From: Tom Zanussi zanussi@kernel.org
[ 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.160259816...
[ rostedt@goodmis.org: wrote parse_synth_field() snippet. ] Fixes: 4b147936fa50 (tracing: Add support for 'synthetic' events) Reported-by: Masami Hiramatsu mhiramat@kernel.org Tested-by: Masami Hiramatsu mhiramat@kernel.org Signed-off-by: Tom Zanussi zanussi@kernel.org Signed-off-by: Steven Rostedt (VMware) rostedt@goodmis.org Signed-off-by: Sasha Levin sashal@kernel.org --- 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);