linux/arch/loongarch/lib/error-inject.c

// SPDX-License-Identifier: GPL-2.0

#include <linux/error-injection.h>
#include <linux/kprobes.h>

void override_function_with_return(struct pt_regs *regs)
{
	instruction_pointer_set(regs, regs->regs[1]);
}
NOKPROBE_SYMBOL(override_function_with_return);
LoongArch: Add support for function error injection Inspired by the commit 42d038c4fb00f ("arm64: Add support for function error injection") and the commit ee55ff803b383 ("riscv: Add support for function error injection"), this patch supports function error injection for LoongArch. Mainly implement two functions: (1) regs_set_return_value() which is used to overwrite the return value, (2) override_function_with_return() which is used to override the probed function returning and jump to its caller. Here is a simple test under CONFIG_FUNCTION_ERROR_INJECTION and CONFIG_FAIL_FUNCTION: # echo sys_clone > /sys/kernel/debug/fail_function/inject # echo 100 > /sys/kernel/debug/fail_function/probability # dmesg bash: fork: Invalid argument # dmesg ... FAULT_INJECTION: forcing a failure. name fail_function, interval 1, probability 100, space 0, times 1 ... Call Trace: [<90000000002238f4>] show_stack+0x5c/0x180 [<90000000012e384c>] dump_stack_lvl+0x60/0x88 [<9000000000b1879c>] should_fail_ex+0x1b0/0x1f4 [<900000000032ead4>] fei_kprobe_handler+0x28/0x6c [<9000000000230970>] kprobe_breakpoint_handler+0xf0/0x118 [<90000000012e3e60>] do_bp+0x2c4/0x358 [<9000000002241924>] exception_handlers+0x1924/0x10000 [<900000000023b7d0>] sys_clone+0x0/0x4 [<90000000012e4744>] do_syscall+0x7c/0x94 [<9000000000221e44>] handle_syscall+0xc4/0x160 Tested-by: Hengqi Chen <hengqi.chen@gmail.com> Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn> 2023-05-01 17:19:52 +08:00			`// SPDX-License-Identifier: GPL-2.0`

			`#include <linux/error-injection.h>`
			`#include <linux/kprobes.h>`

			`void override_function_with_return(struct pt_regs *regs)`
			`{`
			`instruction_pointer_set(regs, regs->regs[1]);`
			`}`
			`NOKPROBE_SYMBOL(override_function_with_return);`