# git rev-parse -q --verify 35f7eea41dba2cdfb11be7a37eb21cf010fd3220^{commit}
# git fetch -q -n -f git://gitlab.ozlabs.ibm.com/linuxppc/linux.git next-test
# git rev-parse -q --verify 35f7eea41dba2cdfb11be7a37eb21cf010fd3220^{commit}
35f7eea41dba2cdfb11be7a37eb21cf010fd3220
# git checkout -q -f -B kisskb 35f7eea41dba2cdfb11be7a37eb21cf010fd3220
# git clean -qxdf
# < git log -1
# commit 35f7eea41dba2cdfb11be7a37eb21cf010fd3220
# Author: Michael Ellerman <mpe@ellerman.id.au>
# Date:   Fri Aug 23 22:29:01 2019 +1000
# 
#     powerpc/64: Fix stacktrace on BE when function_graph is enabled
#     
#     Currently if we oops or warn while function_graph is active the stack
#     trace looks like:
#       .trace_graph_return+0xac/0x100
#       .ftrace_return_to_handler+0x98/0x140
#       .return_to_handler+0x20/0x40
#       .return_to_handler+0x0/0x40
#       .return_to_handler+0x0/0x40
#       .return_to_handler+0x0/0x40
#       .return_to_handler+0x0/0x40
#       .return_to_handler+0x0/0x40
#       .return_to_handler+0x0/0x40
#       .cpu_startup_entry+0x34/0x40
#       .start_secondary+0x680/0x6f0
#       start_secondary_prolog+0x10/0x14
#     
#     Notice the multiple entries that just show .return_to_handler.
#     
#     There is logic in show_stack() to detect this case and print the
#     traced function, but we inadvertently broke it in commit
#     7d56c65a6ff9 ("powerpc/ftrace: Remove mod_return_to_handler") (2014),
#     because that commit accidentally removed the dereference of rth which
#     gets the text address from the function descriptor. Hence this is only
#     broken on big endian (or technically ELFv1).
#     
#     Fix it by using the proper accessor, which is ppc_function_entry().
#     Result is we get a stack trace such as:
#     
#       .trace_graph_return+0x134/0x160
#       .ftrace_return_to_handler+0x94/0x140
#       .return_to_handler+0x20/0x40
#       .return_to_handler+0x0/0x40 (.shared_cede_loop+0x48/0x130)
#       .return_to_handler+0x0/0x40 (.cpuidle_enter_state+0xa0/0x690)
#       .return_to_handler+0x0/0x40 (.cpuidle_enter+0x44/0x70)
#       .return_to_handler+0x0/0x40 (.call_cpuidle+0x68/0xc0)
#       .return_to_handler+0x0/0x40 (.do_idle+0x37c/0x400)
#       .return_to_handler+0x0/0x40 (.cpu_startup_entry+0x30/0x50)
#       .rest_init+0x224/0x348
#     
#     Fixes: 7d56c65a6ff9 ("powerpc/ftrace: Remove mod_return_to_handler")
#     Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
#     Reviewed-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
#     Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
#     Link: https://lore.kernel.org/r/20190823122901.32667-1-mpe@ellerman.id.au
# < /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 35f7eea41dba2cdfb11be7a37eb21cf010fd3220
# < make -s -j 80 ARCH=mips O=/kisskb/build/powerpc-next_mips-defconfig_mipsel CROSS_COMPILE=/opt/cross/kisskb/br-mipsel-o32-full-2016.08-613-ge98b4dd/bin/mipsel-linux-  defconfig
# make -s -j 80 ARCH=mips O=/kisskb/build/powerpc-next_mips-defconfig_mipsel CROSS_COMPILE=/opt/cross/kisskb/br-mipsel-o32-full-2016.08-613-ge98b4dd/bin/mipsel-linux-  
<stdin>:1511:2: warning: #warning syscall clone3 not implemented [-Wcpp]
<stdin>:1511:2: warning: #warning syscall clone3 not implemented [-Wcpp]
FIT description: Linux 5.3.0-rc2-g35f7eea41dba
Created:         Thu Sep  5 22:11:32 2019
 Image 0 (kernel@0)
  Description:  Linux 5.3.0-rc2-g35f7eea41dba
  Created:      Thu Sep  5 22:11:32 2019
  Type:         Kernel Image
  Compression:  gzip compressed
  Data Size:    4707215 Bytes = 4596.89 KiB = 4.49 MiB
  Architecture: MIPS
  OS:           Linux
  Load Address: 0x80100000
  Entry Point:  0x808ae3b0
  Hash algo:    sha1
  Hash value:   cbd84d400265634fc81db2d5a6a457890c97b5c8
 Image 1 (fdt@boston)
  Description:  img,boston Device Tree
  Created:      Thu Sep  5 22:11:32 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:      Thu Sep  5 22:11:32 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:      Thu Sep  5 22:11:32 2019
  Type:         Flat Device Tree
  Compression:  uncompressed
  Data Size:    4615 Bytes = 4.51 KiB = 0.00 MiB
  Architecture: MIPS
  Hash algo:    sha1
  Hash value:   8754eadee600cac22c9c34884cd901aac7e95e8a
 Image 4 (fdt@ocelot_pcb120)
  Description:  MSCC Ocelot PCB120 Device Tree
  Created:      Thu Sep  5 22:11:32 2019
  Type:         Flat Device Tree
  Compression:  uncompressed
  Data Size:    5174 Bytes = 5.05 KiB = 0.00 MiB
  Architecture: MIPS
  Hash algo:    sha1
  Hash value:   1ab7d0871c0a9345c6269fb491bf028224da8256
 Image 5 (fdt@xilfpga)
  Description:  MIPSfpga (xilfpga) Device Tree
  Created:      Thu Sep  5 22:11:32 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-next_mips-defconfig_mipsel
# Build took: 0:01:53.017413