From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 036EA4431 for ; Wed, 15 Mar 2023 12:25:50 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7AB09C433EF; Wed, 15 Mar 2023 12:25:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1678883150; bh=DplOEY++6edKm/qVARx31dm8053/4Mef/iloluR1UJs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=RgG/CbY4mU0jLCbsm8kVVLly26C0qS5AVE69gPtkIgM3n6el5S75l2N+d0JtK81DG 71BMA+iNbFZsqbJsSjbC6ZeY1RA+gbNyBLT1ouYOsaPG4/Bc5Aw2vFjnk8JXQ+dzfa LYPXc/OZmvTGYbnobB+nmzVVexz/RB64wH8I4P1I= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Pierre Gondois , Ard Biesheuvel , Sasha Levin Subject: [PATCH 5.15 034/145] arm64: efi: Make efi_rt_lock a raw_spinlock Date: Wed, 15 Mar 2023 13:11:40 +0100 Message-Id: <20230315115740.191039809@linuxfoundation.org> X-Mailer: git-send-email 2.40.0 In-Reply-To: <20230315115738.951067403@linuxfoundation.org> References: <20230315115738.951067403@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Pierre Gondois [ Upstream commit 0e68b5517d3767562889f1d83fdb828c26adb24f ] 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. [ardb: The EFI runtime services are called with a different set of translation tables, and are permitted to use the SIMD registers. The context switch code preserves/restores neither, and so EFI calls must be made with preemption disabled, rather than only disabling migration.] Fixes: ff7a167961d1 ("arm64: efi: Execute runtime services from a dedicated stack") Signed-off-by: Pierre Gondois Cc: # v6.1+ Signed-off-by: Ard Biesheuvel Signed-off-by: Sasha Levin --- 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 c5d4551a1be71..53cbbb96f7ebf 100644 --- a/arch/arm64/include/asm/efi.h +++ b/arch/arm64/include/asm/efi.h @@ -25,7 +25,7 @@ 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); \ }) #define arch_efi_call_virt(p, f, args...) \ @@ -37,12 +37,12 @@ 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 386bd81ca12bb..9669f3fa2aefe 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; -- 2.39.2