From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from dispatch1-us1.ppe-hosted.com (dispatch1-us1.ppe-hosted.com [67.231.154.184]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 13C5F22C6C3 for ; Fri, 6 Dec 2024 21:50:39 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=67.231.154.184 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1733521842; cv=none; b=e+G+JTrzpXah5QtmlEexDGY1fe0bF2nigesZZetYPEUW8rq0uYDrGEctbYKa21XoxB/wuYCqaVLIEr5Pm/8lu8umNZnIMBeXIbdaG/nEha5fd/yqgk9S7oBXsskslDsHSDsWxCfMAXuW6ZjkhJjaY9NjoeLxrAzdtQyu7DJxVuw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1733521842; c=relaxed/simple; bh=SlOkHsGxtavNtcjtMvgZX7xOljQP1nIyV8Lg4jBIN3Y=; h=Message-ID:Date:MIME-Version:To:From:Subject:Content-Type; b=hurBNbyBxF5CTEKGJClmEj/b2StGdSJcUIZg3WQxqccvb8E8FDGck8chKGaAwy7SKAzX/UMI+MZ1DTz5/DMcECzEkqsFk43riX09ue7t0mOm9q0rRyCUmC9qHTDBOGaQLWVgHPtCWPFZf9Pk8GZZmNiiEyagU47Sa6dW22G/oL4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=candelatech.com; spf=pass smtp.mailfrom=candelatech.com; dkim=pass (1024-bit key) header.d=candelatech.com header.i=@candelatech.com header.b=bo+6+gz6; arc=none smtp.client-ip=67.231.154.184 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=candelatech.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=candelatech.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=candelatech.com header.i=@candelatech.com header.b="bo+6+gz6" X-Virus-Scanned: Proofpoint Essentials engine Received: from mail3.candelatech.com (mail.candelatech.com [208.74.158.173]) by mx1-us1.ppe-hosted.com (PPE Hosted ESMTP Server) with ESMTP id B44EE2C0066; Fri, 6 Dec 2024 21:50:37 +0000 (UTC) Received: from [192.168.100.159] (unknown [50.251.239.81]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail3.candelatech.com (Postfix) with ESMTPSA id A9BDD13C2B0; Fri, 6 Dec 2024 13:50:34 -0800 (PST) DKIM-Filter: OpenDKIM Filter v2.11.0 mail3.candelatech.com A9BDD13C2B0 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=candelatech.com; s=default; t=1733521834; bh=SlOkHsGxtavNtcjtMvgZX7xOljQP1nIyV8Lg4jBIN3Y=; h=Date:To:From:Subject:From; b=bo+6+gz6xa2NCCOO09Fa36ePSUpjoJYMQK5PlnGkEyNn7xqVsZ/upNS5t9dhU7GGP iT+N4qeKpTH7WDM5FkWmBDQbcumzeE78BlsDOD7kNM2SdS/Rrtd0NHUiIC2qfOjTeF OEqpZPE05Gmj/LGWVrRBoLsuYiJjgUAuj8EK91/o= Message-ID: <1ba0cc57-e2ed-caa2-1241-aa5615bee01f@candelatech.com> Date: Fri, 6 Dec 2024 13:50:34 -0800 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.15.1 To: Suren Baghdasaryan , LKML Content-Language: en-US From: Ben Greear Subject: BISECTED: 'alloc_tag: populate memory for module tags as needed' crashes on boot. Organization: Candela Technologies Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-MDID: 1733521838-Ed6IaDlzvP9F X-MDID-O: us5;at1;1733521838;Ed6IaDlzvP9F;;b4c026870a3b52e78af0ca2564020f08 X-PPE-TRUSTED: V=1;DIR=OUT; Hello Suren, My system crashes on bootup, and I bisected to this commit. 