# git rev-parse -q --verify a5b9b743fdb653c37d347b303fb60dff0c743f7e^{commit} a5b9b743fdb653c37d347b303fb60dff0c743f7e already have revision, skipping fetch # git checkout -q -f -B kisskb a5b9b743fdb653c37d347b303fb60dff0c743f7e # git clean -qxdf # < git log -1 # commit a5b9b743fdb653c37d347b303fb60dff0c743f7e # 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/br-mipsel-o32-full-2016.08-613-ge98b4dd/bin/mipsel-linux-gcc --version # < /opt/cross/kisskb/br-mipsel-o32-full-2016.08-613-ge98b4dd/bin/mipsel-linux-ld --version # < git log --format=%s --max-count=1 a5b9b743fdb653c37d347b303fb60dff0c743f7e # < make -s -j 80 ARCH=mips O=/kisskb/build/powerpc-fixes_mips-defconfig_mipsel CROSS_COMPILE=/opt/cross/kisskb/br-mipsel-o32-full-2016.08-613-ge98b4dd/bin/mipsel-linux- defconfig # make -s -j 80 ARCH=mips O=/kisskb/build/powerpc-fixes_mips-defconfig_mipsel CROSS_COMPILE=/opt/cross/kisskb/br-mipsel-o32-full-2016.08-613-ge98b4dd/bin/mipsel-linux- FIT description: Linux 5.4.0-ga5b9b743fdb6 Created: Sat Dec 7 15:24:48 2019 Image 0 (kernel@0) Description: Linux 5.4.0-ga5b9b743fdb6 Created: Sat Dec 7 15:24:48 2019 Type: Kernel Image Compression: gzip compressed Data Size: 4843590 Bytes = 4730.07 KiB = 4.62 MiB Architecture: MIPS OS: Linux Load Address: 0x80100000 Entry Point: 0x808eec30 Hash algo: sha1 Hash value: 00fecb6948b0ee2f5087721a2bc9c5989b3a43b6 Image 1 (fdt@boston) Description: img,boston Device Tree Created: Sat Dec 7 15:24:48 2019 Type: Flat Device Tree Compression: uncompressed Data Size: 3793 Bytes = 3.70 KiB = 0.00 MiB Architecture: MIPS Hash algo: sha1 Hash value: 4799f50d688573234da6e9d7701234d394759ef4 Image 2 (fdt@ni169445) Description: NI 169445 device tree Created: Sat Dec 7 15:24:48 2019 Type: Flat Device Tree Compression: uncompressed Data Size: 1871 Bytes = 1.83 KiB = 0.00 MiB Architecture: MIPS Hash algo: sha1 Hash value: 51b89b31605ee62038c8468c429af091dfc75ec7 Image 3 (fdt@ocelot_pcb123) Description: MSCC Ocelot PCB123 Device Tree Created: Sat Dec 7 15:24:48 2019 Type: Flat Device Tree Compression: uncompressed Data Size: 4639 Bytes = 4.53 KiB = 0.00 MiB Architecture: MIPS Hash algo: sha1 Hash value: 018897896b42c41c943aca35a20e4300dba250c8 Image 4 (fdt@ocelot_pcb120) Description: MSCC Ocelot PCB120 Device Tree Created: Sat Dec 7 15:24:48 2019 Type: Flat Device Tree Compression: uncompressed Data Size: 5198 Bytes = 5.08 KiB = 0.00 MiB Architecture: MIPS Hash algo: sha1 Hash value: 36c7bd0bd79cfc2f7dd6acda6c7996294f4967e6 Image 5 (fdt@xilfpga) Description: MIPSfpga (xilfpga) Device Tree Created: Sat Dec 7 15:24:48 2019 Type: Flat Device Tree Compression: uncompressed Data Size: 2708 Bytes = 2.64 KiB = 0.00 MiB Architecture: MIPS Hash algo: sha1 Hash value: 63d058b780f65e22da30f0a183433765f1807f1d Default Configuration: 'conf@default' Configuration 0 (conf@default) Description: Generic Linux kernel Kernel: kernel@0 Configuration 1 (conf@boston) Description: Boston Linux kernel Kernel: kernel@0 FDT: fdt@boston Configuration 2 (conf@ni169445) Description: NI 169445 Linux Kernel Kernel: kernel@0 FDT: fdt@ni169445 Configuration 3 (conf@ocelot_pcb123) Description: Ocelot Linux kernel Kernel: kernel@0 FDT: fdt@ocelot_pcb123 Configuration 4 (conf@ocelot_pcb120) Description: Ocelot Linux kernel Kernel: kernel@0 FDT: fdt@ocelot_pcb120 Configuration 5 (conf@xilfpga) Description: MIPSfpga Linux kernel Kernel: kernel@0 FDT: fdt@xilfpga Completed OK # rm -rf /kisskb/build/powerpc-fixes_mips-defconfig_mipsel # Build took: 0:01:51.187876