On 25.04.2018 00:18, Taiidan(a)gmx.com wrote:
On 04/17/2018 03:30 AM, Rudolf Marek wrote:
Hi,
I found new microcode here [1], I used cpu00610F01_ver0600111F_2018-03-05_AC55EB96.bin as
a microcode for my Trinity family15h CPU.
I hacked together a new microcode header which contains the equivalence table etc to be
able to load this microcode into the CPU from Linux.
dd if=/lib/firmware/amd-ucode/microcode_amd_fam15h.bin bs=1 count=84 of=header.bin
cat header.bin cpu00610F01_ver0600111F_2018-03-05_AC55EB96.bin >
microcode_amd_fam15h.bin
copy the file to same location and trigger update:
echo 1 > /sys/devices/system/cpu/microcode/reload
[ 6032.948243] microcode: CPU0: new patch_level=0x0600111f
[ 6032.964913] microcode: CPU2: new patch_level=0x0600111f
Please note that the header.bin does contain a size of the microcode blob, but it happens
to be the same, so it works. Normally the container
may contain more microcode blobs. But in my case I use just "right" one for my
CPU.
The new microcode seems to be adding the IBPB feature.
Thanks
Rudolf
[1]
https://github.com/platomav/CPUMicrocodes This didn't work on my
piledriver CPU's :[
When I try to "reload" nothing happens not even an error in dmesg....the
reload command has never worked for me no matter what system I use intel
or amd.
Thanks for helping.
I can't believe everyone else is so nonchalant about all this
considering how important it is I still haven't figured out how to
update the microcode on any of my computers - no guides I have found
actually work and no distros have the new microcode for intel or amd
despite it having been months.
I can't believe everybody is so nonchalant about Rowhammer but many
people make a big thing out of the comparatively tiny Spectre problem.
For the best security one should have both the new microcode and the
lfence msr?
Not for the best but for any security, you have to understand first that
both options only change something if your software is prepared to uti-
lize them. First update your software, then check what it needs / what
the developers expect (the new microcode I'd guess).
Nico