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Subject[PATCH 1/3] tracing/filters: allow user-input to be integer-like string
Suppose we would like to trace all tasks named '123', but this
will fail:
# echo 'parent_comm == 123' > events/sched/sched_process_fork/filter
bash: echo: write error: Invalid argument

Don't guess the type of the filter pred in filter_parse(), but instead
we check it in filter_add_pred().

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
---
kernel/trace/trace_events_filter.c | 26 +++++++++++++-------------
1 files changed, 13 insertions(+), 13 deletions(-)

diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c
index 9f8ecca..a63f965 100644
--- a/kernel/trace/trace_events_filter.c
+++ b/kernel/trace/trace_events_filter.c
@@ -229,6 +229,7 @@ static int is_string_field(const char *type)
int filter_add_pred(struct ftrace_event_call *call, struct filter_pred *pred)
{
struct ftrace_event_field *field;
+ unsigned long long val;

field = find_event_field(call, pred->field_name);
if (!field)
@@ -237,14 +238,14 @@ int filter_add_pred(struct ftrace_event_call *call, struct filter_pred *pred)
pred->offset = field->offset;

if (is_string_field(field->type)) {
- if (!pred->str_val)
- return -EINVAL;
pred->fn = filter_pred_string;
pred->str_len = field->size;
return __filter_add_pred(call, pred);
} else {
- if (pred->str_val)
+ if (strict_strtoull(pred->str_val, 0, &val))
return -EINVAL;
+ pred->val = val;
+ kfree(pred->str_val);
}

switch (field->size) {
@@ -351,12 +352,16 @@ oom:
return -ENOMEM;
}

+/*
+ * The filter format can be
+ * - 0, which means remove all filter preds
+ * - [||/&&] <field> ==/!= <val>
+ */
int filter_parse(char **pbuf, struct filter_pred *pred)
{
- char *tmp, *tok, *val_str = NULL;
+ char *tok, *val_str = NULL;
int tok_n = 0;

- /* field ==/!= number, or/and field ==/!= number, number */
while ((tok = strsep(pbuf, " \n"))) {
if (tok_n == 0) {
if (!strcmp(tok, "0")) {
@@ -419,15 +424,10 @@ int filter_parse(char **pbuf, struct filter_pred *pred)
if (!pred->field_name)
return -ENOMEM;

- pred->val = simple_strtoull(val_str, &tmp, 0);
- if (tmp == val_str) {
- pred->str_val = kstrdup(val_str, GFP_KERNEL);
- if (!pred->str_val)
- return -ENOMEM;
- } else if (*tmp != '\0')
- return -EINVAL;
+ pred->str_val = kstrdup(val_str, GFP_KERNEL);
+ if (!pred->str_val)
+ return -ENOMEM;

return 0;
}

-
--
1.5.4.rc3


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