From mboxrd@z Thu Jan 1 00:00:00 1970 From: Leo Yan Subject: [PATCH v2 2/3] arm64: Add support for function error injection Date: Tue, 6 Aug 2019 18:00:14 +0800 Message-ID: <20190806100015.11256-3-leo.yan@linaro.org> References: <20190806100015.11256-1-leo.yan@linaro.org> Return-path: In-Reply-To: <20190806100015.11256-1-leo.yan@linaro.org> Sender: linux-kernel-owner@vger.kernel.org To: Russell King , 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@lis Cc: Leo Yan List-Id: linux-arch.vger.kernel.org Inspired by the commit 7cd01b08d35f ("powerpc: Add support for function error injection"), this patch supports function error injection for Arm64. This patch mainly support two functions: one is regs_set_return_value() which is used to overwrite the return value; the another function is override_function_with_return() which is to override the probed function returning and jump to its caller. Signed-off-by: Leo Yan --- arch/arm64/Kconfig | 1 + arch/arm64/include/asm/ptrace.h | 5 +++++ arch/arm64/lib/Makefile | 2 ++ arch/arm64/lib/error-inject.c | 18 ++++++++++++++++++ 4 files changed, 26 insertions(+) create mode 100644 arch/arm64/lib/error-inject.c diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 3adcec05b1f6..b15803afb2a0 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -148,6 +148,7 @@ config ARM64 select HAVE_FAST_GUP select HAVE_FTRACE_MCOUNT_RECORD select HAVE_FUNCTION_TRACER + select HAVE_FUNCTION_ERROR_INJECTION select HAVE_FUNCTION_GRAPH_TRACER select HAVE_GCC_PLUGINS select HAVE_HW_BREAKPOINT if PERF_EVENTS diff --git a/arch/arm64/include/asm/ptrace.h b/arch/arm64/include/asm/ptrace.h index b1dd039023ef..891b9995cb4b 100644 --- a/arch/arm64/include/asm/ptrace.h +++ b/arch/arm64/include/asm/ptrace.h @@ -301,6 +301,11 @@ static inline unsigned long regs_return_value(struct pt_regs *regs) return regs->regs[0]; } +static inline void regs_set_return_value(struct pt_regs *regs, unsigned long rc) +{ + regs->regs[0] = rc; +} + /** * regs_get_kernel_argument() - get Nth function argument in kernel * @regs: pt_regs of that context diff --git a/arch/arm64/lib/Makefile b/arch/arm64/lib/Makefile index 33c2a4abda04..f182ccb0438e 100644 --- a/arch/arm64/lib/Makefile +++ b/arch/arm64/lib/Makefile @@ -33,3 +33,5 @@ UBSAN_SANITIZE_atomic_ll_sc.o := n lib-$(CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE) += uaccess_flushcache.o obj-$(CONFIG_CRC32) += crc32.o + +obj-$(CONFIG_FUNCTION_ERROR_INJECTION) += error-inject.o diff --git a/arch/arm64/lib/error-inject.c b/arch/arm64/lib/error-inject.c new file mode 100644 index 000000000000..ed15021da3ed --- /dev/null +++ b/arch/arm64/lib/error-inject.c @@ -0,0 +1,18 @@ +// 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. + * + * 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, procedure_link_pointer(regs)); +} +NOKPROBE_SYMBOL(override_function_with_return); -- 2.17.1 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-yw1-f66.google.com ([209.85.161.66]:36097 "EHLO mail-yw1-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732583AbfHFKBM (ORCPT ); Tue, 6 Aug 2019 06:01:12 -0400 Received: by mail-yw1-f66.google.com with SMTP id x67so29292231ywd.3 for ; Tue, 06 Aug 2019 03:01:12 -0700 (PDT) From: Leo Yan Subject: [PATCH v2 2/3] arm64: Add support for function error injection Date: Tue, 6 Aug 2019 18:00:14 +0800 Message-ID: <20190806100015.11256-3-leo.yan@linaro.org> In-Reply-To: <20190806100015.11256-1-leo.yan@linaro.org> References: <20190806100015.11256-1-leo.yan@linaro.org> Sender: linux-arch-owner@vger.kernel.org List-ID: To: Russell King , 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 Cc: Leo Yan Message-ID: <20190806100014.ZUjJziK0wssfWh8ruc1CoR2YrScosQNkiMa2nDLu1wA@z> Inspired by the commit 7cd01b08d35f ("powerpc: Add support for function error injection"), this patch supports function error injection for Arm64. This patch mainly support two functions: one is regs_set_return_value() which is used to overwrite the return value; the another function is override_function_with_return() which is to override the probed function returning and jump to its caller. Signed-off-by: Leo Yan --- arch/arm64/Kconfig | 1 + arch/arm64/include/asm/ptrace.h | 5 +++++ arch/arm64/lib/Makefile | 2 ++ arch/arm64/lib/error-inject.c | 18 ++++++++++++++++++ 4 files changed, 26 insertions(+) create mode 100644 arch/arm64/lib/error-inject.c diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 3adcec05b1f6..b15803afb2a0 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -148,6 +148,7 @@ config ARM64 select HAVE_FAST_GUP select HAVE_FTRACE_MCOUNT_RECORD select HAVE_FUNCTION_TRACER + select HAVE_FUNCTION_ERROR_INJECTION select HAVE_FUNCTION_GRAPH_TRACER select HAVE_GCC_PLUGINS select HAVE_HW_BREAKPOINT if PERF_EVENTS diff --git a/arch/arm64/include/asm/ptrace.h b/arch/arm64/include/asm/ptrace.h index b1dd039023ef..891b9995cb4b 100644 --- a/arch/arm64/include/asm/ptrace.h +++ b/arch/arm64/include/asm/ptrace.h @@ -301,6 +301,11 @@ static inline unsigned long regs_return_value(struct pt_regs *regs) return regs->regs[0]; } +static inline void regs_set_return_value(struct pt_regs *regs, unsigned long rc) +{ + regs->regs[0] = rc; +} + /** * regs_get_kernel_argument() - get Nth function argument in kernel * @regs: pt_regs of that context diff --git a/arch/arm64/lib/Makefile b/arch/arm64/lib/Makefile index 33c2a4abda04..f182ccb0438e 100644 --- a/arch/arm64/lib/Makefile +++ b/arch/arm64/lib/Makefile @@ -33,3 +33,5 @@ UBSAN_SANITIZE_atomic_ll_sc.o := n lib-$(CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE) += uaccess_flushcache.o obj-$(CONFIG_CRC32) += crc32.o + +obj-$(CONFIG_FUNCTION_ERROR_INJECTION) += error-inject.o diff --git a/arch/arm64/lib/error-inject.c b/arch/arm64/lib/error-inject.c new file mode 100644 index 000000000000..ed15021da3ed --- /dev/null +++ b/arch/arm64/lib/error-inject.c @@ -0,0 +1,18 @@ +// 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. + * + * 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, procedure_link_pointer(regs)); +} +NOKPROBE_SYMBOL(override_function_with_return); -- 2.17.1