Re: drivers/net/wireless/ath/ath10k/htt.h:1677:2: warning: field within 'struct htt_tx_fetch_ind' is less aligned than 'union htt_tx_fetch_ind::(anonymous at drivers/net/wireless/ath/ath10k/htt.h:1677:2)' and is usually due to 'struct htt_tx_fetch_ind' being...

From: Kees Cook
Date: Wed Sep 07 2022 - 20:00:00 EST

On Sat, Sep 03, 2022 at 06:08:27PM +0800, kernel test robot wrote:
> Hi Kees,
>
> FYI, the error/warning still remains.

Thanks for the heads-up. This appears unrelated to the treewide change
-- it just became a bit louder. The unaligned access warning was always
present. "pahole" output shows no changes to struct member offsets nor
struct sizes.

-Kees

>
> tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
> head: d895ec7938c431fe61a731939da76a6461bc6133
> commit: fa7845cfd53f3b1d3f60efa55db89805595bc045 treewide: Replace open-coded flex arrays in unions
> date: 11 months ago
> config: arm-randconfig-r031-20220903 (https://download.01.org/0day-ci/archive/20220903/202209031855.LVCj2Q6u-lkp@xxxxxxxxx/config)
> compiler: clang version 16.0.0 (https://github.com/llvm/llvm-project c55b41d5199d2394dd6cdb8f52180d8b81d809d4)
> reproduce (this is a W=1 build):
> wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
> chmod +x ~/bin/make.cross
> # install arm cross compiling tool for clang build
> # apt-get install binutils-arm-linux-gnueabi
> # https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=fa7845cfd53f3b1d3f60efa55db89805595bc045
> git remote add linus https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
> git fetch --no-tags linus master
> git checkout fa7845cfd53f3b1d3f60efa55db89805595bc045
> # save the config file
> mkdir build_dir && cp config build_dir/.config
> COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=arm SHELL=/bin/bash drivers/net/
>
> If you fix the issue, kindly add following tag where applicable
> Reported-by: kernel test robot <lkp@xxxxxxxxx>
>
> All warnings (new ones prefixed by >>):
>
> In file included from drivers/net/wireless/ath/ath10k/mac.c:8:
> In file included from drivers/net/wireless/ath/ath10k/mac.h:11:
> In file included from drivers/net/wireless/ath/ath10k/core.h:18:
> drivers/net/wireless/ath/ath10k/htt.h:721:34: warning: field prefix within 'struct htt_rx_indication' is less aligned than 'struct htt_rx_indication_prefix' and is usually due to 'struct htt_rx_indication' being packed, which can lead to unaligned accesses [-Wunaligned-access]
> struct htt_rx_indication_prefix prefix;
> ^
> drivers/net/wireless/ath/ath10k/htt.h:742:34: warning: field prefix within 'struct htt_rx_indication_hl' is less aligned than 'struct htt_rx_indication_prefix' and is usually due to 'struct htt_rx_indication_hl' being packed, which can lead to unaligned accesses [-Wunaligned-access]
> struct htt_rx_indication_prefix prefix;
> ^
> >> drivers/net/wireless/ath/ath10k/htt.h:1677:2: warning: field within 'struct htt_tx_fetch_ind' is less aligned than 'union htt_tx_fetch_ind::(anonymous at drivers/net/wireless/ath/ath10k/htt.h:1677:2)' and is usually due to 'struct htt_tx_fetch_ind' being packed, which can lead to unaligned accesses [-Wunaligned-access]
> union {
> ^
> drivers/net/wireless/ath/ath10k/htt.h:1815:2: warning: field within 'struct htt_resp' is less aligned than 'union htt_resp::(anonymous at drivers/net/wireless/ath/ath10k/htt.h:1815:2)' and is usually due to 'struct htt_resp' being packed, which can lead to unaligned accesses [-Wunaligned-access]
> union {
> ^
> drivers/net/wireless/ath/ath10k/mac.c:5942:22: warning: parameter 'changed_flags' set but not used [-Wunused-but-set-parameter]
> unsigned int changed_flags,
> ^
> 5 warnings generated.
> --
> In file included from drivers/net/wireless/ath/ath10k/debug.c:14:
> In file included from drivers/net/wireless/ath/ath10k/core.h:18:
