From patchwork Wed Feb 15 16:10:47 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pierre Gondois X-Patchwork-Id: 653808 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 113E3C636D4 for ; Wed, 15 Feb 2023 16:11:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230019AbjBOQLM (ORCPT ); Wed, 15 Feb 2023 11:11:12 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52952 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230007AbjBOQLL (ORCPT ); Wed, 15 Feb 2023 11:11:11 -0500 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 5ECC13B0DB; Wed, 15 Feb 2023 08:10:59 -0800 (PST) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id C98571042; Wed, 15 Feb 2023 08:11:41 -0800 (PST) Received: from cam-smtp0.cambridge.arm.com (pierre123.nice.arm.com [10.34.100.128]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id EEC963F881; Wed, 15 Feb 2023 08:10:57 -0800 (PST) From: Pierre Gondois To: linux-kernel@vger.kernel.org Cc: Pierre Gondois , Ard Biesheuvel , Catalin Marinas , Will Deacon , linux-efi@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: [PATCH v1] arm64: efi: Make efi_rt_lock a raw_spinlock Date: Wed, 15 Feb 2023 17:10:47 +0100 Message-Id: <20230215161047.94803-1-pierre.gondois@arm.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-efi@vger.kernel.org Running a rt-kernel base on 6.2.0-rc3-rt1 on an Ampere Altra outputs the following: BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:46 in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 9, name: kworker/u320:0 preempt_count: 2, expected: 0 RCU nest depth: 0, expected: 0 3 locks held by kworker/u320:0/9: #0: ffff3fff8c27d128 ((wq_completion)efi_rts_wq){+.+.}-{0:0}, at: process_one_work (./include/linux/atomic/atomic-long.h:41) #1: ffff80000861bdd0 ((work_completion)(&efi_rts_work.work)){+.+.}-{0:0}, at: process_one_work (./include/linux/atomic/atomic-long.h:41) #2: ffffdf7e1ed3e460 (efi_rt_lock){+.+.}-{3:3}, at: efi_call_rts (drivers/firmware/efi/runtime-wrappers.c:101) Preemption disabled at: efi_virtmap_load (./arch/arm64/include/asm/mmu_context.h:248) CPU: 0 PID: 9 Comm: kworker/u320:0 Tainted: G W 6.2.0-rc3-rt1 Hardware name: WIWYNN Mt.Jade Server System B81.03001.0005/Mt.Jade Motherboard, BIOS 1.08.20220218 (SCP: 1.08.20220218) 2022/02/18 Workqueue: efi_rts_wq efi_call_rts Call trace: dump_backtrace (arch/arm64/kernel/stacktrace.c:158) show_stack (arch/arm64/kernel/stacktrace.c:165) dump_stack_lvl (lib/dump_stack.c:107 (discriminator 4)) dump_stack (lib/dump_stack.c:114) __might_resched (kernel/sched/core.c:10134) rt_spin_lock (kernel/locking/rtmutex.c:1769 (discriminator 4)) efi_call_rts (drivers/firmware/efi/runtime-wrappers.c:101) [...] This seems to come from commit ff7a167961d1 ("arm64: efi: Execute runtime services from a dedicated stack") which adds a spinlock. This spinlock is taken through: efi_call_rts() \-efi_call_virt() \-efi_call_virt_pointer() \-arch_efi_call_virt_setup() Make 'efi_rt_lock' a raw_spinlock to avoid being preempted. Signed-off-by: Pierre Gondois --- arch/arm64/include/asm/efi.h | 6 +++--- arch/arm64/kernel/efi.c | 2 +- 2 files changed, 4 insertions(+), 4 deletions(-) diff --git a/arch/arm64/include/asm/efi.h b/arch/arm64/include/asm/efi.h index 31d13a6001df..37dc2e8c3500 100644 --- a/arch/arm64/include/asm/efi.h +++ b/arch/arm64/include/asm/efi.h @@ -33,7 +33,7 @@ int efi_set_mapping_permissions(struct mm_struct *mm, efi_memory_desc_t *md); ({ \ efi_virtmap_load(); \ __efi_fpsimd_begin(); \ - spin_lock(&efi_rt_lock); \ + raw_spin_lock(&efi_rt_lock); \ }) #undef arch_efi_call_virt @@ -42,12 +42,12 @@ int efi_set_mapping_permissions(struct mm_struct *mm, efi_memory_desc_t *md); #define arch_efi_call_virt_teardown() \ ({ \ - spin_unlock(&efi_rt_lock); \ + raw_spin_unlock(&efi_rt_lock); \ __efi_fpsimd_end(); \ efi_virtmap_unload(); \ }) -extern spinlock_t efi_rt_lock; +extern raw_spinlock_t efi_rt_lock; efi_status_t __efi_rt_asm_wrapper(void *, const char *, ...); #define ARCH_EFI_IRQ_FLAGS_MASK (PSR_D_BIT | PSR_A_BIT | PSR_I_BIT | PSR_F_BIT) diff --git a/arch/arm64/kernel/efi.c b/arch/arm64/kernel/efi.c index fab05de2e12d..216933cf47ee 100644 --- a/arch/arm64/kernel/efi.c +++ b/arch/arm64/kernel/efi.c @@ -145,7 +145,7 @@ asmlinkage efi_status_t efi_handle_corrupted_x18(efi_status_t s, const char *f) return s; } -DEFINE_SPINLOCK(efi_rt_lock); +DEFINE_RAW_SPINLOCK(efi_rt_lock); asmlinkage u64 *efi_rt_stack_top __ro_after_init;