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Subject[PATCH] tools lib traceevent: Take care of return value of asprintf
Date
From: He Zhe <zhe.he@windriver.com>

According to the API, if memory allocation wasn't possible, or some other
error occurs, asprintf will return -1, and the contents of strp below are
undefined.

int asprintf(char **strp, const char *fmt, ...);

This patch takes care of return value of asprintf to make it less error
prone and prevent the following build warning.

ignoring return value of ‘asprintf’, declared with attribute warn_unused_result [-Wunused-result]

Signed-off-by: He Zhe <zhe.he@windriver.com>
---
tools/lib/traceevent/parse-filter.c | 42 +++++++++++++++++++++++++++++--------
1 file changed, 33 insertions(+), 9 deletions(-)

diff --git a/tools/lib/traceevent/parse-filter.c b/tools/lib/traceevent/parse-filter.c
index 20eed71..279b572 100644
--- a/tools/lib/traceevent/parse-filter.c
+++ b/tools/lib/traceevent/parse-filter.c
@@ -1912,6 +1912,7 @@ static char *op_to_str(struct tep_event_filter *filter, struct tep_filter_arg *a
int left_val = -1;
int right_val = -1;
int val;
+ int ret;

switch (arg->op.type) {
case TEP_FILTER_OP_AND:
@@ -1958,7 +1959,9 @@ static char *op_to_str(struct tep_event_filter *filter, struct tep_filter_arg *a
default:
break;
}
- asprintf(&str, val ? "TRUE" : "FALSE");
+ ret = asprintf(&str, val ? "TRUE" : "FALSE");
+ if (ret < 0)
+ str = NULL;
break;
}
}
@@ -1976,7 +1979,9 @@ static char *op_to_str(struct tep_event_filter *filter, struct tep_filter_arg *a
break;
}

- asprintf(&str, "(%s) %s (%s)", left, op, right);
+ ret = asprintf(&str, "(%s) %s (%s)", left, op, right);
+ if (ret < 0)
+ str = NULL;
break;

case TEP_FILTER_OP_NOT:
@@ -1992,10 +1997,14 @@ static char *op_to_str(struct tep_event_filter *filter, struct tep_filter_arg *a
right_val = 0;
if (right_val >= 0) {
/* just return the opposite */
- asprintf(&str, right_val ? "FALSE" : "TRUE");
+ ret = asprintf(&str, right_val ? "FALSE" : "TRUE");
+ if (ret < 0)
+ str = NULL;
break;
}
- asprintf(&str, "%s(%s)", op, right);
+ ret = asprintf(&str, "%s(%s)", op, right);
+ if (ret < 0)
+ str = NULL;
break;

default:
@@ -2010,8 +2019,11 @@ static char *op_to_str(struct tep_event_filter *filter, struct tep_filter_arg *a
static char *val_to_str(struct tep_event_filter *filter, struct tep_filter_arg *arg)
{
char *str = NULL;
+ int ret;

- asprintf(&str, "%lld", arg->value.val);
+ ret = asprintf(&str, "%lld", arg->value.val);
+ if (ret < 0)
+ str = NULL;

return str;
}
@@ -2027,6 +2039,7 @@ static char *exp_to_str(struct tep_event_filter *filter, struct tep_filter_arg *
char *rstr;
char *op;
char *str = NULL;
+ int ret;

lstr = arg_to_str(filter, arg->exp.left);
rstr = arg_to_str(filter, arg->exp.right);
@@ -2069,7 +2082,9 @@ static char *exp_to_str(struct tep_event_filter *filter, struct tep_filter_arg *
break;
}

- asprintf(&str, "%s %s %s", lstr, op, rstr);
+ ret = asprintf(&str, "%s %s %s", lstr, op, rstr);
+ if (ret < 0)
+ str = NULL;
out:
free(lstr);
free(rstr);
@@ -2083,6 +2098,7 @@ static char *num_to_str(struct tep_event_filter *filter, struct tep_filter_arg *
char *rstr;
char *str = NULL;
char *op = NULL;
+ int ret;

lstr = arg_to_str(filter, arg->num.left);
rstr = arg_to_str(filter, arg->num.right);
@@ -2113,7 +2129,9 @@ static char *num_to_str(struct tep_event_filter *filter, struct tep_filter_arg *
if (!op)
op = "<=";

- asprintf(&str, "%s %s %s", lstr, op, rstr);
+ ret = asprintf(&str, "%s %s %s", lstr, op, rstr);
+ if (ret < 0)
+ str = NULL;
break;

default:
@@ -2131,6 +2149,7 @@ static char *str_to_str(struct tep_event_filter *filter, struct tep_filter_arg *
{
char *str = NULL;
char *op = NULL;
+ int ret;

switch (arg->str.type) {
case TEP_FILTER_CMP_MATCH:
@@ -2148,8 +2167,10 @@ static char *str_to_str(struct tep_event_filter *filter, struct tep_filter_arg *
if (!op)
op = "!~";

- asprintf(&str, "%s %s \"%s\"",
+ ret = asprintf(&str, "%s %s \"%s\"",
arg->str.field->name, op, arg->str.val);
+ if (ret < 0)
+ str = NULL;
break;

default:
@@ -2162,10 +2183,13 @@ static char *str_to_str(struct tep_event_filter *filter, struct tep_filter_arg *
static char *arg_to_str(struct tep_event_filter *filter, struct tep_filter_arg *arg)
{
char *str = NULL;
+ int ret;

switch (arg->type) {
case TEP_FILTER_ARG_BOOLEAN:
- asprintf(&str, arg->boolean.value ? "TRUE" : "FALSE");
+ ret = asprintf(&str, arg->boolean.value ? "TRUE" : "FALSE");
+ if (ret < 0)
+ str = NULL;
return str;

case TEP_FILTER_ARG_OP:
--
2.7.4
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