module: check kernel param length at compile time, not runtime

[linux-2.6-omap-h63xx.git] / include / linux / moduleparam.h

diff --git a/include/linux/moduleparam.h b/include/linux/moduleparam.h
index 8126e55c5bdcbd3c68d4c6ffc4c83797e3b1ca7c..1eefe6d61b86f6822f92610ad2acfe6d2b366863 100644 (file)
--- a/include/linux/moduleparam.h
+++ b/include/linux/moduleparam.h
@@ -13,6 +13,9 @@
 #define MODULE_PARAM_PREFIX KBUILD_MODNAME "."
 #endif
 
+/* Chosen so that structs with an unsigned long line up. */
+#define MAX_PARAM_PREFIX_LEN (64 - sizeof(unsigned long))
+
 #ifdef MODULE
 #define ___module_cat(a,b) __mod_ ## a ## b
 #define __module_cat(a,b) ___module_cat(a,b)
@@ -62,6 +65,16 @@ struct kparam_array
        void *elem;
 };
 
+/* On alpha, ia64 and ppc64 relocations to global data cannot go into
+   read-only sections (which is part of respective UNIX ABI on these
+   platforms). So 'const' makes no sense and even causes compile failures
+   with some compilers. */
+#if defined(CONFIG_ALPHA) || defined(CONFIG_IA64) || defined(CONFIG_PPC64)
+#define __moduleparam_const
+#else
+#define __moduleparam_const const
+#endif
+
 /* This is the fundamental function for registering boot/module
    parameters.  perm sets the visibility in sysfs: 000 means it's
    not there, read bits mean it's readable, write bits mean it's
@@ -69,9 +82,10 @@ struct kparam_array
 #define __module_param_call(prefix, name, set, get, arg, perm)         \
        /* Default value instead of permissions? */                     \
        static int __param_perm_check_##name __attribute__((unused)) =  \
-       BUILD_BUG_ON_ZERO((perm) < 0 || (perm) > 0777 || ((perm) & 2)); \
+       BUILD_BUG_ON_ZERO((perm) < 0 || (perm) > 0777 || ((perm) & 2))  \
+       + BUILD_BUG_ON_ZERO(sizeof(""prefix) > MAX_PARAM_PREFIX_LEN);   \
        static const char __param_str_##name[] = prefix #name;          \
-       static struct kernel_param const __param_##name                 \
+       static struct kernel_param __moduleparam_const __param_##name   \
        __used                                                          \
     __attribute__ ((unused,__section__ ("__param"),aligned(sizeof(void *)))) \
        = { __param_str_##name, perm, set, get, { arg } }