diff mbox series

[v2,01/10] module: support reading multiple values per modinfo tag

Message ID 20190813121733.52480-2-maennich@google.com (mailing list archive)
State New, archived
Headers show
Series [v2,01/10] module: support reading multiple values per modinfo tag | expand

Commit Message

Matthias Männich Aug. 13, 2019, 12:16 p.m. UTC 
Similar to modpost's get_next_modinfo(), introduce get_next_modinfo() in
kernel/module.c to acquire any further values associated with the same
modinfo tag name. That is useful for any tags that have multiple
occurrences (such as 'alias'), but is in particular introduced here as
part of the symbol namespaces patch series to read the (potentially)
multiple namespaces a module is importing.

Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Reviewed-by: Martijn Coenen <maco@android.com>
Signed-off-by: Matthias Maennich <maennich@google.com>
---
 kernel/module.c | 17 +++++++++++++++--
 1 file changed, 15 insertions(+), 2 deletions(-)

Comments

Greg Kroah-Hartman Aug. 13, 2019, 12:40 p.m. UTC | #1 
On Tue, Aug 13, 2019 at 01:16:58PM +0100, Matthias Maennich wrote:
> Similar to modpost's get_next_modinfo(), introduce get_next_modinfo() in
> kernel/module.c to acquire any further values associated with the same
> modinfo tag name. That is useful for any tags that have multiple
> occurrences (such as 'alias'), but is in particular introduced here as
> part of the symbol namespaces patch series to read the (potentially)
> multiple namespaces a module is importing.
> 
> Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
> Reviewed-by: Martijn Coenen <maco@android.com>
> Signed-off-by: Matthias Maennich <maennich@google.com>

Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff mbox series

Patch

diff --git a/kernel/module.c b/kernel/module.c
index 5933395af9a0..a23067907169 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -2481,7 +2481,8 @@  static char *next_string(char *string, unsigned long *secsize)
 	return string;
 }
 
-static char *get_modinfo(struct load_info *info, const char *tag)
+static char *get_next_modinfo(const struct load_info *info, const char *tag,
+			      char *prev)
 {
 	char *p;
 	unsigned int taglen = strlen(tag);
@@ -2492,13 +2493,25 @@  static char *get_modinfo(struct load_info *info, const char *tag)
 	 * get_modinfo() calls made before rewrite_section_headers()
 	 * must use sh_offset, as sh_addr isn't set!
 	 */
-	for (p = (char *)info->hdr + infosec->sh_offset; p; p = next_string(p, &size)) {
+	char *modinfo = (char *)info->hdr + infosec->sh_offset;
+
+	if (prev) {
+		size -= prev - modinfo;
+		modinfo = next_string(prev, &size);
+	}
+
+	for (p = modinfo; p; p = next_string(p, &size)) {
 		if (strncmp(p, tag, taglen) == 0 && p[taglen] == '=')
 			return p + taglen + 1;
 	}
 	return NULL;
 }
 
+static char *get_modinfo(const struct load_info *info, const char *tag)
+{
+	return get_next_modinfo(info, tag, NULL);
+}
+
 static void setup_modinfo(struct module *mod, struct load_info *info)
 {
 	struct module_attribute *attr;