8b338e2310
* aosp/android-4.19-stable: Revert "xhci: Add grace period after xHC start to prevent premature runtime suspend." Revert "USB: core: Prevent nested device-reset calls" Revert "mm/rmap: Fix anon_vma->degree ambiguity leading to double-reuse" Revert "sched/deadline: Fix priority inheritance with multiple scheduling classes" Revert "kernel/sched: Remove dl_boosted flag comment" Revert "fs: check FMODE_LSEEK to control internal pipe splicing" Linux 4.19.259 tracefs: Only clobber mode/uid/gid on remount if asked net: dp83822: disable rx error interrupt mm: Fix TLB flush for not-first PFNMAP mappings in unmap_region() usb: storage: Add ASUS <0x0b05:0x1932> to IGNORE_UAS platform/x86: acer-wmi: Acer Aspire One AOD270/Packard Bell Dot keymap fixes perf/arm_pmu_platform: fix tests for platform_get_irq() failure Input: iforce - add support for Boeder Force Feedback Wheel ieee802154: cc2520: add rc code in cc2520_tx() tg3: Disable tg3 device on system reboot to avoid triggering AER HID: ishtp-hid-clientHID: ishtp-hid-client: Fix comment typo drm/msm/rd: Fix FIFO-full deadlock Linux 4.19.258 SUNRPC: use _bh spinlocking on ->transport_lock MIPS: loongson32: ls1c: Fix hang during startup x86/nospec: Fix i386 RSB stuffing usb: dwc3: qcom: fix use-after-free on runtime-PM wakeup USB: serial: ch341: fix disabled rx timer on older devices USB: serial: ch341: fix lost character on LCR updates usb: dwc3: fix PHY disable sequence sch_sfb: Also store skb len before calling child enqueue tcp: fix early ETIMEDOUT after spurious non-SACK RTO RDMA/mlx5: Set local port to one when accessing counters ipv6: sr: fix out-of-bounds read when setting HMAC data. i40e: Fix kernel crash during module removal tipc: fix shift wrapping bug in map_get() sch_sfb: Don't assume the skb is still around after enqueueing to child netfilter: nf_conntrack_irc: Fix forged IP logic netfilter: br_netfilter: Drop dst references before setting. soc: brcmstb: pm-arm: Fix refcount leak and __iomem leak bugs scsi: mpt3sas: Fix use-after-free warning debugfs: add debugfs_lookup_and_remove() kprobes: Prohibit probes in gate area ALSA: usb-audio: Fix an out-of-bounds bug in __snd_usb_parse_audio_interface() ALSA: aloop: Fix random zeros in capture data when using jiffies timer ALSA: emu10k1: Fix out of bounds access in snd_emu10k1_pcm_channel_alloc() drm/amdgpu: mmVM_L2_CNTL3 register not initialized correctly fbdev: chipsfb: Add missing pci_disable_device() in chipsfb_pci_init() arm64: cacheinfo: Fix incorrect assignment of signed error value to unsigned fw_level parisc: Add runtime check to prevent PA2.0 kernels on PA1.x machines parisc: ccio-dma: Handle kmalloc failure in ccio_init_resources() drm/radeon: add a force flush to delay work when radeon drm/amdgpu: Check num_gfx_rings for gfx v9_0 rb setup. ALSA: seq: Fix data-race at module auto-loading ALSA: seq: oss: Fix data-race for max_midi_devs access net: mac802154: Fix a condition in the receive path wifi: mac80211: Don't finalize CSA in IBSS mode if state is disconnected usb: gadget: mass_storage: Fix cdrom data transfers on MAC-OS USB: core: Prevent nested device-reset calls s390: fix nospec table alignments s390/hugetlb: fix prepare_hugepage_range() check for 2 GB hugepages usb-storage: Add ignore-residue quirk for NXP PN7462AU USB: cdc-acm: Add Icom PMR F3400 support (0c26:0020) usb: dwc2: fix wrong order of phy_power_on and phy_init usb: typec: altmodes/displayport: correct pin assignment for UFP receptacles USB: serial: option: add support for Cinterion MV32-WA/WB RmNet mode USB: serial: option: add Quectel EM060K modem USB: serial: option: add support for OPPO R11 diag port USB: serial: cp210x: add Decagon UCA device id xhci: