AMD GX-412TC flagged as being vulnerable to Meltdown in 4.9.77

AMD GX-412TC flagged as being vulnerable to Meltdown in 4.9.77

[Nick Lowe]

Hi,

On an APU2C4 which uses a AMD GX-412TC SOC, this is incorrectly
flagged as being vulnerable to Meltdown in 4.9.77

root@LEDE:/sys/devices/system/cpu/vulnerabilities# cat meltdown
Vulnerable

root@LEDE:/sys/devices/system/cpu/vulnerabilities# cat /proc/cpuinfo
processor : 0
vendor_id : AuthenticAMD
cpu family : 22
model : 48
model name : AMD GX-412TC SOC
stepping : 1
microcode : 0x7030105
cpu MHz : 600.000
cache size : 2048 KB
physical id : 0
siblings : 4
core id : 0
cpu cores : 4
apicid : 0
initial apicid : 0
fpu : yes
fpu_exception : yes
cpuid level : 13
wp : yes
flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov
pat pse36 clflush mmx fxsr sse sse2 ht syscall nx mmxext fxsr_opt
pdpe1gb rdtscp lm constant_tsc rep_good acc_power nopl nonstop_tsc
extd_apicid aperfmperf eagerfpu pni pclmulqdq monitor ssse3 cx16
sse4_1 sse4_2 movbe popcnt aes xsave avx f16c lahf_lm cmp_legacy svm
extapic cr8_legacy abm sse4a misalignsse 3dnowprefetch osvw ibs skinit
wdt topoext perfctr_nb bpext ptsc perfctr_l2 cpb hw_pstate retpoline
retpoline_amd vmmcall bmi1 xsaveopt arat npt lbrv svm_lock nrip_save
tsc_scale flushbyasid decodeassists pausefilter pfthreshold
overflow_recov
bugs : fxsave_leak sysret_ss_attrs null_seg cpu_meltdown spectre_v1 spectre_v2
bogomips : 1996.12
TLB size : 1024 4K pages
clflush size : 64
cache_alignment : 64
address sizes : 40 bits physical, 48 bits virtual
power management: ts ttp tm 100mhzsteps hwpstate cpb acc_power [13]

<snip>

Cheers,

Nick

Re: AMD GX-412TC flagged as being vulnerable to Meltdown in 4.9.77

[Nick Lowe]

This following is not present in 4.9.77:

x86/cpu, x86/pti: Do not enable PTI on AMD processor
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git/commit/?h=v4.14.14&id=151d7039757b71ebd9d170af0944562f51149372

Re: AMD GX-412TC flagged as being vulnerable to Meltdown in 4.9.77

[Greg KH]

On Sun, Jan 21, 2018 at 12:43:43PM +0000, Nick Lowe wrote:
> Hi,
> 
> On an APU2C4 which uses a AMD GX-412TC SOC, this is incorrectly
> flagged as being vulnerable to Meltdown in 4.9.77
> 
> root@LEDE:/sys/devices/system/cpu/vulnerabilities# cat meltdown
> Vulnerable
> 
> root@LEDE:/sys/devices/system/cpu/vulnerabilities# cat /proc/cpuinfo
> processor : 0
> vendor_id : AuthenticAMD
> cpu family : 22
> model : 48
> model name : AMD GX-412TC SOC
> stepping : 1
> microcode : 0x7030105
> cpu MHz : 600.000
> cache size : 2048 KB
> physical id : 0
> siblings : 4
> core id : 0
> cpu cores : 4
> apicid : 0
> initial apicid : 0
> fpu : yes
> fpu_exception : yes
> cpuid level : 13
> wp : yes
> flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov
> pat pse36 clflush mmx fxsr sse sse2 ht syscall nx mmxext fxsr_opt
> pdpe1gb rdtscp lm constant_tsc rep_good acc_power nopl nonstop_tsc
> extd_apicid aperfmperf eagerfpu pni pclmulqdq monitor ssse3 cx16
> sse4_1 sse4_2 movbe popcnt aes xsave avx f16c lahf_lm cmp_legacy svm
> extapic cr8_legacy abm sse4a misalignsse 3dnowprefetch osvw ibs skinit
> wdt topoext perfctr_nb bpext ptsc perfctr_l2 cpb hw_pstate retpoline
> retpoline_amd vmmcall bmi1 xsaveopt arat npt lbrv svm_lock nrip_save
> tsc_scale flushbyasid decodeassists pausefilter pfthreshold
> overflow_recov
> bugs : fxsave_leak sysret_ss_attrs null_seg cpu_meltdown spectre_v1 spectre_v2
> bogomips : 1996.12
> TLB size : 1024 4K pages
> clflush size : 64
> cache_alignment : 64
> address sizes : 40 bits physical, 48 bits virtual
> power management: ts ttp tm 100mhzsteps hwpstate cpb acc_power [13]
> 
> <snip>

