From be8e341777c0e560c4db1cfb576f75ab8a041c31 Mon Sep 17 00:00:00 2001 From: Dimitry Andric Date: Mon, 7 Feb 2022 21:59:46 +0100 Subject: [PATCH] bwi: Fix clang 14 warning about possible unaligned access On architectures with strict alignment requirements (e.g. arm), clang 14 warns about a packed struct which encloses a non-packed union: In file included from sys/dev/bwi/bwimac.c:79: sys/dev/bwi/if_bwivar.h:308:7: error: field iv_val within 'struct bwi_fw_iv' is less aligned than 'union (unnamed union at sys/dev/bwi/if_bwivar.h:305:2)' and is usually due to 'struct bwi_fw_iv' being packed, which can lead to unaligned accesses [-Werror,-Wunaligned-access] } iv_val; ^ It appears to help if you also add __packed to the inner union (i.e. iv_val). No change to the layout is intended. MFC after: 3 days Differential Revision: https://reviews.freebsd.org/D34196 (cherry picked from commit 09d0a0fbe859e3fc7bbff0cf48c389b5e55b9e00) --- sys/dev/bwi/if_bwivar.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/sys/dev/bwi/if_bwivar.h b/sys/dev/bwi/if_bwivar.h index 90b4aeab6d2..9961cfca919 100644 --- a/sys/dev/bwi/if_bwivar.h +++ b/sys/dev/bwi/if_bwivar.h @@ -305,7 +305,7 @@ struct bwi_fw_iv { union { uint32_t val32; uint16_t val16; - } iv_val; + } __packed iv_val; } __packed; #define BWI_FW_IV_OFS_MASK __BITS(14, 0)