Add grace period after xHC start to prevent premature runtime suspend. thunderbolt: Use the actual buffer in tb_async_error() hwmon: (gpio-fan) Fix array out of bounds access Input: rk805-pwrkey - fix module autoloading clk: core: Fix runtime PM sequence in clk_core_unprepare() Revert "clk: core: Honor CLK_OPS_PARENT_ENABLE for clk gate ops" clk: core: Honor CLK_OPS_PARENT_ENABLE for clk gate ops drm/i915/reg: Fix spelling mistake "Unsupport" -> "Unsupported" binder: fix UAF of ref->proc caused by race condition USB: serial: ftdi_sio: add Omron CS1W-CIF31 device id vt: Clear selection before changing the font staging: rtl8712: fix use after free bugs serial: fsl_lpuart: RS485 RTS polariy is inverse net/smc: Remove redundant refcount increase Revert "sch_cake: Return __NET_XMIT_STOLEN when consuming enqueued skb" tcp: annotate data-race around challenge_timestamp sch_cake: Return __NET_XMIT_STOLEN when consuming enqueued skb kcm: fix strp_init() order and cleanup ethernet: rocker: fix sleep in atomic context bug in neigh_timer_handler Revert "xhci: turn off port power in shutdown" wifi: cfg80211: debugfs: fix return type in ht40allow_map_read() ieee802154/adf7242: defer destroy_workqueue call platform/x86: pmc_atom: Fix SLP_TYPx bitfield mask drm/msm/dsi: Fix number of regulators for msm8996_dsi_cfg drm/msm/dsi: fix the inconsistent indenting net: dp83822: disable false carrier interrupt Revert "mm: kmemleak: take a full lowmem check in kmemleak_*_phys()" fs: only do a memory barrier for the first set_buffer_uptodate() wifi: iwlegacy: 4965: corrected fix for potential off-by-one overflow in il4965_rs_fill_link_cmd() efi: capsule-loader: Fix use-after-free in efi_capsule_write driver core: Don't probe devices after bus_type.match() probe deferral Linux 4.19.257 net: neigh: don't call kfree_skb() under spin_lock_irqsave() kprobes: don't call disarm_kprobe() for disabled kprobes netfilter: conntrack: NF_CONNTRACK_PROCFS should no longer default to y s390/hypfs: avoid error message under KVM neigh: fix possible DoS due to net iface start/stop loop drm/amd/display: clear optc underflow before turn off odm clock mm/rmap: Fix anon_vma->degree ambiguity leading to double-reuse ftrace: Fix NULL pointer dereference in is_ftrace_trampoline when ftrace is dead fbdev: fb_pm2fb: Avoid potential divide by zero error HID: hidraw: fix memory leak in hidraw_release() media: pvrusb2: fix memory leak in pvr_probe HID: steam: Prevent NULL pointer dereference in steam_{recv,send}_report Bluetooth: L2CAP: Fix build errors in some archs kbuild: Fix include path in scripts/Makefile.modpost x86/bugs: Add "unknown" reporting for MMIO Stale Data s390/mm: do not trigger write fault when vma does not allow VM_WRITE selftests/bpf: Fix test_align verifier log patterns bpf: Fix the off-by-two error in range markings arm64: map FDT as RW for early_init_dt_scan() mm: Force TLB flush for PFNMAP mappings before unlink_file_vma() scsi: storvsc: Remove WQ_MEM_RECLAIM from storvsc_error_wq md: call __md_stop_writes in md_stop mm/hugetlb: fix hugetlb not supporting softdirty tracking s390: fix double free of GS and RI CBs on fork() failure asm-generic: sections: refactor memory_intersects loop: Check for overflow while configuring loop x86/unwind/orc: Unwind ftrace trampolines with correct ORC entry btrfs: check if root is readonly while setting security xattr ixgbe: stop resetting SYSTIME in ixgbe_ptp_start_cyclecounter net: Fix a data-race around sysctl_somaxconn. net: Fix a data-race around netdev_budget_usecs. net: Fix a data-race around netdev_budget. net: Fix a data-race around sysctl_net_busy_read. net: Fix a data-race around sysctl_net_busy_poll. net: Fix a data-race around