4.19-stable review patch. If anyone has any objections, please let me know.
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From: "Steven Rostedt (VMware)" rostedt@goodmis.org
commit 754481e6954cbef53f8bc4412ad48dde611e21d3 upstream.
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 tom.zanussi@linux.intel.com Acked-by: Namhyung Kim namhyung@kernel.org Signed-off-by: Steven Rostedt (VMware) rostedt@goodmis.org Signed-off-by: George Guo guodongtai@kylinos.cn Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- kernel/trace/trace_events_hist.c | 32 ++++++++++++++++---------------- 1 file changed, 16 insertions(+), 16 deletions(-)
--- a/kernel/trace/trace_events_hist.c +++ b/kernel/trace/trace_events_hist.c @@ -1878,8 +1878,8 @@ static int parse_action(char *str, struc if (attrs->n_actions >= HIST_ACTIONS_MAX) return ret;
- if ((strncmp(str, "onmatch(", strlen("onmatch(")) == 0) || - (strncmp(str, "onmax(", strlen("onmax(")) == 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; @@ -1896,34 +1896,34 @@ static int parse_assignment(char *str, s { int ret = 0;
- if ((strncmp(str, "key=", strlen("key=")) == 0) || - (strncmp(str, "keys=", strlen("keys=")) == 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=", strlen("val=")) == 0) || - (strncmp(str, "vals=", strlen("vals=")) == 0) || - (strncmp(str, "values=", strlen("values=")) == 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=", strlen("sort=")) == 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=", strlen("name=")) == 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=", strlen("clock=")) == 0) { + } else if (str_has_prefix(str, "clock=")) { strsep(&str, "="); if (!str) { ret = -EINVAL; @@ -1936,7 +1936,7 @@ static int parse_assignment(char *str, s ret = -ENOMEM; goto out; } - } else if (strncmp(str, "size=", strlen("size=")) == 0) { + } else if (str_has_prefix(str, "size=")) { int map_bits = parse_map_size(str);
if (map_bits < 0) { @@ -3623,7 +3623,7 @@ static struct action_data *onmax_parse(c if (!onmax_fn_name || !str) goto free;
- if (strncmp(onmax_fn_name, "save", strlen("save")) == 0) { + if (str_has_prefix(onmax_fn_name, "save")) { char *params = strsep(&str, ")");
if (!params) { @@ -4414,8 +4414,8 @@ static int parse_actions(struct hist_tri for (i = 0; i < hist_data->attrs->n_actions; i++) { str = hist_data->attrs->action_str[i];
- if (strncmp(str, "onmatch(", strlen("onmatch(")) == 0) { - char *action_str = str + strlen("onmatch("); + if (str_has_prefix(str, "onmatch(")) { + char *action_str = str + sizeof("onmatch(") - 1;
data = onmatch_parse(tr, action_str); if (IS_ERR(data)) { @@ -4423,8 +4423,8 @@ static int parse_actions(struct hist_tri break; } data->fn = action_trace; - } else if (strncmp(str, "onmax(", strlen("onmax(")) == 0) { - char *action_str = str + strlen("onmax("); + } else if (str_has_prefix(str, "onmax(")) { + char *action_str = str + sizeof("onmax(") - 1;
data = onmax_parse(action_str); if (IS_ERR(data)) {