# git rev-parse -q --verify a8a30219ba78b1abb92091102b632f8e9bbdbf03^{commit} a8a30219ba78b1abb92091102b632f8e9bbdbf03 already have revision, skipping fetch # git checkout -q -f -B kisskb a8a30219ba78b1abb92091102b632f8e9bbdbf03 # git clean -qxdf # < git log -1 # commit a8a30219ba78b1abb92091102b632f8e9bbdbf03 # Author: Frederic Barrat # Date: Wed Oct 16 18:28:33 2019 +0200 # # powerpc/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 eeh_add_device_late.part.9+0x50/0x1e0 # LR eeh_add_device_late.part.9+0x3c/0x1e0 # Call Trace: # _dev_info+0x5c/0x6c (unreliable) # pnv_pcibios_bus_add_device+0x60/0xb0 # pcibios_bus_add_device+0x40/0x60 # pci_bus_add_device+0x30/0x100 # pci_bus_add_devices+0x64/0xd0 # cxl_pci_vphb_add+0xe0/0x130 [cxl] # cxl_probe+0x504/0x5b0 [cxl] # local_pci_probe+0x6c/0x110 # 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/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 a8a30219ba78b1abb92091102b632f8e9bbdbf03 # < make -s -j 48 ARCH=powerpc O=/kisskb/build/powerpc-fixes_pmac32_defconfig+kexec_powerpc-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux- pmac32_defconfig # Added to kconfig configs/2006/11/29/pmac32_defconfigkexec # yes \n | make -s -j 48 ARCH=powerpc O=/kisskb/build/powerpc-fixes_pmac32_defconfig+kexec_powerpc-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux- oldconfig yes: standard output: Broken pipe # make -s -j 48 ARCH=powerpc O=/kisskb/build/powerpc-fixes_pmac32_defconfig+kexec_powerpc-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux- In file included from /kisskb/src/sound/ppc/pmac.h:12:0, from /kisskb/src/sound/ppc/awacs.c:16: /kisskb/src/sound/ppc/awacs.c: In function 'snd_pmac_awacs_init': /kisskb/src/include/sound/control.h:208:9: warning: 'speaker_vol' may be used uninitialized in this function [-Wmaybe-uninitialized] return _snd_ctl_add_slave(master, slave, 0); ^ /kisskb/src/sound/ppc/awacs.c:873:36: note: 'speaker_vol' was declared here struct snd_kcontrol *master_vol, *speaker_vol; ^ INFO: Uncompressed kernel (size 0x8c8b4c) overlaps the address of the wrapper(0x400000) INFO: Fixing the link_address of wrapper to (0x900000) Completed OK # rm -rf /kisskb/build/powerpc-fixes_pmac32_defconfig+kexec_powerpc-gcc5 # Build took: 0:01:40.527833