# git rev-parse -q --verify a970174d7a1010cb29a5b0c9fa0626abdefcfcbe^{commit}
a970174d7a1010cb29a5b0c9fa0626abdefcfcbe
already have revision, skipping fetch
# git checkout -q -f -B kisskb a970174d7a1010cb29a5b0c9fa0626abdefcfcbe
# git clean -qxdf
# < git log -1
# commit a970174d7a1010cb29a5b0c9fa0626abdefcfcbe
# Author: Steven Rostedt (Google) <rostedt@goodmis.org>
# Date:   Mon Oct 24 11:45:36 2022 -0400
# 
#     x86/mm: Do not verify W^X at boot up
#     
#     Adding on the kernel command line "ftrace=function" triggered:
#     
#       CPA detected W^X violation: 8000000000000063 -> 0000000000000063 range: 0xffffffffc0013000 - 0xffffffffc0013fff PFN 10031b
#       WARNING: CPU: 0 PID: 0 at arch/x86/mm/pat/set_memory.c:609
#       verify_rwx+0x61/0x6d
#       Call Trace:
#          __change_page_attr_set_clr+0x146/0x8a6
#          change_page_attr_set_clr+0x135/0x268
#          change_page_attr_clear.constprop.0+0x16/0x1c
#          set_memory_x+0x2c/0x32
#          arch_ftrace_update_trampoline+0x218/0x2db
#          ftrace_update_trampoline+0x16/0xa1
#          __register_ftrace_function+0x93/0xb2
#          ftrace_startup+0x21/0xf0
#          register_ftrace_function_nolock+0x26/0x40
#          register_ftrace_function+0x4e/0x143
#          function_trace_init+0x7d/0xc3
#          tracer_init+0x23/0x2c
#          tracing_set_tracer+0x1d5/0x206
#          register_tracer+0x1c0/0x1e4
#          init_function_trace+0x90/0x96
#          early_trace_init+0x25c/0x352
#          start_kernel+0x424/0x6e4
#          x86_64_start_reservations+0x24/0x2a
#          x86_64_start_kernel+0x8c/0x95
#          secondary_startup_64_no_verify+0xe0/0xeb
#     
#     This is because at boot up, kernel text is writable, and there's no
#     reason to do tricks to updated it.  But the verifier does not
#     distinguish updates at boot up and at run time, and causes a warning at
#     time of boot.
#     
#     Add a check for system_state == SYSTEM_BOOTING and allow it if that is
#     the case.
#     
#     [ These SYSTEM_BOOTING special cases are all pretty horrid, but the x86
#       text_poke() code does some odd things at bootup, forcing this for now
#         - Linus ]
#     
#     Link: https://lore.kernel.org/r/20221024112730.180916b3@gandalf.local.home
#     Fixes: 652c5bf380ad0 ("x86/mm: Refuse W^X violations")
#     Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
#     Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
# < /opt/cross/kisskb/korg/gcc-5.5.0-nolibc/aarch64-linux/bin/aarch64-linux-gcc --version
# < /opt/cross/kisskb/korg/gcc-5.5.0-nolibc/aarch64-linux/bin/aarch64-linux-ld --version
# < git log --format=%s --max-count=1 a970174d7a1010cb29a5b0c9fa0626abdefcfcbe
# < make -s -j 160 ARCH=arm64 O=/kisskb/build/linus_arm64-allnoconfig_arm64-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/aarch64-linux/bin/aarch64-linux-  allnoconfig
# < make -s -j 160 ARCH=arm64 O=/kisskb/build/linus_arm64-allnoconfig_arm64-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/aarch64-linux/bin/aarch64-linux-  help
# make -s -j 160 ARCH=arm64 O=/kisskb/build/linus_arm64-allnoconfig_arm64-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/aarch64-linux/bin/aarch64-linux-  olddefconfig
# make -s -j 160 ARCH=arm64 O=/kisskb/build/linus_arm64-allnoconfig_arm64-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/aarch64-linux/bin/aarch64-linux-  
Completed OK
# rm -rf /kisskb/build/linus_arm64-allnoconfig_arm64-gcc5
# Build took: 0:00:20.193513