trace-cmd: Use file long size if no header page is found

Use the long size of the trace.dat file if no header page is
found, instead of using the long size of the host that is
running the report. It makes more sense to use the long size
that the record was running on than to read the host. This
way it at least breaks on all boxes and not just some.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

3 files changed, 9 insertions, 6 deletions

diff --git a/parse-events.c b/parse-events.c
index 30d3ea0..0600973 100644
--- a/parse-events.c
+++ b/parse-events.c
@@ -3536,13 +3536,15 @@ static void parse_header_field(const char *field,
  * @pevent: the handle to the pevent
  * @buf: the buffer storing the header page format string
  * @size: the size of @buf
+ * @long_size: the long size to use if there is no header
  *
  * This parses the header page format for information on the
  * ring buffer used. The @buf should be copied from
  *
  * /sys/kernel/debug/tracing/events/header_page
  */
-int pevent_parse_header_page(struct pevent *pevent, char *buf, unsigned long size)
+int pevent_parse_header_page(struct pevent *pevent, char *buf, unsigned long size,
+                             int long_size)
 {
         if (!size) {
                 /*
@@ -3550,10 +3552,10 @@ int pevent_parse_header_page(struct pevent *pevent, char *buf, unsigned long siz
                  * Sorry but we just use what we find here in user space.
                  */
                 pevent->header_page_ts_size = sizeof(long long);
-                pevent->header_page_size_size = sizeof(long);
-                pevent->header_page_data_offset = sizeof(long long) + sizeof(long);
+                pevent->header_page_size_size = long_size;
+                pevent->header_page_data_offset = sizeof(long long) + long_size;
                 pevent->old_format = 1;
-                return 0;
+                return -1;
         }
         init_input_buf(buf, size);
 
diff --git a/parse-events.h b/parse-events.h
index 00bdc44..92f174e 100644
--- a/parse-events.h
+++ b/parse-events.h
@@ -352,7 +352,8 @@ int pevent_pid_is_registered(struct pevent *pevent, int pid);
 void pevent_print_event(struct pevent *pevent, struct trace_seq *s,
                         struct record *record);
 
-int pevent_parse_header_page(struct pevent *pevent, char *buf, unsigned long size);
+int pevent_parse_header_page(struct pevent *pevent, char *buf, unsigned long size,
+                             int long_size);
 
 int pevent_parse_event(struct pevent *pevent, char *buf, unsigned long size, char *sys);
 
diff --git a/trace-input.c b/trace-input.c
index d00d8c9..c55e94f 100644
--- a/trace-input.c
+++ b/trace-input.c
@@ -200,7 +200,7 @@ static int read_header_files(struct tracecmd_input *handle)
         if (do_read_check(handle, header, size))
                 goto failed_read;
 
-        pevent_parse_header_page(pevent, header, size);
+        pevent_parse_header_page(pevent, header, size, handle->long_size);
         free(header);
 
         /*