[PATCH 3.18 63/68] modpost: expand pattern matching to support substring matches

Greg Kroah-Hartman
2017-05-05T18:42:23Z

From: Paul Gortmaker <paul.gortmaker@windriver.com>

commit 09c20c032b0f753969ae778d9783d946f054d7fe upstream.

Currently the match() function supports a leading * to match any
prefix and a trailing * to match any suffix. However there currently
is not a combination of both that can be used to target matches of
whole families of functions that share a common substring.

Here we expand the *foo and foo* match to also support *foo* with
the goal of targeting compiler generated symbol names that contain
strings like ".constprop." and ".isra."

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
scripts/mod/modpost.c | 12 +++++++++++-
1 file changed, 11 insertions(+), 1 deletion(-)

--- a/scripts/mod/modpost.c
+++ b/scripts/mod/modpost.c
@@ -776,6 +776,7 @@ static const char *sech_name(struct elf_
* "foo" will match an exact string equal to "foo"
* "*foo" will match a string that ends with "foo"
* "foo*" will match a string that begins with "foo"
+ * "*foo*" will match a string that contains "foo"
*/
static int match(const char *sym, const char * const pat[])
{
@@ -784,8 +785,17 @@ static int match(const char *sym, const
p = *pat++;
const char *endp = p + strlen(p) - 1;

+ /* "*foo*" */
+ if (*p == '*' && *endp == '*') {
+ char *here, *bare = strndup(p + 1, strlen(p) - 2);
+
+ here = strstr(sym, bare);
+ free(bare);
+ if (here != NULL)
+ return 1;
+ }
/* "*foo" */
- if (*p == '*') {
+ else if (*p == '*') {
if (strrcmp(sym, p + 1) == 0)
return 1;
}