From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-17.0 required=3.0 tests=BAYES_00,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id EBFD1C2BB9A for ; Thu, 17 Dec 2020 16:06:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B793E239CF for ; Thu, 17 Dec 2020 16:06:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729953AbgLQQFy (ORCPT ); Thu, 17 Dec 2020 11:05:54 -0500 Received: from mail.kernel.org ([198.145.29.99]:53944 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729951AbgLQQFx (ORCPT ); Thu, 17 Dec 2020 11:05:53 -0500 From: guoren@kernel.org Authentication-Results: mail.kernel.org; dkim=permerror (bad message/signature format) To: palmerdabbelt@google.com, paul.walmsley@sifive.com, mhiramat@kernel.org, alankao@andestech.com, rostedt@goodmis.org, bjorn.topel@intel.com, pdp7pdp7@gmail.com Cc: linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, anup@brainfault.org, linux-csky@vger.kernel.org, greentime.hu@sifive.com, zong.li@sifive.com, guoren@kernel.org, me@packi.ch, Guo Ren Subject: [PATCH v5 9/9] riscv: Add support for function error injection Date: Thu, 17 Dec 2020 16:01:45 +0000 Message-Id: <1608220905-1962-10-git-send-email-guoren@kernel.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1608220905-1962-1-git-send-email-guoren@kernel.org> References: <1608220905-1962-1-git-send-email-guoren@kernel.org> Precedence: bulk List-ID: X-Mailing-List: linux-csky@vger.kernel.org From: Guo Ren Inspired by the commit 42d038c4fb00 ("arm64: Add support for function error injection"), this patch supports function error injection for riscv. 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 / [ 313.176875] FAULT_INJECTION: forcing a failure. [ 313.176875] name fail_function, interval 1, probability 100, space 0, times 1 [ 313.184357] CPU: 0 PID: 87 Comm: sh Not tainted 5.8.0-rc5-00007-g6a758cc #117 [ 313.187616] Call Trace: [ 313.189100] [] walk_stackframe+0x0/0xc2 [ 313.191626] [] show_stack+0x40/0x4c [ 313.193927] [] dump_stack+0x7c/0x96 [ 313.194795] [] should_fail+0x140/0x142 [ 313.195923] [] fei_kprobe_handler+0x2c/0x5a [ 313.197687] [] kprobe_breakpoint_handler+0xb4/0x18a [ 313.200054] [] do_trap_break+0x36/0xca [ 313.202147] [] ret_from_exception+0x0/0xc [ 313.204556] [] ret_from_syscall+0x0/0x2 -sh: can't fork: Invalid argument Signed-off-by: Guo Ren Reviewed-by: Masami Hiramatsu Cc: Palmer Dabbelt Cc: Paul Walmsley --- arch/riscv/Kconfig | 1 + arch/riscv/include/asm/ptrace.h | 6 ++++++ arch/riscv/lib/Makefile | 2 ++ arch/riscv/lib/error-inject.c | 10 ++++++++++ 4 files changed, 19 insertions(+) create mode 100644 arch/riscv/lib/error-inject.c diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig index af0ec36..a627ae2 100644 --- a/arch/riscv/Kconfig +++ b/arch/riscv/Kconfig @@ -67,6 +67,7 @@ config RISCV select HAVE_EBPF_JIT if MMU select HAVE_FUTEX_CMPXCHG if FUTEX select HAVE_GCC_PLUGINS + select HAVE_FUNCTION_ERROR_INJECTION select HAVE_GENERIC_VDSO if MMU && 64BIT select HAVE_KPROBES select HAVE_KPROBES_ON_FTRACE diff --git a/arch/riscv/include/asm/ptrace.h b/arch/riscv/include/asm/ptrace.h index 23372bb..cb4abb6 100644 --- a/arch/riscv/include/asm/ptrace.h +++ b/arch/riscv/include/asm/ptrace.h @@ -109,6 +109,12 @@ static inline unsigned long regs_return_value(struct pt_regs *regs) return regs->a0; } +static inline void regs_set_return_value(struct pt_regs *regs, + unsigned long val) +{ + regs->a0 = val; +} + extern int regs_query_register_offset(const char *name); extern unsigned long regs_get_kernel_stack_nth(struct pt_regs *regs, unsigned int n); diff --git a/arch/riscv/lib/Makefile b/arch/riscv/lib/Makefile index 47e7a82..699ed20 100644 --- a/arch/riscv/lib/Makefile +++ b/arch/riscv/lib/Makefile @@ -4,3 +4,5 @@ lib-y += memcpy.o lib-y += memset.o lib-$(CONFIG_MMU) += uaccess.o lib-$(CONFIG_64BIT) += tishift.o + +obj-$(CONFIG_FUNCTION_ERROR_INJECTION) += error-inject.o diff --git a/arch/riscv/lib/error-inject.c b/arch/riscv/lib/error-inject.c new file mode 100644 index 00000000..d667ade --- /dev/null +++ b/arch/riscv/lib/error-inject.c @@ -0,0 +1,10 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include +#include + +void override_function_with_return(struct pt_regs *regs) +{ + instruction_pointer_set(regs, regs->ra); +} +NOKPROBE_SYMBOL(override_function_with_return); -- 2.7.4