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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D022EC433EF for ; Fri, 8 Oct 2021 12:29:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BF7BD60FC2 for ; Fri, 8 Oct 2021 12:29:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241531AbhJHMa7 (ORCPT ); Fri, 8 Oct 2021 08:30:59 -0400 Received: from mail.kernel.org ([198.145.29.99]:60754 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241493AbhJHMa6 (ORCPT ); Fri, 8 Oct 2021 08:30:58 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 1013860F48; Fri, 8 Oct 2021 12:29:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1633696143; bh=/fT89EnJsGeXhhESlz3WvMkeVLw4KkN/f3I7P9dDp9Y=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=sQ0r4b3lc0WUZghApOlyszzr1mHp8U+/0PurlKy1yL3QsbY6qY3jJRtxGpXKn0+Hf fx+Lpb9sX7qbZYiczfUldC6a/MSjtPahlpt3/bcjYAOUF/PZyxy8A/ELtS1yUwinwl bvA1x1pfD6ziohrg71hXn11V6ACK3lE5dLM5cKIlB3eFvNfOZlY5kvCDUdwLsIOhfl bbHDi9lbkBljlwqjkrPhYPQuywFkBY33xZ+ovZJqHexIF2FJ3jb7yoGLjsUDGenvzf l3iChYypnr6osJxYpCosymh+u38WfU6EIP7VKq3Xr2rOEWnoPL8AyYgYqRPpexnQbV I3Ka9JJWs3Yzw== From: Masami Hiramatsu To: Steven Rostedt Cc: "Naveen N . Rao" , Ananth N Mavinakayanahalli , Ingo Molnar , linux-kernel@vger.kernel.org, mhiramat@kernel.org, Sven Schnelle , Catalin Marinas , Will Deacon , Russell King , Nathan Chancellor , Nick Desaulniers , linux-arm-kernel@lists.infradead.org Subject: [PATCH 5/8] arm64: Recover kretprobe modified return address in stacktrace Date: Fri, 8 Oct 2021 21:28:58 +0900 Message-Id: <163369613866.636038.15240679956943005288.stgit@devnote2> X-Mailer: git-send-email 2.25.1 In-Reply-To: <163369609308.636038.15295764725220907794.stgit@devnote2> References: <163369609308.636038.15295764725220907794.stgit@devnote2> User-Agent: StGit/0.19 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Since the kretprobe replaces the function return address with the kretprobe_trampoline on the stack, stack unwinder shows it instead of the correct return address. This checks whether the next return address is the __kretprobe_trampoline(), and if so, try to find the correct return address from the kretprobe instance list. With this fix, now arm64 can enable CONFIG_ARCH_CORRECT_STACKTRACE_ON_KRETPROBE, and pass the kprobe self tests. Signed-off-by: Masami Hiramatsu --- arch/arm64/Kconfig | 1 + arch/arm64/include/asm/stacktrace.h | 2 ++ arch/arm64/kernel/stacktrace.c | 3 +++ 3 files changed, 6 insertions(+) diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 5c7ae4c3954b..edde5171ffb2 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -11,6 +11,7 @@ config ARM64 select ACPI_PPTT if ACPI select ARCH_HAS_DEBUG_WX select ARCH_BINFMT_ELF_STATE + select ARCH_CORRECT_STACKTRACE_ON_KRETPROBE select ARCH_ENABLE_HUGEPAGE_MIGRATION if HUGETLB_PAGE && MIGRATION select ARCH_ENABLE_MEMORY_HOTPLUG select ARCH_ENABLE_MEMORY_HOTREMOVE diff --git a/arch/arm64/include/asm/stacktrace.h b/arch/arm64/include/asm/stacktrace.h index 8aebc00c1718..8f997a602651 100644 --- a/arch/arm64/include/asm/stacktrace.h +++ b/arch/arm64/include/asm/stacktrace.h @@ -9,6 +9,7 @@ #include #include #include +#include #include #include @@ -59,6 +60,7 @@ struct stackframe { #ifdef CONFIG_FUNCTION_GRAPH_TRACER int graph; #endif + struct llist_node *kr_cur; }; extern int unwind_frame(struct task_struct *tsk, struct stackframe *frame); diff --git a/arch/arm64/kernel/stacktrace.c b/arch/arm64/kernel/stacktrace.c index 8982a2b78acf..f1eef5745542 100644 --- a/arch/arm64/kernel/stacktrace.c +++ b/arch/arm64/kernel/stacktrace.c @@ -129,6 +129,8 @@ int notrace unwind_frame(struct task_struct *tsk, struct stackframe *frame) frame->pc = ret_stack->ret; } #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ + if (is_kretprobe_trampoline(frame->pc)) + frame->pc = kretprobe_find_ret_addr(tsk, (void *)frame->fp, &frame->kr_cur); frame->pc = ptrauth_strip_insn_pac(frame->pc); @@ -224,6 +226,7 @@ noinline notrace void arch_stack_walk(stack_trace_consume_fn consume_entry, { struct stackframe frame; + memset(&frame, 0, sizeof(frame)); if (regs) start_backtrace(&frame, regs->regs[29], regs->pc); else if (task == current)