# 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 <fbarrat@linux.ibm.com>
# 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 <fbarrat@linux.ibm.com>
#     Reviewed-by: Sam Bobroff <sbobroff@linux.ibm.com>
#     Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
#     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 120 ARCH=powerpc O=/kisskb/build/powerpc-fixes_85xx_xes_mpc85xx_defconfig_powerpc-gcc4.6 CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/powerpc-linux/bin/powerpc-linux-  85xx/xes_mpc85xx_defconfig
# make -s -j 120 ARCH=powerpc O=/kisskb/build/powerpc-fixes_85xx_xes_mpc85xx_defconfig_powerpc-gcc4.6 CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/powerpc-linux/bin/powerpc-linux-  
/kisskb/src/kernel/rcu/srcutree.c: In function 'init_srcu_struct_fields':
/kisskb/src/kernel/rcu/srcutree.c:140:32: warning: 'levelspread[<U 140>]' may be used uninitialized in this function [-Wuninitialized]
/kisskb/src/kernel/rcu/srcutree.c:88:6: note: 'levelspread[<U 140>]' 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/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/fs/udf/unicode.c: In function 'udf_name_conv_char':
/kisskb/src/fs/udf/unicode.c:132:8: warning: 'c' 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
/kisskb/src/drivers/mtd/nand/raw/fsl_upm.c: In function 'fun_wait_rnb':
/kisskb/src/drivers/mtd/nand/raw/fsl_upm.c:65:20: warning: unused variable 'mtd' [-Wunused-variable]
/kisskb/src/drivers/usb/core/devio.c: In function 'async_completed':
/kisskb/src/drivers/usb/core/devio.c:625:23: warning: 'errno' may be used uninitialized in this function [-Wuninitialized]
INFO: Uncompressed kernel (size 0x818e28) overlaps the address of the wrapper(0x400000)
INFO: Fixing the link_address of wrapper to (0x900000)
Image Name:   Linux-5.4.0-rc2-ga8a30219ba78
Created:      Fri Oct 25 22:32:22 2019
Image Type:   PowerPC Linux Kernel Image (gzip compressed)
Data Size:    4187594 Bytes = 4089.45 KiB = 3.99 MiB
Load Address: 00000000
Entry Point:  00000000
Completed OK
# rm -rf /kisskb/build/powerpc-fixes_85xx_xes_mpc85xx_defconfig_powerpc-gcc4.6
# Build took: 0:00:35.720020