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

From: Leo Yan <leo.yan@linaro.org>
To: Russell King <linux@armlinux.org.uk>,
	Oleg Nesterov <oleg@redhat.com>,
	Catalin Marinas <catalin.marinas@arm.com>,
	Will Deacon <will@kernel.org>,
	Benjamin Herrenschmidt <benh@kernel.crashing.org>,
	Paul Mackerras <paulus@samba.org>,
	Michael Ellerman <mpe@ellerman.id.au>,
	Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
	"H. Peter Anvin" <hpa@zytor.com>,
	x86@kernel.org, Arnd Bergmann <arnd@arndb.de>,
	Alexei Starovoitov <ast@kernel.org>,
	Daniel Borkmann <daniel@iogearbox.net>,
	Martin KaFai Lau <kafai@fb.com>, Song Liu <songliubraving@fb.com>,
	Yonghong Song <yhs@fb.com>,
	"Naveen N. Rao" <naveen.n.rao@linux.vnet.ibm.com>,
	linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org,
	linux-arch@vger.kernel.org, netdev@vger.kernel.org,
	bpf@vger.kernel.org, clang-built-linux@googlegroups.com,
	Masami Hiramatsu <mhiramat@kernel.org>
Cc: Leo Yan <leo.yan@linaro.org>
Subject: [PATCH v2 0/3] arm/arm64: Add support for function error injection
Date: Tue,  6 Aug 2019 18:00:12 +0800	[thread overview]
Message-ID: <20190806100015.11256-1-leo.yan@linaro.org> (raw)

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