linux-stable/arch/csky/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->lr);
}
NOKPROBE_SYMBOL(override_function_with_return);
csky: Add support for function error injection Inspired by the commit 42d038c4fb00 ("arm64: Add support for function error injection"), this patch supports function error injection for csky. 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. Test log: cd /sys/kernel/debug/fail_function/ echo sys_clone > inject echo 100 > probability echo 1 > interval ls / [ 108.644163] FAULT_INJECTION: forcing a failure. [ 108.644163] name fail_function, interval 1, probability 100, space 0, times 1 [ 108.647799] CPU: 0 PID: 104 Comm: sh Not tainted 5.8.0-rc5+ #46 [ 108.648384] Call Trace: [ 108.649339] [<8005eed4>] walk_stackframe+0x0/0xf0 [ 108.649679] [<8005f16a>] show_stack+0x32/0x5c [ 108.649927] [<8040f9d2>] dump_stack+0x6e/0x9c [ 108.650271] [<80406f7e>] should_fail+0x15e/0x1ac [ 108.650720] [<80118ba8>] fei_kprobe_handler+0x28/0x5c [ 108.651519] [<80754110>] kprobe_breakpoint_handler+0x144/0x1cc [ 108.652289] [<8005d6da>] trap_c+0x8e/0x110 [ 108.652816] [<8005ce8c>] csky_trap+0x5c/0x70 -sh: can't fork: Invalid argument Signed-off-by: Guo Ren <guoren@linux.alibaba.com> Cc: Arnd Bergmann <arnd@arndb.de> 2020-07-28 16:30:46 +00:00			`// 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->lr);`
			`}`
			`NOKPROBE_SYMBOL(override_function_with_return);`