From 754481e6954cbef53f8bc4412ad48dde611e21d3 Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (VMware)" Date: Wed, 19 Dec 2018 22:38:21 -0500 Subject: [PATCH] tracing: Use str_has_prefix() helper for histogram code 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 Acked-by: Namhyung Kim Signed-off-by: Steven Rostedt (VMware) --- 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); -- 2.39.5