From 37252db6aa576c34fd794a5a54fb32d7a8b3a07a Mon Sep 17 00:00:00 2001
From: Jiri Kosina
Date: Wed, 26 Oct 2011 13:10:39 +1030
Subject: kmod: prevent kmod_loop_msg overflow in __request_module()

Due to post-increment in condition of kmod_loop_msg in __request_module(),
the system log can be spammed by much more than 5 instances of the 'runaway
loop' message if the number of events triggering it makes the kmod_loop_msg
to overflow.

Fix that by making sure we never increment it past the threshold.

Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
CC: stable@kernel.org
---
 kernel/kmod.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

(limited to 'kernel')

diff --git a/kernel/kmod.c b/kernel/kmod.c
index ddc7644c1305..a4bea97c75b6 100644
--- a/kernel/kmod.c
+++ b/kernel/kmod.c
@@ -114,10 +114,12 @@ int __request_module(bool wait, const char *fmt, ...)
 	atomic_inc(&kmod_concurrent);
 	if (atomic_read(&kmod_concurrent) > max_modprobes) {
 		/* We may be blaming an innocent here, but unlikely */
-		if (kmod_loop_msg++ < 5)
+		if (kmod_loop_msg < 5) {
 			printk(KERN_ERR
 			       "request_module: runaway loop modprobe %s\n",
 			       module_name);
+			kmod_loop_msg++;
+		}
 		atomic_dec(&kmod_concurrent);
 		return -ENOMEM;
 	}
-- 
cgit v1.2.3


From b1e4d20cbf2ef8e27515da032b95fdcbb5b06bf1 Mon Sep 17 00:00:00 2001
From: Michal Schmidt
Date: Mon, 10 Oct 2011 00:03:37 +0200
Subject: params: make dashes and underscores in parameter names truly equal

The user may use "foo-bar" for a kernel parameter defined as "foo_bar".
Make sure it works the other way around too.

Apply the equality of dashes and underscores on early_params and __setup
params as well.

The example given in Documentation/kernel-parameters.txt indicates that
this is the intended behaviour.

With the patch the kernel accepts "log-buf-len=1M" as expected.
https://bugzilla.redhat.com/show_bug.cgi?id=744545

Signed-off-by: Michal Schmidt <mschmidt@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> (neatened implementations)
---
 include/linux/moduleparam.h | 20 ++++++++++++++++++++
 init/main.c                 |  4 ++--
 kernel/params.c             | 21 ++++++++++++++-------
 3 files changed, 36 insertions(+), 9 deletions(-)

(limited to 'kernel')

diff --git a/include/linux/moduleparam.h b/include/linux/moduleparam.h
index ddaae98c53f9..fffb10bd5514 100644
--- a/include/linux/moduleparam.h
+++ b/include/linux/moduleparam.h
@@ -262,6 +262,26 @@ static inline void __kernel_param_unlock(void)
 			    .str = &__param_string_##name, 0, perm);	\
 	__MODULE_PARM_TYPE(name, "string")
 
+/**
+ * parameq - checks if two parameter names match
+ * @name1: parameter name 1
+ * @name2: parameter name 2
+ *
+ * Returns true if the two parameter names are equal.
+ * Dashes (-) are considered equal to underscores (_).
+ */
+extern bool parameq(const char *name1, const char *name2);
+
+/**
+ * parameqn - checks if two parameter names match
+ * @name1: parameter name 1
+ * @name2: parameter name 2
+ * @n: the length to compare
+ *
+ * Similar to parameq(), except it compares @n characters.
+ */
+extern bool parameqn(const char *name1, const char *name2, size_t n);
+
 /* Called on module insert or kernel boot */
 extern int parse_args(const char *name,
 		      char *args,
diff --git a/init/main.c b/init/main.c
index 03b408dff825..63f5f6f8dc3b 100644
--- a/init/main.c
+++ b/init/main.c
@@ -163,7 +163,7 @@ static int __init obsolete_checksetup(char *line)
 	p = __setup_start;
 	do {
 		int n = strlen(p->str);
-		if (!strncmp(line, p->str, n)) {
+		if (parameqn(line, p->str, n)) {
 			if (p->early) {
 				/* Already done in parse_early_param?
 				 * (Needs exact match on param part).
@@ -392,7 +392,7 @@ static int __init do_early_param(char *param, char *val)
 	const struct obs_kernel_param *p;
 
 	for (p = __setup_start; p < __setup_end; p++) {
-		if ((p->early && strcmp(param, p->str) == 0) ||
+		if ((p->early && parameq(param, p->str)) ||
 		    (strcmp(param, "console") == 0 &&
 		     strcmp(p->str, "earlycon") == 0)
 		) {
diff --git a/kernel/params.c b/kernel/params.c
index 22df3e0d142a..821788947e40 100644
--- a/kernel/params.c
+++ b/kernel/params.c
@@ -67,20 +67,27 @@ static void maybe_kfree_parameter(void *param)
 	}
 }
 
-static inline char dash2underscore(char c)
+static char dash2underscore(char c)
 {
 	if (c == '-')
 		return '_';
 	return c;
 }
 
-static inline int parameq(const char *input, const char *paramname)
+bool parameqn(const char *a, const char *b, size_t n)
 {
-	unsigned int i;
-	for (i = 0; dash2underscore(input[i]) == paramname[i]; i++)
-		if (input[i] == '\0')
-			return 1;
-	return 0;
+	size_t i;
+
+	for (i = 0; i < n; i++) {
+		if (dash2underscore(a[i]) != dash2underscore(b[i]))
+			return false;
+	}
+	return true;
+}
+
+bool parameq(const char *a, const char *b)
+{
+	return parameqn(a, b, strlen(a)+1);
 }
 
 static int parse_one(char *param,
-- 
cgit v1.2.3