sysctl_tstamp_allow_data. ratelimit: Fix data-races in ___ratelimit(). net: Fix data-races around netdev_tstamp_prequeue. net: Fix data-races around weight_p and dev_weight_[rt]x_bias. netfilter: nft_tunnel: restrict it to netdev family netfilter: nft_osf: restrict osf to ipv4, ipv6 and inet families netfilter: nft_payload: do not truncate csum_offset and csum_type netfilter: nft_payload: report ERANGE for too long offset and length netfilter: ebtables: reject blobs that don't provide all entry points net: ipvtap - add __init/__exit annotations to module init/exit funcs bonding: 802.3ad: fix no transmission of LACPDUs rose: check NULL rose_loopback_neigh->loopback af_key: Do not call xfrm_probe_algs in parallel xfrm: fix refcount leak in __xfrm_policy_check() kernel/sched: Remove dl_boosted flag comment sched/deadline: Fix priority inheritance with multiple scheduling classes sched/deadline: Fix stale throttling on de-/boosted tasks sched/deadline: Unthrottle PI boosted threads while enqueuing pinctrl: amd: Don't save/restore interrupt status and wake status bits kernel/sys_ni: add compat entry for fadvise64_64 parisc: Fix exception handler for fldw and fstw instructions audit: fix potential double free on error path from fsnotify_add_inode_mark Linux 4.19.256 btrfs: raid56: don't trust any cached sector in __raid56_parity_recover() btrfs: only write the sectors in the vertical stripe which has data stripes tracing/probes: Have kprobes and uprobes use $COMM too tee: add overflow check in register_shm_helper() MIPS: tlbex: Explicitly compare _PAGE_NO_EXEC against 0 video: fbdev: i740fb: Check the argument of i740_calc_vclk() powerpc/64: Init jump labels before parse_early_param() smb3: check xattr value length earlier f2fs: fix to avoid use f2fs_bug_on() in f2fs_new_node_page() ALSA: timer: Use deferred fasync helper ALSA: core: Add async signal helpers watchdog: export lockup_detector_reconfigure RISC-V: Add fast call path of crash_kexec() riscv: mmap with PROT_WRITE but no PROT_READ is invalid mips: cavium-octeon: Fix missing of_node_put() in octeon2_usb_clocks_start vfio: Clear the caps->buf to NULL after free tty: serial: Fix refcount leak bug in ucc_uart.c lib/list_debug.c: Detect uninitialized lists ext4: avoid resizing to a partial cluster size ext4: avoid remove directory when directory is corrupted drivers:md:fix a potential use-after-free bug dmaengine: sprd: Cleanup in .remove() after pm_runtime_get_sync() failed cxl: Fix a memory leak in an error handling path gadgetfs: ep_io - wait until IRQ finishes clk: qcom: ipq8074: dont disable gcc_sleep_clk_src vboxguest: Do not use devm for irq usb: renesas: Fix refcount leak bug usb: host: ohci-ppc-of: Fix refcount leak bug irqchip/tegra: Fix overflow implicit truncation warnings PCI: Add ACS quirk for Broadcom BCM5750x NICs drm/meson: Fix refcount bugs in meson_vpu_has_available_connectors() locking/atomic: Make test_and_*_bit() ordered on failure gcc-plugins: Undefine LATENT_ENTROPY_PLUGIN when plugin disabled for a file igb: Add lock to avoid data race fec: Fix timer capture timing in `fec_ptp_enable_pps()` i40e: Fix to stop tx_timeout recovery if GLOBR fails powerpc/pci: Fix get_phb_number() locking netfilter: nf_tables: really skip inactive sets when allocating name nios2: add force_successful_syscall_return() nios2: restarts apply only to the first sigframe we build... nios2: fix syscall restart checks nios2: traced syscall does need to check the syscall number nios2: don't leave NULLs in sys_call_table[] nios2: page fault et.al. are *not* restartable syscalls... atm: idt77252: fix use-after-free bugs caused by tst_timer xen/xenbus: fix return type in xenbus_file_read() NTB: