From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx0b-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com [148.163.158.5]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id DB88D3F9278; Fri, 21 Aug 2026 19:54:12 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=148.163.158.5 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787342054; cv=none; b=b4SUXfiL24ZDN7S/2phmMxgQdtUsZo66WDiCWk+bglDponZ3hL2RhmEf5q27T2LTJzA74eikUT46nPwbK64PLCpGhmXwLPnxVbqWv2xMvrbDcCX8M2HJXrpQCyuvSgdTVBLu5Ofrhz3UgyaH50Ue8w0pA9izqMka6gl//PHoKs8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787342054; c=relaxed/simple; bh=TgiT8Xnhc5VLifuhTHbl67ng/yIBp4wlIbp5EtKoKcg=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=K1NR8iNILoybXsuN4M41Ke5+kHkqTAFaCqsm11KIho8FhcnxV/NVQckpOUWeGMHCZc8SoVC+u+qB2RuWmCJwJBJPr04qirW2LvtCQ/HVfWf/9Ors7za2GVdXD1gQFF9Dvs02zogSMlYTl6uAqOZ+6ZKB4K5gweJW+8CSUZE9MSc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.ibm.com; spf=pass smtp.mailfrom=linux.ibm.com; dkim=pass (2048-bit key) header.d=ibm.com header.i=@ibm.com header.b=f1qgWRvD; arc=none smtp.client-ip=148.163.158.5 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.ibm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.ibm.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=ibm.com header.i=@ibm.com header.b="f1qgWRvD" Received: from pps.filterd (m0356516.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.18.1.11/8.18.1.11) with ESMTP id 67LIW5bb2254763; Fri, 21 Aug 2026 19:53:16 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=cc :content-transfer-encoding:date:from:in-reply-to:message-id :mime-version:references:subject:to; s=pp1; bh=Y+mdTmXPgPz0paNvu 3GnRv+WInnbZ0GCjERerrKsAso=; b=f1qgWRvDG1qtN2I/6fsZuazodHrXbDBwJ 1Jyk3nc+YOMEs3AzpgQtWuH2a7asHZNUnLP7El7bK8yXUIcc+OmucAHRZ5Pd1aD+ ntWL1d5gfrq5hyCUG9YCOX9K3edAqnRM7775KCBIBIK8OpBJY9sx36BxZACGzZAQ RdtmM8SEoPPfYHFQgz9ff31UxP1ilTJ07zDSzKLAZRImUkTsPQA+TpXH9Gt+u5EC cHecAS44Q7ZdDiZvU/DGFZp1ZzltMnAgLcVR93MhXZ5n3sGucRVq72iPWqsyb6d2 ENEmqd0wMiFt+Sbv3v4SKnRuzshAW4Kap9j9QmkjZ8oRAbTR67cRA== Received: from ppma23.wdc07v.mail.ibm.com (5d.69.3da9.ip4.static.sl-reverse.com [169.61.105.93]) by mx0a-001b2d01.pphosted.com (PPS) with ESMTPS id 4g4yu4krkv-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 21 Aug 2026 19:53:15 +0000 (GMT) Received: from pps.filterd (ppma23.wdc07v.mail.ibm.com [127.0.0.1]) by ppma23.wdc07v.mail.ibm.com (8.18.1.7/8.18.1.7) with ESMTP id 67LJfIZP016594; Fri, 21 Aug 2026 19:53:14 GMT Received: from smtprelay04.fra02v.mail.ibm.com ([9.218.2.228]) by ppma23.wdc07v.mail.ibm.com (PPS) with ESMTPS id 4g33xhpnkv-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 21 Aug 2026 19:53:14 +0000 (GMT) Received: from smtpav03.fra02v.mail.ibm.com (smtpav03.fra02v.mail.ibm.com [10.20.54.102]) by smtprelay04.fra02v.mail.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 67LJrAe010420482 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Fri, 21 Aug 2026 19:53:10 GMT Received: from smtpav03.