From patchwork Fri Oct 15 12:51:37 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Masami Hiramatsu (Google)" X-Patchwork-Id: 12561453 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 63372C433EF for ; Fri, 15 Oct 2021 12:57:59 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 264FF60F93 for ; Fri, 15 Oct 2021 12:57:59 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 264FF60F93 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=8KvtbD/5LLLwSdU96TM/gPH0trpmjvX7MHqeJrShojw=; b=laTB420McX0SDw 2kNCXnufQx0r/1GrwfXE9+mN+7drr59nWMm2hDFeZcGwfWb4jCTnfKOQfRKyKY8ispf3dE2DPm9os BwNXb6+vnIoKOL37hBG5CqAfquUVZmfKOYzMO9lePHy1V/TTX5yUGot8ZcWefLfvwNVa6+SqFmdO9 CHFOP4m//ckMS3uM58E0FFuvidWx/5mfBPjRXbNs9ir0UaKwXiA4cR9JnESwY7tws1O1oO8dq8Ap7 U4/SudjZmBSYZwr7bzNif9KHTexbRrh+1qvz7SEB0ynma9V9i9Mowv56Z320ZciXL/MKEQVR0T7wJ EiYu1rnAqbxMqrSOvijg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1mbMkU-0073dD-1u; Fri, 15 Oct 2021 12:55:47 +0000 Received: from mail.kernel.org ([198.145.29.99]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1mbMgX-0071Mx-Rh for linux-arm-kernel@lists.infradead.org; Fri, 15 Oct 2021 12:51:43 +0000 Received: by mail.kernel.org (Postfix) with ESMTPSA id C86E760ED4; Fri, 15 Oct 2021 12:51:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1634302300; bh=nvZy1sVKYSK6zZvA82X0Qwm/erFQUaJsuPthlqjB5TY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=XZm6dGWKFv/Q7OSnILPwjpJd1t8TNa2SBlAAQC4U0nri4Rcl2AZXSDhMVT/gSEK/w PoNq5LJCXkRttBGHN05+7Sy+hlfCHER5eou9y0L4yepzQXQqs1VB6sUvsMXVO7I5CU /TfKZTkBrz0xULe1iu8a4qwTTq+v7wlgpl6I41dW/uGDOrD9rzanrgnscUSgjyobTB JmIsrvOZ4xPpNDmTu59f2JIiE4WDmUNr3jZRLHv5S7FNifMwieQe4XyDaBd8pZjI3i TTcOawJlIBZbvrBdsQVFG4KrzMFblMpnOag/bycZxPDFuZ2jsXTVWbQOUN8kltKbGk mFX9Jcks6K/Bg== 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 06/10] arm64: Recover kretprobe modified return address in stacktrace Date: Fri, 15 Oct 2021 21:51:37 +0900 Message-Id: <163430229733.459050.8624118341048476904.stgit@devnote2> X-Mailer: git-send-email 2.25.1 In-Reply-To: <163430224341.459050.2369208860773018092.stgit@devnote2> References: <163430224341.459050.2369208860773018092.stgit@devnote2> User-Agent: StGit/0.19 MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20211015_055142_011890_442F4CF4 X-CRM114-Status: GOOD ( 14.81 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.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. For this purpose this adds 'kr_cur' loop cursor to memorize the current kretprobe instance. With this fix, now arm64 can enable CONFIG_ARCH_CORRECT_STACKTRACE_ON_KRETPROBE, and pass the kprobe self tests. Signed-off-by: Masami Hiramatsu --- Changes in v2: - Add comment for kr_cur. - Make the kretprobe related code depends on CONFIG_KRETPROBES. - Initialize "kr_cur" directly in start_backtrace() instead of clearing "frame" data structure by memset(). --- arch/arm64/Kconfig | 1 + arch/arm64/include/asm/stacktrace.h | 4 ++++ arch/arm64/kernel/stacktrace.c | 7 +++++++ 3 files changed, 12 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..a4e046ef4568 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 +60,9 @@ struct stackframe { #ifdef CONFIG_FUNCTION_GRAPH_TRACER int graph; #endif +#ifdef CONFIG_KRETPROBES + struct llist_node *kr_cur; +#endif }; 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..c30624fff6ac 100644 --- a/arch/arm64/kernel/stacktrace.c +++ b/arch/arm64/kernel/stacktrace.c @@ -41,6 +41,9 @@ void start_backtrace(struct stackframe *frame, unsigned long fp, #ifdef CONFIG_FUNCTION_GRAPH_TRACER frame->graph = 0; #endif +#ifdef CONFIG_KRETPROBES + frame->kr_cur = NULL; +#endif /* * Prime the first unwind. @@ -129,6 +132,10 @@ int notrace unwind_frame(struct task_struct *tsk, struct stackframe *frame) frame->pc = ret_stack->ret; } #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ +#ifdef CONFIG_KRETPROBES + if (is_kretprobe_trampoline(frame->pc)) + frame->pc = kretprobe_find_ret_addr(tsk, (void *)frame->fp, &frame->kr_cur); +#endif frame->pc = ptrauth_strip_insn_pac(frame->pc);