# git rev-parse -q --verify d783301058f3d3605f9ad34f0192692ef572d663^{commit}
d783301058f3d3605f9ad34f0192692ef572d663
already have revision, skipping fetch
# git checkout -q -f -B kisskb d783301058f3d3605f9ad34f0192692ef572d663
# git clean -qxdf
# < git log -1
# commit d783301058f3d3605f9ad34f0192692ef572d663
# Author: Gustavo A. R. Silva <gustavo@embeddedor.com>
# Date:   Tue Apr 21 16:19:18 2020 -0500
# 
#     treewide: Replace zero-length array with flexible-array member
#     
#     The current codebase makes use of the zero-length array language
#     extension to the C90 standard, but the preferred mechanism to declare
#     variable-length types such as these ones is a flexible array member[1][2],
#     introduced in C99:
#     
#     struct foo {
#             int stuff;
#             struct boo array[];
#     };
#     
#     By making use of the mechanism above, we will get a compiler warning
#     in case the flexible array does not occur last in the structure, which
#     will help us prevent some kind of undefined behavior bugs from being
#     inadvertently introduced[3] to the codebase from now on.
#     
#     Also, notice that, dynamic memory allocations won't be affected by
#     this change:
#     
#     "Flexible array members have incomplete type, and so the sizeof operator
#     may not be applied. As a quirk of the original implementation of
#     zero-length arrays, sizeof evaluates to zero."[1]
#     
#     sizeof(flexible-array-member) triggers a warning because flexible array
#     members have incomplete type[1]. There are some instances of code in
#     which the sizeof operator is being incorrectly/erroneously applied to
#     zero-length arrays and the result is zero. Such instances may be hiding
#     some bugs. So, this work (flexible-array member conversions) will also
#     help to get completely rid of those sorts of issues.
#     
#     Notice that, currently, more than 250 of these patches have already
#     been merged into mainline during the last merge window, including
#     5.7-rc2. So, in order to make better use of everyone's time, I'm
#     planning to add this treewide patch to my -next tree and then send a
#     pull request to Linus for 5.7-rc3 or -rc4, after getting some acks
#     and/or reviews.
#     
#     This treewide patch has been successfully built (on top of v5.7-rc1) for
#     multiple architectures (arm, arm64, sparc, powerpc, ia64, s390, i386,
#     nios2, c6x, xtensa, openrisc, mips, parisc, x86_64, riscv, sh, sparc64)
#     and 82 different configurations with the help of the 0-day CI guys[5].
#     
#     This issue was found with the help of Coccinelle.
#     
#     [1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
#     [2] https://github.com/KSPP/linux/issues/21
#     [3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour")
#     [4] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/log/?qt=grep&q=replace+zero-length+array+with+flexible-array+member
#     [5] https://github.com/GustavoARSilva/linux-hardening/blob/master/cii/kernel-ci/kspp-fam0-20200420.md
#     
#     Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
# < /opt/cross/kisskb/korg/gcc-8.1.0-nolibc/mips-linux/bin/mips-linux-gcc --version
# < /opt/cross/kisskb/korg/gcc-8.1.0-nolibc/mips-linux/bin/mips-linux-ld --version
# < git log --format=%s --max-count=1 d783301058f3d3605f9ad34f0192692ef572d663
# < make -s -j 24 ARCH=mips O=/kisskb/build/gustavoars_cavium_octeon_defconfig_mips-gcc8 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-8.1.0-nolibc/mips-linux/bin/mips-linux-  cavium_octeon_defconfig
# < make -s -j 24 ARCH=mips O=/kisskb/build/gustavoars_cavium_octeon_defconfig_mips-gcc8 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-8.1.0-nolibc/mips-linux/bin/mips-linux-  help
# make -s -j 24 ARCH=mips O=/kisskb/build/gustavoars_cavium_octeon_defconfig_mips-gcc8 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-8.1.0-nolibc/mips-linux/bin/mips-linux-  olddefconfig
# make -s -j 24 ARCH=mips O=/kisskb/build/gustavoars_cavium_octeon_defconfig_mips-gcc8 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-8.1.0-nolibc/mips-linux/bin/mips-linux-  
Completed OK
# rm -rf /kisskb/build/gustavoars_cavium_octeon_defconfig_mips-gcc8
# Build took: 0:02:00.642795