ntb_tool: uninitialized heap data in tool_fn_write() tools build: Switch to new openssl API for test-libcrypto vsock: Set socket state back to SS_UNCONNECTED in vsock_connect_timeout() vsock: Fix memory leak in vsock_connect() geneve: do not use RT_TOS for IPv6 flowlabel ACPI: property: Return type of acpi_add_nondev_subnodes() should be bool pinctrl: qcom: msm8916: Allow CAMSS GP clocks to be muxed pinctrl: nomadik: Fix refcount leak in nmk_pinctrl_dt_subnode_to_map SUNRPC: Reinitialise the backchannel request buffers before reuse NFSv4/pnfs: Fix a use-after-free bug in open NFSv4.1: RECLAIM_COMPLETE must handle EACCES NFSv4: Fix races in the legacy idmapper upcall apparmor: Fix memleak in aa_simple_write_to_buffer() apparmor: fix reference count leak in aa_pivotroot() apparmor: fix overlapping attachment computation apparmor: fix aa_label_asxprint return check apparmor: Fix failed mount permission check error message apparmor: fix absroot causing audited secids to begin with = apparmor: fix quiet_denied for file rules can: ems_usb: fix clang's -Wunaligned-access warning tracing: Have filter accept "common_cpu" to be consistent btrfs: fix lost error handling when looking up extended ref on log replay mmc: pxamci: Fix an error handling path in pxamci_probe() mmc: pxamci: Fix another error handling path in pxamci_probe() ata: libata-eh: Add missing command name rds: add missing barrier to release_refill ALSA: info: Fix llseek return value when using callback powerpc/ptdump: Fix display of RW pages on FSL_BOOK3E powerpc/mm: Split dump_pagelinuxtables flag_array table firmware: arm_scpi: Ensure scpi_info is not assigned if the probe fails net_sched: cls_route: disallow handle of 0 net/9p: Initialize the iounit field during fid creation Bluetooth: L2CAP: Fix l2cap_global_chan_by_psm regression Revert "net: usb: ax88179_178a needs FLAG_SEND_ZLP" scsi: sg: Allow waiting for commands to complete on removed device tcp: fix over estimation in sk_forced_mem_schedule() KVM: x86: Avoid theoretical NULL pointer dereference in kvm_irq_delivery_to_apic_fast() KVM: x86: Check lapic_in_kernel() before attempting to set a SynIC irq KVM: Add infrastructure and macro to mark VM as bugged btrfs: reject log replay if there is unsupported RO compat flag net_sched: cls_route: remove from list when handle is 0 ACPI: CPPC: Do not prevent CPPC from working in the future dm writecache: set a default MAX_WRITEBACK_JOBS dm raid: fix address sanitizer warning in raid_status dm raid: fix address sanitizer warning in raid_resume intel_th: pci: Add Meteor Lake-P support intel_th: pci: Add Raptor Lake-S PCH support intel_th: pci: Add Raptor Lake-S CPU support ext4: correct the misjudgment in ext4_iget_extra_inode ext4: correct max_inline_xattr_value_size computing ext4: fix extent status tree race in writeback error recovery path ext4: update s_overhead_clusters in the superblock during an on-line resize ext4: fix use-after-free in ext4_xattr_set_entry ext4: make sure ext4_append() always allocates new block ext4: add EXT4_INODE_HAS_XATTR_SPACE macro in xattr.h spmi: trace: fix stack-out-of-bound access in SPMI tracing functions x86/olpc: fix 'logical not is only applied to the left hand side' scsi: zfcp: Fix missing auto port scan and thus missing target ports video: fbdev: s3fb: Check the size of screen before memset_io() video: fbdev: arkfb: Check the size of screen before memset_io() video: fbdev: vt8623fb: Check the size of screen before memset_io() tools/thermal: Fix possible path truncations video: fbdev: arkfb: Fix a divide-by-zero bug in ark_set_pixclock() x86/numa: Use cpumask_available instead of hardcoded NULL check scripts/faddr2line: Fix vmlinux detection on arm64 genelf: Use HAVE_LIBCRYPTO_SUPPORT, not the never defined HAVE_LIBCRYPTO powerpc/pci: Fix PHB numbering when using opal-phbid kprobes: Forbid probing on trampoline and BPF code areas powerpc/cell/axon_msi: Fix refcount leak in setup_msi_msg_address powerpc/xive: Fix refcount leak in xive_get_max_prio powerpc/spufs: Fix refcount leak in spufs_init_isolated_loader powerpc/pci: Prefer PCI domain assignment via DT 'linux,pci-domain' and alias powerpc/32: Do not allow selection of e5500 or e6500 CPUs on PPC32 video: fbdev: sis: fix typos in SiS_GetModeID() video: fbdev: amba-clcd: Fix refcount leak bugs ASoC: qcom: q6dsp: Fix an off-by-one in q6adm_alloc_copp() s390/zcore: fix race when reading from hardware system area iommu/arm-smmu: qcom_iommu: Add of_node_put() when breaking out of loop mfd: t7l66xb: Drop platform disable callback kfifo: fix kfifo_to_user() return type rpmsg: qcom_smd: Fix refcount leak in qcom_smd_parse_edge iommu/exynos: Handle failed IOMMU device registration properly tty: n_gsm: fix missing corner cases in gsmld_poll() tty: n_gsm: fix DM command tty: n_gsm: fix wrong T1 retry count handling vfio/ccw: Do not change FSM state in subchannel event remoteproc: qcom: wcnss: Fix handling of IRQs tty: n_gsm: fix race condition in gsmld_write() tty: n_gsm: fix packet re-transmission without open control channel tty: n_gsm: fix non flow control frames during mux flow off profiling: fix shift too large makes kernel panic serial: 8250_dw: Store LSR into lsr_saved_flags in dw8250_tx_wait_empty() ASoC: mediatek: mt8173-rt5650: Fix refcount leak in mt8173_rt5650_dev_probe ASoC: codecs: da7210: add check for i2c_add_driver ASoC: mt6797-mt6351: Fix refcount leak in mt6797_mt6351_dev_probe ASoC: mediatek: mt8173: Fix refcount leak in mt8173_rt5650_rt5676_dev_probe jbd2: fix assertion 'jh->b_frozen_data == NULL' failure when journal aborted ext4: recover csum seed of tmp_inode after migrating to extents null_blk: fix ida error handling in null_add_dev() RDMA/rxe: Fix error unwind in rxe_create_qp() mm/mmap.c: fix missing call to vm_unacct_memory in mmap_region platform/olpc: Fix uninitialized data in debugfs write USB: serial: fix tty-port initialized comments HID: alps: Declare U1_UNICORN_LEGACY support mmc: cavium-thunderx: Add of_node_put() when breaking out of loop mmc: cavium-octeon: Add of_node_put() when breaking out of loop gpio: gpiolib-of: Fix refcount bugs in of_mm_gpiochip_add_data() RDMA/hfi1: fix potential memory leak in setup_base_ctxt() usb: gadget: udc: amd5536 depends on HAS_DMA scsi: smartpqi: Fix DMA direction for RAID requests mmc: sdhci-of-at91: fix set_uhs_signaling rewriting of MC1R memstick/ms_block: Fix a memory leak memstick/ms_block: Fix some incorrect memory allocation mmc: sdhci-of-esdhc: Fix refcount leak in esdhc_signal_voltage_switch staging: rtl8192u: Fix sleep in atomic context bug in dm_fsync_timer_callback soundwire: bus_type: fix remove and shutdown support clk: qcom: ipq8074: set BRANCH_HALT_DELAY flag for UBI clocks clk: qcom: ipq8074: fix NSS port frequency tables misc: rtsx: Fix an error handling path in rtsx_pci_probe() usb: ohci-nxp: Fix refcount leak in ohci_hcd_nxp_probe usb: host: Fix refcount leak in ehci_hcd_ppc_of_probe fpga: altera-pr-ip: fix unsigned comparison with less than zero mtd: st_spi_fsm: Add a clk_disable_unprepare() in .probe()'s error path mtd: sm_ftl: Fix deadlock caused by cancel_work_sync in sm_release HID: cp2112: prevent a buffer overflow in cp2112_xfer() mtd: maps: Fix refcount leak in ap_flash_init mtd: maps: Fix refcount leak in of_flash_probe_versatile clk: renesas: r9a06g032: Fix UART clkgrp bitsel dccp: put dccp_qpolicy_full() and dccp_qpolicy_push() in the same lock