From nobody Sat May 18 04:30:14 2024 Received: from out187-4.us.a.mail.aliyun.com (out187-4.us.a.mail.aliyun.com [47.90.187.4]) (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 654CD59148; Tue, 23 Apr 2024 09:42:50 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=47.90.187.4 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713865374; cv=none; b=N7nRpR7edyudvCbaSlzZhqdttfMh7co644PAS/3Yvm2twY/8Tq0FZonH5YYV5KCnXRN1wmg9HXGHS4H8cd5f4qeTZRovZ9wMuJZXke1SByahZ8sRO1byoVIUZWFGcyg06sOMi4LfmSiJs1XiLri4wxapcbPq8xiwp0ZIv7Mnvd0= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713865374; c=relaxed/simple; bh=9e3zz2vdIgjObMpzkDW7FZcgOJIxeoqT6M30B1aspn4=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=bL6YN9+RRM7QvKTYWA3G5aRl4rXrm8iEFN7K8gvcrzuXNQv9IvF4+wUxpgmm7nTUbPRtnz3meCBZVHzx64tNixLyR3gHbD1rQtXB8ehMAH7oR5/f2WMM6HFHvcWW9BKF/5RP/ZvfEeLt7TKSj3sH3f6HfwlhyUHSDTcFtVJPgo8= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=antgroup.com; spf=pass smtp.mailfrom=antgroup.com; dkim=pass (1024-bit key) header.d=antgroup.com header.i=@antgroup.com header.b=zju6K1Vf; arc=none smtp.client-ip=47.90.187.4 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=antgroup.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=antgroup.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=antgroup.com header.i=@antgroup.com header.b="zju6K1Vf" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=antgroup.com; s=default; t=1713865359; h=From:To:Subject:Date:Message-Id:MIME-Version; bh=eRmZ9jEKUfe7r0xjaXFGSIKeohTP9cOqduT19L33uX0=; b=zju6K1VfUsO56VJPbdPHuXBWD27e5sYhNer8g9cAM9PkwTuvvf88SG9JJSiMks6tocFF4Ym0KC6mg1ihqOG60HwBsILZ75BUoltfXMqiBpbFnChNCc+Vf02NOEgWjNES3s3xZkxNJSSo3UMD76Dvi2xgblLvRdRB6BRXFNLliJE= X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R781e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=ay29a033018047190;MF=zhubojun.zbj@antgroup.com;NM=1;PH=DS;RN=7;SR=0;TI=SMTPD_---.XJPn8AG_1713864416; Received: from localhost(mailfrom:zhubojun.zbj@antgroup.com fp:SMTPD_---.XJPn8AG_1713864416) by smtp.aliyun-inc.com; Tue, 23 Apr 2024 17:27:02 +0800 From: "=?UTF-8?B?5pyx5Lyv5ZCbKOadsOmTrSk=?=" To: linux-kernel@vger.kernel.org, linux-sgx@vger.kernel.org, jarkko@kernel.org, dave.hansen@linux.intel.com Cc: , "=?UTF-8?B?5YiY5Y+MKOi9qeWxuSk=?=" , "=?UTF-8?B?5pyx5Lyv5ZCbKOadsOmTrSk=?=" Subject: [RFC PATCH 1/1] x86/sgx: Explicitly give up the CPU in EDMM's ioctl() to avoid softlockup Date: Tue, 23 Apr 2024 17:25:50 +0800 Message-Id: <20240423092550.59297-2-zhubojun.zbj@antgroup.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20240423092550.59297-1-zhubojun.zbj@antgroup.com> References: <20240423092550.59297-1-zhubojun.zbj@antgroup.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" EDMM's ioctl()s support batch operations, which may be time-consuming. Try to explicitly give up the CPU at the every end of "for loop" in sgx_enclave_{ modify_types | restrict_permissions | remove_pages} to give other tasks a chance to run, and avoid softlockup warning. The following has been observed on Linux v6.9-rc5 with kernel preemptions disabled(by configuring "PREEMPT_NONE=3Dy"), when kernel is requested to restrict page permissions of a large number of EPC pages. ------------[ cut here ]------------ watchdog: BUG: soft lockup - CPU#45 stuck for 22s! [occlum-run:3905] ... CPU: 45 PID: 3905 Comm: occlum-run Not tainted 6.9.0-rc5 #7 ... RIP: 