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authorIngo Molnar <mingo@kernel.org>2018-05-25 08:11:28 +0200
committerIngo Molnar <mingo@kernel.org>2018-05-25 08:11:28 +0200
commit675c00c3325723751864cc5867d736c58633cf3d (patch)
tree1532b10be02615140ab9460a471294f651c4ab88 /Documentation
parent99c12749b172758f6973fc023484f2fc8b91cd5a (diff)
parentb50694381cfc22dce3a60a291cdae294a5e5777c (diff)
Merge branch 'linus' into locking/core, to pick up fixes
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/ABI/testing/sysfs-class-cxl8
-rw-r--r--Documentation/ABI/testing/sysfs-devices-system-cpu1
-rw-r--r--Documentation/admin-guide/kernel-parameters.txt45
-rw-r--r--Documentation/devicetree/bindings/net/marvell-pp2.txt9
-rw-r--r--Documentation/devicetree/bindings/net/micrel-ksz90x1.txt7
-rw-r--r--Documentation/userspace-api/index.rst1
-rw-r--r--Documentation/userspace-api/spec_ctrl.rst94
-rw-r--r--Documentation/virtual/kvm/cpuid.txt6
8 files changed, 164 insertions, 7 deletions
diff --git a/Documentation/ABI/testing/sysfs-class-cxl b/Documentation/ABI/testing/sysfs-class-cxl
index 640f65e79ef1..8e69345c37cc 100644
--- a/Documentation/ABI/testing/sysfs-class-cxl
+++ b/Documentation/ABI/testing/sysfs-class-cxl
@@ -244,3 +244,11 @@ Description: read only
Returns 1 if the psl timebase register is synchronized
with the core timebase register, 0 otherwise.
Users: https://github.com/ibm-capi/libcxl
+
+What: /sys/class/cxl/<card>/tunneled_ops_supported
+Date: May 2018
+Contact: linuxppc-dev@lists.ozlabs.org
+Description: read only
+ Returns 1 if tunneled operations are supported in capi mode,
+ 0 otherwise.
+Users: https://github.com/ibm-capi/libcxl
diff --git a/Documentation/ABI/testing/sysfs-devices-system-cpu b/Documentation/ABI/testing/sysfs-devices-system-cpu
index 025b7cf3768d..bd4975e132d3 100644
--- a/Documentation/ABI/testing/sysfs-devices-system-cpu
+++ b/Documentation/ABI/testing/sysfs-devices-system-cpu
@@ -478,6 +478,7 @@ What: /sys/devices/system/cpu/vulnerabilities
/sys/devices/system/cpu/vulnerabilities/meltdown
/sys/devices/system/cpu/vulnerabilities/spectre_v1
/sys/devices/system/cpu/vulnerabilities/spectre_v2
+ /sys/devices/system/cpu/vulnerabilities/spec_store_bypass
Date: January 2018
Contact: Linux kernel mailing list <linux-kernel@vger.kernel.org>
Description: Information about CPU vulnerabilities
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 11fc28ecdb6d..f2040d46f095 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -2680,6 +2680,9 @@
allow data leaks with this option, which is equivalent
to spectre_v2=off.
+ nospec_store_bypass_disable
+ [HW] Disable all mitigations for the Speculative Store Bypass vulnerability
+
noxsave [BUGS=X86] Disables x86 extended register state save
and restore using xsave. The kernel will fallback to
enabling legacy floating-point and sse state.
@@ -4025,6 +4028,48 @@
Not specifying this option is equivalent to
spectre_v2=auto.
+ spec_store_bypass_disable=
+ [HW] Control Speculative Store Bypass (SSB) Disable mitigation
+ (Speculative Store Bypass vulnerability)
+
+ Certain CPUs are vulnerable to an exploit against a
+ a common industry wide performance optimization known
+ as "Speculative Store Bypass" in which recent stores
+ to the same memory location may not be observed by
+ later loads during speculative execution. The idea
+ is that such stores are unlikely and that they can
+ be detected prior to instruction retirement at the
+ end of a particular speculation execution window.
+
+ In vulnerable processors, the speculatively forwarded
+ store can be used in a cache side channel attack, for
+ example to read memory to which the attacker does not
+ directly have access (e.g. inside sandboxed code).
+
+ This parameter controls whether the Speculative Store
+ Bypass optimization is used.
+
+ on - Unconditionally disable Speculative Store Bypass
+ off - Unconditionally enable Speculative Store Bypass
+ auto - Kernel detects whether the CPU model contains an
+ implementation of Speculative Store Bypass and
+ picks the most appropriate mitigation. If the
+ CPU is not vulnerable, "off" is selected. If the
+ CPU is vulnerable the default mitigation is
+ architecture and Kconfig dependent. See below.
