Re: [PATCH v2] um: Avoid longjmp/setjmp symbol clashes with libpthread.a

[Thomas Meyer <thomas@m3y3r.de>]

Am Freitag, den 02.06.2017, 10:30 +0200 schrieb Richard Weinberger:
> Thomas,
> 
> Am 02.06.2017 um 10:04 schrieb Thomas Meyer:
> > Am Donnerstag, den 01.06.2017, 22:49 -0700 schrieb Florian
> > Fainelli:
> > I see this in the kernel log:
> > 
> > [    0.000000] ------------[ cut here ]------------
> > [    0.000000] WARNING: CPU: 0 PID: 0 at
> > arch/x86/kernel/fpu/xstate.c:595
> > fpu__init_system_xstate+0x4d0/0x877
> > [    0.000000] XSAVE consistency problem, dumping leaves
> > [    0.000000] Modules linked in:
> > [    0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 4.10.15-
> > 200.fc25.x86_64 #1
> > [    0.000000] Call Trace:
> > [    0.000000]  dump_stack+0x63/0x86
> > [    0.000000]  __warn+0xcb/0xf0
> > [    0.000000]  warn_slowpath_fmt+0x5f/0x80
> > [    0.000000]  ? xfeature_size+0x5a/0x78
> > [    0.000000]  fpu__init_system_xstate+0x4d0/0x877
> > [    0.000000]  ? msr_clear_bit+0x3a/0xa0
> > [    0.000000]  ? 0xffffffffa3000000
> > [    0.000000]  fpu__init_system+0x194/0x1be
> > [    0.000000]  early_cpu_init+0xf7/0xf9
> > [    0.000000]  setup_arch+0xba/0xcf0
> > [    0.000000]  ? printk+0x57/0x73
> > [    0.000000]  ? early_idt_handler_array+0x120/0x120
> > [    0.000000]  start_kernel+0xb2/0x48a
> > [    0.000000]  ? early_idt_handler_array+0x120/0x120
> > [    0.000000]  x86_64_start_reservations+0x24/0x26
> > [    0.000000]  x86_64_start_kernel+0x14d/0x170
> > [    0.000000]  start_cpu+0x14/0x14
> > [    0.000000] ---[ end trace d5213d72358dda94 ]---
> > [    0.000000] CPUID[0d, 00]: eax=00000007 ebx=00000440
> > ecx=00000440 edx=00000000
> 
> Does this also happen with a mainline kernel? Also on KVM or bare
> metal?

Hi,
I just booted into bare metal, same machine, but host is Fedora 26
"Linux localhost.localdomain 4.11.3-300.fc26.x86_64 #1 SMP Thu May 25 18:43:57 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux"

kernel log from host:

[    0.000000] Linux version 4.11.3-300.fc26.x86_64 (mockbuild@bkernel02.phx2.fedoraproject.org) (gcc version 7.1.1 20170503 (Red Hat 7.1.1-1) (GCC) ) #1 SMP Thu May 25 18:43:57 UTC 2017
[    0.000000] x86/fpu: Supporting XSAVE feature 0x001: 'x87 floating point registers'
[    0.000000] x86/fpu: Supporting XSAVE feature 0x002: 'SSE registers'
[    0.000000] x86/fpu: Supporting XSAVE feature 0x004: 'AVX registers'
[    0.000000] x86/fpu: Supporting XSAVE feature 0x008: 'MPX bounds registers'
[    0.000000] x86/fpu: Supporting XSAVE feature 0x010: 'MPX CSR'
[    0.000000] x86/fpu: xstate_offset[2]:  576, xstate_sizes[2]:  256
[    0.000000] x86/fpu: xstate_offset[3]:  832, xstate_sizes[3]:   64
[    0.000000] x86/fpu: xstate_offset[4]:  896, xstate_sizes[4]:   64
[    0.000000] x86/fpu: Enabled xstate features 0x1f, context size is 960 bytes, using 'compacted' format.

The same error happens in restore_fp_registers() with errno 4.

processor       : 0
vendor_id       : GenuineIntel
cpu family      : 6
model           : 142
model name      : Intel(R) Core(TM) i7-7500U CPU @ 2.70GHz
stepping        : 9
microcode       : 0x38
cpu MHz         : 499.853
cache size      : 4096 KB
physical id     : 0
siblings        : 4
core id         : 0
cpu cores       : 2
apicid          : 0
initial apicid  : 0
fpu             : yes
fpu_exception   : yes
cpuid level     : 22
wp              : yes
flags           : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge
mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe
syscall nx pdpe1gb rdtscp lm constant_tsc art arch_perfmon pebs bts
rep_good nopl xtopology nonstop_tsc cpuid aperfmperf tsc_known_freq pni
pclmulqdq dtes64 monitor ds_cpl vmx est tm2 ssse3 sdbg fma cx16 xtpr
pdcm pcid sse4_1 sse4_2 x2apic movbe popcnt tsc_deadline_timer aes
xsave avx f16c rdrand lahf_lm abm 3dnowprefetch epb intel_pt tpr_shadow
vnmi flexpriority ept vpid fsgsbase tsc_adjust bmi1 avx2 smep bmi2 erms
invpcid mpx rdseed adx smap clflushopt xsaveopt xsavec xgetbv1 xsaves
dtherm ida arat pln pts hwp hwp_notify hwp_act_window hwp_epp
bugs            :
bogomips        : 5808.00
clflush size    : 64
cache_alignment : 64
address sizes   : 39 bits physical, 48 bits virtual
power management:

I'll try a host kernel from master, once I find some time.

> Not that UML fails because of this and we're hunting a ghost...
> 
> Thanks,
> //richard
>