From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx0a-001b2d01.pphosted.com (mx0a-001b2d01.pphosted.com [148.163.156.1]) (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 C008D3FB074; Wed, 20 May 2026 15:41:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=148.163.156.1 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779291662; cv=none; b=l4aiZC6omFyrOilZSuRkgtHH+HEAwjJrIV/taG7zWT7pyT/HnFSKHbNh4rjOB0JsCcyXcOuQW8oqvKOgRZGmZDZDZgxvpY0J1squu4U/JRt3D2InAPd3B+U/eCrAiuBqwZmImVovjV+az0ZUQXphcMfyiTisl/WqMlbjrmhLV64= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779291662; c=relaxed/simple; bh=1uqNk2OW4T2BX4f0DYsbJdKnO4ILhTmLZQFcrbqg1Pc=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=aI3KAEHfSlcxm+sYA/BbGGKvadxjUvNcDcm4cXz5DjyDupBx3jlYaVWvsogxI07u03YzX6vpy0kx9OLX1vlyG+XUtVz6+d4N8oktEuu942OJQf6kzNi4Ow9/mYf8MhW+v5WTEx5E5YDHZ9toIeGBpWhb7GpwM7l/NtTyS8JIvVc= 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=LLt4z6q5; arc=none smtp.client-ip=148.163.156.1 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="LLt4z6q5" Received: from pps.filterd (m0356517.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.18.1.11/8.18.1.11) with ESMTP id 64K6k2lD513145; Wed, 20 May 2026 15:40:20 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=Fwe9ecz9H+oPKkp3z AdaLZRBVdDt0f4wFwOsmwqxdFk=; b=LLt4z6q5tiKzAzHNgRov9cJRFGW2Kq2yY BbcoFADK36lXnIEwuqGDTVINpyIiyUfMP8OXzDdLSyjTtFod7ED8THwpBaLBM8SP lO1DwGOxOttsYiVdbhp0L73YVvDSWhJlUU9KDT1SQ6jqBIds1WNlmEE+Zs5/bnGg 8U3XyYv9MiaodOnrm96y26qDc4SxifMBIkTrrYKeQdEkJ6gCqZs4cvrVGnP4/+nZ IEVOpIyZ22WkHK76CxC0RWvEKSQxO5VHI5I8boq4DUEmtnNMFXFXYN7QNoOCvCtl nePqejl1Tt3uF8D+0ZwnLFQNQdCvfKHSX4DAD3kRiAJMajM/Tc1VA== 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 4e6h752taa-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 20 May 2026 15:40:19 +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 64KFd5tP031969; Wed, 20 May 2026 15:40:18 GMT Received: from smtprelay05.fra02v.mail.ibm.com ([9.218.2.225]) by ppma21.wdc07v.mail.ibm.com (PPS) with ESMTPS id 4e73wk801p-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 20 May 2026 15:40:18 +0000 (GMT) Received: from smtpav04.fra02v.mail.ibm.com (smtpav04.fra02v.mail.ibm.com [10.20.54.103]) by smtprelay05.fra02v.mail.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 64KFeEbu47251718 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 20 May 2026 15:40:14 GMT Received: from smtpav04.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 4A3C42004D; Wed, 20 May 2026 15:40:14 +0000 (GMT) Received: from smtpav04.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id B917D20043; Wed, 20 May 2026 15:40:13 +0000 (GMT) Received: from tuxmaker.boeblingen.de.ibm.com (unknown [9.87.85.9]) by smtpav04.fra02v.mail.ibm.com (Postfix) with ESMTP; Wed, 20 May 2026 15:40:13 +0000 (GMT) From: Jens Remus To: linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, x86@kernel.org, Steven Rostedt , Josh Poimboeuf , Indu Bhagat , Peter Zijlstra , Dylan Hatch , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , "H. Peter Anvin" , Mathieu Desnoyers , Kees Cook , Sam James Cc: Jens Remus , bpf@vger.kernel.org, linux-mm@kvack.org, Namhyung Kim , Andrii Nakryiko , "Jose E. Marchesi" , Beau Belgrave , Florian Weimer , "Carlos O'Donell" , Masami Hiramatsu , Jiri Olsa , Arnaldo Carvalho de Melo , Andrew Morton , David Hildenbrand , Lorenzo Stoakes , "Liam R. Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Heiko Carstens , Vasily Gorbik , Ilya Leoshkevich , "Steven Rostedt (Google)" Subject: [PATCH v15 12/20] unwind_user/sframe: Add .sframe validation option Date: Wed, 20 May 2026 17:39:56 +0200 Message-ID: <20260520154004.3845823-13-jremus@linux.ibm.com> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20260520154004.3845823-1-jremus@linux.ibm.com> References: <20260520154004.3845823-1-jremus@linux.ibm.com> Precedence: bulk X-Mailing-List: linux-trace-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-Authority-Analysis: v=2.4 cv=ffCdDUQF c=1 sm=1 tr=0 ts=6a0dd5e4 cx=c_pps a=GFwsV6G8L6GxiO2Y/PsHdQ==:117 a=GFwsV6G8L6GxiO2Y/PsHdQ==:17 a=NGcC8JguVDcA:10 a=VkNPw1HP01LnGYTKEx00:22 a=RnoormkPH1_aCDwRdu11:22 a=U7nrCbtTmkRpXpFmAIza:22 a=VwQbUJbxAAAA:8 a=meVymXHHAAAA:8 a=pGLkceISAAAA:8 a=VnNF1IyMAAAA:8 a=RXKZOtKmAAAA:8 a=iNKnMr3YqTL5pEm6fAYA:9 a=2JgSa4NbpEOStq-L5dxp:22 a=UFF3uGjEBZWolfm0k6KQ:22 X-Proofpoint-ORIG-GUID: -mkfSxAZrBitVU35z00n1maSPFGjEpyV X-Proofpoint-GUID: PcRSCFKq2nBAV8d8RsO-g8IszMq0jrZL X-Proofpoint-Spam-Details-Enc: AW1haW4tMjYwNTIwMDE1MSBTYWx0ZWRfX+4A6NmuzGWeG gmHkZhotg90f9w+n46VxxVYmpLojP/Pt/cjMxbc+bsVsKbKMK3nWoUaXSAZS7+c3S9+4IuyB69u Q3N9BqkINDt6at0tT1rsTSuhQZ0e4OGlWGjyjnhGCSe8a6QPxHKHkxZR5WmP9q2cH/rBdaHOMoW 185O2lPNMtCIlDj3X//0PqtRmPJ02kt8dhD1WK517q5fwGG6zRBOE9WtzjuQVlKHlV4Pb7DdFCk KIdf1PIMU0+Y/CgmbH5Aiz/kHFn0C1EvA8YH3ixcQCFRedYca5C0RDweYn0/B5IPfCzFD2nNFT/ yhnmKZnnSw+TFjiZHfbgd2MEAsA2aPVclD8l6QxCLkVdjYr/lgqi7W7wk8MRyetKECNyQSYLsvV bd0FdsDcOuU3GhXqKbonzTbO0F15lUJBy6pL/1Lkz6tO/yF8oVvYpzMbOaF8iGRnXIf12me2j3l PZE36FK2khAMfW/k9zQ== X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1143,Hydra:6.1.51,FMLib:17.12.100.49 definitions=2026-05-20_03,2026-05-18_01,2025-10-01_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 spamscore=0 phishscore=0 suspectscore=0 adultscore=0 clxscore=1015 impostorscore=0 lowpriorityscore=0 bulkscore=0 malwarescore=0 classifier=typeunknown authscore=0 authtc= authcc= route=outbound adjust=0 reason=mlx scancount=1 engine=8.22.0-2605130000 definitions=main-2605200151 From: Josh Poimboeuf Add a debug feature to validate all .sframe sections when first loading the file rather than on demand. [ Jens Remus: Add support for SFrame V3. Add support for PC-relative FDE function start offset. Adjust to rename of struct sframe_fre to sframe_fre_internal. Use %#x/%#lx format specifiers. ] Signed-off-by: Josh Poimboeuf Signed-off-by: Steven Rostedt (Google) Reviewed-by: Indu Bhagat Signed-off-by: Jens Remus --- Notes (jremus): Changes in v15: - sframe_validate_section(): Fix format specifier for number of FREs in debug message. (Sashiko AI) - Normalize error code usage (.sframe is removed for all but ENOENT): ENOENT: No sframe or no FDE for IP found (FDE found but no FRE is EINVAL) EFAULT: Bad address EINVAL: Invalid input or sframe Changes in v14: - Add debug message if safe_read_fde() fails. - Update function names in debug messages. - Uppercase terms FDE and FRE in debug messages. Changes in v13: - Update to SFrame V3: - Print struct sframe_fde_internal fields fda_off and info2 in debug message. - Adjust to rename of struct sframe_fde_internal field func_start_addr to func_addr. - Use format strings "%#x" and "%#lx" instead of "0x%x" and "0x%lx". - Reword commit message (my changes). arch/Kconfig | 19 ++++++++ kernel/unwind/sframe.c | 101 +++++++++++++++++++++++++++++++++++++++++ 2 files changed, 120 insertions(+) diff --git a/arch/Kconfig b/arch/Kconfig index 37549832bd1f..132249d342a3 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -490,6 +490,25 @@ config HAVE_UNWIND_USER_SFRAME bool select UNWIND_USER +config SFRAME_VALIDATION + bool "Enable .sframe section debugging" + depends on