+ prctl - Control Speculative Store Bypass per thread
+ via prctl. Speculative Store Bypass is enabled
+ for a process by default. The state of the control
+ is inherited on fork.
+ seccomp - Same as "prctl" above, but all seccomp threads
+ will disable SSB unless they explicitly opt out.
+
+ Not specifying this option is equivalent to
+ spec_store_bypass_disable=auto.
+
+ Default mitigations:
+ X86: If CONFIG_SECCOMP=y "seccomp", otherwise "prctl"
+
spia_io_base= [HW,MTD]
spia_fio_base=
spia_pedr=
diff --git a/Documentation/devicetree/bindings/net/marvell-pp2.txt b/Documentation/devicetree/bindings/net/marvell-pp2.txt
index 1814fa13f6ab..fc019df0d863 100644
--- a/Documentation/devicetree/bindings/net/marvell-pp2.txt
+++ b/Documentation/devicetree/bindings/net/marvell-pp2.txt
@@ -21,9 +21,10 @@ Required properties:
- main controller clock (for both armada-375-pp2 and armada-7k-pp2)
- GOP clock (for both armada-375-pp2 and armada-7k-pp2)
- MG clock (only for armada-7k-pp2)
+ - MG Core clock (only for armada-7k-pp2)
- AXI clock (only for armada-7k-pp2)
-- clock-names: names of used clocks, must be "pp_clk", "gop_clk", "mg_clk"
- and "axi_clk" (the 2 latter only for armada-7k-pp2).
+- clock-names: names of used clocks, must be "pp_clk", "gop_clk", "mg_clk",
+ "mg_core_clk" and "axi_clk" (the 3 latter only for armada-7k-pp2).
The ethernet ports are represented by subnodes. At least one port is
required.
@@ -80,8 +81,8 @@ cpm_ethernet: ethernet@0 {
compatible = "marvell,armada-7k-pp22";
reg = <0x0 0x100000>, <0x129000 0xb000>;
clocks = <&cpm_syscon0 1 3>, <&cpm_syscon0 1 9>,
- <&cpm_syscon0 1 5>, <&cpm_syscon0 1 18>;
- clock-names = "pp_clk", "gop_clk", "gp_clk", "axi_clk";
+ <&cpm_syscon0 1 5>, <&cpm_syscon0 1 6>, <&cpm_syscon0 1 18>;
+ clock-names = "pp_clk", "gop_clk", "mg_clk", "mg_core_clk", "axi_clk";
eth0: eth0 {
interrupts = <ICU_GRP_NSR 39 IRQ_TYPE_LEVEL_HIGH>,
diff --git a/Documentation/devicetree/bindings/net/micrel-ksz90x1.txt b/Documentation/devicetree/bindings/net/micrel-ksz90x1.txt
index 42a248301615..e22d8cfea687 100644
--- a/Documentation/devicetree/bindings/net/micrel-ksz90x1.txt
+++ b/Documentation/devicetree/bindings/net/micrel-ksz90x1.txt
@@ -57,6 +57,13 @@ KSZ9031:
- txd2-skew-ps : Skew control of TX data 2 pad
- txd3-skew-ps : Skew control of TX data 3 pad
+ - micrel,force-master:
+ Boolean, force phy to master mode. Only set this option if the phy
+ reference clock provided at CLK125_NDO pin is used as MAC reference
+ clock because the clock jitter in slave mode is to high (errata#2).
+ Attention: The link partner must be configurable as slave otherwise
+ no link will be established.
+
Examples:
mdio {
diff --git a/Documentation/userspace-api/index.rst b/Documentation/userspace-api/index.rst
index 7b2eb1b7d4ca..a3233da7fa88 100644
--- a/Documentation/userspace-api/index.rst
+++ b/Documentation/userspace-api/index.rst
@@ -19,6 +19,7 @@ place where this information is gathered.
no_new_privs
seccomp_filter
unshare
+ spec_ctrl
.. only:: subproject and html
diff --git a/Documentation/userspace-api/spec_ctrl.rst b/Documentation/userspace-api/spec_ctrl.rst
new file mode 100644
index 000000000000..32f3d55c54b7
--- /dev/null
+++ b/Documentation/userspace-api/spec_ctrl.rst
@@ -0,0 +1,94 @@
+===================
+Speculation Control
+===================
+
+Quite some CPUs have speculation-related misfeatures which are in
+fact vulnerabilities causing data leaks in various forms even across
+privilege domains.
