel/trace/trace.c')
-rw-r--r--kernel/trace/trace.c28
1 files changed, 20 insertions, 8 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index b4f348b4653f..2b64b3ec67d9 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -3697,8 +3697,8 @@ static void test_can_verify(void)
void trace_check_vprintf(struct trace_iterator *iter, const char *fmt,
va_list ap)
{
- long text_delta = iter->tr->text_delta;
- long data_delta = iter->tr->data_delta;
+ long text_delta = 0;
+ long data_delta = 0;
const char *p = fmt;
const char *str;
bool good;
@@ -3710,6 +3710,17 @@ void trace_check_vprintf(struct trace_iterator *iter, const char *fmt,
if (static_branch_unlikely(&trace_no_verify))
goto print;
+ /*
+ * When the kernel is booted with the tp_printk command line
+ * parameter, trace events go directly through to printk().
+ * It also is checked by this function, but it does not
+ * have an associated trace_array (tr) for it.
+ */
+ if (iter->tr) {
+ text_delta = iter->tr->text_delta;
+ data_delta = iter->tr->data_delta;
+ }
+
/* Don't bother checking when doing a ftrace_dump() */
if (iter->fmt == static_fmt_buf)
goto print;
@@ -5490,6 +5501,10 @@ static const struct file_operations tracing_iter_fops = {
static const char readme_msg[] =
"tracing mini-HOWTO:\n\n"
+ "By default tracefs removes all OTH file permission bits.\n"
+ "When mounting tracefs an optional group id can be specified\n"
+ "which adds the group to every directory and file in tracefs:\n\n"
+ "\t e.g. mount -t tracefs [-o [gid=<gid>]] nodev /sys/kernel/tracing\n\n"
"# echo 0 > tracing_on : quick way to disable tracing\n"
"# echo 1 > tracing_on : quick way to re-enable tracing\n\n"
" Important files:\n"
@@ -7557,7 +7572,6 @@ static const struct file_operations tracing_pipe_fops = {
.read = tracing_read_pipe,
.splice_read = tracing_splice_read_pipe,
.release = tracing_release_pipe,
- .llseek = no_llseek,
};
static const struct file_operations tracing_entries_fops = {
@@ -7636,7 +7650,6 @@ static const struct file_operations snapshot_raw_fops = {
.read = tracing_buffers_read,
.release = tracing_buffers_release,
.splice_read = tracing_buffers_splice_read,
- .llseek = no_llseek,
};
#endif /* CONFIG_TRACER_SNAPSHOT */
@@ -8466,7 +8479,6 @@ static const struct file_operations tracing_buffers_fops = {
.flush = tracing_buffers_flush,
.splice_read = tracing_buffers_splice_read,
.unlocked_ioctl = tracing_buffers_ioctl,
- .llseek = no_llseek,
.mmap = tracing_buffers_mmap,
};
@@ -10613,10 +10625,10 @@ __init static void enable_instances(void)
* cannot be deleted by user space, so keep the reference
* to it.
*/
- if (start)
+ if (start) {
tr->flags |= TRACE_ARRAY_FL_BOOT;
- else
- trace_array_put(tr);
+ tr->ref++;
+ }
while ((tok = strsep(&curr_str, ","))) {
early_enable_events(tr, tok, true);