# git rev-parse -q --verify 6015b1aca1a233379625385feb01dd014aca60b5^{commit}
6015b1aca1a233379625385feb01dd014aca60b5
already have revision, skipping fetch
# git checkout -q -f -B kisskb 6015b1aca1a233379625385feb01dd014aca60b5
# git clean -qxdf
# < git log -1
# commit 6015b1aca1a233379625385feb01dd014aca60b5
# Author: Linus Torvalds <torvalds@linux-foundation.org>
# Date:   Tue Mar 14 19:32:38 2023 -0700
# 
#     sched_getaffinity: don't assume 'cpumask_size()' is fully initialized
#     
#     The getaffinity() system call uses 'cpumask_size()' to decide how big
#     the CPU mask is - so far so good.  It is indeed the allocation size of a
#     cpumask.
#     
#     But the code also assumes that the whole allocation is initialized
#     without actually doing so itself.  That's wrong, because we might have
#     fixed-size allocations (making copying and clearing more efficient), but
#     not all of it is then necessarily used if 'nr_cpu_ids' is smaller.
#     
#     Having checked other users of 'cpumask_size()', they all seem to be ok,
#     either using it purely for the allocation size, or explicitly zeroing
#     the cpumask before using the size in bytes to copy it.
#     
#     See for example the ublk_ctrl_get_queue_affinity() function that uses
#     the proper 'zalloc_cpumask_var()' to make sure that the whole mask is
#     cleared, whether the storage is on the stack or if it was an external
#     allocation.
#     
#     Fix this by just zeroing the allocation before using it.  Do the same
#     for the compat version of sched_getaffinity(), which had the same logic.
#     
#     Also, for consistency, make sched_getaffinity() use 'cpumask_bits()' to
#     access the bits.  For a cpumask_var_t, it ends up being a pointer to the
#     same data either way, but it's just a good idea to treat it like you
#     would a 'cpumask_t'.  The compat case already did that.
#     
#     Reported-by: Ryan Roberts <ryan.roberts@arm.com>
#     Link: https://lore.kernel.org/lkml/7d026744-6bd6-6827-0471-b5e8eae0be3f@arm.com/
#     Cc: Yury Norov <yury.norov@gmail.com>
#     Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
# < /opt/cross/kisskb/korg/gcc-11.1.0-nolibc/powerpc64-linux/bin/powerpc64-linux-gcc --version
# < /opt/cross/kisskb/korg/gcc-11.1.0-nolibc/powerpc64-linux/bin/powerpc64-linux-ld --version
# < git log --format=%s --max-count=1 6015b1aca1a233379625385feb01dd014aca60b5
# < make -s -j 24 ARCH=powerpc O=/kisskb/build/linus_pmac32_defconfig_powerpc-gcc11 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-11.1.0-nolibc/powerpc64-linux/bin/powerpc64-linux-  pmac32_defconfig
# < make -s -j 24 ARCH=powerpc O=/kisskb/build/linus_pmac32_defconfig_powerpc-gcc11 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-11.1.0-nolibc/powerpc64-linux/bin/powerpc64-linux-  help
# make -s -j 24 ARCH=powerpc O=/kisskb/build/linus_pmac32_defconfig_powerpc-gcc11 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-11.1.0-nolibc/powerpc64-linux/bin/powerpc64-linux-  olddefconfig
# make -s -j 24 ARCH=powerpc O=/kisskb/build/linus_pmac32_defconfig_powerpc-gcc11 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-11.1.0-nolibc/powerpc64-linux/bin/powerpc64-linux-  
Completed OK
# rm -rf /kisskb/build/linus_pmac32_defconfig_powerpc-gcc11
# Build took: 0:03:24.527378