diff options
Diffstat (limited to 'Documentation')
24 files changed, 489 insertions, 55 deletions
diff --git a/Documentation/DocBook/media/v4l/vidioc-expbuf.xml b/Documentation/DocBook/media/v4l/vidioc-expbuf.xml index e287c8fc803b..4165e7bfa4ff 100644 --- a/Documentation/DocBook/media/v4l/vidioc-expbuf.xml +++ b/Documentation/DocBook/media/v4l/vidioc-expbuf.xml @@ -73,7 +73,8 @@ range from zero to the maximal number of valid planes for the currently active format. For the single-planar API, applications must set <structfield> plane </structfield> to zero. Additional flags may be posted in the <structfield> flags </structfield> field. Refer to a manual for open() for details. -Currently only O_CLOEXEC is supported. All other fields must be set to zero. +Currently only O_CLOEXEC, O_RDONLY, O_WRONLY, and O_RDWR are supported. All +other fields must be set to zero. In the case of multi-planar API, every plane is exported separately using multiple <constant> VIDIOC_EXPBUF </constant> calls. </para> @@ -170,8 +171,9 @@ multi-planar API. Otherwise this value must be set to zero. </entry> <entry>__u32</entry> <entry><structfield>flags</structfield></entry> <entry>Flags for the newly created file, currently only <constant> -O_CLOEXEC </constant> is supported, refer to the manual of open() for more -details.</entry> +O_CLOEXEC </constant>, <constant>O_RDONLY</constant>, <constant>O_WRONLY +</constant>, and <constant>O_RDWR</constant> are supported, refer to the manual +of open() for more details.</entry> </row> <row> <entry>__s32</entry> diff --git a/Documentation/assoc_array.txt b/Documentation/assoc_array.txt index f4faec0f66e4..2f2c6cdd73c0 100644 --- a/Documentation/assoc_array.txt +++ b/Documentation/assoc_array.txt @@ -164,10 +164,10 @@ This points to a number of methods, all of which need to be provided: (4) Diff the index keys of two objects. - int (*diff_objects)(const void *a, const void *b); + int (*diff_objects)(const void *object, const void *index_key); - Return the bit position at which the index keys of two objects differ or - -1 if they are the same. + Return the bit position at which the index key of the specified object + differs from the given index key or -1 if they are the same. (5) Free an object. diff --git a/Documentation/block/null_blk.txt b/Documentation/block/null_blk.txt new file mode 100644 index 000000000000..b2830b435895 --- /dev/null +++ b/Documentation/block/null_blk.txt @@ -0,0 +1,72 @@ +Null block device driver +================================================================================ + +I. Overview + +The null block device (/dev/nullb*) is used for benchmarking the various +block-layer implementations. It emulates a block device of X gigabytes in size. +The following instances are possible: + + Single-queue block-layer + - Request-based. + - Single submission queue per device. + - Implements IO scheduling algorithms (CFQ, Deadline, noop). + Multi-queue block-layer + - Request-based. + - Configurable submission queues per device. + No block-layer (Known as bio-based) + - Bio-based. IO requests are submitted directly to the device driver. + - Directly accepts bio data structure and returns them. + +All of them have a completion queue for each core in the system. + +II. Module parameters applicable for all instances: + +queue_mode=[0-2]: Default: 2-Multi-queue + Selects which block-layer the module should instantiate with. + + 0: Bio-based. + 1: Single-queue. + 2: Multi-queue. + +home_node=[0--nr_nodes]: Default: NUMA_NO_NODE + Selects what CPU node the data structures are allocated from. + +gb=[Size in GB]: Default: 250GB + The size of the device reported to the system. + +bs=[Block size (in bytes)]: Default: 512 bytes + The block size reported to the system. + +nr_devices=[Number of devices]: Default: 2 + Number of block devices instantiated. They are instantiated as /dev/nullb0, + etc. + +irq_mode=[0-2]: Default: 1-Soft-irq + The completion mode used for completing IOs to the block-layer. + + 0: None. + 1: Soft-irq. Uses IPI to complete IOs across CPU nodes. Simulates the overhead + when IOs are issued from another CPU node than the home the device is + connected to. + 