# git rev-parse -q --verify 2e2e7910e6eccaed0c3bce8125e60e16d19dfc29^{commit}
# git fetch -q -n -f git://fs.ozlabs.ibm.com/kernel/mpe/kisskb master
# git rev-parse -q --verify 2e2e7910e6eccaed0c3bce8125e60e16d19dfc29^{commit}
2e2e7910e6eccaed0c3bce8125e60e16d19dfc29
# git checkout -q -f -B kisskb 2e2e7910e6eccaed0c3bce8125e60e16d19dfc29
# git clean -qxdf
# < git log -1
# commit 2e2e7910e6eccaed0c3bce8125e60e16d19dfc29
# Author: Nicholas Piggin <npiggin@gmail.com>
# Date:   Tue May 22 09:00:00 2018 +1000
# 
#     powerpc/64s: Add support for a store forwarding barrier at kernel entry/exit
#     
#     On some CPUs we can prevent a vulnerability related to store-to-load
#     forwarding by preventing store forwarding between privilege domains,
#     by inserting a barrier in kernel entry and exit paths.
#     
#     This is known to be the case on at least Power7, Power8 and Power9
#     powerpc CPUs.
#     
#     Barriers must be inserted generally before the first load after moving
#     to a higher privilege, and after the last store before moving to a
#     lower privilege, HV and PR privilege transitions must be protected.
#     
#     Barriers are added as patch sections, with all kernel/hypervisor entry
#     points patched, and the exit points to lower privilge levels patched
#     similarly to the RFI flush patching.
#     
#     Firmware advertisement is not implemented yet, so CPU flush types
#     are hard coded.
#     
#     Thanks to Michal Suchánek for bug fixes and review.
#     
#     Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
#     Signed-off-by: Mauricio Faria de Oliveira <mauricfo@linux.vnet.ibm.com>
#     Signed-off-by: Michael Neuling <mikey@neuling.org>
#     Signed-off-by: Michal Suchánek <msuchanek@suse.de>
#     Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
#     Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
#     (cherry picked from commit a048a07d7f4535baa4cbad6bc024f175317ab938)
# < /opt/cross/kisskb/gcc-4.6.3-nolibc/powerpc-linux/bin/powerpc-linux-gcc --version
# < git log --format=%s --max-count=1 2e2e7910e6eccaed0c3bce8125e60e16d19dfc29
# < make -s -j 48 ARCH=powerpc O=/kisskb/build/mpe_maple_defconfig_powerpc CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/powerpc-linux/bin/powerpc-linux-  maple_defconfig
# make -s -j 48 ARCH=powerpc O=/kisskb/build/mpe_maple_defconfig_powerpc CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/powerpc-linux/bin/powerpc-linux-  
/kisskb/src/kernel/printk/printk.c: In function 'devkmsg_sysctl_set_loglvl':
/kisskb/src/kernel/printk/printk.c:186:16: warning: 'old' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/kernel/rcu/srcutree.c: In function 'init_srcu_struct_fields':
/kisskb/src/kernel/rcu/srcutree.c:119:32: warning: 'levelspread[<U8280>]' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/kernel/rcu/srcutree.c:67:6: note: 'levelspread[<U8280>]' was declared here
/kisskb/src/drivers/tty/serial/8250/8250_core.c: In function 'univ8250_release_irq':
/kisskb/src/drivers/tty/serial/8250/8250_core.c:255:18: warning: 'i' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/drivers/tty/serial/8250/8250_core.c:235:19: note: 'i' was declared here
Completed OK
# rm -rf /kisskb/build/mpe_maple_defconfig_powerpc
# Build took: 0:01:11.129502