Messages in this thread | | | Date | Sat, 30 Dec 2017 19:20:04 +0100 (CET) | From | Thomas Gleixner <> | Subject | Re: x86/pti: smp_processor_id() called while preemptible in resume-from-sleep |
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On Sat, 30 Dec 2017, Dominik Brodowski wrote:
> On Sat, Dec 30, 2017 at 04:03:07PM +0100, Thomas Gleixner wrote: > > On Sat, 30 Dec 2017, Dominik Brodowski wrote: > > > resume-from-sleep (mem/S3) on v4.15-rc5-149-g5aa90a845892 triggers the > > > following bug. If I boot with "pti=off", the kernel does not show this > > > issue, and neither did kernels before pti was merged: > > > > > > [ 39.951703] ACPI: Low-level resume complete > > > [ 39.951832] ACPI: EC: EC started > > > [ 39.951840] PM: Restoring platform NVS memory > > > [ 39.954648] Enabling non-boot CPUs ... > > > [ 39.954792] x86: Booting SMP configuration: > > > [ 39.954800] smpboot: Booting Node 0 Processor 1 APIC 0x2 > > > [ 39.954834] BUG: using smp_processor_id() in preemptible [00000000] code: sh/465 > > > [ 39.954841] caller is native_cpu_up+0x2f0/0xa30 > > > > I can't reproduce at the moment and I can't find a possible reason for this > > by code inspection. > > Thanks for taking a look at it! > > > Can you please provide your .config file > > See attached. > > > and perhaps decode the two offending call sites with > > > > scripts/faddr2line vmlinux native_cpu_up+0x2f0/0xa30 native_cpu_up+0x447/0xa30 > > native_cpu_up+0x2f0/0xa30: > invalidate_user_asid at arch/x86/include/asm/tlbflush.h:343
Ah, that makes sense. Missed that in the maze.
What makes less sense is that tlbflush itself. I'm surely missing something subtle, but from a first look that tlbflush is pointless.
> (inlined by) __native_flush_tlb at arch/x86/include/asm/tlbflush.h:351 > (inlined by) smpboot_setup_warm_reset_vector at arch/x86/kernel/smpboot.c:129 > (inlined by) do_boot_cpu at arch/x86/kernel/smpboot.c:950 > (inlined by) native_cpu_up at arch/x86/kernel/smpboot.c:1070 > > native_cpu_up+0x447/0xa30: > kern_pcid at arch/x86/include/asm/tlbflush.h:105 > (inlined by) invalidate_user_asid at arch/x86/include/asm/tlbflush.h:342 > (inlined by) __native_flush_tlb at arch/x86/include/asm/tlbflush.h:351 > (inlined by) smpboot_restore_warm_reset_vector at arch/x86/kernel/smpboot.c:146
This one even more so as the stale comment suggests, that there was some page table fiddling at some point in the past.
> (inlined by) do_boot_cpu at arch/x86/kernel/smpboot.c:1022 > (inlined by) native_cpu_up at arch/x86/kernel/smpboot.c:1070
Let me think about it and do some archaeological research.
Thanks,
tglx
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