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>, 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>, Arnd Bergmann <arnd@arndb.de>, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, bpf@vger.kernel.org, Masami Hiramatsu <mhiramat@kernel.org>, Justin He <Justin.He@arm.com> Cc: Leo Yan <leo.yan@linaro.org> Subject: [PATCH 1/2] arm64: Add support for function error injection Date: Tue, 16 Jul 2019 19:13:00 +0800 [thread overview] Message-ID: <20190716111301.1855-2-leo.yan@linaro.org> (raw) In-Reply-To: <20190716111301.1855-1-leo.yan@linaro.org> This patch implement regs_set_return_value() and override_function_with_return() to support function error injection for arm64. In the exception flow, arm64's general register x30 contains the value for the link register; so we can just update pt_regs::pc with it rather than redirecting execution to a dummy function that returns. This patch is heavily inspired by the commit 7cd01b08d35f ("powerpc: Add support for function error injection"). Signed-off-by: Leo Yan <leo.yan@linaro.org> --- arch/arm64/Kconfig | 1 + arch/arm64/include/asm/error-injection.h | 13 +++++++++++++ arch/arm64/include/asm/ptrace.h | 5 +++++ arch/arm64/lib/Makefile | 2 ++ arch/arm64/lib/error-inject.c | 19 +++++++++++++++++++ 5 files changed, 40 insertions(+) create mode 100644 arch/arm64/include/asm/error-injection.h create mode 100644 arch/arm64/lib/error-inject.c diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 697ea0510729..a6d9e622977d 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -142,6 +142,7 @@ config ARM64 select HAVE_EFFICIENT_UNALIGNED_ACCESS 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/error-injection.h b/arch/arm64/include/asm/error-injection.h new file mode 100644 index 000000000000..da057e8ed224 --- /dev/null +++ b/arch/arm64/include/asm/error-injection.h @@ -0,0 +1,13 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ + +#ifndef __ASM_ERROR_INJECTION_H_ +#define __ASM_ERROR_INJECTION_H_ + +#include <linux/compiler.h> +#include <linux/linkage.h> +#include <asm/ptrace.h> +#include <asm-generic/error-injection.h> + +void override_function_with_return(struct pt_regs *regs); + +#endif /* __ASM_ERROR_INJECTION_H_ */ diff --git a/arch/arm64/include/asm/ptrace.h b/arch/arm64/include/asm/ptrace.h index dad858b6adc6..3aafbbe218a2 100644 --- a/arch/arm64/include/asm/ptrace.h +++ b/arch/arm64/include/asm/ptrace.h @@ -294,6 +294,11 @@ 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..35661c2de4b0 --- /dev/null +++ b/arch/arm64/lib/error-inject.c @@ -0,0 +1,19 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include <linux/error-injection.h> +#include <linux/kprobes.h> + +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->regs[30]' contains the the link register for the probed + * function and assign it to 'regs->pc', so when kprobe returns + * back from exception it will override the end of probed function + * and drirectly return to the predefined function's caller. + */ + regs->pc = regs->regs[30]; +} +NOKPROBE_SYMBOL(override_function_with_return); -- 2.17.1
WARNING: multiple messages have this Message-ID (diff)
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>, 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>, Arnd Bergmann <arnd@arndb.de>, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, bpf@vger.kernel.org, Masami Hiramatsu <mhiramat@kernel.org>, Justin He <Justin.He@arm.com> Cc: Leo Yan <leo.yan@linaro.org> Subject: [PATCH 1/2] arm64: Add support for function error injection Date: Tue, 16 Jul 2019 19:13:00 +0800 [thread overview] Message-ID: <20190716111301.1855-2-leo.yan@linaro.org> (raw) In-Reply-To: <20190716111301.1855-1-leo.yan@linaro.org> This patch implement regs_set_return_value() and override_function_with_return() to support function error injection for arm64. In the exception flow, arm64's general register x30 contains the value for the link register; so we can just update pt_regs::pc with it rather than redirecting execution to a dummy function that returns. This patch is heavily inspired by the commit 7cd01b08d35f ("powerpc: Add support for function error injection"). Signed-off-by: Leo Yan <leo.yan@linaro.org> --- arch/arm64/Kconfig | 1 + arch/arm64/include/asm/error-injection.h | 13 +++++++++++++ arch/arm64/include/asm/ptrace.h | 5 +++++ arch/arm64/lib/Makefile | 2 ++ arch/arm64/lib/error-inject.c | 19 +++++++++++++++++++ 5 files changed, 40 insertions(+) create mode 100644 arch/arm64/include/asm/error-injection.h create mode 100644 arch/arm64/lib/error-inject.c diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 697ea0510729..a6d9e622977d 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -142,6 +142,7 @@ config ARM64 select HAVE_EFFICIENT_UNALIGNED_ACCESS 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/error-injection.h b/arch/arm64/include/asm/error-injection.h new file mode 100644 index 000000000000..da057e8ed224 --- /dev/null +++ b/arch/arm64/include/asm/error-injection.h @@ -0,0 +1,13 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ + +#ifndef __ASM_ERROR_INJECTION_H_ +#define __ASM_ERROR_INJECTION_H_ + +#include <linux/compiler.h> +#include <linux/linkage.h> +#include <asm/ptrace.h> +#include <asm-generic/error-injection.h> + +void override_function_with_return(struct pt_regs *regs); + +#endif /* __ASM_ERROR_INJECTION_H_ */ diff --git a/arch/arm64/include/asm/ptrace.h b/arch/arm64/include/asm/ptrace.h index dad858b6adc6..3aafbbe218a2 100644 --- a/arch/arm64/include/asm/ptrace.h +++ b/arch/arm64/include/asm/ptrace.h @@ -294,6 +294,11 @@ 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..35661c2de4b0 --- /dev/null +++ b/arch/arm64/lib/error-inject.c @@ -0,0 +1,19 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include <linux/error-injection.h> +#include <linux/kprobes.h> + +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->regs[30]' contains the the link register for the probed + * function and assign it to 'regs->pc', so when kprobe returns + * back from exception it will override the end of probed function + * and drirectly return to the predefined function's caller. + */ + regs->pc = regs->regs[30]; +} +NOKPROBE_SYMBOL(override_function_with_return); -- 2.17.1 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2019-07-16 11:13 UTC|newest] Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top 2019-07-16 11:12 [PATCH 0/2] arm/arm64: Add support for function error injection Leo Yan 2019-07-16 11:12 ` Leo Yan 2019-07-16 11:13 ` Leo Yan [this message] 2019-07-16 11:13 ` [PATCH 1/2] arm64: " Leo Yan 2019-07-25 1:42 ` Leo Yan 2019-07-25 1:42 ` Leo Yan 2019-07-31 16:08 ` Will Deacon 2019-07-31 16:08 ` Will Deacon 2019-07-31 16:58 ` Leo Yan 2019-07-31 16:58 ` Leo Yan 2019-07-16 11:13 ` [PATCH 2/2] arm: " Leo Yan 2019-07-16 11:13 ` Leo Yan 2019-07-25 1:48 ` Leo Yan 2019-07-25 1:48 ` Leo Yan 2019-07-17 7:52 ` [PATCH 0/2] arm/arm64: " Masami Hiramatsu 2019-07-17 7:52 ` Masami Hiramatsu 2019-07-17 8:14 ` Leo Yan 2019-07-17 8:14 ` Leo Yan
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