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 451B5C433F5 for ; Tue, 5 Oct 2021 14:02:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 266AA61165 for ; Tue, 5 Oct 2021 14:02:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235338AbhJEOD6 (ORCPT ); Tue, 5 Oct 2021 10:03:58 -0400 Received: from mail.kernel.org ([198.145.29.99]:40884 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235406AbhJEOCi (ORCPT ); Tue, 5 Oct 2021 10:02:38 -0400 Received: from gandalf.local.home (cpe-66-24-58-225.stny.res.rr.com [66.24.58.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 2AF4F61A35; Tue, 5 Oct 2021 13:58:30 +0000 (UTC) Received: from rostedt by gandalf.local.home with local (Exim 4.94.2) (envelope-from ) id 1mXkxh-0055ne-7Z; Tue, 05 Oct 2021 09:58:29 -0400 Message-ID: <20211005135829.077894983@goodmis.org> User-Agent: quilt/0.66 Date: Tue, 05 Oct 2021 09:57:52 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Ingo Molnar , Andrew Morton , Josh Poimboeuf , Masami Hiramatsu , Andrii Nakryiko Subject: [for-linus][PATCH 19/27] x86/kprobes: Add UNWIND_HINT_FUNC on kretprobe_trampoline() References: <20211005135733.485175654@goodmis.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Josh Poimboeuf Add UNWIND_HINT_FUNC on __kretprobe_trampoline() code so that ORC information is generated on the __kretprobe_trampoline() correctly. Also, this uses STACK_FRAME_NON_STANDARD_FP(), CONFIG_FRAME_POINTER- -specific version of STACK_FRAME_NON_STANDARD(). Link: https://lkml.kernel.org/r/163163049242.489837.11970969750993364293.stgit@devnote2 Signed-off-by: Josh Poimboeuf Signed-off-by: Masami Hiramatsu Tested-by: Andrii Nakryiko Signed-off-by: Steven Rostedt (VMware) --- arch/x86/include/asm/unwind_hints.h | 5 +++++ arch/x86/kernel/kprobes/core.c | 13 +++++++++++-- 2 files changed, 16 insertions(+), 2 deletions(-) diff --git a/arch/x86/include/asm/unwind_hints.h b/arch/x86/include/asm/unwind_hints.h index 8e574c0afef8..8b33674288ea 100644 --- a/arch/x86/include/asm/unwind_hints.h +++ b/arch/x86/include/asm/unwind_hints.h @@ -52,6 +52,11 @@ UNWIND_HINT sp_reg=ORC_REG_SP sp_offset=8 type=UNWIND_HINT_TYPE_FUNC .endm +#else + +#define UNWIND_HINT_FUNC \ + UNWIND_HINT(ORC_REG_SP, 8, UNWIND_HINT_TYPE_FUNC, 0) + #endif /* __ASSEMBLY__ */ #endif /* _ASM_X86_UNWIND_HINTS_H */ diff --git a/arch/x86/kernel/kprobes/core.c b/arch/x86/kernel/kprobes/core.c index 79cd23dba5b5..d1436d7463fd 100644 --- a/arch/x86/kernel/kprobes/core.c +++ b/arch/x86/kernel/kprobes/core.c @@ -1025,6 +1025,7 @@ asm( /* We don't bother saving the ss register */ #ifdef CONFIG_X86_64 " pushq %rsp\n" + UNWIND_HINT_FUNC " pushfq\n" SAVE_REGS_STRING " movq %rsp, %rdi\n" @@ -1035,6 +1036,7 @@ asm( " popfq\n" #else " pushl %esp\n" + UNWIND_HINT_FUNC " pushfl\n" SAVE_REGS_STRING " movl %esp, %eax\n" @@ -1048,8 +1050,15 @@ asm( ".size __kretprobe_trampoline, .-__kretprobe_trampoline\n" ); NOKPROBE_SYMBOL(__kretprobe_trampoline); -STACK_FRAME_NON_STANDARD(__kretprobe_trampoline); - +/* + * __kretprobe_trampoline() skips updating frame pointer. The frame pointer + * saved in trampoline_handler() points to the real caller function's + * frame pointer. Thus the __kretprobe_trampoline() doesn't have a + * standard stack frame with CONFIG_FRAME_POINTER=y. + * Let's mark it non-standard function. Anyway, FP unwinder can correctly + * unwind without the hint. + */ +STACK_FRAME_NON_STANDARD_FP(__kretprobe_trampoline); /* * Called from __kretprobe_trampoline -- 2.32.0