diff mbox series

LoongArch: Add support for function error injection

Message ID	1678173001-16852-1-git-send-email-yangtiezhu@loongson.cn
State	New
Headers	Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; From: Tiezhu Yang <yangtiezhu@loongson.cn> To: Huacai Chen <chenhuacai@kernel.org>, WANG Xuerui <kernel@xen0n.name> Cc: loongarch@lists.linux.dev, linux-kernel@vger.kernel.org, loongson-kernel@lists.loongnix.cn Subject: [PATCH] LoongArch: Add support for function error injection Date: Tue, 7 Mar 2023 15:10:01 +0800 Message-Id: <1678173001-16852-1-git-send-email-yangtiezhu@loongson.cn> Precedence: bulk
Series	LoongArch: Add support for function error injection \| LoongArch: Add support for function error injection

Commit Message

Tiezhu Yang March 7, 2023, 7:10 a.m. UTC

  Inspired by the commit 42d038c4fb00 ("arm64: Add support for function error
injection") and commit ee55ff803b38 ("riscv: Add support for function error
injection"), support 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

Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
---
 arch/loongarch/Kconfig              |  1 +
 arch/loongarch/include/asm/ptrace.h |  6 ++++++
 arch/loongarch/lib/Makefile         |  2 ++
 arch/loongarch/lib/error-inject.c   | 10 ++++++++++
 4 files changed, 19 insertions(+)
 create mode 100644 arch/loongarch/lib/error-inject.c

Comments

Tiezhu Yang March 10, 2023, 2:07 a.m. UTC | #1

This feature is related with kprobes, add Masami to CC.

On 03/07/2023 03:10 PM, Tiezhu Yang wrote:
> Inspired by the commit 42d038c4fb00 ("arm64: Add support for function error
> injection") and commit ee55ff803b38 ("riscv: Add support for function error
> injection"), support 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
>
> Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
> ---
>  arch/loongarch/Kconfig              |  1 +
>  arch/loongarch/include/asm/ptrace.h |  6 ++++++
>  arch/loongarch/lib/Makefile         |  2 ++
>  arch/loongarch/lib/error-inject.c   | 10 ++++++++++
>  4 files changed, 19 insertions(+)
>  create mode 100644 arch/loongarch/lib/error-inject.c
>
> diff --git a/arch/loongarch/Kconfig b/arch/loongarch/Kconfig
> index 7fd5125..b16ff7e 100644
> --- a/arch/loongarch/Kconfig
> +++ b/arch/loongarch/Kconfig
> @@ -99,6 +99,7 @@ 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 d761db9..db7332a 100644
> --- a/arch/loongarch/include/asm/ptrace.h
> +++ b/arch/loongarch/include/asm/ptrace.h
> @@ -154,6 +154,12 @@ 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 40bde63..30b1595 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 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 0000000..afc9e1c
> --- /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);
>

Masami Hiramatsu (Google) March 10, 2023, 3:22 p.m. UTC | #2

On Fri, 10 Mar 2023 10:07:09 +0800
Tiezhu Yang <yangtiezhu@loongson.cn> wrote:

> This feature is related with kprobes, add Masami to CC.
> 
> On 03/07/2023 03:10 PM, Tiezhu Yang wrote:
> > Inspired by the commit 42d038c4fb00 ("arm64: Add support for function error
> > injection") and commit ee55ff803b38 ("riscv: Add support for function error
> > injection"), support 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
> >
> > Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>

Thanks for porting! This looks good to me.

Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>

Thanks!

> > ---
> >  arch/loongarch/Kconfig              |  1 +
> >  arch/loongarch/include/asm/ptrace.h |  6 ++++++
> >  arch/loongarch/lib/Makefile         |  2 ++
> >  arch/loongarch/lib/error-inject.c   | 10 ++++++++++
> >  4 files changed, 19 insertions(+)
> >  create mode 100644 arch/loongarch/lib/error-inject.c
> >
> > diff --git a/arch/loongarch/Kconfig b/arch/loongarch/Kconfig
> > index 7fd5125..b16ff7e 100644
> > --- a/arch/loongarch/Kconfig
> > +++ b/arch/loongarch/Kconfig
> > @@ -99,6 +99,7 @@ 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 d761db9..db7332a 100644
> > --- a/arch/loongarch/include/asm/ptrace.h
> > +++ b/arch/loongarch/include/asm/ptrace.h
> > @@ -154,6 +154,12 @@ 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 40bde63..30b1595 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 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 0000000..afc9e1c
> > --- /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);
> >
>

Huacai Chen March 11, 2023, 1:15 a.m. UTC | #3

Queued for loongarch-next, thanks.

