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authorLinus Torvalds <torvalds@linux-foundation.org>2016-03-04 16:57:04 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2016-03-04 16:57:04 -0800
commit78baab7aa843ef01644195d341bee118cbe4bf19 (patch)
tree73502edec6885609de4bd359cc0fc1b33af7a333
parente3c2ef41f88e50c8557270868600d3132028af3b (diff)
parente57cbaf0eb006eaa207395f3bfd7ce52c1b5539c (diff)
downloadlinux-78baab7aa843ef01644195d341bee118cbe4bf19.tar.bz2
Merge tag 'trace-fixes-v4.5-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing fix from Steven Rostedt: "A feature was added in 4.3 that allowed users to filter trace points on a tasks "comm" field. But this prevented filtering on a comm field that is within a trace event (like sched_migrate_task). When trying to filter on when a program migrated, this change prevented the filtering of the sched_migrate_task. To fix this, the event fields are examined first, and then the extra fields like "comm" and "cpu" are examined. Also, instead of testing to assign the comm filter function based on the field's name, the generic comm field is given a new filter type (FILTER_COMM). When this field is used to filter the type is checked. The same is done for the cpu filter field. Two new special filter types are added: "COMM" and "CPU". This allows users to still filter the tasks comm for events that have "comm" as one of their fields, in cases that users would like to filter sched_migrate_task on the comm of the task that called the event, and not the comm of the task that is being migrated" * tag 'trace-fixes-v4.5-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: tracing: Do not have 'comm' filter override event 'comm' field
-rw-r--r--include/linux/trace_events.h2
-rw-r--r--kernel/trace/trace_events.c14
-rw-r--r--kernel/trace/trace_events_filter.c13
3 files changed, 17 insertions, 12 deletions
diff --git a/include/linux/trace_events.h b/include/linux/trace_events.h
index 429fdfc3baf5..925730bc9fc1 100644
--- a/include/linux/trace_events.h
+++ b/include/linux/trace_events.h
@@ -568,6 +568,8 @@ enum {
FILTER_DYN_STRING,
FILTER_PTR_STRING,
FILTER_TRACE_FN,
+ FILTER_COMM,
+ FILTER_CPU,
};
extern int trace_event_raw_init(struct trace_event_call *call);
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index ab09829d3b97..05ddc0820771 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -97,16 +97,16 @@ trace_find_event_field(struct trace_event_call *call, char *name)
struct ftrace_event_field *field;
struct list_head *head;
- field = __find_event_field(&ftrace_generic_fields, name);
+ head = trace_get_fields(call);
+ field = __find_event_field(head, name);
if (field)
return field;
- field = __find_event_field(&ftrace_common_fields, name);
+ field = __find_event_field(&ftrace_generic_fields, name);
if (field)
return field;
- head = trace_get_fields(call);
- return __find_event_field(head, name);
+ return __find_event_field(&ftrace_common_fields, name);
}
static int __trace_define_field(struct list_head *head, const char *type,
@@ -171,8 +171,10 @@ static int trace_define_generic_fields(void)
{
int ret;
- __generic_field(int, cpu, FILTER_OTHER);
- __generic_field(char *, comm, FILTER_PTR_STRING);
+ __generic_field(int, CPU, FILTER_CPU);
+ __generic_field(int, cpu, FILTER_CPU);
+ __generic_field(char *, COMM, FILTER_COMM);
+ __generic_field(char *, comm, FILTER_COMM);
return ret;
}
diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c
index f93a219b18da..6816302542b2 100644
--- a/kernel/trace/trace_events_filter.c
+++ b/kernel/trace/trace_events_filter.c
@@ -1043,13 +1043,14 @@ static int init_pred(struct filter_parse_state *ps,
return -EINVAL;
}
- if (is_string_field(field)) {
+ if (field->filter_type == FILTER_COMM) {
+ filter_build_regex(pred);
+ fn = filter_pred_comm;
+ pred->regex.field_len = TASK_COMM_LEN;
+ } else if (is_string_field(field)) {
filter_build_regex(pred);
- if (!strcmp(field->name, "comm")) {
- fn = filter_pred_comm;
- pred->regex.field_len = TASK_COMM_LEN;
- } else if (field->filter_type == FILTER_STATIC_STRING) {
+ if (field->filter_type == FILTER_STATIC_STRING) {
fn = filter_pred_string;
pred->regex.field_len = field->size;
} else if (field->filter_type == FILTER_DYN_STRING)
@@ -1072,7 +1073,7 @@ static int init_pred(struct filter_parse_state *ps,
}
pred->val = val;
- if (!strcmp(field->name, "cpu"))
+ if (field->filter_type == FILTER_CPU)
fn = filter_pred_cpu;
else
fn = select_comparison_fn(pred->op, field->size,