# git rev-parse -q --verify f112cb18162f4956fda5f69509e1857ce922ba58^{commit} f112cb18162f4956fda5f69509e1857ce922ba58 already have revision, skipping fetch # 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/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 f112cb18162f4956fda5f69509e1857ce922ba58 # < make -s -j 20 ARCH=powerpc O=/kisskb/build/powerpc-fixes_83xx_mpc836x_mds_defconfig_powerpc-gcc4.6 CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/powerpc-linux/bin/powerpc-linux- 83xx/mpc836x_mds_defconfig # make -s -j 20 ARCH=powerpc O=/kisskb/build/powerpc-fixes_83xx_mpc836x_mds_defconfig_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/drivers/base/regmap/regmap.c: In function 'regmap_raw_read': /kisskb/src/drivers/base/regmap/regmap.c:2591:6: warning: 'ret' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/drivers/base/regmap/regmap.c: In function '_regmap_raw_write': /kisskb/src/drivers/base/regmap/regmap.c:1852:6: warning: 'ret' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/drivers/tty/serial/8250/8250_core.c: In function 'univ8250_release_irq': /kisskb/src/drivers/tty/serial/8250/8250_core.c:248:18: warning: 'i' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/drivers/tty/serial/8250/8250_core.c:228:19: note: 'i' was declared here INFO: Uncompressed kernel (size 0x5329e4) overlaps the address of the wrapper(0x400000) INFO: Fixing the link_address of wrapper to (0x600000) INFO: Uncompressed kernel (size 0x522338) overlaps the address of the wrapper(0x400000) INFO: Fixing the link_address of wrapper to (0x600000) Image Name: Linux-5.4.0-rc2-gf112cb18162f Created: Fri Oct 25 19:30:44 2019 Image Type: PowerPC Linux Kernel Image (gzip compressed) Data Size: 2590515 Bytes = 2529.80 KiB = 2.47 MiB Load Address: 00000000 Entry Point: 00000000 Image Name: Linux-5.4.0-rc2-gf112cb18162f Created: Fri Oct 25 19:30:44 2019 Image Type: PowerPC Linux Kernel Image (gzip compressed) Data Size: 2621406 Bytes = 2559.97 KiB = 2.50 MiB Load Address: 00600000 Entry Point: 00600290 Completed OK # rm -rf /kisskb/build/powerpc-fixes_83xx_mpc836x_mds_defconfig_powerpc-gcc4.6 # Build took: 0:00:48.638609