[PATCH v2 0/3] arm/arm64: Add support for function error injection

[Leo Yan]

This small patch set is to add support for function error injection;
this can be used to eanble more advanced debugging feature, e.g.
CONFIG_BPF_KPROBE_OVERRIDE.

The patch 01/03 is to consolidate the function definition which can be
suared cross architectures, patches 02,03/03 are used for enabling
function error injection on arm64 and arm architecture respectively.

I tested on arm64 platform Juno-r2 and one of my laptop with x86
architecture with below steps; I don't test for Arm architecture so
only pass compilation.

- Enable kernel configuration:
  CONFIG_BPF_KPROBE_OVERRIDE
  CONFIG_BTRFS_FS
  CONFIG_BPF_EVENTS=y
  CONFIG_KPROBES=y
  CONFIG_KPROBE_EVENTS=y
  CONFIG_BPF_KPROBE_OVERRIDE=y

- Build samples/bpf on with Debian rootFS:
  # cd $kernel
  # make headers_install
  # make samples/bpf/ LLC=llc-7 CLANG=clang-7

- Run the sample tracex7:
  # dd if=/dev/zero of=testfile.img bs=1M seek=1000 count=1
  # DEVICE=$(losetup --show -f testfile.img)
  # mkfs.btrfs -f $DEVICE
  # ./tracex7 testfile.img
  [ 1975.211781] BTRFS error (device (efault)): open_ctree failed
  mount: /mnt/linux-kernel/linux-cs-dev/samples/bpf/tmpmnt: mount(2) system call failed: Cannot allocate memory.

Changes from v1:
* Consolidated the function definition into asm-generic header (Will);
* Used APIs to access pt_regs elements (Will);
* Fixed typos in the comments (Will).


Leo Yan (3):
  error-injection: Consolidate override function definition
  arm64: Add support for function error injection
  arm: Add support for function error injection

 arch/arm/Kconfig                           |  1 +
 arch/arm/include/asm/ptrace.h              |  5 +++++
 arch/arm/lib/Makefile                      |  2 ++
 arch/arm/lib/error-inject.c                | 19 +++++++++++++++++++
 arch/arm64/Kconfig                         |  1 +
 arch/arm64/include/asm/ptrace.h            |  5 +++++
 arch/arm64/lib/Makefile                    |  2 ++
 arch/arm64/lib/error-inject.c              | 18 ++++++++++++++++++
 arch/powerpc/include/asm/error-injection.h | 13 -------------
 arch/x86/include/asm/error-injection.h     | 13 -------------
 include/asm-generic/error-injection.h      |  6 ++++++
 include/linux/error-injection.h            |  6 +++---
 12 files changed, 62 insertions(+), 29 deletions(-)
 create mode 100644 arch/arm/lib/error-inject.c
 create mode 100644 arch/arm64/lib/error-inject.c
 delete mode 100644 arch/powerpc/include/asm/error-injection.h
 delete mode 100644 arch/x86/include/asm/error-injection.h

-- 
2.17.1