Re: [GIT PULL] x86/topology changes for v5.3

From: Thomas Gleixner
Date: Tue Jul 09 2019 - 18:27:59 EST


On Tue, 9 Jul 2019, Linus Torvalds wrote:

> On Tue, Jul 9, 2019 at 2:45 PM Linus Torvalds
> <torvalds@xxxxxxxxxxxxxxxxxxxx> wrote:
> >
> > and I suspect it's the sensitive bit pinning. But I'll delve all the way.
>
> Confirmed. Bisection says
>
> 873d50d58f67ef15d2777b5e7f7a5268bb1fbae2 is the first bad commit
> commit 873d50d58f67ef15d2777b5e7f7a5268bb1fbae2
> Author: Kees Cook <keescook@xxxxxxxxxxxx>
> Date: Mon Jun 17 21:55:02 2019 -0700
>
> x86/asm: Pin sensitive CR4 bits
>
> this is on a bog-standard Intel setup with F30, both desktop and
> laptop (i9-9900k and i7-8565u respectively).
>
> I haven't confirmed yet whether reverting just that one commit is
> required, or if I need to revert the cr0 one too.
>
> I also don't have any logs, because the boot never gets far enough. I
> assume that there was a problem bringing up a non-boot CPU, and the
> eventual hang ends up being due to that.

Hrm. I just build the tip of your tree and bootet it. It hangs at:

[ 4.788678] ACPI: 4 ACPI AML tables successfully acquired and loaded
[ 4.793860] ACPI: [Firmware Bug]: BIOS _OSI(Linux) query ignored
[ 4.821476] ACPI: Dynamic OEM Table Load:

That's way after the secondary CPUs have been brought up. tip/master boots
without problems with the same config. Let me try x86/asm alone and also a
revert of the CR4/CR0 stuff.

And while writing this the softlockup detector muttered:

[ 245.849408] INFO: task swapper/0:1 blocked for more than 120 seconds.
[ 245.853406] Not tainted 5.2.0+ #69
[ 245.857318] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 245.865405] swapper/0 D 0 1 0 0x80004000
[ 245.869405] Call Trace:
[ 245.871859] ? __schedule+0x2bb/0x690
[ 245.877410] ? acpi_ps_complete_op+0x259/0x279
[ 245.881406] schedule+0x29/0x90
[ 245.884540] schedule_timeout+0x20d/0x310
[ 245.889409] ? acpi_os_release_object+0xa/0x10
[ 245.893406] ? acpi_ps_delete_parse_tree+0x2d/0x59
[ 245.897405] __down_timeout+0x9b/0x100
[ 245.901150] down_timeout+0x43/0x50
[ 245.905407] acpi_os_wait_semaphore+0x48/0x60
[ 245.909408] acpi_ut_acquire_mutex+0x45/0x89
[ 245.913406] ? acpi_ns_init_one_package+0x44/0x44
[ 245.917406] acpi_walk_namespace+0x62/0xc2
[ 245.921406] acpi_ns_initialize_objects+0x40/0x7b
[ 245.925407] acpi_ex_load_table_op+0x157/0x1b9
[ 245.933406] acpi_ex_opcode_6A_0T_1R+0x158/0x1c2
[ 245.937406] acpi_ds_exec_end_op+0xca/0x401
[ 245.941406] acpi_ps_parse_loop+0x492/0x5c6
[ 245.945406] acpi_ps_parse_aml+0x91/0x2b8
[ 245.949405] acpi_ps_execute_method+0x15d/0x191
[ 245.953406] acpi_ns_evaluate+0x1bf/0x24c
[ 245.957406] acpi_evaluate_object+0x137/0x240
[ 245.961408] ? kmem_cache_alloc_trace+0x15b/0x1c0
[ 245.965406] acpi_processor_set_pdc+0x135/0x180
[ 245.969408] early_init_pdc+0xb3/0xd0
[ 245.973064] acpi_ns_walk_namespace+0xda/0x1aa
[ 245.977407] ? set_no_mwait+0x23/0x23
[ 245.981062] ? set_no_mwait+0x23/0x23
[ 245.985406] acpi_walk_namespace+0x9a/0xc2
[ 245.989406] ? acpi_sleep_proc_init+0x24/0x24
[ 245.993407] ? do_early_param+0x8e/0x8e
[ 245.997235] acpi_early_processor_set_pdc+0x31/0x49
[ 246.001406] acpi_init+0x17c/0x321


Thanks,

tglx