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Subject[PATCH 01/21] tools lib traceevent: Handle dynamic array's element size properly
Date
From: Jiri Olsa <jolsa@redhat.com>

Fixing the dynamic array format field parsing.

Currently the event_read_fields function could segfault while parsing
dynamic array other than string type. The reason is the event->pevent
does not need to be set and gets dereferenced unconditionaly.

Also adding proper initialization of field->elementsize based on the
parsed dynamic type.

Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/1359060403-32422-1-git-send-email-jolsa@redhat.com
[ committer note: Made a char pointer parameter const, as requested by Steven ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
tools/lib/traceevent/event-parse.c | 39 ++++++++++++++++++++++++++++++++++++--
1 file changed, 37 insertions(+), 2 deletions(-)

diff --git a/tools/lib/traceevent/event-parse.c b/tools/lib/traceevent/event-parse.c
index bb8b3db..82b0606 100644
--- a/tools/lib/traceevent/event-parse.c
+++ b/tools/lib/traceevent/event-parse.c
@@ -1223,6 +1223,34 @@ static int field_is_long(struct format_field *field)
return 0;
}

+static unsigned int type_size(const char *name)
+{
+ /* This covers all FIELD_IS_STRING types. */
+ static struct {
+ const char *type;
+ unsigned int size;
+ } table[] = {
+ { "u8", 1 },
+ { "u16", 2 },
+ { "u32", 4 },
+ { "u64", 8 },
+ { "s8", 1 },
+ { "s16", 2 },
+ { "s32", 4 },
+ { "s64", 8 },
+ { "char", 1 },
+ { },
+ };
+ int i;
+
+ for (i = 0; table[i].type; i++) {
+ if (!strcmp(table[i].type, name))
+ return table[i].size;
+ }
+
+ return 0;
+}
+
static int event_read_fields(struct event_format *event, struct format_field **fields)
{
struct format_field *field = NULL;
@@ -1232,6 +1260,8 @@ static int event_read_fields(struct event_format *event, struct format_field **f
int count = 0;

do {
+ unsigned int size_dynamic = 0;
+
type = read_token(&token);
if (type == EVENT_NEWLINE) {
free_token(token);
@@ -1390,6 +1420,7 @@ static int event_read_fields(struct event_format *event, struct format_field **f
field->type = new_type;
strcat(field->type, " ");
strcat(field->type, field->name);
+ size_dynamic = type_size(field->name);
free_token(field->name);
strcat(field->type, brackets);
field->name = token;
@@ -1478,10 +1509,14 @@ static int event_read_fields(struct event_format *event, struct format_field **f
if (field->flags & FIELD_IS_ARRAY) {
if (field->arraylen)
field->elementsize = field->size / field->arraylen;
+ else if (field->flags & FIELD_IS_DYNAMIC)
+ field->elementsize = size_dynamic;
else if (field->flags & FIELD_IS_STRING)
field->elementsize = 1;
- else
- field->elementsize = event->pevent->long_size;
+ else if (field->flags & FIELD_IS_LONG)
+ field->elementsize = event->pevent ?
+ event->pevent->long_size :
+ sizeof(long);
} else
field->elementsize = field->size;

--
1.8.1.1.361.gec3ae6e


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