diff options
Diffstat (limited to 'Documentation')
59 files changed, 1358 insertions, 265 deletions
diff --git a/Documentation/ABI/testing/sysfs-class-led-trigger-pattern b/Documentation/ABI/testing/sysfs-class-led-trigger-pattern index fb3d1e03b881..1e5d172e0646 100644 --- a/Documentation/ABI/testing/sysfs-class-led-trigger-pattern +++ b/Documentation/ABI/testing/sysfs-class-led-trigger-pattern @@ -37,8 +37,8 @@ Description: 0-| / \/ \/ +---0----1----2----3----4----5----6------------> time (s) - 2. To make the LED go instantly from one brigntess value to another, - we should use use zero-time lengths (the brightness must be same as + 2. To make the LED go instantly from one brightness value to another, + we should use zero-time lengths (the brightness must be same as the previous tuple's). So the format should be: "brightness_1 duration_1 brightness_1 0 brightness_2 duration_2 brightness_2 0 ...". For example: diff --git a/Documentation/ABI/testing/sysfs-class-net-dsa b/Documentation/ABI/testing/sysfs-class-net-dsa index f240221e071e..985d84c585c6 100644 --- a/Documentation/ABI/testing/sysfs-class-net-dsa +++ b/Documentation/ABI/testing/sysfs-class-net-dsa @@ -1,4 +1,4 @@ -What: /sys/class/net/<iface>/tagging +What: /sys/class/net/<iface>/dsa/tagging Date: August 2018 KernelVersion: 4.20 Contact: netdev@vger.kernel.org diff --git a/Documentation/admin-guide/cgroup-v2.rst b/Documentation/admin-guide/cgroup-v2.rst index 8384c681a4b2..476722b7b636 100644 --- a/Documentation/admin-guide/cgroup-v2.rst +++ b/Documentation/admin-guide/cgroup-v2.rst @@ -1879,10 +1879,8 @@ following two functions. wbc_init_bio(@wbc, @bio) Should be called for each bio carrying writeback data and - associates the bio with the inode's owner cgroup and the - corresponding request queue. This must be called after - a queue (device) has been associated with the bio and - before submission. + associates the bio with the inode's owner cgroup. Can be + called anytime between bio allocation and submission. wbc_account_io(@wbc, @page, @bytes) Should be called for each data segment being written out. @@ -1901,7 +1899,7 @@ the configuration, the bio may be executed at a lower priority and if the writeback session is holding shared resources, e.g. a journal entry, may lead to priority inversion. There is no one easy solution for the problem. Filesystems can try to work around specific problem -cases by skipping wbc_init_bio() or using bio_associate_create_blkg() +cases by skipping wbc_init_bio() or using bio_associate_blkcg() directly. diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index b90fe3b6bc6c..aefd358a5ca3 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -856,7 +856,8 @@ causing system reset or hang due to sending INIT from AP to BSP. - disable_counter_freezing [HW] + perf_v4_pmi= [X86,INTEL] + Format: <bool> Disable Intel PMU counter freezing feature. The feature only exists starting from Arch Perfmon v4 (Skylake and newer). @@ -1068,7 +1069,7 @@ earlyprintk=serial[,0x...[,baudrate]] earlyprintk=ttySn[,baudrate] earlyprintk=dbgp[debugController#] - earlyprintk=pciserial,bus:device.function[,baudrate] + earlyprintk=pciserial[,force],bus:device.function[,baudrate] earlyprintk=xdbc[xhciController#] earlyprintk is useful when the kernel crashes before @@ -1100,6 +1101,10 @@ The sclp output can only be used on s390. + The optional "force" to "pciserial" enables use of a + PCI device even when its classcode is not of the + UART class. + edac_report= [HW,EDAC] Control how to report EDAC event Format: {"on" | "off" | "force"} on: enable EDAC to report H/W event. May be overridden @@ -3500,6 +3505,10 @@ before loading. See Documentation/blockdev/ramdisk.txt. + psi= [KNL] Enable or disable pressure stall information + tracking. + Format: <bool> + psmouse.proto= [HW,MOUSE] Highest PS2 mouse protocol