From 42d038c4fb00f1ec1a4c4616784da4561385b628 Mon Sep 17 00:00:00 2001 From: Leo Yan Date: Tue, 6 Aug 2019 18:00:14 +0800 Subject: arm64: Add support for function error injection 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. Reviewed-by: Masami Hiramatsu Signed-off-by: Leo Yan Signed-off-by: Will Deacon --- arch/arm64/lib/error-inject.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) create mode 100644 arch/arm64/lib/error-inject.c (limited to 'arch/arm64/lib/error-inject.c') 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); -- cgit