From nobody Sun Dec 28 21:15:37 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A70C6C4167B for ; Tue, 5 Dec 2023 13:31:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1442249AbjLENaw (ORCPT ); Tue, 5 Dec 2023 08:30:52 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49808 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1442151AbjLENan (ORCPT ); Tue, 5 Dec 2023 08:30:43 -0500 Received: from mx0b-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com [148.163.158.5]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BC2D618C for ; Tue, 5 Dec 2023 05:30:48 -0800 (PST) Received: from pps.filterd (m0360072.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 3B5DMxFA014022; Tue, 5 Dec 2023 13:30:27 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-transfer-encoding; s=pp1; bh=e9OcvWXQrgehwaXmvt4tAvWEvIUngGRk7okHHuNXNu8=; b=USSGjNXGbVoQdlEof6nTQQ29zTg3rNY0xAfubxVONrDwUdQaKge9EwinfeHaTaqEjGT6 UAKObtMQPmu8gFVLCUQURXc7I3EYHPRiF3JWSgcDdKroHciQvB2lRXYdRic/OWKxQ+zr 6IQ5eVGQ8BWBXhf04meHw+62VT8uOC+qviCUEsQz5tlB/+Y0LmAlLwORGcmQY/kvrP6M J6uOK361lhlf7RUuGtYijPaqjRn/KCAidab/diS/4NiuUdD9zfutIQqKfrPe0luCvd3o O6NE1/G3e3ueSB6hC5q2/jXBzJgmLz8hOsqO90YDGdTaHzse8Q46h/5W/FY8WBpI+jMn 6w== 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 3ut4pq8aym-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 05 Dec 2023 13:30:26 +0000 Received: from pps.filterd (ppma21.wdc07v.mail.ibm.com [127.0.0.1]) by ppma21.wdc07v.mail.ibm.com (8.17.1.19/8.17.1.19) with ESMTP id 3B5Aw7r7026459; Tue, 5 Dec 2023 13:30:26 GMT Received: from smtprelay04.fra02v.mail.ibm.com ([9.218.2.228]) by ppma21.wdc07v.mail.ibm.com (PPS) with ESMTPS id 3urv8dukc8-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 05 Dec 2023 13:30:26 +0000 Received: from smtpav07.fra02v.mail.ibm.com (smtpav07.fra02v.mail.ibm.com [10.20.54.106]) by smtprelay04.fra02v.mail.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 3B5DUOOJ42861128 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 5 Dec 2023 13:30:24 GMT Received: from smtpav07.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 1C55120040; Tue, 5 Dec 2023 13:30:24 +0000 (GMT) Received: from smtpav07.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 0068820043; Tue, 5 Dec 2023 13:30:24 +0000 (GMT) Received: from tuxmaker.boeblingen.de.ibm.com (unknown [9.152.85.9]) by smtpav07.fra02v.mail.ibm.com (Postfix) with ESMTPS; Tue, 5 Dec 2023 13:30:23 +0000 (GMT) Received: by tuxmaker.boeblingen.de.ibm.com (Postfix, from userid 55390) id B3ABEE12C5; Tue, 5 Dec 2023 14:30:23 +0100 (CET) From: Sven Schnelle To: Thomas Gleixner , Peter Zijlstra , Andy Lutomirski Cc: linux-kernel@vger.kernel.org, Heiko Carstens Subject: [PATCH 1/3] entry: move exit to usermode functions to header file Date: Tue, 5 Dec 2023 14:30:13 +0100 Message-Id: <20231205133015.752543-2-svens@linux.ibm.com> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20231205133015.752543-1-svens@linux.ibm.com> References: <20231205133015.752543-1-svens@linux.ibm.