# git rev-parse -q --verify f112cb18162f4956fda5f69509e1857ce922ba58^{commit} # git fetch -q -n -f git://gitlab.ozlabs.ibm.com/linuxppc/linux.git fixes-test # git rev-parse -q --verify f112cb18162f4956fda5f69509e1857ce922ba58^{commit} f112cb18162f4956fda5f69509e1857ce922ba58 # git checkout -q -f -B kisskb f112cb18162f4956fda5f69509e1857ce922ba58 # git clean -qxdf # < git log -1 # commit f112cb18162f4956fda5f69509e1857ce922ba58 # Author: Frederic Barrat # Date: Wed Oct 16 18:28:33 2019 +0200 # # powernv/eeh: Fix oops when probing cxl devices # # Recent cleanup in the way EEH support is added to a device causes a # kernel oops when the cxl driver probes a device and creates virtual # devices discovered on the FPGA: # # BUG: Kernel NULL pointer dereference at 0x000000a0 # Faulting instruction address: 0xc000000000048070 # Oops: Kernel access of bad area, sig: 7 [#1] # ... # NIP [c000000000048070] eeh_add_device_late.part.9+0x50/0x1e0 # LR [c00000000004805c] eeh_add_device_late.part.9+0x3c/0x1e0 # Call Trace: # [c000200e43983900] [c00000000079e250] _dev_info+0x5c/0x6c (unreliable) # [c000200e43983980] [c0000000000d1ad0] pnv_pcibios_bus_add_device+0x60/0xb0 # [c000200e439839f0] [c0000000000606d0] pcibios_bus_add_device+0x40/0x60 # [c000200e43983a10] [c0000000006aa3a0] pci_bus_add_device+0x30/0x100 # [c000200e43983a80] [c0000000006aa4d4] pci_bus_add_devices+0x64/0xd0 # [c000200e43983ac0] [c00800001c429118] cxl_pci_vphb_add+0xe0/0x130 [cxl] # [c000200e43983b00] [c00800001c4242ac] cxl_probe+0x504/0x5b0 [cxl] # [c000200e43983bb0] [c0000000006bba1c] local_pci_probe+0x6c/0x110 # [c000200e43983c30] [c000000000159278] work_for_cpu_fn+0x38/0x60 # # The root cause is that those cxl virtual devices don't have a # representation in the device tree and therefore no associated pci_dn # structure. In eeh_add_device_late(), pdn is NULL, so edev is NULL and # we oops. # # We never had explicit support for EEH for those virtual # devices. Instead, EEH events are reported to the (real) pci device and # handled by the cxl driver. Which can then forward to the virtual # devices and handle dependencies. The fact that we try adding EEH # support for the virtual devices is new and a side-effect of the recent # cleanup. # # This patch fixes it by skipping adding EEH support on powernv for # devices which don't have a pci_dn structure. # # The cxl driver doesn't create virtual devices on pseries so this patch # doesn't fix it there intentionally. # # Fixes: b905f8cdca77 ("powerpc/eeh: EEH for pSeries hot plug") # Signed-off-by: Frederic Barrat # Reviewed-by: Sam Bobroff # Signed-off-by: Michael Ellerman # Link: https://lore.kernel.org/r/20191016162833.22509-1-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 f112cb18162f4956fda5f69509e1857ce922ba58 # < make -s -j 24 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 24 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-rc2-gf112cb18162f Created: Fri Oct 25 19:17:02 2019 Image 0 (kernel@0) Description: Linux 5.4.0-rc2-gf112cb18162f Created: Fri Oct 25 19:17:02 2019 Type: Kernel Image Compression: gzip compressed Data Size: 4788474 Bytes = 4676.24 KiB = 4.57 MiB Architecture: MIPS OS: Linux Load Address: 0x80100000 Entry Point: 0x808d5390 Hash algo: sha1 Hash value: bcf5fb540f63d5e183a3de63aee48dab5e5af6a1 Image 1 (fdt@boston) Description: img,boston Device Tree Created: Fri Oct 25 19:17:02 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: Fri Oct 25 19:17:02 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: Fri Oct 25 19:17:02 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: Fri Oct 25 19:17:02 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: Fri Oct 25 19:17:02 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: 0:01:52.399747