2: Timer: Waits a specific period (completion_nsec) for each IO before + completion. + +completion_nsec=[ns]: Default: 10.000ns + Combined with irq_mode=2 (timer). The time each completion event must wait. + +submit_queues=[0..nr_cpus]: + The number of submission queues attached to the device driver. If unset, it + defaults to 1 on single-queue and bio-based instances. For multi-queue, + it is ignored when use_per_node_hctx module parameter is 1. + +hw_queue_depth=[0..qdepth]: Default: 64 + The hardware queue depth of the device. + +III: Multi-queue specific parameters + +use_per_node_hctx=[0/1]: Default: 0 + 0: The number of submit queues are set to the value of the submit_queues + parameter. + 1: The multi-queue block layer is instantiated with a hardware dispatch + queue for each CPU node in the system. diff --git a/Documentation/device-mapper/cache.txt b/Documentation/device-mapper/cache.txt index 274752f8bdf9..719320b5ed3f 100644 --- a/Documentation/device-mapper/cache.txt +++ b/Documentation/device-mapper/cache.txt @@ -266,10 +266,12 @@ E.g. Invalidation is removing an entry from the cache without writing it back. Cache blocks can be invalidated via the invalidate_cblocks message, which takes an arbitrary number of cblock ranges. Each cblock -must be expressed as a decimal value, in the future a variant message -that takes cblock ranges expressed in hexidecimal may be needed to -better support efficient invalidation of larger caches. The cache must -be in passthrough mode when invalidate_cblocks is used. +range's end value is "one past the end", meaning 5-10 expresses a range +of values from 5 to 9. Each cblock must be expressed as a decimal +value, in the future a variant message that takes cblock ranges +expressed in hexidecimal may be needed to better support efficient +invalidation of larger caches. The cache must be in passthrough mode +when invalidate_cblocks is used. invalidate_cblocks [<cblock>|<cblock begin>-<cblock end>]* diff --git a/Documentation/devicetree/bindings/arm/omap/mpu.txt b/Documentation/devicetree/bindings/arm/omap/mpu.txt index 1a5a42ce21bb..83f405bde138 100644 --- a/Documentation/devicetree/bindings/arm/omap/mpu.txt +++ b/Documentation/devicetree/bindings/arm/omap/mpu.txt @@ -7,10 +7,18 @@ The MPU contain CPUs, GIC, L2 cache and a local PRCM. Required properties: - compatible : Should be "ti,omap3-mpu" for OMAP3 Should be "ti,omap4-mpu" for OMAP4 + Should be "ti,omap5-mpu" for OMAP5 - ti,hwmods: "mpu" Examples: +- For an OMAP5 SMP system: + +mpu { + compatible = "ti,omap5-mpu"; + ti,hwmods = "mpu" +}; + - For an OMAP4 SMP system: mpu { diff --git a/Documentation/devicetree/bindings/arm/pmu.txt b/Documentation/devicetree/bindings/arm/pmu.txt index 343781b9f246..3e1e498fea96 100644 --- a/Documentation/devicetree/bindings/arm/pmu.txt +++ b/Documentation/devicetree/bindings/arm/pmu.txt @@ -7,6 +7,7 @@ representation in the device tree should be done as under:- Required properties: - compatible : should be one of + "arm,armv8-pmuv3" "arm,cortex-a15-pmu" "arm,cortex-a9-pmu" "arm,cortex-a8-pmu" diff --git a/Documentation/devicetree/bindings/arm/samsung/exynos-adc.txt b/Documentation/devicetree/bindings/arm/samsung/exynos-adc.txt index 47ada1dff216..5d49f2b37f68 100644 --- a/Documentation/devicetree/bindings/arm/samsung/exynos-adc.txt +++ b/Documentation/devicetree/bindings/arm/samsung/exynos-adc.txt @@ -49,7 +49,7 @@ adc@12D10000 { /* NTC thermistor is a hwmon device */ ncp15wb473@0 { compatible = "ntc,ncp15wb473"; - pullup-uV = <1800000>; + pullup-uv = <1800000>; pullup-ohm = <47000>; pulldown-ohm = <0>; io-channels = <&adc 4>; diff --git a/Documentation/devicetree/bindings/clock/exynos4-clock.txt b/Documentation/devicetree/bindings/clock/exynos4-clock.txt index c6bf8a6c8f52..a2ac2d9ac71a 100644 --- a/Documentation/devicetree/bindings/clock/exynos4-clock.txt +++ b/Documentation/devicetree/bindings/clock/exynos4-clock.txt @@ -6,7 +6,7 @@ SoC's in the Exynos4 family. Required Properties: -- comptible: should be one of the following. +- compatible: should be one of the following. - "samsung,exynos4210-clock" - controller compatible with Exynos4210 SoC. - "samsung,exynos4412-clock" - controller