linux-kernel - [PATCH v2 01/10] module: support reading multiple values per modinfo tag

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Tue, 13 Aug 2019 13:16:58 +0100
From:   Matthias Maennich <maennich@...gle.com>
To:     linux-kernel@...r.kernel.org, maco@...roid.com
Cc:     kernel-team@...roid.com, maennich@...gle.com, arnd@...db.de,
        geert@...ux-m68k.org, gregkh@...uxfoundation.org, hpa@...or.com,
        jeyu@...nel.org, joel@...lfernandes.org,
        kstewart@...uxfoundation.org, linux-arch@...r.kernel.org,
        linux-kbuild@...r.kernel.org, linux-m68k@...ts.linux-m68k.org,
        linux-modules@...r.kernel.org, linux-scsi@...r.kernel.org,
        linux-usb@...r.kernel.org, lucas.de.marchi@...il.com,
        maco@...gle.com, michal.lkml@...kovi.net, mingo@...hat.com,
        oneukum@...e.com, pombredanne@...b.com, sam@...nborg.org,
        sboyd@...eaurora.org, sspatil@...gle.com,
        stern@...land.harvard.edu, tglx@...utronix.de,
        usb-storage@...ts.one-eyed-alien.net, x86@...nel.org,
        yamada.masahiro@...ionext.com
Subject: [PATCH v2 01/10] module: support reading multiple values per modinfo tag

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@...lfernandes.org>
Reviewed-by: Martijn Coenen <maco@...roid.com>
Signed-off-by: Matthias Maennich <maennich@...gle.com>
---
 kernel/module.c | 17 +++++++++++++++--
 1 file changed, 15 insertions(+), 2 deletions(-)

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;
-- 
2.23.0.rc1.153.gdeed80330f-goog