diff options
| author | Tiezhu Yang <yangtiezhu@loongson.cn> | 2023-05-01 12:19:52 +0300 |
|---|---|---|
| committer | Huacai Chen <chenhuacai@loongson.cn> | 2023-05-01 12:19:52 +0300 |
| commit | 8b5ee2c66d5c4c1312fd193d4138e6963160ba43 (patch) | |
| tree | ee327696a53f8044b20325adc0f586aa671dea71 | |
| parent | d4c937c2a57bbba24790be6fe7a791456f5fbb60 (diff) | |
| download | linux-8b5ee2c66d5c4c1312fd193d4138e6963160ba43.tar.xz | |
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>
| -rw-r--r-- | arch/loongarch/Kconfig | 1 | ||||
| -rw-r--r-- | arch/loongarch/include/asm/ptrace.h | 5 | ||||
| -rw-r--r-- | arch/loongarch/lib/Makefile | 2 | ||||
| -rw-r--r-- | arch/loongarch/lib/error-inject.c | 10 |
4 files changed, 18 insertions, 0 deletions
diff --git a/arch/loongarch/Kconfig b/arch/loongarch/Kconfig index 3e5d6acbf240..629a6dac33e1 100644 --- a/arch/loongarch/Kconfig +++ b/arch/loongarch/Kconfig @@ -100,6 +100,7 @@ config LOONGARCH select HAVE_FAST_GUP select HAVE_FTRACE_MCOUNT_RECORD select HAVE_FUNCTION_ARG_ACCESS_API + select HAVE_FUNCTION_ERROR_INJECTION select HAVE_FUNCTION_GRAPH_TRACER select HAVE_FUNCTION_TRACER select HAVE_GENERIC_VDSO diff --git a/arch/loongarch/include/asm/ptrace.h b/arch/loongarch/include/asm/ptrace.h index d761db943335..35f0958163ac 100644 --- a/arch/loongarch/include/asm/ptrace.h +++ b/arch/loongarch/include/asm/ptrace.h @@ -154,6 +154,11 @@ static inline long regs_return_value(struct pt_regs *regs) return regs->regs[4]; } +static inline void regs_set_return_value(struct pt_regs *regs, unsigned long val) +{ + regs->regs[4] = val; +} + #define instruction_pointer(regs) ((regs)->csr_era) #define profile_pc(regs) instruction_pointer(regs) diff --git a/arch/loongarch/lib/Makefile b/arch/loongarch/lib/Makefile index 271ed45f51bb..d60d4e096cfa 100644 --- a/arch/loongarch/lib/Makefile +++ b/arch/loongarch/lib/Makefile @@ -5,3 +5,5 @@ lib-y += delay.o memset.o memcpy.o memmove.o \ clear_user.o copy_user.o csum.o dump_tlb.o unaligned.o + +obj-$(CONFIG_FUNCTION_ERROR_INJECTION) += error-inject.o diff --git a/arch/loongarch/lib/error-inject.c b/arch/loongarch/lib/error-inject.c new file mode 100644 index 000000000000..afc9e1c7c973 --- /dev/null +++ b/arch/loongarch/lib/error-inject.c @@ -0,0 +1,10 @@ +// 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); |