extension to probe for; one of (bare|imps|exps|lifebook|any). psmouse.rate= [HW,MOUSE] Set desired mouse report rate, in reports @@ -4190,9 +4199,13 @@ spectre_v2= [X86] Control mitigation of Spectre variant 2 (indirect branch speculation) vulnerability. + The default operation protects the kernel from + user space attacks. - on - unconditionally enable - off - unconditionally disable + on - unconditionally enable, implies + spectre_v2_user=on + off - unconditionally disable, implies + spectre_v2_user=off auto - kernel detects whether your CPU model is vulnerable @@ -4202,6 +4215,12 @@ CONFIG_RETPOLINE configuration option, and the compiler with which the kernel was built. + Selecting 'on' will also enable the mitigation + against user space to user space task attacks. + + Selecting 'off' will disable both the kernel and + the user space protections. + Specific mitigations can also be selected manually: retpoline - replace indirect branches @@ -4211,6 +4230,48 @@ Not specifying this option is equivalent to spectre_v2=auto. + spectre_v2_user= + [X86] Control mitigation of Spectre variant 2 + (indirect branch speculation) vulnerability between + user space tasks + + on - Unconditionally enable mitigations. Is + enforced by spectre_v2=on + + off - Unconditionally disable mitigations. Is + enforced by spectre_v2=off + + prctl - Indirect branch speculation is enabled, + but mitigation can be enabled via prctl + per thread. The mitigation control state + is inherited on fork. + + prctl,ibpb + - Like "prctl" above, but only STIBP is + controlled per thread. IBPB is issued + always when switching between different user + space processes. + + seccomp + - Same as "prctl" above, but all seccomp + threads will enable the mitigation unless + they explicitly opt out. + + seccomp,ibpb + - Like "seccomp" above, but only STIBP is + controlled per thread. IBPB is issued + always when switching between different + user space processes. + + auto - Kernel selects the mitigation depending on + the available CPU features and vulnerability. + + Default mitigation: + If CONFIG_SECCOMP=y then "seccomp", otherwise "prctl" + + Not specifying this option is equivalent to + spectre_v2_user=auto. + spec_store_bypass_disable= [HW] Control Speculative Store Bypass (SSB) Disable mitigation (Speculative Store Bypass vulnerability) @@ -4709,6 +4770,8 @@ prevent spurious wakeup); n = USB_QUIRK_DELAY_CTRL_MSG (Device needs a pause after every control message); + o = USB_QUIRK_HUB_SLOW_RESET (Hub needs extra + delay after resetting its port); Example: quirks=0781:5580:bk,0a5c:5834:gij usbhid.mousepoll= diff --git a/Documentation/admin-guide/pm/cpufreq.rst b/Documentation/admin-guide/pm/cpufreq.rst index 47153e64dfb5..7eca9026a9ed 100644 --- a/Documentation/admin-guide/pm/cpufreq.rst +++ b/Documentation/admin-guide/pm/cpufreq.rst @@ -150,7 +150,7 @@ data structures necessary to handle the given policy and, possibly, to add a governor ``sysfs`` interface to it. Next, the governor is started by invoking its ``->start()`` callback. -That callback it expected to register per-CPU utilization update callbacks for +That callback is expected to register per-CPU utilization update callbacks for all of the online CPUs belonging to the given policy with the CPU scheduler. The utilization update callbacks will be invoked by the CPU scheduler on important events, like task enqueue and dequeue, on every iteration of the diff --git a/Documentation/admin-guide/security-bugs.rst b/Documentation/admin-guide/security-bugs.rst index 164bf71149fd..30187d49dc2c 100644 --- a/Documentation/admin-guide/security-bugs.rst +++ b/Documentation/admin-guide/security-bugs.rst @@ -32,16 +32,17 @@ Disclosure and embargoed information The security list is not a disclosure channel. For that, see Coordination below. -Once a robust fix has been developed, our