compatible with Exynos4412 SoC. diff --git a/Documentation/devicetree/bindings/clock/exynos5250-clock.txt b/Documentation/devicetree/bindings/clock/exynos5250-clock.txt index 24765c146e31..0f2f920e8734 100644 --- a/Documentation/devicetree/bindings/clock/exynos5250-clock.txt +++ b/Documentation/devicetree/bindings/clock/exynos5250-clock.txt @@ -5,7 +5,7 @@ controllers within the Exynos5250 SoC. Required Properties: -- comptible: should be one of the following. +- compatible: should be one of the following. - "samsung,exynos5250-clock" - controller compatible with Exynos5250 SoC. - reg: physical base address of the controller and length of memory mapped @@ -159,6 +159,8 @@ clock which they consume. mixer 343 hdmi 344 g2d 345 + mdma0 346 + smmu_mdma0 347 [Clock Muxes] diff --git a/Documentation/devicetree/bindings/clock/exynos5420-clock.txt b/Documentation/devicetree/bindings/clock/exynos5420-clock.txt index 32aa34ecad36..458f34789e5d 100644 --- a/Documentation/devicetree/bindings/clock/exynos5420-clock.txt +++ b/Documentation/devicetree/bindings/clock/exynos5420-clock.txt @@ -5,7 +5,7 @@ controllers within the Exynos5420 SoC. Required Properties: -- comptible: should be one of the following. +- compatible: should be one of the following. - "samsung,exynos5420-clock" - controller compatible with Exynos5420 SoC. - reg: physical base address of the controller and length of memory mapped diff --git a/Documentation/devicetree/bindings/clock/exynos5440-clock.txt b/Documentation/devicetree/bindings/clock/exynos5440-clock.txt index 4499e9966bc9..9955dc9c7d96 100644 --- a/Documentation/devicetree/bindings/clock/exynos5440-clock.txt +++ b/Documentation/devicetree/bindings/clock/exynos5440-clock.txt @@ -5,7 +5,7 @@ controllers within the Exynos5440 SoC. Required Properties: -- comptible: should be "samsung,exynos5440-clock". +- compatible: should be "samsung,exynos5440-clock". - reg: physical base address of the controller and length of memory mapped region. diff --git a/Documentation/devicetree/bindings/gpio/8xxx_gpio.txt b/Documentation/devicetree/bindings/gpio/8xxx_gpio.txt index b0019eb5330e..798cfc9d3839 100644 --- a/Documentation/devicetree/bindings/gpio/8xxx_gpio.txt +++ b/Documentation/devicetree/bindings/gpio/8xxx_gpio.txt @@ -5,16 +5,42 @@ This is for the non-QE/CPM/GUTs GPIO controllers as found on Every GPIO controller node must have #gpio-cells property defined, this information will be used to translate gpio-specifiers. +See bindings/gpio/gpio.txt for details of how to specify GPIO +information for devices. + +The GPIO module usually is connected to the SoC's internal interrupt +controller, see bindings/interrupt-controller/interrupts.txt (the +interrupt client nodes section) for details how to specify this GPIO +module's interrupt. + +The GPIO module may serve as another interrupt controller (cascaded to +the SoC's internal interrupt controller). See the interrupt controller +nodes section in bindings/interrupt-controller/interrupts.txt for +details. Required properties: -- compatible : "fsl,<CHIP>-gpio" followed by "fsl,mpc8349-gpio" for - 83xx, "fsl,mpc8572-gpio" for 85xx and "fsl,mpc8610-gpio" for 86xx. -- #gpio-cells : Should be two. The first cell is the pin number and the - second cell is used to specify optional parameters (currently unused). - - interrupts : Interrupt mapping for GPIO IRQ. - - interrupt-parent : Phandle for the interrupt controller that - services interrupts for this device. -- gpio-controller : Marks the port as GPIO controller. +- compatible: "fsl,<chip>-gpio" followed by "fsl,mpc8349-gpio" + for 83xx, "fsl,mpc8572-gpio" for 85xx, or + "fsl,mpc8610-gpio" for 86xx. +- #gpio-cells: Should be two. The first cell is the pin number + and the second cell is used to specify optional + parameters (currently unused). +- interrupt-parent: Phandle for the interrupt controller that + services interrupts for this device. +- interrupts: Interrupt mapping for GPIO IRQ. +- gpio-controller: Marks the port as GPIO controller. + +Optional properties: +- interrupt-controller: Empty boolean property which marks the GPIO + module as an IRQ controller. +- #interrupt-cells: Should