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 8C5F420040; Fri, 21 Aug 2026 19:53:10 +0000 (GMT) Received: from smtpav03.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 4EA252004B; Fri, 21 Aug 2026 19:53:10 +0000 (GMT) Received: from tuxmaker.boeblingen.de.ibm.com (unknown [9.87.85.9]) by smtpav03.fra02v.mail.ibm.com (Postfix) with ESMTP; Fri, 21 Aug 2026 19:53:10 +0000 (GMT) From: Jens Remus To: linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-s390@vger.kernel.org, x86@kernel.org, Steven Rostedt , Josh Poimboeuf , Peter Zijlstra , Mathieu Desnoyers Cc: Jens Remus , Heiko Carstens , Vasily Gorbik , Alexander Gordeev , Ilya Leoshkevich , Indu Bhagat , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , "H. Peter Anvin" , Namhyung Kim , Andrii Nakryiko , Kees Cook , Sam James , Fangrui Song Subject: [RFC PATCH v2 19/24] unwind_user/eh_frame/x86: Enable eh_frame unwinding on x86 Date: Fri, 21 Aug 2026 21:52:54 +0200 Message-ID: <20260821195259.2688377-20-jremus@linux.ibm.com> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260821195259.2688377-1-jremus@linux.ibm.com> References: <20260821195259.2688377-1-jremus@linux.ibm.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-TM-AS-GCONF: 00 X-Proofpoint-Reinject: loops=2 maxloops=12 X-Proofpoint-Spam-Info: AW1haW4tMjYwODIxMDE1NSBTYWx0ZWRfX7P16kilAz/Cg Lq/sSi7M8fKGWynnhYOI+Kza/6SGI/O/WNq/fSqjEbktt6d3IWsHxHCJo+GdfSCxnJ4nrgueh0n Vh5XwJKguDm8wOsvkWo9ptgtUCuIT9Y= X-Proofpoint-GUID: hX6K2Yi5jUq9h32bOLekL6f4ADhy0INj X-Proofpoint-ORIG-GUID: MB8ma26FyBMsQ5YMuoUB-JXbpT_uSI9A X-Authority-Analysis: v=2.4 cv=RPmD2Yi+ c=1 sm=1 tr=0 ts=6a88acab cx=c_pps a=3Bg1Hr4SwmMryq2xdFQyZA==:117 a=3Bg1Hr4SwmMryq2xdFQyZA==:17 a=Sv0fKeRqtYgA:10 a=VkNPw1HP01LnGYTKEx00:22 a=RnoormkPH1_aCDwRdu11:22 a=Y2IxJ9c9Rs8Kov3niI8_:22 a=VnNF1IyMAAAA:8 a=TKDeGWYlhpvMKGhGT-EA:9 X-Proofpoint-Spam-Details-Enc: AW1haW4tMjYwODIxMDE1NSBTYWx0ZWRfX42idbx157ijU ecZfUaHcpMcqMrpf64CuqiHi7T9YZVpLzRwVU2D7WsjVfF24QOhfk2qOzm+usBRMBt7qdX7aYqT ue2++I+Gzfss0TNxoRooL5m6BuZcupxQ+wIFOrZoHl7NqjEiiM+MSv8rptMoOIFYMXJGxdkA1J5 JIpvI3wHakZWEVScZ2kdaqStEF8WyY5PZaYrgl4VnRBLBvEC9xZa1g7W7JR647eBdN77ir/UCIH Ks/jLqCBvFZSIBBj3ayZxPsp6ZfnKpmWthERW/9P8R9IEDBwBlw6/OyPEK8D/FDVUtNx4fdvx+U 7RXNGEAYseI0kyMNjAHPtOlfntHH3/U21kA0JxrYti6b91dR4Zkg8jIuqGhFjrU33XmmtgeRHb+ Hp60ofot2kfPMdnmOd4JnnTqhflQ56CEqepdG0QXSfbuotw+sFeHFyNHXR2yD6cSYCPqq5rzpQH Y8zOQ/NDI0Y2Z3L4hig== X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1176,Hydra:6.1.134,FMLib:17.12.100.49 definitions=2026-08-21_06,2026-08-21_02,2025-10-01_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 clxscore=1015 phishscore=0 adultscore=0 spamscore=0 priorityscore=1501 bulkscore=0 impostorscore=0 malwarescore=0 lowpriorityscore=0 suspectscore=0 classifier=typeunknown authscore=0 authtc= authcc= route=outbound adjust=0 reason=mlx scancount=1 engine=8.22.0-2606150000 definitions=main-2608210155 The x86-64 .eh_frame implementation works well with GCC and Clang generated code. Enable it. Signed-off-by: Jens Remus --- arch/x86/Kconfig | 1 + arch/x86/include/asm/unwind_user.h | 40 +++++++++++++++++++++ arch/x86/include/asm/unwind_user_eh_frame.h | 22 ++++++++++++ 3 files changed, 63 insertions(+) create mode 100644 arch/x86/include/asm/unwind_user_eh_frame.h diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index bdad90f210e4..fe7919915084 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -300,6 +300,7 @@ config X86 select HAVE_SYSCALL_TRACEPOINTS select HAVE_UACCESS_VALIDATION if HAVE_OBJTOOL select HAVE_UNSTABLE_SCHED_CLOCK + select HAVE_UNWIND_USER_EH_FRAME if X86_64 select HAVE_UNWIND_USER_FP if X86_64 select HAVE_USER_RETURN_NOTIFIER select HAVE_GENERIC_VDSO diff --git a/arch/x86/include/asm/unwind_user.h b/arch/x86/include/asm/unwind_user.h index c96645c824d1..df1966bcb0f6 100644 --- a/arch/x86/include/asm/unwind_user.h +++ b/arch/x86/include/asm/unwind_user.h @@ -4,6 +4,7 @@ #ifdef CONFIG_UNWIND_USER +#include #include #include @@ -15,6 +16,45 @@ static inline int unwind_user_word_size(struct pt_regs *regs) return user_64bit_mode(regs) ? 8 : 4; } +#ifdef CONFIG_X86_64 + +static inline int unwind_user_get_reg(unsigned long *val, unsigned int regnum) +{ + struct pt_regs *regs = task_pt_regs(current); + + /* TODO: eh_frame is currently limited to x86-64 */ + if (!user_64bit_mode(regs)) + return -EINVAL; + + switch (regnum) { + /* DWARF register numbers 0..15 */ + case 0: *val = regs->ax; break; + case 1: *val = regs->dx; break; + case 2: *val = regs->cx; break; + case 3: *val = regs->bx; break; + case 4: *val = regs->si; break; + case 5: *val = regs->di; break; + case 6: *val = regs->bp; break; + case 7: *val = regs->sp; break; + case 8: *val = regs->r8; break; + case 9: *val = regs->r9; break; + case 10: *val = regs->r10; break; + case 11: *val = regs->r11; break; + case 12: *val = regs->r12; break; + case 13: *val = regs->r13; break; + case 14: *val = regs->r14; break; + case 15: *val = regs->r15; break; + default: + pr_debug("%s (%d): %s(%u): unsupported register number\n", + current->comm, current->pid, __func__, regnum); + return -EINVAL; + } + return 0; +} +#define unwind_user_get_reg unwind_user_get_reg + +#endif /* CONFIG_X86_64 */ + #endif /* CONFIG_UNWIND_USER */ #ifdef CONFIG_HAVE_UNWIND_USER_FP diff --git a/arch/x86/include/asm/unwind_user_eh_frame.h b/arch/x86/include/asm/unwind_user_eh_frame.h new file mode 100644 index 000000000000..fdccbda2fe4b --- /dev/null +++ b/arch/x86/include/asm/unwind_user_eh_frame.h @@ -0,0 +1,22 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_X86_UNWIND_USER_EH_FRAME_H +#define _ASM_X86_UNWIND_USER_EH_FRAME_H + +#ifdef CONFIG_X86_64 + +#define EH_FRAME_REG_SP 7 /* designated stack pointer register */ +#define EH_FRAME_REG_FP 6 /* designated frame pointer register */ +#define EH_FRAME_REG_RA 16 /* (pseudo) return address register */ + +/* Instructions must be 1-byte aligned */ +#define EH_FRAME_MAX_CODE_ALIGN 1 + +/* Stack grows towards lower addresses and SP must be 8-byte aligned */ +#define EH_FRAME_MIN_DATA_ALIGN -8 +#define EH_FRAME_MAX_DATA_ALIGN -1 + +#endif + +#include + +#endif /* _ASM_X86_UNWIND_USER_EH_FRAME_H */ -- 2.53.0