# git rev-parse -q --verify 70b20dd7f897c6c14ab9e0d8400aed520ab5f09b^{commit} 70b20dd7f897c6c14ab9e0d8400aed520ab5f09b already have revision, skipping fetch # git checkout -q -f -B kisskb 70b20dd7f897c6c14ab9e0d8400aed520ab5f09b # git clean -qxdf # < git log -1 # commit 70b20dd7f897c6c14ab9e0d8400aed520ab5f09b # Author: Linus Torvalds # Date: Wed Aug 15 19:08:10 2018 -0700 # # ALSA: update dell-wmi mic-mute registration to new world order # # Commit c647f806b8c2 ("ALSA: hda - Allow multiple ADCs for mic mute LED # controls") changed the return value of the snd_hda_gen_add_micmute_led() # without actually updating the callers. # # Admittedly, almost no callers actually cared about the return value. # But one call site very much did: the Dell wmi code. It would see the # registration return zero, which _used_ to mean "failed" but now means # "success", and clear the dell_micmute_led_set_func pointer. # # End result: the successful registration would end up calling the Dell # code that thought it had all failed, and call through a NULL pointer. # # To make matters worse, it ends up being a tail-call, and with the # retpoline sequence you don't even see the caller (dell_micmute_update()) # in the stack trace, so the error ended up way less obvious than it # should have been. # # Fixes: c647f806b8c2 "ALSA: hda - Allow multiple ADCs for mic mute LED controls" # Cc: Takashi Iwai # Signed-off-by: Linus Torvalds # < /opt/cross/kisskb/br-microblaze-full-2016.08-613-ge98b4dd/bin/microblazeel-linux-gcc --version # < git log --format=%s --max-count=1 70b20dd7f897c6c14ab9e0d8400aed520ab5f09b # < make -s -j 10 ARCH=microblaze O=/kisskb/build/linus_nommu_defconfig_microblaze CROSS_COMPILE=/opt/cross/kisskb/br-microblaze-full-2016.08-613-ge98b4dd/bin/microblazeel-linux- nommu_defconfig # make -s -j 10 ARCH=microblaze O=/kisskb/build/linus_nommu_defconfig_microblaze CROSS_COMPILE=/opt/cross/kisskb/br-microblaze-full-2016.08-613-ge98b4dd/bin/microblazeel-linux- Kernel: arch/microblaze/boot/linux.bin is ready (#1) Completed OK # rm -rf /kisskb/build/linus_nommu_defconfig_microblaze # Build took: 0:00:50.523229