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-TM-AS-GCONF: 00 X-Proofpoint-ORIG-GUID: Ucp59YmbGAkSeOHjaR7tXYrrzrG5qNgr X-Proofpoint-GUID: Ucp59YmbGAkSeOHjaR7tXYrrzrG5qNgr X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.272,Aquarius:18.0.997,Hydra:6.0.619,FMLib:17.11.176.26 definitions=2023-12-05_08,2023-12-05_01,2023-05-22_02 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 impostorscore=0 phishscore=0 spamscore=0 malwarescore=0 adultscore=0 suspectscore=0 clxscore=1015 mlxscore=0 priorityscore=1501 mlxlogscore=763 bulkscore=0 lowpriorityscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2311060000 definitions=main-2312050105 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" To allow inlining, move exit_to_user_mode() and exit_to_user_mode_loop() to common.h. Signed-off-by: Sven Schnelle --- include/linux/entry-common.h | 95 +++++++++++++++++++++++++++++++++++- kernel/entry/common.c | 89 +-------------------------------- 2 files changed, 96 insertions(+), 88 deletions(-) diff --git a/include/linux/entry-common.h b/include/linux/entry-common.h index d95ab85f96ba..f0f1a26dc638 100644 --- a/include/linux/entry-common.h +++ b/include/linux/entry-common.h @@ -7,6 +7,10 @@ #include #include #include +#include +#include +#include +#include =20 #include =20 @@ -258,6 +262,85 @@ static __always_inline void arch_exit_to_user_mode(voi= d) { } */ void arch_do_signal_or_restart(struct pt_regs *regs); =20 +/** + * exit_to_user_mode_loop - do any pending work before leaving to user spa= ce + */ +static __always_inline unsigned long exit_to_user_mode_loop(struct pt_regs= *regs, + unsigned long ti_work) +{ + /* + * Before returning to user space ensure that all pending work + * items have been completed. + */ + while (ti_work & EXIT_TO_USER_MODE_WORK) { + + local_irq_enable_exit_to_user(ti_work); + + if (ti_work & _TIF_NEED_RESCHED) + schedule(); + + if (ti_work & _TIF_UPROBE) + uprobe_notify_resume(regs); + + if (ti_work & _TIF_PATCH_PENDING) + klp_update_patch_state(current); + + if (ti_work & (_TIF_SIGPENDING | _TIF_NOTIFY_SIGNAL)) + arch_do_signal_or_restart(regs); + + if (ti_work & _TIF_NOTIFY_RESUME) + resume_user_mode_work(regs); + + /* Architecture specific TIF work */ + arch_exit_to_user_mode_work(regs, ti_work); + + /* + * Disable interrupts and reevaluate the work flags as they + * might have changed while interrupts and preemption was + * enabled above. + */ + local_irq_disable_exit_to_user(); + + /* Check if any of the above work has queued a deferred wakeup */ + tick_nohz_user_enter_prepare(); + + ti_work =3D read_thread_flags(); + } + + /* Return the latest work state for arch_exit_to_user_mode() */ + return ti_work; +} + +/** + * exit_to_user_mode_prepare - call exit_to_user_mode_loop() if required + * + * 1) check that interrupts are disabled + * 2) call tick_nohz_user_enter_prepare() + * 3) call exit_to_user_mode_loop() if any flags from + * EXIT_TO_USER_MODE_WORK are set + * 4) check that interrupts are still disabled + */ +static __always_inline void exit_to_user_mode_prepare(struct pt_regs *regs) +{ + unsigned long ti_work; + + lockdep_assert_irqs_disabled(); + + /* Flush pending rcuog wakeup before the last need_resched() check */ + tick_nohz_user_enter_prepare(); + + ti_work =3D read_thread_flags(); + if (unlikely(ti_work & EXIT_TO_USER_MODE_WORK)) + ti_work =3D exit_to_user_mode_loop(regs, ti_work); + + arch_exit_to_user_mode_prepare(regs, ti_work); + + /* Ensure that kernel state is sane for a return to userspace */ + kmap_assert_nomap(); + lockdep_assert_irqs_disabled(); + lockdep_sys_exit(); +} + /** * exit_to_user_mode - Fixup state when exiting to user mode * @@ -276,7 +359,17 @@ void arch_do_signal_or_restart(struct pt_regs *regs); * non-instrumentable. * The caller has to invoke syscall_exit_to_user_mode_work() before this. */ -void exit_to_user_mode(void); +static __always_inline void exit_to_user_mode(void) +{ + instrumentation_begin(); + trace_hardirqs_on_prepare(); + lockdep_hardirqs_on_prepare(); + instrumentation_end(); + + user_enter_irqoff(); + arch_exit_to_user_mode(); + lockdep_hardirqs_on(CALLER_ADDR0); +} =20 /** * syscall_exit_to_user_mode_work - Handle work before returning to user m= ode diff --git a/kernel/entry/common.c b/kernel/entry/common.c index d7ee4bc3f2ba..6ba2bcfbe32c 100644 --- a/kernel/entry/common.c +++ b/kernel/entry/common.c @@ -123,94 +123,9 @@ noinstr void syscall_enter_from_user_mode_prepare(stru= ct pt_regs *regs) instrumentation_end(); } =20 -/* See comment for exit_to_user_mode() in entry-common.h */ -static __always_inline void __exit_to_user_mode(void) -{ - instrumentation_begin(); - trace_hardirqs_on_prepare(); - lockdep_hardirqs_on_prepare(); - instrumentation_end(); - - user_enter_irqoff(); - arch_exit_to_user_mode(); - lockdep_hardirqs_on(CALLER_ADDR0); -} - -void noinstr exit_to_user_mode(void) -{ - __exit_to_user_mode(); -} - /* Workaround to allow gradual conversion of architecture code */ void __weak arch_do_signal_or_restart(struct pt_regs *regs) { } =20 -static unsigned long exit_to_user_mode_loop(struct pt_regs *regs, - unsigned long ti_work) -{ - /* - * Before returning to user space ensure that all pending work - * items have been completed. - */ - while (ti_work & EXIT_TO_USER_MODE_WORK) { - - local_irq_enable_exit_to_user(ti_work); - - if (ti_work & _TIF_NEED_RESCHED) - schedule(); - - if (ti_work & _TIF_UPROBE) - uprobe_notify_resume(regs); - - if (ti_work & _TIF_PATCH_PENDING) - klp_update_patch_state(current); - - if (ti_work & (_TIF_SIGPENDING | _TIF_NOTIFY_SIGNAL)) - arch_do_signal_or_restart(regs); - - if (ti_work & _TIF_NOTIFY_RESUME) - resume_user_mode_work(regs); - - /* Architecture specific TIF work */ - arch_exit_to_user_mode_work(regs, ti_work); - - /* - * Disable interrupts and reevaluate the work flags as they - * might have changed while interrupts and preemption was - * enabled above. - */ - local_irq_disable_exit_to_user(); - - /* Check if any of the above work has queued a deferred wakeup */ - tick_nohz_user_enter_prepare(); - - ti_work =3D read_thread_flags(); - } - - /* Return the latest work state for arch_exit_to_user_mode() */ - return ti_work; -} - -static void exit_to_user_mode_prepare(struct pt_regs *regs) -{ - unsigned long ti_work; - - lockdep_assert_irqs_disabled(); - - /* Flush pending rcuog wakeup before the last need_resched() check */ - tick_nohz_user_enter_prepare(); - - ti_work =3D read_thread_flags(); - if (unlikely(ti_work & EXIT_TO_USER_MODE_WORK)) - ti_work =3D exit_to_user_mode_loop(regs, ti_work); - - arch_exit_to_user_mode_prepare(regs, ti_work); - - /* Ensure that kernel state is sane for a return to userspace */ - kmap_assert_nomap(); - lockdep_assert_irqs_disabled(); - lockdep_sys_exit(); -} - /* * If SYSCALL_EMU is set, then the only reason to report is when * SINGLESTEP is set (i.e. PTRACE_SYSEMU_SINGLESTEP). This syscall @@ -295,7 +210,7 @@ __visible noinstr void syscall_exit_to_user_mode(struct= pt_regs *regs) instrumentation_begin(); __syscall_exit_to_user_mode_work(regs); instrumentation_end(); - __exit_to_user_mode(); + exit_to_user_mode(); } =20 noinstr void irqentry_enter_from_user_mode(struct pt_regs *regs) @@ -308,7 +223,7 @@ noinstr void irqentry_exit_to_user_mode(struct pt_regs = *regs) instrumentation_begin(); exit_to_user_mode_prepare(regs); instrumentation_end(); - __exit_to_user_mode(); + exit_to_user_mode(); } =20 noinstr irqentry_state_t irqentry_enter(struct pt_regs *regs) --=20 2.40.1