Kalle Valo <kvalo@xxxxxxxxxxxxxx> writes: > Arnd Bergmann <arnd@xxxxxxxx> writes: > >> gcc-10 correctly points out a bug with a zero-length array in >> struct ath10k_pci: >> >> drivers/net/wireless/ath/ath10k/ahb.c: In function 'ath10k_ahb_remove': >> drivers/net/wireless/ath/ath10k/ahb.c:30:9: error: array subscript 0 >> is outside the bounds of an interior zero-length array 'struct >> ath10k_ahb[0]' [-Werror=zero-length-bounds] >> 30 | return &((struct ath10k_pci *)ar->drv_priv)->ahb[0]; >> | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ >> In file included from drivers/net/wireless/ath/ath10k/ahb.c:13: >> drivers/net/wireless/ath/ath10k/pci.h:185:20: note: while referencing 'ahb' >> 185 | struct ath10k_ahb ahb[0]; >> | ^~~ >> >> The last addition to the struct ignored the comments and added >> new members behind the array that must remain last. >> >> Change it to a flexible-array member and move it last again to >> make it work correctly, prevent the same thing from happening >> again (all compilers warn about flexible-array members in the >> middle of a struct) and get it to build without warnings. > > Very good find, thanks! This bug would cause all sort of strange memory > corruption issues. This motivated me to switch to using GCC 10.x and I noticed that you had already upgraded crosstool so it was a trivial thing to do, awesome :) https://mirrors.edge.kernel.org/pub/tools/crosstool/ I use crosstool like this using GNUmakefile: CROSS_COMPILE=/opt/cross/gcc-10.1.0-nolibc/x86_64-linux/bin/x86_64-linux- include Makefile I think it's handy trick and would be good to mention that in the crosstool main page. That way I could just point people to the crosstool main page when they are using ancient compilers and would need to upgrade. -- https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches
