Speculative Store Bypass (SSB) is a speculative execution side channel
vulnerability identified by Jann Horn of Google Project Zero (GPZ) and
Ken Johnson of the Microsoft Security Response Center (MSRC)
https://bugs.chromium.org/p/project-zero/issues/detail?id=1528.
Updated Intel microcode introduces a MSR bit to disable SSB as a
mitigation for the vulnerability.
Introduce a sysctl hw.spec_store_bypass_disable to provide global
control over the SSBD bit, akin to the existing sysctl that controls
IBRS. The sysctl can be set to one of three values:
0: off
1: on
2: auto
Future work will enable applications to control SSBD on a per-process
basis (when it is not enabled globally).
SSBD bit detection and control was verified with prerelease microcode.
Security: CVE-2018-3639
Tested by: emaste (previous version, without updated microcode)
Sponsored by: The FreeBSD Foundation
MFC after: 3 days
This change adds support for a UBS<->RS232 adapter based on CH340 (or an
analogue) that I own. The device seems to have a newer internal version
(0x30) and the existing code incorrectly configures line control for it
resulting in garbled transmission. The changes are based on what I
learned in Linux drivers for the same hardware.
Additional changes:
- use UCHCOM_REG_LCR1 / UCHCOM_REG_LCR2 instead of explicit 0x18 and
0x25
- use NULL instead of 0 where a pointer is expected
Reviewed by: hselasky
MFC after: 3 weeks
Differential Revision: https://reviews.freebsd.org/D15498
Also, add definitions for more bits of UCHCOM_REG_LCR1 as seen in the
Linux driver. UCHCOM_LCR1_PARENB definition was different from that in
the Linux driver and clashed with newly added UCHCOM_LCR1_RX. I took a
liberty to change UCHCOM_LCR1_PARENB to the Linux definition as it was
unused in the driver anyway. This change should make
uchcom_cfg_set_break() easier to understand.
Approved by: hselasky
MFC after: 2 weeks
Product IDs are specified in vendor documents. The previously used
device ID is not. This is a cosmetic change. No functionality depends
on those IDs.
Reviewed by: hselasky
MFC after: 2 weeks
I have a system that is very unstable after resuming from suspend-to-RAM
but only if HPET is used as the event timer. The theory is that SMM
code / firmware could be enabling HPET for its own uses and unexpected
interrupts cause a trouble for it. Originally I wanted to solve the
problem in hpet_suspend() method, but that was insufficient as the event
timer could get reprogrammed again.
So, it's better, for my case and in general, to stop the event timer(s)
before entering the hardware suspend.
MFC after: 4 weeks
Differential Revision: https://reviews.freebsd.org/D15413
When we issue shootdown IPIs, we first assign zero to pm_gens to
indicate the need to flush on the next context switch in case our IPI
misses the context, next we read pm_active. On context switch we set
our bit in pm_active, then we read pm_gen. It is crucial that both
threads see the memory in the program order, otherwise invalidation
thread might read pm_active bit as zero and the context switching
thread might read pm_gen as zero.
IA32 allows CPU for both reads to see zero. We must use the barriers
between write and read. The pm_active bit set is already locked, so
only the invalidation functions need it.
I never saw it in real life, or at least I do not have a good
reproduction case. I found this during code inspection when hunting
for the Xen TLB issue reported by cperciva.
Reviewed by: alc, markj
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Differential revision: https://reviews.freebsd.org/D15506
dyn_lookup_ipv[46]_state_locked(). These checks are remnants of not
ready to be committed code, and they are there by accident.
Due to the race these checks can lead to creating of duplicate states
when concurrent threads in the same time will try to add state for two
packets of the same flow, but in reverse directions and matched by
different parent rules.
Reported by: lev
MFC after: 3 days
They're only useful when multiple threads may share an epoch record,
and that can't happen with non-preemptible sections.
Reviewed by: mmacy
Differential Revision: https://reviews.freebsd.org/D15507
Per vnet(9), CURVNET_SET and CURVNET_RESTORE cannot be used as a single
statement for a conditional and CURVNET_RESTORE must be in the same
block as CURVNET_SET (or a subblock).
Reviewed by: andrew
Sponsored by: The FreeBSD Foundation
boot1.efi have some trouble to read MBR partitions, it needs them to be
aligned a certain way while loader.efi can cope with them either way.
We want to switch to loader.efi as the main efi loader everywhere, it seems
that arm64 using MBR partition will be the guinea pig.
Tested On: RPI3, Pine64
Reviewed by: imp
Approved by: gjb
Remove 'top.local.hs'. This was not noticed since
/srv/obj/fbsd/srv/src/freebsd/svn/head/amd64.amd64/usr.bin/top/top.local.h
existed locally on my machine despite "make clean". Only fully removing
the objdir allowed me to observe the error directly.
Pointyhat to: me
This leaves at WARNS=6:
35 warnings in top.c
88 warnings in machine.c
all of which are either "incompatible-pointer-types-discards-qualifiers"
or "cast-qual"
- Replace caddr_t with "void *". This reduces
the number of warnings at WARNS=6
- use "static" where possible
- sprinkle const where possible
This leaves at WARNS=6:
35 warnings in top.c
88 warnings in machine.c
7 warnings in commands.c
all of which are either "incompatible-pointer-types-discards-qualifiers"
or "cast-qual"
- Replace caddr_t with "void *". This reduces
the number of warnings at WARNS=6
- use "static" where possible
- sprinkle const where possible
This leaves at WARNS=6:
35 warnings in top.c
72 warnings in machine.c
5 warnings in commands.c
all of which are either "incompatible-pointer-types-discards-qualifiers"
or "cast-qual"
r329190; sparc64 kernels are always 64-bit but with that revision
in place, the loader was treating them as 32-bit ones.
- In order to reduce the likelihood of this kind of breakage in the
future, #ifdef out md_load() on sparc64 and make md_load_dual() -
which is currently local to metadata.c anyway - static.
- Make md_getboothowto() - also local to metadata.c - static.
- Get rid of the unused DTB pointer on sparc64.