be two. Defines the number of integer + cells required to specify an interrupt within + this interrupt controller. The first cell + defines the pin number, the second cell + defines additional flags (trigger type, + trigger polarity). Note that the available + set of trigger conditions supported by the + GPIO module depends on the actual SoC. Example of gpio-controller nodes for a MPC8347 SoC: @@ -22,39 +48,27 @@ Example of gpio-controller nodes for a MPC8347 SoC: #gpio-cells = <2>; compatible = "fsl,mpc8347-gpio", "fsl,mpc8349-gpio"; reg = <0xc00 0x100>; - interrupts = <74 0x8>; interrupt-parent = <&ipic>; + interrupts = <74 0x8>; gpio-controller; + interrupt-controller; + #interrupt-cells = <2>; }; gpio2: gpio-controller@d00 { #gpio-cells = <2>; compatible = "fsl,mpc8347-gpio", "fsl,mpc8349-gpio"; reg = <0xd00 0x100>; - interrupts = <75 0x8>; interrupt-parent = <&ipic>; + interrupts = <75 0x8>; gpio-controller; }; -See booting-without-of.txt for details of how to specify GPIO -information for devices. - -To use GPIO pins as interrupt sources for peripherals, specify the -GPIO controller as the interrupt parent and define GPIO number + -trigger mode using the interrupts property, which is defined like -this: - -interrupts = <number trigger>, where: - - number: GPIO pin (0..31) - - trigger: trigger mode: - 2 = trigger on falling edge - 3 = trigger on both edges - -Example of device using this is: +Example of a peripheral using the GPIO module as an IRQ controller: funkyfpga@0 { compatible = "funky-fpga"; ... - interrupts = <4 3>; interrupt-parent = <&gpio1>; + interrupts = <4 3>; }; diff --git a/Documentation/devicetree/bindings/mmc/ti-omap.txt b/Documentation/devicetree/bindings/mmc/ti-omap.txt new file mode 100644 index 000000000000..8de579969763 --- /dev/null +++ b/Documentation/devicetree/bindings/mmc/ti-omap.txt @@ -0,0 +1,54 @@ +* TI MMC host controller for OMAP1 and 2420 + +The MMC Host Controller on TI OMAP1 and 2420 family provides +an interface for MMC, SD, and SDIO types of memory cards. + +This file documents differences between the core properties described +by mmc.txt and the properties used by the omap mmc driver. + +Note that this driver will not work with omap2430 or later omaps, +please see the omap hsmmc driver for the current omaps. + +Required properties: +- compatible: Must be "ti,omap2420-mmc", for OMAP2420 controllers +- ti,hwmods: For 2420, must be "msdi<n>", where n is controller + instance starting 1 + +Examples: + + msdi1: mmc@4809c000 { + compatible = "ti,omap2420-mmc"; + ti,hwmods = "msdi1"; + reg = <0x4809c000 0x80>; + interrupts = <83>; + dmas = <&sdma 61 &sdma 62>; + dma-names = "tx", "rx"; + }; + +* TI MMC host controller for OMAP1 and 2420 + +The MMC Host Controller on TI OMAP1 and 2420 family provides +an interface for MMC, SD, and SDIO types of memory cards. + +This file documents differences between the core properties described +by mmc.txt and the properties used by the omap mmc driver. + +Note that this driver will not work with omap2430 or later omaps, +please see the omap hsmmc driver for the current omaps. + +Required properties: +- compatible: Must be "ti,omap2420-mmc", for OMAP2420 controllers +- ti,hwmods: For 2420, must be "msdi<n>", where n is controller + instance starting 1 + +Examples: + + msdi1: mmc@4809c000 { + compatible = "ti,omap2420-mmc"; + ti,hwmods = "msdi1"; + reg = <0x4809c000 0x80>; + interrupts = <83>; + dmas = <&sdma 61 &sdma 62>; + dma-names = "tx", "rx"; + }; + diff --git a/Documentation/devicetree/bindings/net/davinci_emac.txt b/Documentation/devicetree/bindings/net/davinci_emac.txt index 48b259e29e87..bad381faf036 100644 --- a/Documentation/devicetree/bindings/net/davinci_emac.txt +++ b/Documentation/devicetree/bindings/net/davinci_emac.txt @@ -4,7 +4,7 @@ This file provides information, what the device node for the davinci_emac interface contains. Required properties: -- compatible: "ti,davinci-dm6467-emac"; +- compatible: "ti,davinci-dm6467-emac" or "ti,am3517-emac" - reg: Offset and length of the register set for the device - ti,davinci-ctrl-reg-offset: offset to control register - ti,davinci-ctrl-mod-reg-offset: offset to control