Changes in 4.9.320 9p: missing chunk of "fs/9p: Don't update file type when updating file attributes" random: remove stale maybe_reseed_primary_crng random: remove stale urandom_init_wait random: remove variable limit random: fix comment for unused random_min_urandom_seed random: convert get_random_int/long into get_random_u32/u64 random: move random_min_urandom_seed into CONFIG_SYSCTL ifdef block random: invalidate batched entropy after crng init random: silence compiler warnings and fix race random: add wait_for_random_bytes() API random: add get_random_{bytes,u32,u64,int,long,once}_wait family random: warn when kernel uses unseeded randomness random: do not ignore early device randomness random: suppress spammy warnings about unseeded randomness random: reorder READ_ONCE() in get_random_uXX random: fix warning message on ia64 and parisc random: use a different mixing algorithm for add_device_randomness() random: set up the NUMA crng instances after the CRNG is fully initialized random: fix possible sleeping allocation from irq context random: rate limit unseeded randomness warnings random: add a spinlock_t to struct batched_entropy char/random: silence a lockdep splat with printk() Revert "char/random: silence a lockdep splat with printk()" random: always use batched entropy for get_random_u{32,64} random: fix data race on crng_node_pool crypto: chacha20 - Fix keystream alignment for chacha20_block() random: always fill buffer in get_random_bytes_wait random: optimize add_interrupt_randomness drivers/char/random.c: remove unused dont_count_entropy random: Fix whitespace pre random-bytes work random: Return nbytes filled from hw RNG random: add a config option to trust the CPU's hwrng random: remove preempt disabled region random: Make crng state queryable random: make CPU trust a boot parameter drivers/char/random.c: constify poolinfo_table drivers/char/random.c: remove unused stuct poolinfo::poolbits drivers/char/random.c: make primary_crng static random: only read from /dev/random after its pool has received 128 bits random: move rand_initialize() earlier random: document get_random_int() family latent_entropy: avoid build error when plugin cflags are not set random: fix soft lockup when trying to read from an uninitialized blocking pool random: Support freezable kthreads in add_hwgenerator_randomness() fdt: add support for rng-seed random: Use wait_event_freezable() in add_hwgenerator_randomness() char/random: Add a newline at the end of the file Revert "hwrng: core - Freeze khwrng thread during suspend" crypto: Deduplicate le32_to_cpu_array() and cpu_to_le32_array() crypto: blake2s - generic C library implementation and selftest lib/crypto: blake2s: move hmac construction into wireguard lib/crypto: sha1: re-roll loops to reduce code size random: Don't wake crng_init_wait when crng_init == 1 random: Add a urandom_read_nowait() for random APIs that don't warn random: add GRND_INSECURE to return best-effort non-cryptographic bytes random: ignore GRND_RANDOM in getentropy(2) random: make /dev/random be almost like /dev/urandom random: fix crash on multiple early calls to add_bootloader_randomness() random: remove the blocking pool random: delete code to pull data into pools random: remove kernel.random.read_wakeup_threshold random: remove unnecessary unlikely() random: convert to ENTROPY_BITS for better code readability random: Add and use pr_fmt() random: fix typo in add_timer_randomness() random: remove some dead code of poolinfo random: split primary/secondary crng init paths random: avoid warnings for !CONFIG_NUMA builds x86: Remove arch_has_random, arch_has_random_seed powerpc: Remove arch_has_random, arch_has_random_seed linux/random.h: Remove arch_has_random, arch_has_random_seed linux/random.h: Use false with bool linux/random.h: Mark CONFIG_ARCH_RANDOM functions __must_check powerpc: Use bool in archrandom.h random: add arch_get_random_*long_early() random: avoid arch_get_random_seed_long() when collecting IRQ randomness random: remove dead code left over from blocking pool MAINTAINERS: co-maintain random.c crypto: blake2s - include <linux/bug.h> instead of <asm/bug.h> crypto: blake2s - adjust include guard naming random: document add_hwgenerator_randomness() with other input functions random: remove unused irq_flags argument from add_interrupt_randomness() random: use BLAKE2s instead of SHA1 in extraction random: do not sign extend bytes for rotation when mixing random: do not re-init if crng_reseed completes before primary init random: mix bootloader randomness into pool random: harmonize "crng init done" messages random: use IS_ENABLED(CONFIG_NUMA) instead of ifdefs random: initialize ChaCha20 constants with correct endianness random: early initialization of ChaCha constants random: avoid superfluous call to RDRAND in CRNG extraction random: don't reset crng_init_cnt on urandom_read() random: fix typo in comments random: cleanup poolinfo abstraction crypto: chacha20 - Fix chacha20_block() keystream alignment (again) random: cleanup integer types random: remove incomplete last_data logic random: remove unused extract_entropy() reserved argument random: try to actively add entropy rather than passively wait for it random: rather than entropy_store abstraction, use global random: remove unused OUTPUT_POOL constants random: de-duplicate INPUT_POOL constants random: prepend remaining pool constants with POOL_ random: cleanup fractional entropy shift constants random: access input_pool_data directly rather than through pointer random: simplify arithmetic function flow in account() random: continually use hwgenerator randomness random: access primary_pool directly rather than through pointer random: only call crng_finalize_init() for primary_crng random: use computational hash for entropy extraction random: simplify entropy debiting random: use linear min-entropy accumulation crediting random: always wake up entropy writers after extraction random: make credit_entropy_bits() always safe random: remove use_input_pool parameter from crng_reseed() random: remove batched entropy locking random: fix locking in crng_fast_load() random: use RDSEED instead of RDRAND in entropy extraction random: inline leaves of rand_initialize() random: ensure early RDSEED goes through mixer on init random: do not xor RDRAND when writing into /dev/random random: absorb fast pool into input pool after fast load random: use hash function for crng_slow_load() random: remove outdated INT_MAX >> 6 check in urandom_read() random: zero buffer after reading entropy from userspace random: tie batched entropy generation to base_crng generation random: remove ifdef'd out interrupt bench random: remove unused tracepoints random: add proper SPDX header random: deobfuscate irq u32/u64 contributions random: introduce drain_entropy() helper to declutter crng_reseed() random: remove useless header comment random: remove whitespace and reorder includes random: group initialization wait functions random: group entropy extraction functions random: group entropy collection functions random: group userspace read/write functions random: group sysctl functions random: rewrite header introductory comment workqueue: make workqueue available early during boot random: defer fast pool mixing to worker random: do not take pool spinlock at boot random: unify early init crng load accounting random: check for crng_init == 0 in add_device_randomness() hwrng: core - do not use multiple blank lines hwrng: core - rewrite better comparison to NULL hwrng: core - Rewrite the header hwrng: core - Move hwrng miscdev minor number to include/linux/miscdevice.h hwrng: core - remove unused PFX macro hwrng: use rng source with best quality hwrng: remember rng chosen by user random: pull add_hwgenerator_randomness() declaration into random.h random: clear fast pool, crng, and batches in cpuhp bring up random: round-robin registers as ulong, not u32 random: only wake up writers after zap if threshold was passed random: cleanup UUID handling random: unify cycles_t and jiffies usage and types random: do crng pre-init loading in worker rather than irq random: give sysctl_random_min_urandom_seed a more sensible value random: don't let 644 read-only sysctls be written to random: replace custom notifier chain with standard one random: use SipHash as interrupt entropy accumulator random: make consistent usage of crng_ready() random: reseed more often immediately after booting random: check for signal and try earlier when generating entropy random: skip fast_init if hwrng provides large chunk of entropy random: treat bootloader trust toggle the same way as cpu trust toggle random: re-add