On Wed, Aug 07, 2019 at 09:08:11AM +0900, Masami Hiramatsu wrote:

On Tue,  6 Aug 2019 18:00:12 +0800
Leo Yan [off-list ref] wrote:

quoted

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).

This looks good to me.

Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>

Thank you!

Thanks a lot for reviewing, Masami.

Leo.