# git rev-parse -q --verify 26bc672134241a080a83b2ab9aa8abede8d30e1c^{commit}
26bc672134241a080a83b2ab9aa8abede8d30e1c
already have revision, skipping fetch
# git checkout -q -f -B kisskb 26bc672134241a080a83b2ab9aa8abede8d30e1c
# git clean -qxdf
# < git log -1
# commit 26bc672134241a080a83b2ab9aa8abede8d30e1c
# Merge: 7111fa1151e3 fa729c4df558
# Author: Linus Torvalds <torvalds@linux-foundation.org>
# Date:   Tue Nov 5 09:44:02 2019 -0800
# 
#     Merge tag 'for-linus-2019-11-05' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux
#     
#     Pull clone3 stack argument update from Christian Brauner:
#      "This changes clone3() to do basic stack validation and to set up the
#       stack depending on whether or not it is growing up or down.
#     
#       With clone3() the expectation is now very simply that the .stack
#       argument points to the lowest address of the stack and that
#       .stack_size specifies the initial stack size. This is diferent from
#       legacy clone() where the "stack" argument had to point to the lowest
#       or highest address of the stack depending on the architecture.
#     
#       clone3() was released with 5.3. Currently, it is not documented and
#       very unclear to userspace how the stack and stack_size argument have
#       to be passed. After talking to glibc folks we concluded that changing
#       clone3() to determine stack direction and doing basic validation is
#       the right course of action.
#     
#       Note, this is a potentially user visible change. In the very unlikely
#       case, that it breaks someone's use-case we will revert. (And then e.g.
#       place the new behavior under an appropriate flag.)
#     
#       Note that passing an empty stack will continue working just as before.
#       Breaking someone's use-case is very unlikely. Neither glibc nor musl
#       currently expose a wrapper for clone3(). There is currently also no
#       real motivation for anyone to use clone3() directly. First, because
#       using clone{3}() with stacks requires some assembly (see glibc and
#       musl). Second, because it does not provide features that legacy
#       clone() doesn't. New features for clone3() will first happen in v5.5
#       which is why v5.4 is still a good time to try and make that change now
#       and backport it to v5.3.
#     
#       I did a codesearch on https://codesearch.debian.net, github, and
#       gitlab and could not find any software currently relying directly on
#       clone3(). I expect this to change once we land CLONE_CLEAR_SIGHAND
#       which was a request coming from glibc at which point they'll likely
#       start using it"
#     
#     * tag 'for-linus-2019-11-05' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux:
#       clone3: validate stack arguments
# < /opt/cross/kisskb/or1k-linux-5.4.0-20170218/or1k-linux/bin/or1k-linux-gcc --version
# < /opt/cross/kisskb/or1k-linux-5.4.0-20170218/or1k-linux/bin/or1k-linux-ld --version
# < git log --format=%s --max-count=1 26bc672134241a080a83b2ab9aa8abede8d30e1c
# < make -s -j 48 ARCH=openrisc O=/kisskb/build/linus_or1ksim_defconfig_or32 CROSS_COMPILE=/opt/cross/kisskb/or1k-linux-5.4.0-20170218/or1k-linux/bin/or1k-linux-  or1ksim_defconfig
# make -s -j 48 ARCH=openrisc O=/kisskb/build/linus_or1ksim_defconfig_or32 CROSS_COMPILE=/opt/cross/kisskb/or1k-linux-5.4.0-20170218/or1k-linux/bin/or1k-linux-  
<stdin>:1511:2: warning: #warning syscall clone3 not implemented [-Wcpp]
Completed OK
# rm -rf /kisskb/build/linus_or1ksim_defconfig_or32
# Build took: 0:00:23.359187