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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2020-06-09 19:30:21 +0300 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-06-09 19:30:21 +0300 |
| commit | 8b4d37db9a566deaf22065ba1ba9b19c9fb964b4 (patch) | |
| tree | ab77206e602ab244f667ea6a57199d2facc47cd9 /arch/x86/include/asm/msr-index.h | |
| parent | abfbb29297c27e3f101f348dc9e467b0fe70f919 (diff) | |
| parent | 3798cc4d106e91382bfe016caa2edada27c2bb3f (diff) | |
| download | linux-8b4d37db9a566deaf22065ba1ba9b19c9fb964b4.tar.xz | |
Merge branch 'x86/srbds' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 srbds fixes from Thomas Gleixner:
"The 9th episode of the dime novel "The performance killer" with the
subtitle "Slow Randomizing Boosts Denial of Service".
SRBDS is an MDS-like speculative side channel that can leak bits from
the random number generator (RNG) across cores and threads. New
microcode serializes the processor access during the execution of
RDRAND and RDSEED. This ensures that the shared buffer is overwritten
before it is released for reuse. This is equivalent to a full bus
lock, which means that many threads running the RNG instructions in
parallel have the same effect as the same amount of threads issuing a
locked instruction targeting an address which requires locking of two
cachelines at once.
The mitigation support comes with the usual pile of unpleasant
ingredients:
- command line options
- sysfs file
- microcode checks
- a list of vulnerable CPUs identified by model and stepping this
time which requires stepping match support for the cpu match logic.
- the inevitable slowdown of affected CPUs"
* branch 'x86/srbds' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/speculation: Add Ivy Bridge to affected list
x86/speculation: Add SRBDS vulnerability and mitigation documentation
x86/speculation: Add Special Register Buffer Data Sampling (SRBDS) mitigation
x86/cpu: Add 'table' argument to cpu_matches()
Diffstat (limited to 'arch/x86/include/asm/msr-index.h')
| -rw-r--r-- | arch/x86/include/asm/msr-index.h | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/arch/x86/include/asm/msr-index.h b/arch/x86/include/asm/msr-index.h index ef452b817f44..e8370e64a155 100644 --- a/arch/x86/include/asm/msr-index.h +++ b/arch/x86/include/asm/msr-index.h @@ -128,6 +128,10 @@ #define TSX_CTRL_RTM_DISABLE BIT(0) /* Disable RTM feature */ #define TSX_CTRL_CPUID_CLEAR BIT(1) /* Disable TSX enumeration */ +/* SRBDS support */ +#define MSR_IA32_MCU_OPT_CTRL 0x00000123 +#define RNGDS_MITG_DIS BIT(0) + #define MSR_IA32_SYSENTER_CS 0x00000174 #define MSR_IA32_SYSENTER_ESP 0x00000175 #define MSR_IA32_SYSENTER_EIP 0x00000176 |