preference is to release the -fix in a timely fashion, treating it no differently than any of the other -thousands of changes and fixes the Linux kernel project releases every -month. - -However, at the request of the reporter, we will postpone releasing the -fix for up to 5 business days after the date of the report or after the -embargo has lifted; whichever comes first. The only exception to that -rule is if the bug is publicly known, in which case the preference is to -release the fix as soon as it's available. +Once a robust fix has been developed, the release process starts. Fixes +for publicly known bugs are released immediately. + +Although our preference is to release fixes for publicly undisclosed bugs +as soon as they become available, this may be postponed at the request of +the reporter or an affected party for up to 7 calendar days from the start +of the release process, with an exceptional extension to 14 calendar days +if it is agreed that the criticality of the bug requires more time. The +only valid reason for deferring the publication of a fix is to accommodate +the logistics of QA and large scale rollouts which require release +coordination. Whilst embargoed information may be shared with trusted individuals in order to develop a fix, such information will not be published alongside diff --git a/Documentation/arm64/silicon-errata.txt b/Documentation/arm64/silicon-errata.txt index 76ccded8b74c..8f9577621144 100644 --- a/Documentation/arm64/silicon-errata.txt +++ b/Documentation/arm64/silicon-errata.txt @@ -57,6 +57,7 @@ stable kernels. | ARM | Cortex-A73 | #858921 | ARM64_ERRATUM_858921 | | ARM | Cortex-A55 | #1024718 | ARM64_ERRATUM_1024718 | | ARM | Cortex-A76 | #1188873 | ARM64_ERRATUM_1188873 | +| ARM | Cortex-A76 | #1286807 | ARM64_ERRATUM_1286807 | | ARM | MMU-500 | #841119,#826419 | N/A | | | | | | | Cavium | ThunderX ITS | #22375, #24313 | CAVIUM_ERRATUM_22375 | diff --git a/Documentation/core-api/xarray.rst b/Documentation/core-api/xarray.rst index a4e705108f42..dbe96cb5558e 100644 --- a/Documentation/core-api/xarray.rst +++ b/Documentation/core-api/xarray.rst @@ -74,7 +74,8 @@ using :c:func:`xa_load`. xa_store will overwrite any entry with the new entry and return the previous entry stored at that index. You can use :c:func:`xa_erase` instead of calling :c:func:`xa_store` with a ``NULL`` entry. There is no difference between an entry that has never -been stored to and one that has most recently had ``NULL`` stored to it. +been stored to, one that has been erased and one that has most recently +had ``NULL`` stored to it. You can conditionally replace an entry at an index by using :c:func:`xa_cmpxchg`. Like :c:func:`cmpxchg`, it will only succeed if @@ -105,23 +106,44 @@ may result in the entry being marked at some, but not all of the other indices. Storing into one index may result in the entry retrieved by some, but not all of the other indices changing. +Sometimes you need to ensure that a subsequent call to :c:func:`xa_store` +will not need to allocate memory. The :c:func:`xa_reserve` function +will store a reserved entry at the indicated index. Users of the normal +API will see this entry as containing ``NULL``. If you do not need to +use the reserved entry, you can call :c:func:`xa_release` to remove the +unused entry. If another user has stored to the entry in the meantime, +:c:func:`xa_release` will do nothing; if instead you want the entry to +become ``NULL``, you should use :c:func:`xa_erase`. + +If all entries in the array are ``NULL``, the :c:func:`xa_empty` function +will return ``true``. + Finally, you can remove all entries from an XArray by calling :c:func:`xa_destroy`. If the XArray entries are pointers, you may wish to free the entries first. You can do this by iterating over all present entries in the XArray using the :c:func:`xa_for_each` iterator. -ID assignment -------------- +Allocating XArrays +------------------ + +If you use :c:func:`DEFINE_XARRAY_ALLOC` to define the XArray, or +initialise it by passing ``XA_FLAGS_ALLOC`` to :c:func:`xa_init_flags`, +the XArray changes to track whether entries are in use or not. You can call :c:func:`xa_alloc` to store the entry at any unused index in the XArray. If you need to modify the array from interrupt context, you can use :c:func:`xa_alloc_bh` or :c:func:`xa_alloc_irq` to disable -interrupts while allocating the ID. Unlike :c:func:`xa_store`, allocating -a ``NULL`` pointer does not delete an entry. Instead it reserves an -entry like :c:func:`xa_reserve` and you can release it using either -:c:func:`xa_erase` or :c:func:`xa_release`. To use ID assignment, the -XArray must be defined with :c:func:`DEFINE_XARRAY_ALLOC`, or initialised -by passing ``XA_FLAGS_ALLOC`` to :c:func:`xa_init_flags`, +interrupts while allocating the ID. + +Using :c:func:`xa_store`, :c:func:`xa_cmpxchg` or :c:func:`xa_insert` +will mark the entry as being allocated. Unlike a normal XArray, storing +``NULL`` will mark the entry as being in use, like :c:func:`xa_reserve`. +To free an entry, use :c:func:`xa_erase` (or :c:func:`xa_release` if +you only want to free the entry if it's ``NULL``). + +You cannot use ``XA_MARK_0`` with an allocating XArray as this mark +is used to track whether an entry is free or not. The other marks are +available for your use. Memory allocation ----------------- @@ -158,6 +180,8 @@ Takes RCU read lock: Takes xa_lock internally: * :c:func:`xa_store` + * :c:func:`xa_store_bh` + * :c:func:`xa_store_irq` * :c:func:`xa_insert` * :c:func:`xa_erase` * :c:func:`xa_erase_bh` @@ -167,6 +191,9 @@ Takes xa_lock internally: * :c:func:`xa_alloc` * :c:func:`xa_alloc_bh` * :c:func:`xa_alloc_irq` + * :c:func:`xa_reserve` + * :c:func:`xa_reserve_bh` + * :c:func:`xa_reserve_irq` * :c:func:`xa_destroy` * :c:func:`xa_set_mark` * :c:func:`xa_clear_mark` @@ -177,6 +204,7 @@ Assumes xa_lock held on entry: * :c:func:`__xa_erase` * :c:func:`__xa_cmpxchg` * :c:func:`__xa_alloc` + * :c:func:`__xa_reserve` * :c:func:`__xa_set_mark` * :c:func:`__xa_clear_mark` @@ -234,7 +262,8 @@ Sharing the XArray with interrupt context is also possible, either using :c:func:`xa_lock_irqsave` in both the interrupt handler and process context, or :c:func:`xa_lock_irq` in process context and :c:func:`xa_lock` in the interrupt handler. Some of the more common patterns have helper -functions such as :c:func:`xa_erase_bh` and :c:func:`xa_erase_irq`. +functions such as :c:func:`xa_store_bh`, :c:func:`xa_store_irq`, +:c:func:`xa_erase_bh` and :c:func:`xa_erase_irq`. Sometimes you need to protect access to the XArray with a mutex because that lock sits above another mutex in the locking hierarchy. That does @@ -322,7 +351,8 @@ to :c:func:`xas_retry`, and retry the operation if it returns ``true``. - :c:func:`xa_is_zero` - Zero entries appear as ``NULL`` through the Normal API, but occupy an entry in the XArray which can be used to reserve the index for - future use. + future use. This is used by allocating XArrays for allocated entries + which are ``NULL``. Other internal entries may be added in the future. As far as possible, they will be handled by :c:func:`xas_retry`. diff --git a/Documentation/cpu-freq/cpufreq-stats.txt b/Documentation/cpu-freq/cpufreq-stats.txt index a873855c811d..14378cecb172 100644 --- a/Documentation/cpu-freq/cpufreq-stats.txt +++ b/Documentation/cpu-freq/cpufreq-stats.txt @@ -86,9 +86,11 @@ transitions. This will give a fine grained information about all the CPU frequency transitions. The cat output here is a two dimensional matrix, where an entry <i,j> (row i, column j) represents the count of number of transitions from -Freq_i to Freq_j. Freq_i is in descending order with increasing