HAVE_UNWIND_USER_SFRAME + depends on DYNAMIC_DEBUG + help + When adding an .sframe section for a task, validate the entire + section immediately rather than on demand. + + This is a debug feature which is helpful for rooting out .sframe + section issues. If the .sframe section is corrupt, it will fail to + load immediately, with more information provided in dynamic printks. + + This has a significant page cache footprint due to its reading of the + entire .sframe section for every loaded executable and shared + library. Also, it's done for all processes, even those which don't + get stack traced by the kernel. Not recommended for general use. + + If unsure, say N. + config HAVE_PERF_REGS bool help diff --git a/kernel/unwind/sframe.c b/kernel/unwind/sframe.c index f931932bd34a..b5f984fb2df2 100644 --- a/kernel/unwind/sframe.c +++ b/kernel/unwind/sframe.c @@ -382,6 +382,103 @@ int sframe_find(unsigned long ip, struct unwind_user_frame *frame) return ret; } +#ifdef CONFIG_SFRAME_VALIDATION + +static int safe_read_fde(struct sframe_section *sec, + unsigned int fde_num, struct sframe_fde_internal *fde) +{ + int ret; + + if (!user_read_access_begin((void __user *)sec->sframe_start, + sec->sframe_end - sec->sframe_start)) + return -EFAULT; + ret = __read_fde(sec, fde_num, fde); + user_read_access_end(); + return ret; +} + +static int safe_read_fre(struct sframe_section *sec, + struct sframe_fde_internal *fde, + unsigned long fre_addr, + struct sframe_fre_internal *fre) +{ + int ret; + + if (!user_read_access_begin((void __user *)sec->sframe_start, + sec->sframe_end - sec->sframe_start)) + return -EFAULT; + ret = __read_fre(sec, fde, fre_addr, fre); + user_read_access_end(); + return ret; +} + +static int sframe_validate_section(struct sframe_section *sec) +{ + unsigned long prev_ip = 0; + unsigned int i; + + for (i = 0; i < sec->num_fdes; i++) { + struct sframe_fre_internal *fre, *prev_fre = NULL; + unsigned long ip, fre_addr; + struct sframe_fde_internal fde; + struct sframe_fre_internal fres[2]; + bool which = false; + unsigned int j; + int ret; + + ret = safe_read_fde(sec, i, &fde); + if (ret) { + dbg_sec("safe_read_fde(%u) failed\n", i); + return ret; + } + + ip = fde.func_addr; + if (ip <= prev_ip) { + dbg_sec("FDE %u not sorted\n", i); + return -EINVAL; + } + prev_ip = ip; + + fre_addr = sec->fres_start + fde.fres_off; + for (j = 0; j < fde.fres_num; j++) { + int ret; + + fre = which ? fres : fres + 1; + which = !which; + + ret = safe_read_fre(sec, &fde, fre_addr, fre); + if (ret) { + dbg_sec("FDE %u: safe_read_fre(%u) failed\n", i, j); + dbg_sec("FDE: func_addr:%#lx func_size:%#x fda_off:%#x fres_off:%#x fres_num:%u info:%u info2:%u rep_size:%u\n", + fde.func_addr, fde.func_size, + fde.fda_off, + fde.fres_off, fde.fres_num, + fde.info, fde.info2, + fde.rep_size); + return ret; + } + + fre_addr += fre->size; + + if (prev_fre && fre->ip_off <= prev_fre->ip_off) { + dbg_sec("FDE %u: FRE %u not sorted\n", i, j); + return -EINVAL; + } + + prev_fre = fre; + } + } + + return 0; +} + +#else /* !CONFIG_SFRAME_VALIDATION */ + +static int sframe_validate_section(struct sframe_section *sec) { return 0; } + +#endif /* !CONFIG_SFRAME_VALIDATION */ + + static void free_section(struct sframe_section *sec) { dbg_free(sec); @@ -500,6 +597,10 @@ int sframe_add_section(unsigned long sframe_start, unsigned long sframe_end, goto err_free; } + ret = sframe_validate_section(sec); + if (ret) + goto err_free; + ret = mtree_insert_range(sframe_mt, sec->text_start, sec->text_end - 1, sec, GFP_KERNEL_ACCOUNT); if (ret) { -- 2.51.0