From aaa4dd1b47f5ff5ef477fec5dcc6c397b457f1c2 Mon Sep 17 00:00:00 2001 From: Wang Kefeng Date: Sun, 4 Dec 2022 04:46:40 +0100 Subject: ARM: 9279/1: support function error injection This enables HAVE_FUNCTION_ERROR_INJECTION by adding necessary regs_set_return_value() and override_function_with_return(). Simply tested according to Documentation/fault-injection/fault-injection.rst. Signed-off-by: Kefeng Wang Signed-off-by: Russell King (Oracle) --- arch/arm/Kconfig | 1 + arch/arm/include/asm/ptrace.h | 4 ++++ arch/arm/lib/Makefile | 2 ++ arch/arm/lib/error-inject.c | 10 ++++++++++ 4 files changed, 17 insertions(+) create mode 100644 arch/arm/lib/error-inject.c diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index b3427536731d..981bbfa62b7d 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -97,6 +97,7 @@ 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 select HAVE_FUNCTION_GRAPH_TRACER 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 1408a6a15d0e..483b8ddfcb82 100644 --- a/arch/arm/include/asm/ptrace.h +++ b/arch/arm/include/asm/ptrace.h @@ -163,6 +163,10 @@ static inline unsigned long user_stack_pointer(struct pt_regs *regs) ((current_stack_pointer | (THREAD_SIZE - 1)) - 7) - 1; \ }) +static inline void regs_set_return_value(struct pt_regs *regs, unsigned long rc) +{ + regs->ARM_r0 = rc; +} /* * Update ITSTATE after normal execution of an IT block instruction. diff --git a/arch/arm/lib/Makefile b/arch/arm/lib/Makefile index 42fb75c06647..650404be6768 100644 --- a/arch/arm/lib/Makefile +++ b/arch/arm/lib/Makefile @@ -44,3 +44,5 @@ 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..5a5b405792ba --- /dev/null +++ b/arch/arm/lib/error-inject.c @@ -0,0 +1,10 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include +#include + +void override_function_with_return(struct pt_regs *regs) +{ + instruction_pointer_set(regs, regs->ARM_lr); +} +NOKPROBE_SYMBOL(override_function_with_return); -- cgit