# git rev-parse -q --verify 3bf9c3bd86cdde4aa4d12c2705d93e1d90464710^{commit} 3bf9c3bd86cdde4aa4d12c2705d93e1d90464710 already have revision, skipping fetch # git checkout -q -f -B kisskb 3bf9c3bd86cdde4aa4d12c2705d93e1d90464710 # git clean -qxdf # < git log -1 # commit 3bf9c3bd86cdde4aa4d12c2705d93e1d90464710 # Author: Frederic Barrat # Date: Mon Jun 24 16:41:48 2019 +0200 # # ocxl: Fix concurrent AFU open and device removal # # If an ocxl device is unbound through sysfs at the same time its AFU is # being opened by a user process, the open code may dereference freed # stuctures, which can lead to kernel oops messages. You'd have to hit a # tiny time window, but it's possible. It's fairly easy to test by # making the time window bigger artificially. # # Fix it with a combination of 2 changes: # - when an AFU device is found in the IDR by looking for the device # minor number, we should hold a reference on the device until after # the context is allocated. A reference on the AFU structure is kept # when the context is allocated, so we can release the reference on # the device after the context allocation. # - with the fix above, there's still another even tinier window, # between the time the AFU device is found in the IDR and the # reference on the device is taken. We can fix this one by removing # the IDR entry earlier, when the device setup is removed, instead # of waiting for the 'release' device callback. With proper locking # around the IDR. # # Fixes: 75ca758adbaf ("ocxl: Create a clear delineation between ocxl backend & frontend") # Cc: stable@vger.kernel.org # v5.2+ # Signed-off-by: Frederic Barrat # Reviewed-by: Greg Kurz # Signed-off-by: Michael Ellerman # Link: https://lore.kernel.org/r/20190624144148.32022-1-fbarrat@linux.ibm.com # < /opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux-gcc --version # < /opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux-ld --version # < git log --format=%s --max-count=1 3bf9c3bd86cdde4aa4d12c2705d93e1d90464710 # < make -s -j 80 ARCH=powerpc O=/kisskb/build/powerpc-fixes_mpc86xx_defconfig_powerpc-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux- mpc86xx_defconfig # make -s -j 80 ARCH=powerpc O=/kisskb/build/powerpc-fixes_mpc86xx_defconfig_powerpc-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux- /kisskb/src/arch/powerpc/boot/dts/fsl/mvme7100.dts:135.22-137.4: Warning (pci_bridge): /pcie@f1008000: missing ranges for PCI bridge (or not a bridge) also defined at /kisskb/src/arch/powerpc/boot/dts/fsl/mpc8641si-post.dtsi:92.7-117.3 /kisskb/src/arch/powerpc/boot/dts/fsl/mpc8641si-post.dtsi:102.9-116.4: Warning (pci_bridge): /pcie@f1008000/pcie@0: missing ranges for PCI bridge (or not a bridge) /kisskb/src/arch/powerpc/boot/dts/fsl/mvme7100.dts:139.22-141.4: Warning (pci_bridge): /pcie@f1009000: missing ranges for PCI bridge (or not a bridge) also defined at /kisskb/src/arch/powerpc/boot/dts/fsl/mpc8641si-post.dtsi:119.7-144.3 /kisskb/src/arch/powerpc/boot/dts/fsl/mpc8641si-post.dtsi:129.9-143.4: Warning (pci_bridge): /pcie@f1009000/pcie@0: missing ranges for PCI bridge (or not a bridge) arch/powerpc/boot/dts/fsl/mvme7100.dtb: Warning (pci_device_bus_num): Failed prerequisite 'pci_bridge' /kisskb/src/arch/powerpc/boot/dts/fsl/mvme7100.dts:30.11-32.6: Warning (i2c_bus_reg): /soc@f1000000/i2c@3000/rtc@68: missing or empty reg property INFO: Uncompressed kernel (size 0xad976c) overlaps the address of the wrapper(0x400000) INFO: Fixing the link_address of wrapper to (0xb00000) Image Name: Linux-5.4.0-g3bf9c3bd86cd Created: Sat Dec 7 00:00:12 2019 Image Type: PowerPC Linux Kernel Image (gzip compressed) Data Size: 5344928 Bytes = 5219.66 KiB = 5.10 MiB Load Address: 00000000 Entry Point: 00000000 Completed OK # rm -rf /kisskb/build/powerpc-fixes_mpc86xx_defconfig_powerpc-gcc5 # Build took: 0:01:56.092296