Messages in this thread Patch in this message | | | From | <> | Subject | [PATCH v3] tools lib traceevent: Take care of return value of asprintf | Date | Thu, 20 Feb 2020 09:58:50 +0800 |
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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> --- v2: directly check the return value without saving to a variable v3: as asked, not remove those that already save the return value
tools/lib/traceevent/parse-filter.c | 29 +++++++++++++++++++---------- 1 file changed, 19 insertions(+), 10 deletions(-)
diff --git a/tools/lib/traceevent/parse-filter.c b/tools/lib/traceevent/parse-filter.c index 20eed71..c271aee 100644 --- a/tools/lib/traceevent/parse-filter.c +++ b/tools/lib/traceevent/parse-filter.c @@ -1958,7 +1958,8 @@ static char *op_to_str(struct tep_event_filter *filter, struct tep_filter_arg *a default: break; } - asprintf(&str, val ? "TRUE" : "FALSE"); + if (asprintf(&str, val ? "TRUE" : "FALSE") < 0) + str = NULL; break; } } @@ -1976,7 +1977,8 @@ static char *op_to_str(struct tep_event_filter *filter, struct tep_filter_arg *a break; } - asprintf(&str, "(%s) %s (%s)", left, op, right); + if (asprintf(&str, "(%s) %s (%s)", left, op, right) < 0) + str = NULL; break; case TEP_FILTER_OP_NOT: @@ -1992,10 +1994,12 @@ 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"); + if (asprintf(&str, right_val ? "FALSE" : "TRUE") < 0) + str = NULL; break; } - asprintf(&str, "%s(%s)", op, right); + if (asprintf(&str, "%s(%s)", op, right) < 0) + str = NULL; break; default: @@ -2011,7 +2015,8 @@ static char *val_to_str(struct tep_event_filter *filter, struct tep_filter_arg * { char *str = NULL; - asprintf(&str, "%lld", arg->value.val); + if (asprintf(&str, "%lld", arg->value.val) < 0) + str = NULL; return str; } @@ -2069,7 +2074,8 @@ static char *exp_to_str(struct tep_event_filter *filter, struct tep_filter_arg * break; } - asprintf(&str, "%s %s %s", lstr, op, rstr); + if (asprintf(&str, "%s %s %s", lstr, op, rstr) < 0) + str = NULL; out: free(lstr); free(rstr); @@ -2113,7 +2119,8 @@ 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); + if (asprintf(&str, "%s %s %s", lstr, op, rstr) < 0) + str = NULL; break; default: @@ -2148,8 +2155,9 @@ static char *str_to_str(struct tep_event_filter *filter, struct tep_filter_arg * if (!op) op = "!~"; - asprintf(&str, "%s %s \"%s\"", - arg->str.field->name, op, arg->str.val); + if (asprintf(&str, "%s %s \"%s\"", + arg->str.field->name, op, arg->str.val) < 0) + str = NULL; break; default: @@ -2165,7 +2173,8 @@ static char *arg_to_str(struct tep_event_filter *filter, struct tep_filter_arg * switch (arg->type) { case TEP_FILTER_ARG_BOOLEAN: - asprintf(&str, arg->boolean.value ? "TRUE" : "FALSE"); + if (asprintf(&str, arg->boolean.value ? "TRUE" : "FALSE") < 0) + str = NULL; return str; case TEP_FILTER_ARG_OP: -- 2.7.4
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