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 37CD5C636D7 for ; Thu, 16 Feb 2023 16:43:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229886AbjBPQnT (ORCPT ); Thu, 16 Feb 2023 11:43:19 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42082 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229525AbjBPQnR (ORCPT ); Thu, 16 Feb 2023 11:43:17 -0500 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id A8EE5A5D6; Thu, 16 Feb 2023 08:43:15 -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 DAA381042; Thu, 16 Feb 2023 08:43:57 -0800 (PST) Received: from [10.34.100.128] (pierre123.nice.arm.com [10.34.100.128]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 389A93F881; Thu, 16 Feb 2023 08:43:14 -0800 (PST) Message-ID: <19209817-6451-76de-70a4-1f89808bc82a@arm.com> Date: Thu, 16 Feb 2023 17:43:09 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.7.1 Subject: Re: [PATCH v1] arm64: efi: Make efi_rt_lock a raw_spinlock Content-Language: en-US To: linux-kernel@vger.kernel.org Cc: Ard Biesheuvel , Catalin Marinas , Will Deacon , linux-efi@vger.kernel.org, linux-arm-kernel@lists.infradead.org References: <20230215161047.94803-1-pierre.gondois@arm.com> From: Pierre Gondois In-Reply-To: <20230215161047.94803-1-pierre.gondois@arm.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello, Please ignore this patch for now. While running a kernel with this patch, the following was triggered once (among multiple reboots). IRQ flags might need to be saved, along with this present patch. Regards, Pierre random: crng init done [Firmware Bug]: Unable to handle write to read-only memory in EFI runtime service ------------[ cut here ]------------ WARNING: CPU: 7 PID: 325 at drivers/firmware/efi/runtime-wrappers.c:113 efi_call_virt_check_flags+0x48/0xb0 Modules linked in: btrfs blake2b_generic libcrc32c xor xor_neon raid6_pq crct10dif_ce CPU: 7 PID: 325 Comm: kworker/u64:1 Tainted: G W I 6.2.0-rc8-rt1-[...] Hardware name: MiTAC RAPTOR EV-883832-X3-0001/RAPTOR, BIOS 1.0 06/28/2019 Workqueue: efi_rts_wq efi_call_rts pstate: 00000085 (nzcv daIf -PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : efi_call_virt_check_flags+0x48/0xb0 lr : efi_call_rts+0x240/0x4b0 sp : ffff80000def3cf0 x29: ffff80000def3cf0 x28: ffff000801d10b05 x27: ffff80000b16d000 x26: 0000000000000000 x25: ffff80000b17e4a0 x24: ffff80000c84bd48 x23: ffff80000c84bd00 x22: ffff80000c84bd0c x21: 0000000000000080 x20: ffff80000a41d0e0 x19: 0000000000000000 x18: ffff80000a22b3a8 x17: 0000000000000000 x16: ffff80000d2dc000 x15: 0000000000000000 x14: 0000000000000000 x13: 0000000000000000 x12: 0000000000000000 x11: 0000000000000000 x10: 0000000000000000 x9 : ffff80000927cd60 x8 : 0000000000000000 x7 : 0000000000000000 x6 : 0000000000000000 x5 : ffff80000a7d1008 x4 : 0000008ffd1d0018 x3 : 0000000000000000 x2 : 0000000000000001 x1 : ffff80000a41d0e0 x0 : 0000000000000080 Call trace: efi_call_virt_check_flags+0x48/0xb0 efi_call_rts+0x240/0x4b0 process_one_work+0x2c8/0x7a0 worker_thread+0x54/0x410 kthread+0x130/0x140 ret_from_fork+0x10/0x20 irq event stamp: 540538 hardirqs last enabled at (540537): [] efi_virtmap_load+0x28c/0x328 hardirqs last disabled at (540538): [] el1_abort+0x28/0x100 softirqs last enabled at (534078): [] __local_bh_enable_ip+0xa8/0x2a8 softirqs last disabled at (534066): [] neigh_managed_work+0x8/0x100 ---[ end trace 0000000000000000 ]--- Disabling lock debugging due to kernel taint efi: [Firmware Bug]: IRQ flags corrupted (0x00000000=>0x00000080) by EFI set_variable ------------[ cut here ]------------ WARNING: CPU: 0 PID: 14 at drivers/firmware/efi/runtime-wrappers.c:341 virt_efi_set_variable+0x164/0x1c0 Modules linked in: btrfs blake2b_generic libcrc32c xor xor_neon raid6_pq crct10dif_ce CPU: 0 PID: 14 Comm: kworker/0:1 Tainted: G W I 6.2.0-rc8-rt1-custom-[...] Hardware name: MiTAC RAPTOR EV-883832-X3-0001/RAPTOR, BIOS 1.0 06/28/2019 Workqueue: events refresh_nv_rng_seed pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : virt_efi_set_variable+0x164/0x1c0 lr : virt_efi_set_variable+0x150/0x1c0 sp : ffff80000c84bcc0 x29: ffff80000c84bcc0 x28: ffff008f35feb905 x27: ffff80000b16d000 x26: ffff80000b16ced0 x25: 0000000000000000 x24: ffff80000c344000 x23: ffff80000a41b2b0 x22: ffff80000c84bd38 x21: 8000000000000015 x20: ffff80000b63ecf8 x19: ffff80000c344480 x18: ffff80000a22b3a8 x17: 000000005a8ae2d0 x16: 0000000000000000 x15: ffff80000b16cfb8 x14: 0000000000000001 x13: 0000000000000030 x12: 0101010101010101 x11: 0000000571f160b9 x10: 0000000000002460 x9 : ffff8000095e2064 x8 : ffff80000a7d1008 x7 : 0000000000000004 x6 : ffff80000c84bb28 x5 : ffff80000c84c000 x4 : ffff80000c848000 x3 : ffff80000c84bc40 x2 : 0000000000000001 x1 : 0000000000000000 x0 : 8000000000000015 Call trace: virt_efi_set_variable+0x164/0x1c0 refresh_nv_rng_seed+0x84/0xb8 process_one_work+0x2c8/0x7a0 worker_thread+0x54/0x410 kthread+0x130/0x140 ret_from_fork+0x10/0x20 irq event stamp: 35886 hardirqs last enabled at (35885): [] _raw_spin_unlock_irq+0x40/0xb8 hardirqs last disabled at (35886): [] _raw_spin_lock_irq+0x94/0x98 softirqs last enabled at (10754): [] __local_bh_enable_ip+0xa8/0x2a8 softirqs last disabled at (10746): [] srcu_invoke_callbacks+0x100/0x1a8 ---[ end trace 0000000000000000 ]--- [...] In-situ OAM (IOAM) with IPv6 efi: EFI Runtime Services are disabled! efivars: get_next_variable: status=8000000000000007 [...] rtc-efi rtc-efi.0: can't read time rtc-efi rtc-efi.0: can't read time rtc-efi rtc-efi.0: can't read time rtc-efi rtc-efi.0: can't read time rtc-efi rtc-efi.0: can't read time rtc-efi rtc-efi.0: can't read time rtc-efi rtc-efi.0: can't read time rtc-efi rtc-efi.0: can't read time rtc-efi rtc-efi.0: can't read time rtc-efi rtc-efi.0: can't read time rtc-efi rtc-efi.0: can't read time rtc-efi rtc-efi.0: can't read time rtc-efi rtc-efi.0: can't read time [...] On 2/15/23 17:10, Pierre Gondois wrote: > 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; >