From: "Steven Rostedt (Google)" rostedt@goodmis.org
[ Upstream commit b3bc8547d3be60898818885f5bf22d0a62e2eb48 ]
The macro TRACE_DEFINE_ENUM is used to convert enums in the kernel to their actual value when they are exported to user space via the trace event format file.
Currently only the enums in the "print fmt" (TP_printk in the TRACE_EVENT macro) have the enums converted. But the enums can be used to denote array size:
field:unsigned int fc_ineligible_rc[EXT4_FC_REASON_MAX]; offset:12; size:36; signed:0;
The EXT4_FC_REASON_MAX has no meaning to userspace but it needs to know that information to know how to parse the array.
Have the array indexes also be parsed as well.
Link: https://lore.kernel.org/all/cover.1646922487.git.riteshh@linux.ibm.com/
Reported-by: Ritesh Harjani riteshh@linux.ibm.com Tested-by: Ritesh Harjani riteshh@linux.ibm.com Signed-off-by: Steven Rostedt (Google) rostedt@goodmis.org Signed-off-by: Sasha Levin sashal@kernel.org --- kernel/trace/trace_events.c | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+)
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index 4acc77e049e5..c1363f9d8d48 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -2202,6 +2202,33 @@ static void update_event_printk(struct trace_event_call *call, } }
+static void update_event_fields(struct trace_event_call *call, + struct trace_eval_map *map) +{ + struct ftrace_event_field *field; + struct list_head *head; + char *ptr; + int len = strlen(map->eval_string); + + head = trace_get_fields(call); + list_for_each_entry(field, head, link) { + ptr = strchr(field->type, '['); + if (!ptr) + continue; + ptr++; + + if (!isalpha(*ptr) && *ptr != '_') + continue; + + if (strncmp(map->eval_string, ptr, len) != 0) + continue; + + ptr = eval_replace(ptr, map, len); + /* enum/sizeof string smaller than value */ + WARN_ON_ONCE(!ptr); + } +} + void trace_event_eval_update(struct trace_eval_map **map, int len) { struct trace_event_call *call, *p; @@ -2237,6 +2264,7 @@ void trace_event_eval_update(struct trace_eval_map **map, int len) first = false; } update_event_printk(call, map[i]); + update_event_fields(call, map[i]); } } }