From: Tom Zanussi <[email protected]>
[ Upstream commit 10819e25799aae564005b6049a45e9808797b3bb ]
Since synthetic event array types are derived from the field name,
there may be a semicolon at the end of the type which should be
stripped off.
If there are more characters following that, normal type string
checking will result in an invalid type.
Without this patch, you can end up with an invalid field type string
that gets displayed in both the synthetic event description and the
event format:
Before:
# echo 'myevent char str[16]; int v' >> synthetic_events
# cat synthetic_events
myevent char[16]; str; int v
name: myevent
ID: 1936
format:
field:unsigned short common_type; offset:0; size:2;
signed:0;
field:unsigned char common_flags; offset:2; size:1;
signed:0;
field:unsigned char common_preempt_count; offset:3; size:1;
signed:0;
field:int common_pid; offset:4; size:4; signed:1;
field:char str[16];; offset:8; size:16; signed:1;
field:int v; offset:40; size:4; signed:1;
print fmt: "str=%s, v=%d", REC->str, REC->v
After:
# echo 'myevent char str[16]; int v' >> synthetic_events
# cat synthetic_events
myevent char[16] str; int v
# cat events/synthetic/myevent/format
name: myevent
ID: 1936
format:
field:unsigned short common_type; offset:0; size:2;
signed:0;
field:unsigned char common_flags; offset:2; size:1;
signed:0;
field:unsigned char common_preempt_count; offset:3; size:1;
signed:0;
field:int common_pid; offset:4; size:4; signed:1;
field:char str[16]; offset:8; size:16; signed:1;
field:int v; offset:40; size:4; signed:1;
print fmt: "str=%s, v=%d", REC->str, REC->v
Link:
https://lkml.kernel.org/r/6587663b56c2d45ab9d8c8472a2110713cdec97d.1602598160.git.zanu...@kernel.org
[ <[email protected]>: wrote parse_synth_field() snippet. ]
Fixes: 4b147936fa50 (tracing: Add support for 'synthetic' events)
Reported-by: Masami Hiramatsu <[email protected]>
Tested-by: Masami Hiramatsu <[email protected]>
Signed-off-by: Tom Zanussi <[email protected]>
Signed-off-by: Steven Rostedt (VMware) <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
---
kernel/trace/trace_events_synth.c | 12 +++++++++---
1 file changed, 9 insertions(+), 3 deletions(-)
diff --git a/kernel/trace/trace_events_synth.c
b/kernel/trace/trace_events_synth.c
index 46a96686e93c6..c8892156db341 100644
--- a/kernel/trace/trace_events_synth.c
+++ b/kernel/trace/trace_events_synth.c
@@ -132,7 +132,7 @@ static int synth_field_string_size(char *type)
start += sizeof("char[") - 1;
end = strchr(type, ']');
- if (!end || end < start)
+ if (!end || end < start || type + strlen(type) > end + 1)
return -EINVAL;
len = end - start;
@@ -502,8 +502,14 @@ static struct synth_field *parse_synth_field(int argc,
const char **argv,
if (field_type[0] == ';')
field_type++;
len = strlen(field_type) + 1;
- if (array)
- len += strlen(array);
+
+ if (array) {
+ int l = strlen(array);
+
+ if (l && array[l - 1] == ';')
+ l--;
+ len += l;
+ }
if (prefix)
len += strlen(prefix);
--
2.25.1
