@@ -819,13 +819,15 @@ static void print_array(struct trace_iterator *iter, void *pos,
len = *(int *)pos >> 16;
if (field)
- offset += field->offset;
+ offset += field->offset + sizeof(int);
- if (offset + len >= iter->ent_size) {
+ if (offset + len > iter->ent_size) {
trace_seq_puts(&iter->seq, "<OVERFLOW>");
return;
}
+ pos = (void *)iter->ent + offset;
+
for (i = 0; i < len; i++, pos++) {
if (i)
trace_seq_putc(&iter->seq, ',');
@@ -861,9 +863,9 @@ static void print_fields(struct trace_iterator *iter, struct trace_event_call *c
len = *(int *)pos >> 16;
if (field->filter_type == FILTER_RDYN_STRING)
- offset += field->offset;
+ offset += field->offset + sizeof(int);
- if (offset + len >= iter->ent_size) {
+ if (offset + len > iter->ent_size) {
trace_seq_puts(&iter->seq, "<OVERFLOW>");
break;
}
Both print_fields() and print_array() do not handle if dynamic data ends at the last byte of the payload for both __dyn_loc and __rel_loc field types. For __rel_loc, the offset was off by 4 bytes, leading to incorrect strings and data being printed out. In print_array() the buffer pos was missed from being advanced, which results in the first payload byte being used as the offset base instead of the field offset. Advance __rel_loc offset by 4 to ensure correct offset and advance pos to the field offset to ensure correct data is displayed when printing arrays. Change >= to > when checking if data is in-bounds, since it's valid for dynamic data to include the last byte of the payload. Example outputs for event 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:__rel_loc char text[]; offset:8; size:4; signed:1; Output before: tp_rel_loc: text=<OVERFLOW> Output after: tp_rel_loc: text=Test Fixes: 80a76994b2d8 ("tracing: Add "fields" option to show raw trace event fields") Reported-by: Doug Cook <dcook@linux.microsoft.com> Signed-off-by: Beau Belgrave <beaub@linux.microsoft.com> --- kernel/trace/trace_output.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-)