module register diff --git a/Documentation/devicetree/bindings/net/fsl-fec.txt b/Documentation/devicetree/bindings/net/fsl-fec.txt index d53639221403..845ff848d895 100644 --- a/Documentation/devicetree/bindings/net/fsl-fec.txt +++ b/Documentation/devicetree/bindings/net/fsl-fec.txt @@ -15,6 +15,7 @@ Optional properties: only if property "phy-reset-gpios" is available. Missing the property will have the duration be 1 millisecond. Numbers greater than 1000 are invalid and 1 millisecond will be used instead. +- phy-supply: regulator that powers the Ethernet PHY. Example: @@ -25,4 +26,5 @@ ethernet@83fec000 { phy-mode = "mii"; phy-reset-gpios = <&gpio2 14 0>; /* GPIO2_14 */ local-mac-address = [00 04 9F 01 1B B9]; + phy-supply = <®_fec_supply>; }; diff --git a/Documentation/devicetree/bindings/net/smsc-lan91c111.txt b/Documentation/devicetree/bindings/net/smsc-lan91c111.txt index 953049b4248a..5a41a8658daa 100644 --- a/Documentation/devicetree/bindings/net/smsc-lan91c111.txt +++ b/Documentation/devicetree/bindings/net/smsc-lan91c111.txt @@ -8,3 +8,7 @@ Required properties: Optional properties: - phy-device : phandle to Ethernet phy - local-mac-address : Ethernet mac address to use +- reg-io-width : Mask of sizes (in bytes) of the IO accesses that + are supported on the device. Valid value for SMSC LAN91c111 are + 1, 2 or 4. If it's omitted or invalid, the size would be 2 meaning + 16-bit access only. diff --git a/Documentation/devicetree/bindings/spi/nvidia,tegra20-spi.txt b/Documentation/devicetree/bindings/spi/nvidia,tegra20-spi.txt deleted file mode 100644 index 6b9e51896693..000000000000 --- a/Documentation/devicetree/bindings/spi/nvidia,tegra20-spi.txt +++ /dev/null @@ -1,5 +0,0 @@ -NVIDIA Tegra 2 SPI device - -Required properties: -- compatible : should be "nvidia,tegra20-spi". -- gpios : should specify GPIOs used for chipselect. diff --git a/Documentation/devicetree/bindings/vendor-prefixes.txt b/Documentation/devicetree/bindings/vendor-prefixes.txt index ce95ed1c6d3e..edbb8d88c85e 100644 --- a/Documentation/devicetree/bindings/vendor-prefixes.txt +++ b/Documentation/devicetree/bindings/vendor-prefixes.txt @@ -32,12 +32,14 @@ est ESTeem Wireless Modems fsl Freescale Semiconductor GEFanuc GE Fanuc Intelligent Platforms Embedded Systems, Inc. gef GE Fanuc Intelligent Platforms Embedded Systems, Inc. +gmt Global Mixed-mode Technology, Inc. hisilicon Hisilicon Limited. hp Hewlett Packard ibm International Business Machines (IBM) idt Integrated Device Technologies, Inc. img Imagination Technologies Ltd. intercontrol Inter Control Group +lg LG Corporation linux Linux-specific binding lsi LSI Corp. (LSI Logic) marvell Marvell Technology Group Ltd. diff --git a/Documentation/gpio/00-INDEX b/Documentation/gpio/00-INDEX new file mode 100644 index 000000000000..1de43ae46ae6 --- /dev/null +++ b/Documentation/gpio/00-INDEX @@ -0,0 +1,14 @@ +00-INDEX + - This file +gpio.txt + - Introduction to GPIOs and their kernel interfaces +consumer.txt + - How to obtain and use GPIOs in a driver +driver.txt + - How to write a GPIO driver +board.txt + - How to assign GPIOs to a consumer device and a function +sysfs.txt + - Information about the GPIO sysfs interface +gpio-legacy.txt + - Historical documentation of the deprecated GPIO integer interface diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 50680a59a2ff..b9e9bd854298 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -1529,6 +1529,8 @@ bytes respectively. Such letter suffixes can also be entirely omitted. * atapi_dmadir: Enable ATAPI DMADIR bridge support + * disable: Disable this device. + If there are multiple matching configurations changing the same attribute, the last one is used. diff --git a/Documentation/mic/mpssd/mpssd.c b/Documentation/mic/mpssd/mpssd.c index 0c980ad40b17..4d17487d5ad9 100644 --- a/Documentation/mic/mpssd/mpssd.c +++ b/Documentation/mic/mpssd/mpssd.c @@ -313,7 +313,7 @@ static struct mic_device_desc *get_device_desc(struct mic_info *mic, int type) int i; void *dp = get_dp(mic, type); - for (i = mic_aligned_size(struct mic_bootparam); i < PAGE_SIZE; + for (i = sizeof(struct mic_bootparam); i < PAGE_SIZE; i += mic_total_desc_size(d)) { d = dp + i; @@ -445,8 +445,8 @@ init_vr(struct mic_info *mic, int fd, int type, __func__, mic->name, vr0->va, vr0->info, vr_size, vring_size(MIC_VRING_ENTRIES, MIC_VIRTIO_RING_ALIGN)); mpsslog("magic 0x%x expected 0x%x\n", - vr0->info->magic, MIC_MAGIC + type); - assert(vr0->info->magic == MIC_MAGIC + type); + le32toh(vr0->info->magic), MIC_MAGIC + type); + assert(le32toh(vr0->info->magic) == MIC_MAGIC + type); if (vr1) { vr1->va = (struct mic_vring *) &va[MIC_DEVICE_PAGE_END + vr_size]; @@ -458,8 +458,8 @@ init_vr(struct mic_info *mic, int fd, int type, __func__, mic->name, vr1->va, vr1->info, vr_size, vring_size(MIC_VRING_ENTRIES, MIC_VIRTIO_RING_ALIGN)); mpsslog("magic 0x%x expected 0x%x\n", - vr1->info->magic, MIC_MAGIC + type + 1); - assert(vr1->info->magic == MIC_MAGIC + type + 1); + le32toh(vr1->info->magic), MIC_MAGIC + type + 1); + assert(le32toh(vr1->info->magic) == MIC_MAGIC + type + 1); } done: return va; @@ -520,7 +520,7 @@ static void * virtio_net(void *arg) { static __u8 vnet_hdr[2][sizeof(struct virtio_net_hdr)]; - static __u8 vnet_buf[2][MAX_NET_PKT_SIZE] __aligned(64); + static __u8 vnet_buf[2][MAX_NET_PKT_SIZE] __attribute__ ((aligned(64))); struct iovec vnet_iov[2][2] = { { { .iov_base = vnet_hdr[0], .iov_len = sizeof(vnet_hdr[0]) }, { .iov_base = vnet_buf[0], .iov_len = sizeof(vnet_buf[0]) } }, @@ -1412,6 +1412,12 @@ mic_config(void *arg) } do { + ret = lseek(fd, 0, SEEK_SET); + if (ret < 0) { + mpsslog("%s: Failed to seek to file start '%s': %s\n", + mic->name, pathname, strerror(errno)); + goto close_error1; + } ret = read(fd, value, sizeof(value)); if (ret < 0) { mpsslog("%s: Failed to read sysfs entry '%s': %s\n", diff --git a/Documentation/module-signing.txt b/Documentation/module-signing.txt new file mode 100644 index 000000000000..2b40e04d3c49 --- /dev/null +++ b/Documentation/module-signing.txt @@ -0,0 +1,240 @@ + ============================== + KERNEL MODULE SIGNING FACILITY + ============================== + +CONTENTS + + - Overview. + - Configuring module signing. + - Generating signing keys. + - Public keys in the kernel. + - Manually signing modules. + - Signed modules and stripping. + - Loading signed modules. + - Non-valid signatures and unsigned modules. + - Administering/protecting the private key. + + +======== +OVERVIEW +======== + +The kernel module signing facility cryptographically signs modules during +installation and then checks the signature upon loading the module. This +allows increased kernel security by disallowing the loading of unsigned modules +or modules signed with an invalid key. Module signing increases security by +making it harder to load a malicious module into the kernel. The module +signature checking is done by the kernel so that it is not necessary to have +trusted userspace bits. + +This facility uses X.509 ITU-T standard certificates to encode the public keys +involved. The signatures are not themselves encoded in any industrial standard +type. The facility currently only supports the RSA public key encryption +standard (though it is pluggable and permits others to be used). The possible +hash algorithms that can be used are SHA-1, SHA-224, SHA-256, SHA-384, and +SHA-512 (the algorithm is selected by data in the signature). + + +========================== +CONFIGURING MODULE SIGNING +========================== + +The module signing facility is enabled by going to the "Enable Loadable Module +Support" section of the kernel configuration and turning on + + CONFIG_MODULE_SIG "Module signature verification" + +This has a number of options available: + + (1) "Require modules to be validly signed" (CONFIG_MODULE_SIG_FORCE) + + This specifies how the kernel should deal with a module that has a + signature for which the key is not known or a module that is unsigned. + + If this is off (ie. "permissive"), then modules for which the key is not + available and modules that are unsigned are permitted, but the kernel will + be marked as being tainted. + + If this is on (ie. "restrictive"), only modules that have a valid + signature that can be verified by a public key in the kernel's possession + will be loaded. All other modules will generate an