> drivers/net/wireless/ath/ath10k/htt.h:721:34: warning: field prefix within 'struct htt_rx_indication' is less aligned than 'struct htt_rx_indication_prefix' and is usually due to 'struct htt_rx_indication' being packed, which can lead to unaligned accesses [-Wunaligned-access]
> struct htt_rx_indication_prefix prefix;
> ^
> drivers/net/wireless/ath/ath10k/htt.h:742:34: warning: field prefix within 'struct htt_rx_indication_hl' is less aligned than 'struct htt_rx_indication_prefix' and is usually due to 'struct htt_rx_indication_hl' being packed, which can lead to unaligned accesses [-Wunaligned-access]
> struct htt_rx_indication_prefix prefix;
> ^
> >> drivers/net/wireless/ath/ath10k/htt.h:1677:2: warning: field within 'struct htt_tx_fetch_ind' is less aligned than 'union htt_tx_fetch_ind::(anonymous at drivers/net/wireless/ath/ath10k/htt.h:1677:2)' and is usually due to 'struct htt_tx_fetch_ind' being packed, which can lead to unaligned accesses [-Wunaligned-access]
> union {
> ^
> drivers/net/wireless/ath/ath10k/htt.h:1815:2: warning: field within 'struct htt_resp' is less aligned than 'union htt_resp::(anonymous at drivers/net/wireless/ath/ath10k/htt.h:1815:2)' and is usually due to 'struct htt_resp' being packed, which can lead to unaligned accesses [-Wunaligned-access]
> union {
> ^
> 4 warnings generated.
> --
> In file included from drivers/net/wireless/ath/ath10k/ce.c:8:
> In file included from drivers/net/wireless/ath/ath10k/hif.h:11:
> In file included from drivers/net/wireless/ath/ath10k/core.h:18:
> drivers/net/wireless/ath/ath10k/htt.h:721:34: warning: field prefix within 'struct htt_rx_indication' is less aligned than 'struct htt_rx_indication_prefix' and is usually due to 'struct htt_rx_indication' being packed, which can lead to unaligned accesses [-Wunaligned-access]
> struct htt_rx_indication_prefix prefix;
> ^
> drivers/net/wireless/ath/ath10k/htt.h:742:34: warning: field prefix within 'struct htt_rx_indication_hl' is less aligned than 'struct htt_rx_indication_prefix' and is usually due to 'struct htt_rx_indication_hl' being packed, which can lead to unaligned accesses [-Wunaligned-access]
> struct htt_rx_indication_prefix prefix;
> ^
> >> drivers/net/wireless/ath/ath10k/htt.h:1677:2: warning: field within 'struct htt_tx_fetch_ind' is less aligned than 'union htt_tx_fetch_ind::(anonymous at drivers/net/wireless/ath/ath10k/htt.h:1677:2)' and is usually due to 'struct htt_tx_fetch_ind' being packed, which can lead to unaligned accesses [-Wunaligned-access]
> union {
> ^
> drivers/net/wireless/ath/ath10k/htt.h:1815:2: warning: field within 'struct htt_resp' is less aligned than 'union htt_resp::(anonymous at drivers/net/wireless/ath/ath10k/htt.h:1815:2)' and is usually due to 'struct htt_resp' being packed, which can lead to unaligned accesses [-Wunaligned-access]
> union {
> ^
> drivers/net/wireless/ath/ath10k/ce.c:127:1: warning: unused function 'ath10k_get_ring_byte' [-Wunused-function]
> ath10k_get_ring_byte(unsigned int offset,
> ^
> drivers/net/wireless/ath/ath10k/ce.c:212:1: warning: unused function 'ath10k_ce_shadow_dest_ring_write_index_set' [-Wunused-function]
> ath10k_ce_shadow_dest_ring_write_index_set(struct ath10k *ar,
> ^
> drivers/net/wireless/ath/ath10k/ce.c:449:20: warning: unused function 'ath10k_ce_error_intr_enable' [-Wunused-function]
> static inline void ath10k_ce_error_intr_enable(struct ath10k *ar,
> ^
> 7 warnings generated.
>
>
> vim +1677 drivers/net/wireless/ath/ath10k/htt.h
>
> 1670
> 1671 struct htt_tx_fetch_ind {
> 1672 u8 pad0;
> 1673 __le16 fetch_seq_num;
> 1674 __le32 token;
> 1675 __le16 num_resp_ids;
> 1676 __le16 num_records;
> > 1677 union {
> 1678 /* ath10k_htt_get_tx_fetch_ind_resp_ids() */
> 1679 DECLARE_FLEX_ARRAY(__le32, resp_ids);
> 1680 DECLARE_FLEX_ARRAY(struct htt_tx_fetch_record, records);
> 1681 };
> 1682 } __packed;
> 1683
>
> --
> 0-DAY CI Kernel Test Service
> https://01.org/lkp

--
Kees Cook