Messages in this thread | | | Date | Mon, 7 Nov 2022 16:14:12 +0000 | From | Will Deacon <> | Subject | Re: [PATCH v2] firmware: arm_sdei: Fix sleep from invalid context BUG |
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On Tue, Oct 18, 2022 at 03:04:53PM +0200, Pierre Gondois wrote: > On an Ampere Altra, > Running a preemp_rt kernel based on v5.19-rc3-rt5 on an > Ampere Altra triggers: > [ 15.683141] BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:46 > [ 15.683154] in_atomic(): 0, irqs_disabled(): 128, non_block: 0, pid: 24, name: cpuhp/0 > [ 15.683157] preempt_count: 0, expected: 0 > [ 15.683159] RCU nest depth: 0, expected: 0 > [ 15.683163] 3 locks held by cpuhp/0/24: > [ 15.683167] #0: ffffda30217c70d0 (cpu_hotplug_lock){++++}-{0:0}, at: cpuhp_thread_fun+0x5c/0x248 > [ 15.683201] #1: ffffda30217c7120 (cpuhp_state-up){+.+.}-{0:0}, at: cpuhp_thread_fun+0x5c/0x248 > [ 15.683205] #2: ffffda3021c711f0 (sdei_list_lock){....}-{3:3}, at: sdei_cpuhp_up+0x3c/0x130 > [ 15.683224] irq event stamp: 36 > [ 15.683226] hardirqs last enabled at (35): [<ffffda301e85b7bc>] finish_task_switch+0xb4/0x2b0 > [ 15.683236] hardirqs last disabled at (36): [<ffffda301e812fec>] cpuhp_thread_fun+0x21c/0x248 > [ 15.683238] softirqs last enabled at (0): [<ffffda301e80b184>] copy_process+0x63c/0x1ac0 > [ 15.683245] softirqs last disabled at (0): [<0000000000000000>] 0x0 > [ 15.683258] CPU: 0 PID: 24 Comm: cpuhp/0 Not tainted 5.19.0-rc3-rt5-[...] > [ 15.683265] Hardware name: WIWYNN Mt.Jade Server System B81.03001.0005/Mt.Jade Motherboard, BIOS 1.08.20220218 (SCP: 1.08.20220218) 2022/02/18 > [ 15.683268] Call trace: > [ 15.683271] dump_backtrace+0x114/0x120 > [ 15.683277] show_stack+0x20/0x70 > [ 15.683279] dump_stack_lvl+0x9c/0xd8 > [ 15.683288] dump_stack+0x18/0x34 > [ 15.683289] __might_resched+0x188/0x228 > [ 15.683292] rt_spin_lock+0x70/0x120 > [ 15.683301] sdei_cpuhp_up+0x3c/0x130 > [ 15.683303] cpuhp_invoke_callback+0x250/0xf08 > [ 15.683305] cpuhp_thread_fun+0x120/0x248 > [ 15.683308] smpboot_thread_fn+0x280/0x320 > [ 15.683315] kthread+0x130/0x140 > [ 15.683321] ret_from_fork+0x10/0x20 > > sdei_cpuhp_up() is called in the STARTING hotplug section, > which runs whith interrupts disabled. Move CPUHP_AP_ARM_SDEI_ > state to the _ONLINE section to execute the cpuhp cb with > preemption enabled. > > Some SDEI calls (e.g. SDEI_1_0_FN_SDEI_PE_MASK) take actions on the > calling CPU. It is checked that preemption is disabled for them. > _ONLINE cpuhp cb are executed in the 'per CPU hotplug thread'. > Preemption is enabled in those threads, but their cpumask is limited > to 1 CPU. > Move 'WARN_ON_ONCE(preemptible())' statements so that SDEI cpuhp cb > don't trigger them. This means that no check will be done for some > cases, e.g. sdei_mask_local_cpu() invocations. > > Also add a check for the SDEI_1_0_FN_SDEI_PRIVATE_RESET SDEI call > which acts on the calling CPU. > > Suggested-by: James Morse <james.morse@arm.com> > Signed-off-by: Pierre Gondois <pierre.gondois@arm.com> > --- > drivers/firmware/arm_sdei.c | 28 ++++++++++++++-------------- > include/linux/cpuhotplug.h | 2 +- > 2 files changed, 15 insertions(+), 15 deletions(-)
James -- are you taking care of this one, or should I queue it via arm64?
Will
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