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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4B6ECC433FE for ; Wed, 9 Nov 2022 06:50:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229754AbiKIGuW (ORCPT ); Wed, 9 Nov 2022 01:50:22 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49664 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229751AbiKIGuO (ORCPT ); Wed, 9 Nov 2022 01:50:14 -0500 Received: from sin.source.kernel.org (sin.source.kernel.org [145.40.73.55]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6AE3217423; Tue, 8 Nov 2022 22:50:13 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by sin.source.kernel.org (Postfix) with ESMTPS id CF837CE1D14; Wed, 9 Nov 2022 06:50:11 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3FA54C433C1; Wed, 9 Nov 2022 06:50:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1667976609; bh=ut7EzIUNIiE0yhwgdV7ZbRJKon0eflJ3Fbn5UHXoL04=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=TMNa28F5RRTMFGUaIb/uf6YrbkzsOwFQK8PGvRMUQ9xyrB9/PuUT9ztiKteYlIM2r JC3eJrbZoUguf6W7EPJaY6zTNH83U6UY9BO6o932xt14lvKbh6uT9k+Q2nh5lwAcSo cb6vXzzkKiqqUVNgkZBru/VUoh+Dkff6049EZ3xDzChiRDGwG+ac5tKbDNJoM/72Aj PNCz/PMJh6y9xCF7FfR6CBOPbaNsnlFmy+xkbs9a9P/lT6vA0NK8J/8Dex2oZgKPqu nuR9B2r8wqaAHjkKyvg035wpt9Oj1y7dryM6AGVBWoUBeFzqMCN+WC+9nEUPRJnMqd AnsobWmxO0v3w== From: guoren@kernel.org To: anup@brainfault.org, paul.walmsley@sifive.com, palmer@dabbelt.com, conor.dooley@microchip.com, heiko@sntech.de, peterz@infradead.org, arnd@arndb.de, linux-arch@vger.kernel.org, keescook@chromium.org, paulmck@kernel.org, frederic@kernel.org, nsaenzju@redhat.com, changbin.du@intel.com, vincent.chen@sifive.com Cc: linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, Guo Ren , Guo Ren , Palmer Dabbelt Subject: [PATCH 2/2] riscv: stacktrace: Make walk_stackframe cross pt_regs frame Date: Wed, 9 Nov 2022 01:49:37 -0500 Message-Id: <20221109064937.3643993-3-guoren@kernel.org> X-Mailer: git-send-email 2.36.1 In-Reply-To: <20221109064937.3643993-1-guoren@kernel.org> References: <20221109064937.3643993-1-guoren@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Guo Ren The current walk_stackframe with FRAME_POINTER would stop unwinding at ret_from_exception: BUG: sleeping function called from invalid context at kernel/locking/rwsem.c:1518 in_atomic(): 0, irqs_disabled(): 1, non_block: 0, pid: 1, name: init CPU: 0 PID: 1 Comm: init Not tainted 5.10.113-00021-g15c15974895c-dirty #192 Call Trace: [] walk_stackframe+0x0/0xee [] show_stack+0x32/0x4a [] dump_stack_lvl+0x72/0x8e [] dump_stack+0x14/0x1c [] ___might_sleep+0x12e/0x138 [] __might_sleep+0x10/0x18 [] down_read+0x22/0xa4 [] do_page_fault+0xb0/0x2fe [] ret_from_exception+0x0/0xc The optimization would help walk_stackframe cross the pt_regs frame and get more backtrace of debug info: BUG: sleeping function called from invalid context at kernel/locking/rwsem.c:1518 in_atomic(): 0, irqs_disabled(): 1, non_block: 0, pid: 1, name: init CPU: 0 PID: 1 Comm: init Not tainted 5.10.113-00021-g15c15974895c-dirty #192 Call Trace: [] walk_stackframe+0x0/0xee [] show_stack+0x32/0x4a [] dump_stack_lvl+0x72/0x8e [] dump_stack+0x14/0x1c [] ___might_sleep+0x12e/0x138 [] __might_sleep+0x10/0x18 [] down_read+0x22/0xa4 [] do_page_fault+0xb0/0x2fe [] ret_from_exception+0x0/0xc [] riscv_intc_irq+0x1a/0x72 [] ret_from_exception+0x0/0xc [] vma_link+0x54/0x160 [] mmap_region+0x2cc/0x4d0 [] do_mmap+0x2d8/0x3ac [] vm_mmap_pgoff+0x70/0xb8 [] vm_mmap+0x2a/0x36 [] elf_map+0x72/0x84 [] load_elf_binary+0x69a/0xec8 [] bprm_execve+0x246/0x53a [] kernel_execve+0xe8/0x124 [] run_init_process+0xfa/0x10c [] try_to_run_init_process+0x12/0x3c [] kernel_init+0xb4/0xf8 [] ret_from_exception+0x0/0xc Here is the error injection test code for the above output: drivers/irqchip/irq-riscv-intc.c: static asmlinkage void riscv_intc_irq(struct pt_regs *regs) { unsigned long cause = regs->cause & ~CAUSE_IRQ_FLAG; + u32 tmp; __get_user(tmp, (u32 *)0); Signed-off-by: Guo Ren Signed-off-by: Guo Ren Cc: Palmer Dabbelt Cc: Changbin Du --- arch/riscv/kernel/entry.S | 2 +- arch/riscv/kernel/stacktrace.c | 9 +++++++++ 2 files changed, 10 insertions(+), 1 deletion(-) diff --git a/arch/riscv/kernel/entry.S b/arch/riscv/kernel/entry.S index b9eda3fcbd6d..329cf51fcd4d 100644 --- a/arch/riscv/kernel/entry.S +++ b/arch/riscv/kernel/entry.S @@ -248,7 +248,7 @@ ret_from_syscall_rejected: andi t0, t0, _TIF_SYSCALL_WORK bnez t0, handle_syscall_trace_exit -ret_from_exception: +ENTRY(ret_from_exception) REG_L s0, PT_STATUS(sp) csrc CSR_STATUS, SR_IE #ifdef CONFIG_TRACE_IRQFLAGS diff --git a/arch/riscv/kernel/stacktrace.c b/arch/riscv/kernel/stacktrace.c index bcfe9eb55f80..75c8dd64fc48 100644 --- a/arch/riscv/kernel/stacktrace.c +++ b/arch/riscv/kernel/stacktrace.c @@ -16,6 +16,8 @@ #ifdef CONFIG_FRAME_POINTER +extern asmlinkage void ret_from_exception(void); + void notrace walk_stackframe(struct task_struct *task, struct pt_regs *regs, bool (*fn)(void *, unsigned long), void *arg) { @@ -59,6 +61,13 @@ void notrace walk_stackframe(struct task_struct *task, struct pt_regs *regs, fp = frame->fp; pc = ftrace_graph_ret_addr(current, NULL, frame->ra, &frame->ra); + if (pc == (unsigned long)ret_from_exception) { + if (unlikely(!__kernel_text_address(pc) || !fn(arg, pc))) + break; + + pc = ((struct pt_regs *)sp)->epc; + fp = ((struct pt_regs *)sp)->s0; + } } } -- 2.36.1