# git rev-parse -q --verify 0c69905577499b8e057767e08a763443ebf504fb^{commit}
0c69905577499b8e057767e08a763443ebf504fb
already have revision, skipping fetch
# git checkout -q -f -B kisskb 0c69905577499b8e057767e08a763443ebf504fb
# git clean -qxdf
# < git log -1
# commit 0c69905577499b8e057767e08a763443ebf504fb
# Author: Michael Ellerman <mpe@ellerman.id.au>
# Date:   Wed May 25 13:26:39 2022 +1000
# 
#     powerpc: Don't select HAVE_IRQ_EXIT_ON_IRQ_STACK
#     
#     The HAVE_IRQ_EXIT_ON_IRQ_STACK option tells generic code that irq_exit()
#     is called while still running on the hard irq stack (hardirq_ctx[] in
#     the powerpc code).
#     
#     Selecting the option means the generic code will *not* switch to the
#     softirq stack before running softirqs, because the code is already
#     running on the (mostly empty) hard irq stack.
#     
#     But since commit 1b1b6a6f4cc0 ("powerpc: handle irq_enter/irq_exit in
#     interrupt handler wrappers"), irq_exit() is now called on the regular task
#     stack, not the hard irq stack.
#     
#     That's because previously irq_exit() was called in __do_irq() which is
#     run on the hard irq stack, but now it is called in
#     interrupt_async_exit_prepare() which is called from do_irq() constructed
#     by the wrapper macro, which is after the switch back to the task stack.
#     
#     So drop HAVE_IRQ_EXIT_ON_IRQ_STACK from the Kconfig. This will mean an
#     extra stack switch when processing some interrupts, but should
#     significantly reduce the likelihood of stack overflow.
#     
#     It also means the softirq stack will be used for running softirqs from
#     other interrupts that don't use the hard irq stack, eg. timer interrupts.
#     
#     Fixes: 1b1b6a6f4cc0 ("powerpc: handle irq_enter/irq_exit in interrupt handler wrappers")
#     Cc: stable@vger.kernel.org # v5.12+
#     Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
#     Link: https://lore.kernel.org/r/20220525032639.1947280-1-mpe@ellerman.id.au
# < /opt/cross/kisskb/korg/gcc-8.5.0-nolibc/x86_64-linux/bin/x86_64-linux-gcc --version
# < /opt/cross/kisskb/korg/gcc-8.5.0-nolibc/x86_64-linux/bin/x86_64-linux-ld --version
# < git log --format=%s --max-count=1 0c69905577499b8e057767e08a763443ebf504fb
# < make -s -j 120 ARCH=x86 O=/kisskb/build/powerpc-fixes_x86_64_defconfig_x86_64-gcc8 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-8.5.0-nolibc/x86_64-linux/bin/x86_64-linux-  x86_64_defconfig
# < make -s -j 120 ARCH=x86 O=/kisskb/build/powerpc-fixes_x86_64_defconfig_x86_64-gcc8 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-8.5.0-nolibc/x86_64-linux/bin/x86_64-linux-  help
# make -s -j 120 ARCH=x86 O=/kisskb/build/powerpc-fixes_x86_64_defconfig_x86_64-gcc8 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-8.5.0-nolibc/x86_64-linux/bin/x86_64-linux-  olddefconfig
# make -s -j 120 ARCH=x86 O=/kisskb/build/powerpc-fixes_x86_64_defconfig_x86_64-gcc8 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-8.5.0-nolibc/x86_64-linux/bin/x86_64-linux-  
Completed OK
# rm -rf /kisskb/build/powerpc-fixes_x86_64_defconfig_x86_64-gcc8
# Build took: 0:00:57.402387