[RFC PATCH 18/30] codetag: add codetag query helper functions

[Suren Baghdasaryan <surenb@xxxxxxxxxx>]

From: Kent Overstreet <kent.overstreet@xxxxxxxxx>

Provide codetag_query_parse() to parse codetag queries and
codetag_matches_query() to check if the query affects a given codetag.

Signed-off-by: Kent Overstreet <kent.overstreet@xxxxxxxxx>
---
 include/linux/codetag.h |  27 ++++++++
 lib/codetag.c           | 135 ++++++++++++++++++++++++++++++++++++++++
 2 files changed, 162 insertions(+)

diff --git a/include/linux/codetag.h b/include/linux/codetag.h
index 386733e89b31..0c605417ebbe 100644
--- a/include/linux/codetag.h
+++ b/include/linux/codetag.h
@@ -80,4 +80,31 @@ static inline void codetag_load_module(struct module *mod) {}
 static inline void codetag_unload_module(struct module *mod) {}
 #endif
 
+/* Codetag query parsing */
+
+struct codetag_query {
+       const char      *filename;
+       const char      *module;
+       const char      *function;
+       const char      *class;
+       unsigned int    first_line, last_line;
+       unsigned int    first_index, last_index;
+       unsigned int    cur_index;
+
+       bool            match_line:1;
+       bool            match_index:1;
+
+       unsigned int    set_enabled:1;
+       unsigned int    enabled:2;
+
+       unsigned int    set_frequency:1;
+       unsigned int    frequency;
+};
+
+char *codetag_query_parse(struct codetag_query *q, char *buf);
+bool codetag_matches_query(struct codetag_query *q,
+                          const struct codetag *ct,
+                          const struct codetag_module *mod,
+                          const char *class);
+
 #endif /* _LINUX_CODETAG_H */
diff --git a/lib/codetag.c b/lib/codetag.c
index f0a3174f9b71..288ccfd5cbd0 100644
--- a/lib/codetag.c
+++ b/lib/codetag.c
@@ -246,3 +246,138 @@ void codetag_unload_module(struct module *mod)
        }
        mutex_unlock(&codetag_lock);
 }
+
+/* Codetag query parsing */
+
+#define CODETAG_QUERY_TOKENS() \
+       x(func)                 \
+       x(file)                 \
+       x(line)                 \
+       x(module)               \
+       x(class)                \
+       x(index)
+
+enum tokens {
+#define x(name)                TOK_##name,
+       CODETAG_QUERY_TOKENS()
+#undef x
+};
+
+static const char * const token_strs[] = {
+#define x(name)                #name,
+       CODETAG_QUERY_TOKENS()
+#undef x
+       NULL
+};
+
+static int parse_range(char *str, unsigned int *first, unsigned int *last)
+{
+       char *first_str = str;
+       char *last_str = strchr(first_str, '-');
+
+       if (last_str)
+               *last_str++ = '\0';
+
+       if (kstrtouint(first_str, 10, first))
+               return -EINVAL;
+
+       if (!last_str)
+               *last = *first;
+       else if (kstrtouint(last_str, 10, last))
+               return -EINVAL;
+
+       return 0;
+}
+
+char *codetag_query_parse(struct codetag_query *q, char *buf)
+{
+       while (1) {
+               char *p = buf;
+               char *str1 = strsep_no_empty(&p, " \t\r\n");
+               char *str2 = strsep_no_empty(&p, " \t\r\n");
+               int ret, token;
+
+               if (!str1 || !str2)
+                       break;
+
+               token = match_string(token_strs, ARRAY_SIZE(token_strs), str1);
+               if (token < 0)
+                       break;
+
+               switch (token) {
+               case TOK_func:
+                       q->function = str2;
+                       break;
+               case TOK_file:
+                       q->filename = str2;
+                       break;
+               case TOK_line:
+                       ret = parse_range(str2, &q->first_line, &q->last_line);
+                       if (ret)
+                               return ERR_PTR(ret);
+                       q->match_line = true;
+                       break;
+               case TOK_module:
+                       q->module = str2;
+                       break;
+               case TOK_class:
+                       q->class = str2;
+                       break;
+               case TOK_index:
+                       ret = parse_range(str2, &q->first_index, 
&q->last_index);
+                       if (ret)
+                               return ERR_PTR(ret);
+                       q->match_index = true;
+                       break;
+               }
+
+               buf = p;
+       }
+
+       return buf;
+}
+
+bool codetag_matches_query(struct codetag_query *q,
+                          const struct codetag *ct,
+                          const struct codetag_module *mod,
+                          const char *class)
+{
+       size_t classlen = q->class ? strlen(q->class) : 0;
+
+       if (q->module &&
+           (!mod->mod ||
+            strcmp(q->module, ct->modname)))
+               return false;
+
+       if (q->filename &&
+           strcmp(q->filename, ct->filename) &&
+           strcmp(q->filename, kbasename(ct->filename)))
+               return false;
+
+       if (q->function &&
+           strcmp(q->function, ct->function))
+               return false;
+
+       /* match against the line number range */
+       if (q->match_line &&
+           (ct->lineno < q->first_line ||
+            ct->lineno > q->last_line))
+               return false;
+
+       /* match against the class */
+       if (classlen &&
+           (strncmp(q->class, class, classlen) ||
+            (class[classlen] && class[classlen] != ':')))
+               return false;
+
+       /* match against the fault index */
+       if (q->match_index &&
+           (q->cur_index < q->first_index ||
+            q->cur_index > q->last_index)) {
+               q->cur_index++;
+               return false;
+       }
+
+       q->cur_index++;
+       return true;
+}
-- 
2.37.2.672.g94769d06f0-goog