On Sat, 22 Dec 2018 11:20:09 -0500
Steven Rostedt <rost...@goodmis.org> wrote:
> From: "Steven Rostedt (VMware)" <rost...@goodmis.org>
>
> The tracing histogram code contains a lot of instances of the construct:
>
> strncmp(str, "const", sizeof("const") - 1)
>
> This can be prone to bugs due to typos or bad cut and paste. Use the
> str_has_prefix() helper macro instead that removes the need for having two
> copies of the constant string.
>
> Cc: Tom Zanussi <zanu...@linux.intel.com>
I have no idea why I copied your intel email. The linux.intel.com
appears to be no longer active. I'm going to rebase to fix this email
address.
-- Steve
> Signed-off-by: Steven Rostedt (VMware) <rost...@goodmis.org>
> ---
> kernel/trace/trace_events_hist.c | 28 ++++++++++++++--------------
> 1 file changed, 14 insertions(+), 14 deletions(-)
>
> diff --git a/kernel/trace/trace_events_hist.c
> b/kernel/trace/trace_events_hist.c
> index c5448c103770..9d590138f870 100644
> --- a/kernel/trace/trace_events_hist.c
> +++ b/kernel/trace/trace_events_hist.c
> @@ -1881,8 +1881,8 @@ static int parse_action(char *str, struct
> hist_trigger_attrs *attrs)
> if (attrs->n_actions >= HIST_ACTIONS_MAX)
> return ret;
>
> - if ((strncmp(str, "onmatch(", sizeof("onmatch(") - 1) == 0) ||
> - (strncmp(str, "onmax(", sizeof("onmax(") - 1) == 0)) {
> + if ((str_has_prefix(str, "onmatch(")) ||
> + (str_has_prefix(str, "onmax("))) {
> attrs->action_str[attrs->n_actions] = kstrdup(str, GFP_KERNEL);
> if (!attrs->action_str[attrs->n_actions]) {
> ret = -ENOMEM;
> @@ -1899,34 +1899,34 @@ static int parse_assignment(char *str, struct
> hist_trigger_attrs *attrs)
> {
> int ret = 0;
>
> - if ((strncmp(str, "key=", sizeof("key=") - 1) == 0) ||
> - (strncmp(str, "keys=", sizeof("keys=") - 1) == 0)) {
> + if ((str_has_prefix(str, "key=")) ||
> + (str_has_prefix(str, "keys="))) {
> attrs->keys_str = kstrdup(str, GFP_KERNEL);
> if (!attrs->keys_str) {
> ret = -ENOMEM;
> goto out;
> }
> - } else if ((strncmp(str, "val=", sizeof("val=") - 1) == 0) ||
> - (strncmp(str, "vals=", sizeof("vals=") - 1) == 0) ||
> - (strncmp(str, "values=", sizeof("values=") - 1) == 0)) {
> + } else if ((str_has_prefix(str, "val=")) ||
> + (str_has_prefix(str, "vals=")) ||
> + (str_has_prefix(str, "values="))) {
> attrs->vals_str = kstrdup(str, GFP_KERNEL);
> if (!attrs->vals_str) {
> ret = -ENOMEM;
> goto out;
> }
> - } else if (strncmp(str, "sort=", sizeof("sort=") - 1) == 0) {
> + } else if (str_has_prefix(str, "sort=")) {
> attrs->sort_key_str = kstrdup(str, GFP_KERNEL);
> if (!attrs->sort_key_str) {
> ret = -ENOMEM;
> goto out;
> }
> - } else if (strncmp(str, "name=", sizeof("name=") - 1) == 0) {
> + } else if (str_has_prefix(str, "name=")) {
> attrs->name = kstrdup(str, GFP_KERNEL);
> if (!attrs->name) {
> ret = -ENOMEM;
> goto out;
> }
> - } else if (strncmp(str, "clock=", sizeof("clock=") - 1) == 0) {
> + } else if (str_has_prefix(str, "clock=")) {
> strsep(&str, "=");
> if (!str) {
> ret = -EINVAL;
> @@ -1939,7 +1939,7 @@ static int parse_assignment(char *str, struct
> hist_trigger_attrs *attrs)
> ret = -ENOMEM;
> goto out;
> }
> - } else if (strncmp(str, "size=", sizeof("size=") - 1) == 0) {
> + } else if (str_has_prefix(str, "size=")) {
> int map_bits = parse_map_size(str);
>
> if (map_bits < 0) {
> @@ -3558,7 +3558,7 @@ static struct action_data *onmax_parse(char *str)
> if (!onmax_fn_name || !str)
> goto free;
>
> - if (strncmp(onmax_fn_name, "save", sizeof("save") - 1) == 0) {
> + if (str_has_prefix(onmax_fn_name, "save")) {
> char *params = strsep(&str, ")");
>
> if (!params) {
> @@ -4346,7 +4346,7 @@ static int parse_actions(struct hist_trigger_data
> *hist_data)
> for (i = 0; i < hist_data->attrs->n_actions; i++) {
> str = hist_data->attrs->action_str[i];
>
> - if (strncmp(str, "onmatch(", sizeof("onmatch(") - 1) == 0) {
> + if (str_has_prefix(str, "onmatch(")) {
> char *action_str = str + sizeof("onmatch(") - 1;
>
> data = onmatch_parse(tr, action_str);
> @@ -4355,7 +4355,7 @@ static int parse_actions(struct hist_trigger_data
> *hist_data)
> break;
> }
> data->fn = action_trace;
> - } else if (strncmp(str, "onmax(", sizeof("onmax(") - 1) == 0) {
> + } else if (str_has_prefix(str, "onmax(")) {
> char *action_str = str + sizeof("onmax(") - 1;
>
> data = onmax_parse(action_str);
