# 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/gcc-4.6.3-nolibc/arm-unknown-linux-gnueabi/bin/arm-unknown-linux-gnueabi-gcc --version # < git log --format=%s --max-count=1 70b20dd7f897c6c14ab9e0d8400aed520ab5f09b # < make -s -j 10 ARCH=arm O=/kisskb/build/linus_iop32x_defconfig_arm CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/arm-unknown-linux-gnueabi/bin/arm-unknown-linux-gnueabi- iop32x_defconfig # make -s -j 10 ARCH=arm O=/kisskb/build/linus_iop32x_defconfig_arm CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/arm-unknown-linux-gnueabi/bin/arm-unknown-linux-gnueabi- :1332:2: warning: #warning syscall io_pgetevents not implemented [-Wcpp] /kisskb/src/kernel/printk/printk.c: In function 'devkmsg_sysctl_set_loglvl': /kisskb/src/kernel/printk/printk.c:183:16: warning: 'old' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/drivers/base/regmap/regmap.c: In function 'regmap_raw_read': /kisskb/src/drivers/base/regmap/regmap.c:2511:6: warning: 'ret' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/drivers/base/regmap/regmap.c: In function '_regmap_raw_write': /kisskb/src/drivers/base/regmap/regmap.c:1833:6: warning: 'ret' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/fs/proc/inode.c: In function 'proc_reg_open': /kisskb/src/include/linux/list.h:65:12: warning: 'pdeo' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/fs/proc/inode.c:339:21: note: 'pdeo' was declared here Completed OK # rm -rf /kisskb/build/linus_iop32x_defconfig_arm # Build took: 0:01:20.353507