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authorRusty Russell <rusty@rustcorp.com.au>2009-03-31 23:05:29 +0400
committerRusty Russell <rusty@rustcorp.com.au>2009-03-31 06:35:30 +0400
commite180a6b7759a99a28cbcce3547c4c80822cb6c2a (patch)
treed52b950935f3192d13bdd4ad9377b39bab21325e /include/linux/moduleparam.h
parent15f7176eb1cccec0a332541285ee752b935c1c85 (diff)
downloadlinux-e180a6b7759a99a28cbcce3547c4c80822cb6c2a.tar.xz
param: fix charp parameters set via sysfs
Impact: fix crash on reading from /sys/module/.../ieee80211_default_rc_algo The module_param type "charp" simply sets a char * pointer in the module to the parameter in the commandline string: this is why we keep the (mangled) module command line around. But when set via sysfs (as about 11 charp parameters can be) this memory is freed on the way out of the write(). Future reads hit random mem. So we kstrdup instead: we have to check we're not in early commandline parsing, and we have to note when we've used it so we can reliably kfree the parameter when it's next overwritten, and also on module unload. (Thanks to Randy Dunlap for CONFIG_SYSFS=n fixes) Reported-by: Sitsofe Wheeler <sitsofe@yahoo.com> Diagnosed-by: Frederic Weisbecker <fweisbec@gmail.com> Tested-by: Frederic Weisbecker <fweisbec@gmail.com> Tested-by: Christof Schmitt <christof.schmitt@de.ibm.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Diffstat (limited to 'include/linux/moduleparam.h')
-rw-r--r--include/linux/moduleparam.h10
1 files changed, 10 insertions, 0 deletions
diff --git a/include/linux/moduleparam.h b/include/linux/moduleparam.h
index e4af3399ef48..a4f0b931846c 100644
--- a/include/linux/moduleparam.h
+++ b/include/linux/moduleparam.h
@@ -138,6 +138,16 @@ extern int parse_args(const char *name,
unsigned num,
int (*unknown)(char *param, char *val));
+/* Called by module remove. */
+#ifdef CONFIG_SYSFS
+extern void destroy_params(const struct kernel_param *params, unsigned num);
+#else
+static inline void destroy_params(const struct kernel_param *params,
+ unsigned num)
+{
+}
+#endif /* !CONFIG_SYSFS */
+
/* All the helper functions */
/* The macros to do compile-time type checking stolen from Jakub
Jelinek, who IIRC came up with this idea for the 2.4 module init code. */