What does the latest 4.14.y release, or Linus's tree show for this CPU?

thanks,

greg k-h

Re: AMD GX-412TC flagged as being vulnerable to Meltdown in 4.9.77

[Greg KH]

On Sun, Jan 21, 2018 at 12:49:29PM +0000, Nick Lowe wrote:
> This following is not present in 4.9.77:
> 
> x86/cpu, x86/pti: Do not enable PTI on AMD processor
> https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git/commit/?h=v4.14.14&id=151d7039757b71ebd9d170af0944562f51149372

Hm, can you provide a working backport for 4.9.y for this, that seems to
be why I didn't include it there.  Same for 4.4.y...

thanks,

greg k-h

Re: AMD GX-412TC flagged as being vulnerable to Meltdown in 4.9.77

[Greg KH]

On Sun, Jan 21, 2018 at 02:25:10PM +0100, Greg KH wrote:
> On Sun, Jan 21, 2018 at 12:49:29PM +0000, Nick Lowe wrote:
> > This following is not present in 4.9.77:
> > 
> > x86/cpu, x86/pti: Do not enable PTI on AMD processor
> > https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git/commit/?h=v4.14.14&id=151d7039757b71ebd9d170af0944562f51149372
> 
> Hm, can you provide a working backport for 4.9.y for this, that seems to
> be why I didn't include it there.  Same for 4.4.y...

Odd, I seem to be missing a few more patches here for 4.9 and 4.4, I'll
dig through the tree to see what went wrong here...

greg k-h

Re: AMD GX-412TC flagged as being vulnerable to Meltdown in 4.9.77

[Nick Lowe]

> Hm, can you provide a working backport for 4.9.y for this, that seems to
> be why I didn't include it there.  Same for 4.4.y...

Hi Greg,

I have sent on the request on to Tom Lendacky by email as it is his patch.

Regards,

Nick

Re: AMD GX-412TC flagged as being vulnerable to Meltdown in 4.9.77

[Greg KH]

On Sun, Jan 21, 2018 at 03:31:27PM +0000, Nick Lowe wrote:
> > Hm, can you provide a working backport for 4.9.y for this, that seems to
> > be why I didn't include it there.  Same for 4.4.y...
> 
> Hi Greg,
> 
> I have sent on the request on to Tom Lendacky by email as it is his patch.

There's some patches before that one that are needed, so it's not Tom's
fault, yet :)

thanks,

greg k-h

Re: AMD GX-412TC flagged as being vulnerable to Meltdown in 4.9.77

[Greg KH]

On Sun, Jan 21, 2018 at 04:39:29PM +0100, Greg KH wrote:
> On Sun, Jan 21, 2018 at 03:31:27PM +0000, Nick Lowe wrote:
> > > Hm, can you provide a working backport for 4.9.y for this, that seems to
> > > be why I didn't include it there.  Same for 4.4.y...
> > 
> > Hi Greg,
> > 
> > I have sent on the request on to Tom Lendacky by email as it is his patch.
> 
> There's some patches before that one that are needed, so it's not Tom's
> fault, yet :)

Ok, I have it now figured out, the patch is queued up for the next 4.9.y
and 4.4.y releases, thanks.

greg k-h