# 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/gcc-4.6.3-nolibc/powerpc-linux/bin/powerpc-linux-gcc --version # < /opt/cross/kisskb/gcc-4.6.3-nolibc/powerpc-linux/bin/powerpc-linux-ld --version # < git log --format=%s --max-count=1 a8a30219ba78b1abb92091102b632f8e9bbdbf03 # < make -s -j 24 ARCH=powerpc O=/kisskb/build/powerpc-fixes_mpc885_ads_defconfig+HUGETLB_powerpc-gcc4.6 CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/powerpc-linux/bin/powerpc-linux- mpc885_ads_defconfig # Added to kconfig CONFIG_HUGETLBFS=y # yes \n | make -s -j 24 ARCH=powerpc O=/kisskb/build/powerpc-fixes_mpc885_ads_defconfig+HUGETLB_powerpc-gcc4.6 CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/powerpc-linux/bin/powerpc-linux- oldconfig yes: standard output: Broken pipe # make -s -j 24 ARCH=powerpc O=/kisskb/build/powerpc-fixes_mpc885_ads_defconfig+HUGETLB_powerpc-gcc4.6 CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/powerpc-linux/bin/powerpc-linux- /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:338:21: note: 'pdeo' was declared here /kisskb/src/kernel/printk/printk.c: In function 'devkmsg_sysctl_set_loglvl': /kisskb/src/kernel/printk/printk.c:204:16: warning: 'old' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/mm/hugetlb.c: In function 'alloc_pool_huge_page': /kisskb/src/mm/hugetlb.c:1497:5: warning: 'page' may be used uninitialized in this function [-Wuninitialized] Image Name: Linux-5.4.0-rc2-ga8a30219ba78 Created: Fri Oct 25 23:18:25 2019 Image Type: PowerPC Linux Kernel Image (gzip compressed) Data Size: 1868773 Bytes = 1824.97 KiB = 1.78 MiB Load Address: 00400000 Entry Point: 004001dc Completed OK # rm -rf /kisskb/build/powerpc-fixes_mpc885_ads_defconfig+HUGETLB_powerpc-gcc4.6 # Build took: 0:00:48.974452