rows and -Freq_j is in descending order with increasing columns. The output here also -contains the actual freq values for each row and column for better readability. +Freq_i to Freq_j. Freq_i rows and Freq_j columns follow the sorting order in +which the driver has provided the frequency table initially to the cpufreq core +and so can be sorted (ascending or descending) or unsorted. The output here +also contains the actual freq values for each row and column for better +readability. If the transition table is bigger than PAGE_SIZE, reading this will return an -EFBIG error. diff --git a/Documentation/crypto/asymmetric-keys.txt b/Documentation/crypto/asymmetric-keys.txt index 5969bf42562a..8763866b11cf 100644 --- a/Documentation/crypto/asymmetric-keys.txt +++ b/Documentation/crypto/asymmetric-keys.txt @@ -183,6 +183,10 @@ and looks like the following: void (*describe)(const struct key *key, struct seq_file *m); void (*destroy)(void *payload); + int (*query)(const struct kernel_pkey_params *params, + struct kernel_pkey_query *info); + int (*eds_op)(struct kernel_pkey_params *params, + const void *in, void *out); int (*verify_signature)(const struct key *key, const struct public_key_signature *sig); }; @@ -207,12 +211,22 @@ There are a number of operations defined by the subtype: asymmetric key will look after freeing the fingerprint and releasing the reference on the subtype module. - (3) verify_signature(). + (3) query(). - Optional. These are the entry points for the key usage operations. - Currently there is only the one defined. If not set, the caller will be - given -ENOTSUPP. The subtype may do anything it likes to implement an - operation, including offloading to hardware. + Mandatory. This is a function for querying the capabilities of a key. + + (4) eds_op(). + + Optional. This is the entry point for the encryption, decryption and + signature creation operations (which are distinguished by the operation ID + in the parameter struct). The subtype may do anything it likes to + implement an operation, including offloading to hardware. + + (5) verify_signature(). + + Optional. This is the entry point for signature verification. The + subtype may do anything it likes to implement an operation, including + offloading to hardware. ========================== @@ -234,6 +248,8 @@ Examples of blob formats for which parsers could be implemented include: - X.509 ASN.1 stream. - Pointer to TPM key. - Pointer to UEFI key. + - PKCS#8 private key [RFC 5208]. + - PKCS#5 encrypted private key [RFC 2898]. During key instantiation each parser in the list is tried until one doesn't return -EBADMSG. diff --git a/Documentation/devicetree/bindings/arm/cpu-capacity.txt b/Documentation/devicetree/bindings/arm/cpu-capacity.txt index 9b5685a1d15d..84262cdb8d29 100644 --- a/Documentation/devicetree/bindings/arm/cpu-capacity.txt +++ b/Documentation/devicetree/bindings/arm/cpu-capacity.txt @@ -59,9 +59,11 @@ mhz values (normalized w.r.t. the highest value found while parsing the DT). =========================================== Example 1 (ARM 64-bit, 6-cpu system, two clusters): -capacities-dmips-mhz are scaled w.r.t. 1024 (cpu@0 and cpu@1) -supposing cluster0@max-freq=1100 and custer1@max-freq=850, -final capacities are 1024 for cluster0 and 446 for cluster1 +The capacities-dmips-mhz or DMIPS/MHz values (scaled to 1024) +are 1024 and 578 for cluster0 and cluster1. Further normalization +is done by the operating system based on cluster0@max-freq=1100 and +custer1@max-freq=850, final capacities are 1024 for cluster0 and +446 for cluster1 (576*850/1100). cpus { #address-cells = <2>; diff --git a/Documentation/devicetree/bindings/arm/shmobile.txt b/Documentation/devicetree/bindings/arm/shmobile.txt index f5e0f82fd503..58c4256d37a3 100644 --- a/Documentation/devicetree/bindings/arm/shmobile.txt +++ b/ |