From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756001AbYLAMzz (ORCPT ); Mon, 1 Dec 2008 07:55:55 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755327AbYLAMzV (ORCPT ); Mon, 1 Dec 2008 07:55:21 -0500 Received: from ozlabs.org ([203.10.76.45]:44011 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752848AbYLAMzU (ORCPT ); Mon, 1 Dec 2008 07:55:20 -0500 To: linux-kernel@vger.kernel.org From: Rusty Russell Date: Mon, 1 Dec 2008 23:25:16 +1030 Subject: [RFC 3/8] param: make sure charp isn't used as a core_param MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200812012325.16654.rusty@rustcorp.com.au> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org "charp" sets a variable to point to a char string in a command line. This doesn't work if the command line isn't going to stick around. Add a compile-breaking check for this case, and make a note of it. Signed-off-by: Rusty Russell --- include/linux/moduleparam.h | 3 +++ kernel/params.c | 7 +++++++ 2 files changed, 10 insertions(+) diff --git a/include/linux/moduleparam.h b/include/linux/moduleparam.h --- a/include/linux/moduleparam.h +++ b/include/linux/moduleparam.h @@ -118,11 +118,15 @@ struct kparam_array * early in boot. This is for compatibility with __setup(), and it * makes sense as truly core parameters aren't tied to the particular * file they're in. + * + * Note: You can't use 'charp' here (which keeps a pointer into our + * tmp cmdline). */ #define core_param(name, var, type, perm) \ param_check_##type(name, &(var)); \ __module_param_call("", "__core_param", name, param_set_##type, \ - param_get_##type, &var, perm) + param_get_##type, &var, perm \ + + BUILD_BUG_ON_ZERO(param_##type##_keeps_reference)) #endif /* !MODULE */ /* Actually copy string: maxlen param is usually sizeof(string). */ @@ -150,42 +154,52 @@ extern int param_set_byte(const char *va extern int param_set_byte(const char *val, struct kernel_param *kp); extern int param_get_byte(char *buffer, struct kernel_param *kp); #define param_check_byte(name, p) __param_check(name, p, unsigned char) +#define param_byte_keeps_reference 0 extern int param_set_short(const char *val, struct kernel_param *kp); extern int param_get_short(char *buffer, struct kernel_param *kp); #define param_check_short(name, p) __param_check(name, p, short) +#define param_short_keeps_reference 0 extern int param_set_ushort(const char *val, struct kernel_param *kp); extern int param_get_ushort(char *buffer, struct kernel_param *kp); #define param_check_ushort(name, p) __param_check(name, p, unsigned short) +#define param_ushort_keeps_reference 0 extern int param_set_int(const char *val, struct kernel_param *kp); extern int param_get_int(char *buffer, struct kernel_param *kp); #define param_check_int(name, p) __param_check(name, p, int) +#define param_int_keeps_reference 0 extern int param_set_uint(const char *val, struct kernel_param *kp); extern int param_get_uint(char *buffer, struct kernel_param *kp); #define param_check_uint(name, p) __param_check(name, p, unsigned int) +#define param_uint_keeps_reference 0 extern int param_set_long(const char *val, struct kernel_param *kp); extern int param_get_long(char *buffer, struct kernel_param *kp); #define param_check_long(name, p) __param_check(name, p, long) +#define param_long_keeps_reference 0 extern int param_set_ulong(const char *val, struct kernel_param *kp); extern int param_get_ulong(char *buffer, struct kernel_param *kp); #define param_check_ulong(name, p) __param_check(name, p, unsigned long) +#define param_ulong_keeps_reference 0 extern int param_set_charp(const char *val, struct kernel_param *kp); extern int param_get_charp(char *buffer, struct kernel_param *kp); #define param_check_charp(name, p) __param_check(name, p, char *) +#define param_charp_keeps_reference 1 extern int param_set_bool(const char *val, struct kernel_param *kp); extern int param_get_bool(char *buffer, struct kernel_param *kp); #define param_check_bool(name, p) __param_check(name, p, int) +#define param_bool_keeps_reference 0 extern int param_set_invbool(const char *val, struct kernel_param *kp); extern int param_get_invbool(char *buffer, struct kernel_param *kp); #define param_check_invbool(name, p) __param_check(name, p, int) +#define param_invbool_keeps_reference 0 /* Comma-separated array: *nump is set to number they actually specified. */ #define module_param_array_named(name, array, type, nump, perm) \