error. + + Irrespective of the setting here, if the module has a signature block that + cannot be parsed, it will be rejected out of hand. + + + (2) "Automatically sign all modules" (CONFIG_MODULE_SIG_ALL) + + If this is on then modules will be automatically signed during the + modules_install phase of a build. If this is off, then the modules must + be signed manually using: + + scripts/sign-file + + + (3) "Which hash algorithm should modules be signed with?" + + This presents a choice of which hash algorithm the installation phase will + sign the modules with: + + CONFIG_SIG_SHA1 "Sign modules with SHA-1" + CONFIG_SIG_SHA224 "Sign modules with SHA-224" + CONFIG_SIG_SHA256 "Sign modules with SHA-256" + CONFIG_SIG_SHA384 "Sign modules with SHA-384" + CONFIG_SIG_SHA512 "Sign modules with SHA-512" + + The algorithm selected here will also be built into the kernel (rather + than being a module) so that modules signed with that algorithm can have + their signatures checked without causing a dependency loop. + + +======================= +GENERATING SIGNING KEYS +======================= + +Cryptographic keypairs are required to generate and check signatures. A +private key is used to generate a signature and the corresponding public key is +used to check it. The private key is only needed during the build, after which +it can be deleted or stored securely. The public key gets built into the +kernel so that it can be used to check the signatures as the modules are +loaded. + +Under normal conditions, the kernel build will automatically generate a new +keypair using openssl if one does not exist in the files: + + signing_key.priv + signing_key.x509 + +during the building of vmlinux (the public part of the key needs to be built +into vmlinux) using parameters in the: + + x509.genkey + +file (which is also generated if it does not already exist). + +It is strongly recommended that you provide your own x509.genkey file. + +Most notably, in the x509.genkey file, the req_distinguished_name section +should be altered from the default: + + [ req_distinguished_name ] + O = Magrathea + CN = Glacier signing key + emailAddress = slartibartfast@magrathea.h2g2 + +The generated RSA key size can also be set with: + + [ req ] + default_bits = 4096 + + +It is also possible to manually generate the key private/public files using the +x509.genkey key generation configuration file in the root node of the Linux +kernel sources tree and the openssl command. The following is an example to +generate the public/private key files: + + openssl req -new -nodes -utf8 -sha256 -days 36500 -batch -x509 \ + -config x509.genkey -outform DER -out signing_key.x509 \ + -keyout signing_key.priv + + +========================= +PUBLIC KEYS IN THE KERNEL +========================= + +The kernel contains a ring of public keys that can be viewed by root. They're +in a keyring called ".system_keyring" that can be seen by: + + [root@deneb ~]# cat /proc/keys + ... + 223c7853 I------ 1 perm 1f030000 0 0 keyring .system_keyring: 1 + 302d2d52 I------ 1 perm 1f010000 0 0 asymmetri Fedora kernel signing key: d69a84e6bce3d216b979e9505b3e3ef9a7118079: X509.RSA a7118079 [] + ... + +Beyond the public key generated specifically for module signing, any file +placed in the kernel source root directory or the kernel build root directory +whose name is suffixed with ".x509" will be assumed to be an X.509 public key +and will be added to the keyring. + +Further, the architecture code may take public keys from a hardware store and +add those in also (e.g. from the UEFI key database). + +Finally, it is possible to add additional public keys by doing: + + keyctl padd asymmetric "" [.system_keyring-ID] <[key-file] + +e.g.: + + keyctl padd asymmetric "" 0x223c7853 <my_public_key.x509 + +Note, however, that the kernel will only permit keys to be added to +.system_keyring _if_ the new key's X.509 wrapper is validly signed by a key +that is already resident in the .system_keyring at the time the key was added. + + +========================= +MANUALLY SIGNING MODULES +========================= + +To manually sign a module, use the scripts/sign-file tool available in +the Linux kernel