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 A6689332614; Tue, 18 Aug 2026 14:50:31 +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=1787064637; cv=none; b=BKJwmzzzraDiKpHVmniBNis5L/NvoStr/ffy4cxnRfB6BGLeGVjiQDSVD3n9OfgweuFMJI2S8406v4af5QINY1S397Jh/vVChwjKmGP0poPu2bjIR5TUcYPvN+P/dkTi2JlQRYuX+ldmOaOdFGqqHlJ9pjJwcpxA/RM9L5bBLLM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787064637; c=relaxed/simple; bh=TgiT8Xnhc5VLifuhTHbl67ng/yIBp4wlIbp5EtKoKcg=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Bg8A5L8I5xctox8G8GXrXM9FhN/Q1ano5t9tGwjpEMIbiVtZlGiGQoLlpl+JBsmkX9+VVTRK3jIH9my6HmntCJ9SWtwgrVMaoL1JkdYKRzT8LVFNpwyLwlVjXL2wOsw/U27P0exuTDgBctgY4zRRKo34gRtLSOKTPW9lJKLJCn0= 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=EJWfh785; 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="EJWfh785" 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 67IE3q5E401906; Tue, 18 Aug 2026 14:50:14 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=EJWfh785Gl9SgiQr7AwbltrX+doRbU/fR LwsRK0IV1N3UOqxq3fJkJ7ne9fVj2nE7BAdanqP4c2koPZa/chLx6OJJUVREu3vv cQJhaYsCd+a+zq7/E8JHERC+V0SbKP1y+Qqz6+YFSp2Lh83HhZtEoYsuIyU3b0rD pQ9fc8Jz5IlMeHSyO+WjYShRjKnsxhhw9dBhL+eb75ZpFU0FycdDj0bpOWDTcjcZ sq4KrpBXQh+voEMzF7AWXOpyrONKmTh6dBfFKIgkEXvHrbp6OjBUhnqsdDlBzF/9 GMFIxh386YTT86+bq+5OcSAYpiYjrLyjD3Sjdkrps+XAOFWZ2iHWw== Received: from ppma21.wdc07v.mail.ibm.com (5b.69.3da9.ip4.static.sl-reverse.com [169.61.105.91]) by mx0a-001b2d01.pphosted.com (PPS) with ESMTPS id 4g2dhm0qp6-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 18 Aug 2026 14:50:13 +0000 (GMT) Received: from pps.filterd (ppma21.wdc07v.mail.ibm.com [127.0.0.1]) by ppma21.wdc07v.mail.ibm.com (8.18.1.7/8.18.1.7) with ESMTP id 67IEfOdH014762; Tue, 18 Aug 2026 14:50:12 GMT Received: from smtprelay05.fra02v.mail.ibm.com ([9.218.2.225]) by ppma21.wdc07v.mail.ibm.com (PPS) with ESMTPS id 4g33ek3r87-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 18 Aug 2026 14:50:12 +0000 (GMT) Received: from smtpav05.fra02v.mail.ibm.com (smtpav05.fra02v.mail.ibm.com [10.20.54.104]) by smtprelay05.fra02v.mail.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 67IEo3tT39584242 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 18 Aug 2026 14:50:03 GMT Received: from smtpav05.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id B5EBE20040; Tue, 18 Aug 2026 14:50:03 +0000 (GMT) Received: from smtpav05.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 6D6362004B; Tue, 18 Aug 2026 14:50:03 +0000 (GMT) Received: from tuxmaker.boeblingen.de.ibm.com (unknown [9.87.85.9]) by smtpav05.fra02v.mail.ibm.com (Postfix) with ESMTP; Tue, 18 Aug 2026 14:50:03 +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 Subject: [RFC PATCH v1 20/25] unwind_user/eh_frame/x86: Enable eh_frame unwinding on x86 Date: Tue, 18 Aug 2026 16:49:49 +0200 Message-ID: <20260818144954.2320378-21-jremus@linux.ibm.com> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260818144954.2320378-1-jremus@linux.ibm.com> References: <20260818144954.2320378-1-jremus@linux.ibm.com> Precedence: bulk X-Mailing-List: linux-s390@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-Details-Enc: AW1haW4tMjYwODE4MDEwNyBTYWx0ZWRfX1d8kHklq4oDh qR4gu3EKLxIH2H6af2/tFoGatTv0RSz3dUC6OGuPybXidi/6OguOOpI1qUmpEf+omNupfqXwVV1 m0njASuR8qu1Tzx0isUw0inKwarDPbTPyO80owWXYfwEacJ4wiFcS9mOvYRqeBkgf4ol3PFtg0H nw/YV+TenMASA0/ULS0uCECLbYW/UPZP8wbzEahyFIld3N1FLOuivkxdtTpIblhhDDMjgrMt08w 4m5STs49i4l4nrZ6tZgZaXRV6rke0/kbPrbwY5vlQpDLV73IApD4E17R4anpZlEAKHPray8bKO1 DEyq0KUm9tkx95jpud9s3FqJl2DxdZSlRrG9GDiZnsrzVdr9us4M4wumAjrzU/1b+8vFdv8f5QZ 2XJ4/9D/NV2mbqfOlFx+UeMoi3InQLA3A5+82Ifg+SFS25b84RG9uE6y9T6gbFKCeTOvuKjQneJ pochYYMmYYf/CgHTGlA== X-Proofpoint-Spam-Info: AW1haW4tMjYwODE4MDEwNyBTYWx0ZWRfX4dlFwffqua8d 36q2ijmGmJcp32QgX0E0svsuYGUKF4+TARoYPZ9NgqjLj+zJ67kyJVrqWJqYMwn7bbvk4iVygO5 PXvc5nznVBl9532iN6qOm4wCxUlSO4M= X-Authority-Analysis: v=2.4 cv=JKkLdcKb c=1 sm=1 tr=0 ts=6a847125 cx=c_pps a=GFwsV6G8L6GxiO2Y/PsHdQ==:117 a=GFwsV6G8L6GxiO2Y/PsHdQ==:17 a=Sv0fKeRqtYgA:10 a=VkNPw1HP01LnGYTKEx00:22 a=RnoormkPH1_aCDwRdu11:22 a=Y2IxJ9c9Rs8Kov3niI8_:22 a=VnNF1IyMAAAA:8 a=TKDeGWYlhpvMKGhGT-EA:9 X-Proofpoint-ORIG-GUID: s2pENtJPPp-RNFhBqfL1gEj1gc3OogDn X-Proofpoint-GUID: iZq1MtKPvsvjYKRpHGf-XAOdce5efOHG 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=2026-08-18_02,2026-08-18_01,2025-10-01_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 suspectscore=0 bulkscore=0 malwarescore=0 priorityscore=1501 lowpriorityscore=0 clxscore=1015 adultscore=0 impostorscore=0 spamscore=0 phishscore=0 classifier=typeunknown authscore=0 authtc= authcc= route=outbound adjust=0 reason=mlx scancount=1 engine=8.22.0-2606150000 definitions=main-2608180107 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