0010:sgx_enclave_restrict_permissions+0xba/0x1f0 Code: 48 c1 e6 05 48 89 d1 48 8d 5c 24 40 b8 0e 00 00 00 48 2b 8e 70 8e= f5 93 48 c1 e9 05 48 c1 e1 0c 48 03 8e 68 8e f5 93 0f 01 cf 00 00 00 = 40 0f 85 b2 00 00 00 85 c0 0f 85 db 00 00 00 4c 89 ef RSP: 0018:ffffb55a6591fa80 EFLAGS: 00000202 RAX: 0000000000000000 RBX: ffffb55a6591fac0 RCX: ffffb581e7384000 RDX: ffffb59a9e4e8080 RSI: 0000000000000020 RDI: ffff91d69e8cc000 RBP: ffffb55a6591fb70 R08: 0000000000000002 R09: ffff91d646e12be0 R10: 000000000000006e R11: 0000000000000002 R12: 000000072052d000 R13: ffff91d69e8cc000 R14: ffffb55a6591fbd8 R15: ffff91d69e8cc020 FS: 00007fe10dbda740(0000) GS:ffff92163e480000(0000) knlGS:00000000000= 00000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fc041811000 CR3: 00000040d95c8005 CR4: 0000000000770ef0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe07f0 DR7: 0000000000000400 PKRU: 55555554 Call Trace: ? show_regs+0x67/0x70 ? watchdog_timer_fn+0x1f3/0x280 ? __pfx_watchdog_timer_fn+0x10/0x10 ? __hrtimer_run_queues+0xc8/0x220 ? hrtimer_interrupt+0x10c/0x250 ? __sysvec_apic_timer_interrupt+0x53/0x130 ? sysvec_apic_timer_interrupt+0x7b/0x90 ? asm_sysvec_apic_timer_interrupt+0x1b/0x20 ? sgx_enclave_restrict_permissions+0xba/0x1f0 ? __pte_offset_map_lock+0x94/0x110 ? sgx_encl_test_and_clear_young_cb+0x40/0x60 sgx_ioctl+0x1ab/0x900 ? do_syscall_64+0x79/0x110 ? apply_to_page_range+0x14/0x20 ? sgx_encl_test_and_clear_young+0x6c/0x80 ? sgx_vma_fault+0x132/0x4f0 __x64_sys_ioctl+0x95/0xd0 x64_sys_call+0x1209/0x20c0 do_syscall_64+0x6d/0x110 ? do_syscall_64+0x79/0x110 ? do_pte_missing+0x2e8/0xcc0 ? __pte_offset_map+0x1c/0x190 ? __handle_mm_fault+0x7b9/0xe60 ? __count_memcg_events+0x70/0x100 ? handle_mm_fault+0x256/0x360 ? do_user_addr_fault+0x3c1/0x860 ? irqentry_exit_to_user_mode+0x67/0x190 ? irqentry_exit+0x3b/0x50 ? exc_page_fault+0x89/0x180 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7fe10e2ee5cb Code: 0f 1e fa 48 8b 05 c5 78 0d 00 64 c7 00 26 00 00 00 48 c7 c0 ff ff= ff ff c3 66 0f 1f 44 00 00 f3 0f 1e fa b8 10 00 00 00 0f 05 <48> 3d 01 f0 = ff ff 73 01 c3 48 8b 0d 95 78 0d 00 f7 d8 64 89 01 48 RSP: 002b:00007fffb2c75518 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000780000000 RCX: 00007fe10e2ee5cb RDX: 00007fffb2c75520 RSI: 00000000c028a405 RDI: 0000000000000005 RBP: 0000000000000005 R08: 0000000000000000 R09: 00007fffb2c75594 R10: 00007fffb2c755c8 R11: 0000000000000246 R12: 00000000c028a405 R13: 00007fffb2c75520 R14: 0000000780000000 R15: 00007fe10e1a7980 ------------[ end trace ]------------ Signed-off-by: Bojun Zhu --- arch/x86/kernel/cpu/sgx/ioctl.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/arch/x86/kernel/cpu/sgx/ioctl.c b/arch/x86/kernel/cpu/sgx/ioct= l.c index b65ab214bdf5..2340a82fa796 100644 --- a/arch/x86/kernel/cpu/sgx/ioctl.c +++ b/arch/x86/kernel/cpu/sgx/ioctl.c @@ -806,6 +806,9 @@ sgx_enclave_restrict_permissions(struct sgx_encl *encl, } =20 mutex_unlock(&encl->lock); + + if (need_resched()) + cond_resched(); } =20 ret =3D 0; @@ -1010,6 +1013,9 @@ static long sgx_enclave_modify_types(struct sgx_encl = *encl, entry->type =3D page_type; =20 mutex_unlock(&encl->lock); + + if (need_resched()) + cond_resched(); } =20 ret =3D 0; @@ -1156,6 +1162,9 @@ static long sgx_encl_remove_pages(struct sgx_encl *en= cl, kfree(entry); =20 mutex_unlock(&encl->lock); + + if (need_resched()) + cond_resched(); } =20 ret =3D 0; --=20 2.25.1