0f9b685626daa2f8e19a9788625c9b624c223e45 is the first bad commit commit 0f9b685626daa2f8e19a9788625c9b624c223e45 Author: Suren Baghdasaryan Date: Wed Oct 23 10:07:57 2024 -0700 alloc_tag: populate memory for module tags as needed The memory reserved for module tags does not need to be backed by physical pages until there are tags to store there. Change the way we reserve this memory to allocate only virtual area for the tags and populate it with physical pages as needed when we load a module. The crash looks like this: BUG: unable to handle page fault for address: fffffbfff4041000 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 44d0e7067 P4D 44d0e7067 PUD 44d0e3067 PMD 10bb38067 PTE 0 Oops: Oops: 0000 [#1] PREEMPT SMP KASAN CPU: 0 UID: 0 PID: 319 Comm: systemd-udevd Not tainted 6.12.0-rc6+ #21 Hardware name: Default string Default string/SKYBAY, BIOS 5.12 02/15/2023 RIP: 0010:kasan_check_range+0xa5/0x190 Code: 8d 5a 07 4c 0f 49 da 49 c1 fb 03 45 85 db 0f 84 ce 00 00 00 45 89 db 4a 8d 14 d8 eb 0d 48 83 c0 08 48 39 d0 0f 84 b29 RSP: 0018:ffff88812c26f980 EFLAGS: 00010206 RAX: fffffbfff4041000 RBX: fffffbfff404101e RCX: ffffffff814ec29b [ OK DX: fffffbfff4041018 RSI: 00000000000000f0 RDI: ffffffffa0208000 0m] Finished BP: fffffbfff4041000 R08: 0000000000000001 R09: fffffbfff404101d ;1;39msystemd-udR10: ffffffffa02080ef R11: 0000000000000003 R12: ffffffffa0208000 ev-trig…e R13: ffffc90000dac7c8 R14: ffffc90000dac7e8 R15: dffffc0000000000 - Coldplug All uFS: 00007fe869216b40(0000) GS:ffff88841da00000(0000) knlGS:0000000000000000 dev Devices. CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: fffffbfff4041000 CR3: 0000000121e86002 CR4: 00000000003706f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: [ OK ? __die+0x1f/0x60 0m] Reached targ ? page_fault_oops+0x258/0x910 et sysi ? dump_pagetable+0x690/0x690 nit.target - ? search_bpf_extables+0x22/0x250 System Initiali ? trace_page_fault_kernel+0x120/0x120 zation. ? search_bpf_extables+0x164/0x250 ? kasan_check_range+0xa5/0x190 ? fixup_exception+0x4d/0xc70 ? exc_page_fault+0xe1/0xf0 [ OK ? asm_exc_page_fault+0x22/0x30 0m] Reached targ ? load_module+0x3d7b/0x7560 et netw ? kasan_check_range+0xa5/0x190 ork.target - __asan_memcpy+0x38/0x60 Network. load_module+0x3d7b/0x7560 ? module_frob_arch_sections+0x30/0x30 ? lockdep_lock+0xbe/0x1b0 ? rw_verify_area+0x18d/0x5e0 ? kernel_read_file+0x246/0x870 ? __x64_sys_fspick+0x290/0x290 ? init_module_from_file+0xd1/0x130 init_module_from_file+0xd1/0x130 ? __ia32_sys_init_module+0xa0/0xa0 ? lock_acquire+0x2d/0xb0 ? idempotent_init_module+0x116/0x790 ? do_raw_spin_unlock+0x54/0x220 idempotent_init_module+0x226/0x790 ? init_module_from_file+0x130/0x130 ? vm_mmap_pgoff+0x203/0x2e0 __x64_sys_finit_module+0xba/0x130 do_syscall_64+0x69/0x160 entry_SYSCALL_64_after_hwframe+0x4b/0x53 RIP: 0033:0x7fe869de327d Code: 5d c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 248 RSP: 002b:00007ffe34a828d8 EFLAGS: 00000246 ORIG_RAX: 0000000000000139 RAX: ffffffffffffffda RBX: 0000557fa8f3f3f0 RCX: 00007fe869de327d RDX: 0000000000000000 RSI: 00007fe869f4943c RDI: 0000000000000006 RBP: 00007fe869f4943c R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000006 R11: 0000000000000246 R12: 0000000000020000 R13: 0000557fa8f3f030 R14: 0000000000000000 R15: 0000557fa8f3d110 Modules linked in: CR2: fffffbfff4041000 ---[ end trace 0000000000000000 ]--- I suspect you only hit this with an unlucky amount of debugging enabled. The kernel config I used is found here: http://www.candelatech.com/downloads/cfg-kasan-crash-regression.config I will be happy to test fixes. Thanks, Ben -- Ben Greear Candela Technologies Inc http://www.candelatech.com