source tree. The script requires 4 arguments: + + 1. The hash algorithm (e.g., sha256) + 2. The private key filename + 3. The public key filename + 4. The kernel module to be signed + +The following is an example to sign a kernel module: + + scripts/sign-file sha512 kernel-signkey.priv \ + kernel-signkey.x509 module.ko + +The hash algorithm used does not have to match the one configured, but if it +doesn't, you should make sure that hash algorithm is either built into the +kernel or can be loaded without requiring itself. + + +============================ +SIGNED MODULES AND STRIPPING +============================ + +A signed module has a digital signature simply appended at the end. The string +"~Module signature appended~." at the end of the module's file confirms that a +signature is present but it does not confirm that the signature is valid! + +Signed modules are BRITTLE as the signature is outside of the defined ELF +container. Thus they MAY NOT be stripped once the signature is computed and +attached. Note the entire module is the signed payload, including any and all +debug information present at the time of signing. + + +====================== +LOADING SIGNED MODULES +====================== + +Modules are loaded with insmod, modprobe, init_module() or finit_module(), +exactly as for unsigned modules as no processing is done in userspace. The +signature checking is all done within the kernel. + + +========================================= +NON-VALID SIGNATURES AND UNSIGNED MODULES +========================================= + +If CONFIG_MODULE_SIG_FORCE is enabled or enforcemodulesig=1 is supplied on +the kernel command line, the kernel will only load validly signed modules +for which it has a public key. Otherwise, it will also load modules that are +unsigned. Any module for which the kernel has a key, but which proves to have +a signature mismatch will not be permitted to load. + +Any module that has an unparseable signature will be rejected. + + +========================================= +ADMINISTERING/PROTECTING THE PRIVATE KEY +========================================= + +Since the private key is used to sign modules, viruses and malware could use +the private key to sign modules and compromise the operating system. The +private key must be either destroyed or moved to a secure location and not kept +in the root node of the kernel source tree. diff --git a/Documentation/networking/ip-sysctl.txt b/Documentation/networking/ip-sysctl.txt index 3c12d9a7ed00..8a984e994e61 100644 --- a/Documentation/networking/ip-sysctl.txt +++ b/Documentation/networking/ip-sysctl.txt @@ -16,8 +16,12 @@ ip_default_ttl - INTEGER Default: 64 (as recommended by RFC1700) ip_no_pmtu_disc - BOOLEAN - Disable Path MTU Discovery. - default FALSE + Disable Path MTU Discovery. If enabled and a + fragmentation-required ICMP is received, the PMTU to this + destination will be set to min_pmtu (see below). You will need + to raise min_pmtu to the smallest interface MTU on your system + manually if you want to avoid locally generated fragments. + Default: FALSE min_pmtu - INTEGER default 552 - minimum discovered Path MTU diff --git a/Documentation/networking/packet_mmap.txt b/Documentation/networking/packet_mmap.txt index c01223628a87..8e48e3b14227 100644 --- a/Documentation/networking/packet_mmap.txt +++ b/Documentation/networking/packet_mmap.txt @@ -123,6 +123,16 @@ Transmission process is similar to capture as shown below. [shutdown] close() --------> destruction of the transmission socket and deallocation of all associated resources. +Socket creation and destruction is also straight forward, and is done +the same way as in capturing described in the previous paragraph: + + int fd = socket(PF_PACKET, mode, 0); + +The protocol can optionally be 0 in case we only want to transmit +via this socket, which avoids an expensive call to packet_rcv(). +In this case, you also need to bind(2) the TX_RING with sll_protocol = 0 +set. Otherwise, htons(ETH_P_ALL) or any other protocol, for example. + Binding the socket to your network interface is mandatory (with zero copy) to know the header size of frames used in the circular buffer. |