Huacai

On Fri, Mar 10, 2023 at 11:22 PM Masami Hiramatsu <mhiramat@kernel.org> wrote:
>
> On Fri, 10 Mar 2023 10:07:09 +0800
> Tiezhu Yang <yangtiezhu@loongson.cn> wrote:
>
> > This feature is related with kprobes, add Masami to CC.
> >
> > On 03/07/2023 03:10 PM, Tiezhu Yang wrote:
> > > Inspired by the commit 42d038c4fb00 ("arm64: Add support for function error
> > > injection") and commit ee55ff803b38 ("riscv: Add support for function error
> > > injection"), support 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
> > >
> > > Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
>
> Thanks for porting! This looks good to me.
>
> Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
>
> Thanks!
>
> > > ---
> > >  arch/loongarch/Kconfig              |  1 +
> > >  arch/loongarch/include/asm/ptrace.h |  6 ++++++
> > >  arch/loongarch/lib/Makefile         |  2 ++
> > >  arch/loongarch/lib/error-inject.c   | 10 ++++++++++
> > >  4 files changed, 19 insertions(+)
> > >  create mode 100644 arch/loongarch/lib/error-inject.c
> > >
> > > diff --git a/arch/loongarch/Kconfig b/arch/loongarch/Kconfig
> > > index 7fd5125..b16ff7e 100644
> > > --- a/arch/loongarch/Kconfig
> > > +++ b/arch/loongarch/Kconfig
> > > @@ -99,6 +99,7 @@ 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 d761db9..db7332a 100644
> > > --- a/arch/loongarch/include/asm/ptrace.h
> > > +++ b/arch/loongarch/include/asm/ptrace.h
> > > @@ -154,6 +154,12 @@ 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 40bde63..30b1595 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 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 0000000..afc9e1c
> > > --- /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);
> > >
> >
>
>
> --
> Masami Hiramatsu (Google) <mhiramat@kernel.org>

Hengqi Chen March 13, 2023, 3:24 a.m. UTC | #4

On 2023/3/10 10:07, Tiezhu Yang wrote:
> This feature is related with kprobes, add Masami to CC.
> 
> On 03/07/2023 03:10 PM, Tiezhu Yang wrote:
>> Inspired by the commit 42d038c4fb00 ("arm64: Add support for function error
>> injection") and commit ee55ff803b38 ("riscv: Add support for function error
>> injection"), support 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
>>
>> Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
>> ---
>>  arch/loongarch/Kconfig              |  1 +
>>  arch/loongarch/include/asm/ptrace.h |  6 ++++++
>>  arch/loongarch/lib/Makefile         |  2 ++
>>  arch/loongarch/lib/error-inject.c   | 10 ++++++++++
>>  4 files changed, 19 insertions(+)
>>  create mode 100644 arch/loongarch/lib/error-inject.c
>>
>> diff --git a/arch/loongarch/Kconfig b/arch/loongarch/Kconfig
>> index 7fd5125..b16ff7e 100644
>> --- a/arch/loongarch/Kconfig
>> +++ b/arch/loongarch/Kconfig
>> @@ -99,6 +99,7 @@ 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 d761db9..db7332a 100644
>> --- a/arch/loongarch/include/asm/ptrace.h
>> +++ b/arch/loongarch/include/asm/ptrace.h
>> @@ -154,6 +154,12 @@ 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 40bde63..30b1595 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 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 0000000..afc9e1c
>> --- /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);
>>
> 
> 

Tested-by: Hengqi Chen <hengqi.chen@gmail.com>

diff mbox series

Patch

diff --git a/arch/loongarch/Kconfig b/arch/loongarch/Kconfig
index 7fd5125..b16ff7e 100644
--- a/arch/loongarch/Kconfig
+++ b/arch/loongarch/Kconfig
@@ -99,6 +99,7 @@  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 d761db9..db7332a 100644
--- a/arch/loongarch/include/asm/ptrace.h
+++ b/arch/loongarch/include/asm/ptrace.h
@@ -154,6 +154,12 @@  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 40bde63..30b1595 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 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 0000000..afc9e1c
--- /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);