+
+The kernel provides mitigation for such vulnerabilities in various
+forms. Some of these mitigations are compile-time configurable and some
+can be supplied on the kernel command line.
+
+There is also a class of mitigations which are very expensive, but they can
+be restricted to a certain set of processes or tasks in controlled
+environments. The mechanism to control these mitigations is via
+:manpage:`prctl(2)`.
+
+There are two prctl options which are related to this:
+
+ * PR_GET_SPECULATION_CTRL
+
+ * PR_SET_SPECULATION_CTRL
+
+PR_GET_SPECULATION_CTRL
+-----------------------
+
+PR_GET_SPECULATION_CTRL returns the state of the speculation misfeature
+which is selected with arg2 of prctl(2). The return value uses bits 0-3 with
+the following meaning:
+
+==== ===================== ===================================================
+Bit Define Description
+==== ===================== ===================================================
+0 PR_SPEC_PRCTL Mitigation can be controlled per task by
+ PR_SET_SPECULATION_CTRL.
+1 PR_SPEC_ENABLE The speculation feature is enabled, mitigation is
+ disabled.
+2 PR_SPEC_DISABLE The speculation feature is disabled, mitigation is
+ enabled.
+3 PR_SPEC_FORCE_DISABLE Same as PR_SPEC_DISABLE, but cannot be undone. A
+ subsequent prctl(..., PR_SPEC_ENABLE) will fail.
+==== ===================== ===================================================
+
+If all bits are 0 the CPU is not affected by the speculation misfeature.
+
+If PR_SPEC_PRCTL is set, then the per-task control of the mitigation is
+available. If not set, prctl(PR_SET_SPECULATION_CTRL) for the speculation
+misfeature will fail.
+
+PR_SET_SPECULATION_CTRL
+-----------------------
+
+PR_SET_SPECULATION_CTRL allows to control the speculation misfeature, which
+is selected by arg2 of :manpage:`prctl(2)` per task. arg3 is used to hand
+in the control value, i.e. either PR_SPEC_ENABLE or PR_SPEC_DISABLE or
+PR_SPEC_FORCE_DISABLE.
+
+Common error codes
+------------------
+======= =================================================================
+Value Meaning
+======= =================================================================
+EINVAL The prctl is not implemented by the architecture or unused
+ prctl(2) arguments are not 0.
+
+ENODEV arg2 is selecting a not supported speculation misfeature.
+======= =================================================================
+
+PR_SET_SPECULATION_CTRL error codes
+-----------------------------------
+======= =================================================================
+Value Meaning
+======= =================================================================
+0 Success
+
+ERANGE arg3 is incorrect, i.e. it's neither PR_SPEC_ENABLE nor
+ PR_SPEC_DISABLE nor PR_SPEC_FORCE_DISABLE.
+
+ENXIO Control of the selected speculation misfeature is not possible.
+ See PR_GET_SPECULATION_CTRL.
+
+EPERM Speculation was disabled with PR_SPEC_FORCE_DISABLE and caller
+ tried to enable it again.
+======= =================================================================
+
+Speculation misfeature controls
+-------------------------------
+- PR_SPEC_STORE_BYPASS: Speculative Store Bypass
+
+ Invocations:
+ * prctl(PR_GET_SPECULATION_CTRL, PR_SPEC_STORE_BYPASS, 0, 0, 0);
+ * prctl(PR_SET_SPECULATION_CTRL, PR_SPEC_STORE_BYPASS, PR_SPEC_ENABLE, 0, 0);
+ * prctl(PR_SET_SPECULATION_CTRL, PR_SPEC_STORE_BYPASS, PR_SPEC_DISABLE, 0, 0);
+ * prctl(PR_SET_SPECULATION_CTRL, PR_SPEC_STORE_BYPASS, PR_SPEC_FORCE_DISABLE, 0, 0);
diff --git a/Documentation/virtual/kvm/cpuid.txt b/Documentation/virtual/kvm/cpuid.txt
index d4f33eb805dd..ab022dcd0911 100644
--- a/Documentation/virtual/kvm/cpuid.txt
+++ b/Documentation/virtual/kvm/cpuid.txt
@@ -72,8 +72,8 @@ KVM_FEATURE_CLOCKSOURCE_STABLE_BIT || 24 || host will warn if no guest-side
flag || value || meaning
==================================================================================
-KVM_HINTS_DEDICATED || 0 || guest checks this feature bit to
- || || determine if there is vCPU pinning
- || || and there is no vCPU over-commitment,
+KVM_HINTS_REALTIME || 0 || guest checks this feature bit to
+ || || determine that vCPUs are never
+ || || preempted for an unlimited time,
|| || allowing optimizations
----------------------------------------------------------------------------------