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

From: Leo Yan <leo.yan@linaro.org>
To: Masami Hiramatsu <mhiramat@kernel.org>
Cc: 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
Subject: Re: [PATCH v2 0/3] arm/arm64: Add support for function error injection
Date: Wed, 7 Aug 2019 09:31:39 +0800	[thread overview]
Message-ID: <20190807013139.GB6724@leoy-ThinkPad-X240s> (raw)
In-Reply-To: <20190807090811.1e50eb3e1d5a7b85743748e7@kernel.org>

On Wed, Aug 07, 2019 at 09:08:11AM +0900, Masami Hiramatsu wrote:
> On Tue,  6 Aug 2019 18:00:12 +0800
> Leo Yan <leo.yan@linaro.org> wrote:
> 
> > 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.