From mboxrd@z Thu Jan 1 00:00:00 1970 From: Russell King - ARM Linux admin Subject: Re: [PATCH v2 3/3] arm: Add support for function error injection Date: Thu, 29 Aug 2019 07:57:29 +0100 Message-ID: <20190829065729.GU13294@shell.armlinux.org.uk> References: <20190806100015.11256-1-leo.yan@linaro.org> <20190806100015.11256-4-leo.yan@linaro.org> <20190819091808.GB5599@leoy-ThinkPad-X240s> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20190819091808.GB5599@leoy-ThinkPad-X240s> Sender: netdev-owner@vger.kernel.org To: Leo Yan Cc: Oleg Nesterov , Catalin Marinas , Will Deacon , Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman , Thomas Gleixner , Ingo Molnar , Borislav Petkov , "H. Peter Anvin" , x86@kernel.org, Arnd Bergmann , Alexei Starovoitov , Daniel Borkmann , Martin KaFai Lau , Song Liu , Yonghong Song , "Naveen N. Rao" , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-arch@vger.kernel.org List-Id: linux-arch.vger.kernel.org I'm sorry, I can't apply this, it produces loads of: include/linux/error-injection.h:7:10: fatal error: asm/error-injection.h: No such file or directory Since your patch 1 has been merged by the ARM64 people, I can't take it until next cycle. On Mon, Aug 19, 2019 at 05:18:08PM +0800, Leo Yan wrote: > Hi Russell, > > On Tue, Aug 06, 2019 at 06:00:15PM +0800, Leo Yan wrote: > > This patch implements arm specific functions regs_set_return_value() and > > override_function_with_return() to support function error injection. > > > > In the exception flow, it updates pt_regs::ARM_pc with pt_regs::ARM_lr > > so can override the probed function return. > > Gentle ping ... Could you review this patch? > > Thanks, > Leo. > > > Signed-off-by: Leo Yan > > --- > > arch/arm/Kconfig | 1 + > > arch/arm/include/asm/ptrace.h | 5 +++++ > > arch/arm/lib/Makefile | 2 ++ > > arch/arm/lib/error-inject.c | 19 +++++++++++++++++++ > > 4 files changed, 27 insertions(+) > > create mode 100644 arch/arm/lib/error-inject.c > > > > diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig > > index 33b00579beff..2d3d44a037f6 100644 > > --- a/arch/arm/Kconfig > > +++ b/arch/arm/Kconfig > > @@ -77,6 +77,7 @@ config ARM > > select HAVE_EXIT_THREAD > > select HAVE_FAST_GUP if ARM_LPAE > > select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL > > + select HAVE_FUNCTION_ERROR_INJECTION if !THUMB2_KERNEL > > select HAVE_FUNCTION_GRAPH_TRACER if !THUMB2_KERNEL && !CC_IS_CLANG > > select HAVE_FUNCTION_TRACER if !XIP_KERNEL > > select HAVE_GCC_PLUGINS > > diff --git a/arch/arm/include/asm/ptrace.h b/arch/arm/include/asm/ptrace.h > > index 91d6b7856be4..3b41f37b361a 100644 > > --- a/arch/arm/include/asm/ptrace.h > > +++ b/arch/arm/include/asm/ptrace.h > > @@ -89,6 +89,11 @@ static inline long regs_return_value(struct pt_regs *regs) > > return regs->ARM_r0; > > } > > > > +static inline void regs_set_return_value(struct pt_regs *regs, unsigned long rc) > > +{ > > + regs->ARM_r0 = rc; > > +} > > + > > #define instruction_pointer(regs) (regs)->ARM_pc > > > > #ifdef CONFIG_THUMB2_KERNEL > > diff --git a/arch/arm/lib/Makefile b/arch/arm/lib/Makefile > > index b25c54585048..8f56484a7156 100644 > > --- a/arch/arm/lib/Makefile > > +++ b/arch/arm/lib/Makefile > > @@ -42,3 +42,5 @@ ifeq ($(CONFIG_KERNEL_MODE_NEON),y) > > CFLAGS_xor-neon.o += $(NEON_FLAGS) > > obj-$(CONFIG_XOR_BLOCKS) += xor-neon.o > > endif > > + > > +obj-$(CONFIG_FUNCTION_ERROR_INJECTION) += error-inject.o > > diff --git a/arch/arm/lib/error-inject.c b/arch/arm/lib/error-inject.c > > new file mode 100644 > > index 000000000000..2d696dc94893 > > --- /dev/null > > +++ b/arch/arm/lib/error-inject.c > > @@ -0,0 +1,19 @@ > > +// SPDX-License-Identifier: GPL-2.0 > > + > > +#include > > +#include > > + > > +void override_function_with_return(struct pt_regs *regs) > > +{ > > + /* > > + * 'regs' represents the state on entry of a predefined function in > > + * the kernel/module and which is captured on a kprobe. > > + * > > + * 'regs->ARM_lr' contains the the link register for the probed > > + * function, when kprobe returns back from exception it will override > > + * the end of probed function and directly return to the predefined > > + * function's caller. > > + */ > > + instruction_pointer_set(regs, regs->ARM_lr); > > +} > > +NOKPROBE_SYMBOL(override_function_with_return); > > -- > > 2.17.1 > > > -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTC broadband for 0.8mile line in suburbia: sync at 12.1Mbps down 622kbps up According to speedtest.net: 11.9Mbps down 500kbps up From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from pandora.armlinux.org.uk ([78.32.30.218]:40420 "EHLO pandora.armlinux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726330AbfH2G6i (ORCPT ); Thu, 29 Aug 2019 02:58:38 -0400 Date: Thu, 29 Aug 2019 07:57:29 +0100 From: Russell King - ARM Linux admin Subject: Re: [PATCH v2 3/3] arm: Add support for function error injection Message-ID: <20190829065729.GU13294@shell.armlinux.org.uk> References: <20190806100015.11256-1-leo.yan@linaro.org> <20190806100015.11256-4-leo.yan@linaro.org> <20190819091808.GB5599@leoy-ThinkPad-X240s> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190819091808.GB5599@leoy-ThinkPad-X240s> Sender: linux-arch-owner@vger.kernel.org List-ID: To: Leo Yan Cc: Oleg Nesterov , Catalin Marinas , Will Deacon , Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman , Thomas Gleixner , Ingo Molnar , Borislav Petkov , "H. Peter Anvin" , x86@kernel.org, Arnd Bergmann , Alexei Starovoitov , Daniel Borkmann , Martin KaFai Lau , Song Liu , Yonghong Song , "Naveen N. Rao" , 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 Message-ID: <20190829065729.o7Qw-aPsZMAz7ebEgGWecCcHPMrBEG6sQNd839Eje3I@z> I'm sorry, I can't apply this, it produces loads of: include/linux/error-injection.h:7:10: fatal error: asm/error-injection.h: No such file or directory Since your patch 1 has been merged by the ARM64 people, I can't take it until next cycle. On Mon, Aug 19, 2019 at 05:18:08PM +0800, Leo Yan wrote: > Hi Russell, > > On Tue, Aug 06, 2019 at 06:00:15PM +0800, Leo Yan wrote: > > This patch implements arm specific functions regs_set_return_value() and > > override_function_with_return() to support function error injection. > > > > In the exception flow, it updates pt_regs::ARM_pc with pt_regs::ARM_lr > > so can override the probed function return. > > Gentle ping ... Could you review this patch? > > Thanks, > Leo. > > > Signed-off-by: Leo Yan > > --- > > arch/arm/Kconfig | 1 + > > arch/arm/include/asm/ptrace.h | 5 +++++ > > arch/arm/lib/Makefile | 2 ++ > > arch/arm/lib/error-inject.c | 19 +++++++++++++++++++ > > 4 files changed, 27 insertions(+) > > create mode 100644 arch/arm/lib/error-inject.c > > > > diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig > > index 33b00579beff..2d3d44a037f6 100644 > > --- a/arch/arm/Kconfig > > +++ b/arch/arm/Kconfig > > @@ -77,6 +77,7 @@ config ARM > > select HAVE_EXIT_THREAD > > select HAVE_FAST_GUP if ARM_LPAE > > select HAVE_FTRACE_MCOUNT_RECORD if !XIP_KERNEL > > + select HAVE_FUNCTION_ERROR_INJECTION if !THUMB2_KERNEL > > select HAVE_FUNCTION_GRAPH_TRACER if !THUMB2_KERNEL && !CC_IS_CLANG > > select HAVE_FUNCTION_TRACER if !XIP_KERNEL > > select HAVE_GCC_PLUGINS > > diff --git a/arch/arm/include/asm/ptrace.h b/arch/arm/include/asm/ptrace.h > > index 91d6b7856be4..3b41f37b361a 100644 > > --- a/arch/arm/include/asm/ptrace.h > > +++ b/arch/arm/include/asm/ptrace.h > > @@ -89,6 +89,11 @@ static inline long regs_return_value(struct pt_regs *regs) > > return regs->ARM_r0; > > } > > > > +static inline void regs_set_return_value(struct pt_regs *regs, unsigned long rc) > > +{ > > + regs->ARM_r0 = rc; > > +} > > + > > #define instruction_pointer(regs) (regs)->ARM_pc > > > > #ifdef CONFIG_THUMB2_KERNEL > > diff --git a/arch/arm/lib/Makefile b/arch/arm/lib/Makefile > > index b25c54585048..8f56484a7156 100644 > > --- a/arch/arm/lib/Makefile > > +++ b/arch/arm/lib/Makefile > > @@ -42,3 +42,5 @@ ifeq ($(CONFIG_KERNEL_MODE_NEON),y) > > CFLAGS_xor-neon.o += $(NEON_FLAGS) > > obj-$(CONFIG_XOR_BLOCKS) += xor-neon.o > > endif > > + > > +obj-$(CONFIG_FUNCTION_ERROR_INJECTION) += error-inject.o > > diff --git a/arch/arm/lib/error-inject.c b/arch/arm/lib/error-inject.c > > new file mode 100644 > > index 000000000000..2d696dc94893 > > --- /dev/null > > +++ b/arch/arm/lib/error-inject.c > > @@ -0,0 +1,19 @@ > > +// SPDX-License-Identifier: GPL-2.0 > > + > > +#include > > +#include > > + > > +void override_function_with_return(struct pt_regs *regs) > > +{ > > + /* > > + * 'regs' represents the state on entry of a predefined function in > > + * the kernel/module and which is captured on a kprobe. > > + * > > + * 'regs->ARM_lr' contains the the link register for the probed > > + * function, when kprobe returns back from exception it will override > > + * the end of probed function and directly return to the predefined > > + * function's caller. > > + */ > > + instruction_pointer_set(regs, regs->ARM_lr); > > +} > > +NOKPROBE_SYMBOL(override_function_with_return); > > -- > > 2.17.1 > > > -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTC broadband for 0.8mile line in suburbia: sync at 12.1Mbps down 622kbps up According to speedtest.net: 11.9Mbps down 500kbps up