From fe2f4fe139b321a38daafc715aeb7d21d9e8e5ad Mon Sep 17 00:00:00 2001 From: Johan Hovold Date: Mon, 23 Nov 2020 11:23:18 +0100 Subject: [PATCH] params: use type alignment for kernel parameters Specify type alignment for kernel parameters instead of sizeof(void *). The alignment attribute is used to prevent gcc from increasing the alignment of objects with static extent as an optimisation, something which would mess up the __param array stride. Using __alignof__(struct kernel_param) rather than sizeof(void *) is preferred since it better indicates why it is there and doesn't break should the type size or alignment change. Note that on m68k the alignment of struct kernel_param is actually two and that adding a 1- or 2-byte field to the 20-byte struct would cause a breakage with the current 4-byte alignment. Link: https://lore.kernel.org/lkml/20201103175711.10731-1-johan@kernel.org Signed-off-by: Johan Hovold Signed-off-by: Jessica Yu --- include/linux/moduleparam.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/include/linux/moduleparam.h b/include/linux/moduleparam.h index 742074ad9f6e6..15ecc6cc3a3b1 100644 --- a/include/linux/moduleparam.h +++ b/include/linux/moduleparam.h @@ -288,8 +288,8 @@ struct kparam_array /* Default value instead of permissions? */ \ static const char __param_str_##name[] = prefix #name; \ static struct kernel_param __moduleparam_const __param_##name \ - __used \ - __section("__param") __attribute__ ((aligned(sizeof(void *)))) \ + __used __section("__param") \ + __aligned(__alignof__(struct kernel_param)) \ = { __param_str_##name, THIS_MODULE, ops, \ VERIFY_OCTAL_PERMISSIONS(perm), level, flags, { arg } } -- 2.30.2