removed comment about get_random_{u32,u64} reseeding random: mix build-time latent entropy into pool at init random: do not split fast init input in add_hwgenerator_randomness() random: do not allow user to keep crng key around on stack random: check for signal_pending() outside of need_resched() check random: check for signals every PAGE_SIZE chunk of /dev/[u]random random: make random_get_entropy() return an unsigned long random: document crng_fast_key_erasure() destination possibility random: fix sysctl documentation nits init: call time_init() before rand_initialize() ia64: define get_cycles macro for arch-override s390: define get_cycles macro for arch-override parisc: define get_cycles macro for arch-override alpha: define get_cycles macro for arch-override powerpc: define get_cycles macro for arch-override timekeeping: Add raw clock fallback for random_get_entropy() m68k: use fallback for random_get_entropy() instead of zero mips: use fallback for random_get_entropy() instead of just c0 random arm: use fallback for random_get_entropy() instead of zero nios2: use fallback for random_get_entropy() instead of zero x86/tsc: Use fallback for random_get_entropy() instead of zero um: use fallback for random_get_entropy() instead of zero sparc: use fallback for random_get_entropy() instead of zero xtensa: use fallback for random_get_entropy() instead of zero uapi: rename ext2_swab() to swab() and share globally in swab.h random: insist on random_get_entropy() existing in order to simplify random: do not use batches when !crng_ready() random: do not pretend to handle premature next security model random: order timer entropy functions below interrupt functions random: do not use input pool from hard IRQs random: help compiler out with fast_mix() by using simpler arguments siphash: use one source of truth for siphash permutations random: use symbolic constants for crng_init states random: avoid initializing twice in credit race random: remove ratelimiting for in-kernel unseeded randomness random: use proper jiffies comparison macro random: handle latent entropy and command line from random_init() random: credit architectural init the exact amount random: use static branch for crng_ready() random: remove extern from functions in header random: use proper return types on get_random_{int,long}_wait() random: move initialization functions out of hot pages random: move randomize_page() into mm where it belongs random: convert to using fops->write_iter() random: wire up fops->splice_{read,write}_iter() random: check for signals after page of pool writes Revert "random: use static branch for crng_ready()" crypto: drbg - add FIPS 140-2 CTRNG for noise source crypto: drbg - always seeded with SP800-90B compliant noise source crypto: drbg - prepare for more fine-grained tracking of seeding state crypto: drbg - track whether DRBG was seeded with !rng_is_initialized() crypto: drbg - move dynamic ->reseed_threshold adjustments to __drbg_seed() crypto: drbg - always try to free Jitter RNG instance crypto: drbg - make reseeding from get_random_bytes() synchronous random: avoid checking crng_ready() twice in random_init() random: mark bootloader randomness code as __init random: account for arch randomness in bits ASoC: cs42l52: Fix TLV scales for mixer controls ASoC: cs53l30: Correct number of volume levels on SX controls ASoC: cs42l52: Correct TLV for Bypass Volume ASoC: cs42l56: Correct typo in minimum level for SX volume controls ata: libata-core: fix NULL pointer deref in ata_host_alloc_pinfo() ASoC: wm8962: Fix suspend while playing music scsi: vmw_pvscsi: Expand vcpuHint to 16 bits scsi: lpfc: Fix port stuck in bypassed state after LIP in PT2PT topology virtio-mmio: fix missing put_device() when vm_cmdline_parent registration failed nfc: nfcmrvl: Fix memory leak in nfcmrvl_play_deferred ipv6: Fix signed integer overflow in l2tp_ip6_sendmsg net: ethernet: mtk_eth_soc: fix misuse of mem alloc interface netdev[napi]_alloc_frag random: credit cpu and bootloader seeds by default pNFS: Don't keep retrying if the server replied NFS4ERR_LAYOUTUNAVAILABLE misc: atmel-ssc: Fix IRQ check in ssc_probe irqchip/gic/realview: Fix refcount leak in realview_gic_of_init irqchip/gic-v3: Iterate over possible CPUs by for_each_possible_cpu() comedi: vmk80xx: fix expression for tx buffer size USB: serial: option: add support for Cinterion MV31 with new baseline USB: serial: io_ti: add Agilent E5805A support usb: gadget: lpc32xx_udc: Fix refcount leak in lpc32xx_udc_probe serial: 8250: Store to lsr_save_flags after lsr read ext4: fix bug_on ext4_mb_use_inode_pa ext4: make variable "count" signed ext4: add reserved GDT blocks check l2tp: don't use inet_shutdown on ppp session destroy l2tp: fix race in pppol2tp_release with session object destroy s390/mm: use non-quiescing sske for KVM switch to keyed guest xprtrdma: fix incorrect header size calculations swiotlb: fix info leak with DMA_FROM_DEVICE Reinstate some of "swiotlb: rework "fix info leak with DMA_FROM_DEVICE"" fuse: fix pipe buffer lifetime for direct_io tcp: change source port randomizarion at connect() time tcp: add some entropy in __inet_hash_connect() secure_seq: use the 64 bits of the siphash for port offset calculation tcp: use different parts of the port_offset for index and offset tcp: add small random increments to the source port tcp: dynamically allocate the perturb table used by source ports tcp: increase source port perturb table to 2^16 tcp: drop the hash_32() part from the index calculation Linux 4.9.320 Conflicts: crypto/chacha20_generic.c drivers/char/random.c drivers/of/fdt.c include/crypto/chacha20.h lib/chacha20.c Merge resolution notes: - Added CHACHA20_KEY_SIZE and CHACHA20_BLOCK_SIZE constants to chacha.h, to minimize changes from the 4.9.320 version of random.c - Updated lib/vsprintf.c for "random: replace custom notifier chain with standard one". Change-Id: Ia7a12d8883b808f88bbe807d6150552bb084f6b3 Signed-off-by: Eric Biggers <ebiggers@google.com>
Documentation for /proc/sys/ kernel version 2.2.10 (c) 1998, 1999, Rik van Riel <riel@nl.linux.org> 'Why', I hear you ask, 'would anyone even _want_ documentation for them sysctl files? If anybody really needs it, it's all in the source...' Well, this documentation is written because some people either don't know they need to tweak something, or because they don't have the time or knowledge to read the source code. Furthermore, the programmers who built sysctl have built it to be actually used, not just for the fun of programming it :-) ============================================================== Legal blurb: As usual, there are two main things to consider: 1. you get what you pay for 2. it's free The consequences are that I won't guarantee the correctness of this document, and if you come to me complaining about how you screwed up your system because of wrong documentation, I won't feel sorry for you. I might even laugh at you... But of course, if you _do_ manage to screw up your system using only the sysctl options used in this file, I'd like to hear of it. Not only to have a great laugh, but also to make sure that you're the last RTFMing person to screw up. In short, e-mail your suggestions, corrections and / or horror stories to: <riel@nl.linux.org> Rik van Riel. ============================================================== Introduction: Sysctl is a means of configuring certain aspects of the kernel at run-time, and the /proc/sys/ directory is there so that you don't even need special tools to do it! In fact, there are only four things needed to use these config facilities: - a running Linux system - root access - common sense (this is especially hard to come by these days) - knowledge of what all those values mean As a quick 'ls /proc/sys' will show, the directory consists of several (arch-dependent?) subdirs. Each subdir is mainly about one part of the kernel, so you can do configuration on a piece by piece basis, or just some 'thematic frobbing'. The subdirs are about: abi/ execution domains & personalities debug/ <empty> dev/ device specific information (eg dev/cdrom/info) fs/ specific filesystems filehandle, inode, dentry and quota tuning binfmt_misc <Documentation/binfmt_misc.txt> kernel/ global kernel info / tuning miscellaneous stuff net/ networking stuff, for documentation look in: <Documentation/networking/> proc/ <empty> sunrpc/ SUN Remote Procedure Call (NFS) vm/ memory management tuning buffer and cache management user/ Per user per user namespace limits These are the subdirs I have on my system. There might be more or other subdirs in another setup. If you see another dir, I'd really like to hear about it :-)