net: rose: fix netdev reference changes netdevsim: Avoid allocation warnings triggered from user space net/mlx5e: Fix the value of MLX5E_MAX_RQ_NUM_MTTS wifi: libertas: Fix possible refcount leak in if_usb_probe() wifi: wil6210: debugfs: fix uninitialized variable use in `wil_write_file_wmi()` i2c: mux-gpmux: Add of_node_put() when breaking out of loop i2c: cadence: Support PEC for SMBus block read Bluetooth: hci_intel: Add check for platform_driver_register can: pch_can: pch_can_error(): initialize errc before using it can: error: specify the values of data[5..7] of CAN error frames can: usb_8dev: do not report txerr and rxerr during bus-off can: kvaser_usb_leaf: do not report txerr and rxerr during bus-off can: kvaser_usb_hydra: do not report txerr and rxerr during bus-off can: sun4i_can: do not report txerr and rxerr during bus-off can: hi311x: do not report txerr and rxerr during bus-off can: sja1000: do not report txerr and rxerr during bus-off can: rcar_can: do not report txerr and rxerr during bus-off can: pch_can: do not report txerr and rxerr during bus-off wifi: p54: add missing parentheses in p54_flush() wifi: p54: Fix an error handling path in p54spi_probe() selftests: timers: clocksource-switch: fix passing errors from child wifi: wil6210: debugfs: fix info leak in wil_write_file_wmi() selftests: timers: valid-adjtimex: build fix for newer toolchains fs: check FMODE_LSEEK to control internal pipe splicing libbpf: Fix the name of a reused map tcp: make retransmitted SKB fit into the send window mediatek: mt76: mac80211: Fix missing of_node_put() in mt76_led_init() media: platform: mtk-mdp: Fix mdp_ipi_comm structure alignment crypto: hisilicon - Kunpeng916 crypto driver don't sleep when in softirq Change-Id: I1a4bb33f07f7ac850e069a5ac664d668f42b377f Signed-off-by: UtsavBalar1231 <utsavbalar1231@gmail.com> Conflicts: drivers/usb/dwc3/core.c |
||
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.. | ||
hw-vuln | ||
LSM | ||
mm | ||
pm | ||
bcache.rst | ||
binfmt-misc.rst | ||
braille-console.rst | ||
bug-bisect.rst | ||
bug-hunting.rst | ||
cgroup-v2.rst | ||
conf.py | ||
devices.rst | ||
devices.txt | ||
dynamic-debug-howto.rst | ||
index.rst | ||
init.rst | ||
initrd.rst | ||
java.rst | ||
kernel-parameters.rst | ||
kernel-parameters.txt | ||
md.rst | ||
module-signing.rst | ||
mono.rst | ||
parport.rst | ||
ramoops.rst | ||
ras.rst | ||
README.rst | ||
reporting-bugs.rst | ||
security-bugs.rst | ||
serial-console.rst | ||
sysfs-rules.rst | ||
sysrq.rst | ||
tainted-kernels.rst | ||
thunderbolt.rst | ||
unicode.rst | ||
vga-softcursor.rst |
.. _readme: Linux kernel release 4.x <http://kernel.org/> ============================================= These are the release notes for Linux version 4. Read them carefully, as they tell you what this is all about, explain how to install the kernel, and what to do if something goes wrong. What is Linux? -------------- Linux is a clone of the operating system Unix, written from scratch by Linus Torvalds with assistance from a loosely-knit team of hackers across the Net. It aims towards POSIX and Single UNIX Specification compliance. It has all the features you would expect in a modern fully-fledged Unix, including true multitasking, virtual memory, shared libraries, demand loading, shared copy-on-write executables, proper memory management, and multistack networking including IPv4 and IPv6. It is distributed under the GNU General Public License v2 - see the accompanying COPYING file for more details. On what hardware does it run? ----------------------------- Although originally developed first for 32-bit x86-based PCs (386 or higher), today Linux also runs on (at least) the Compaq Alpha AXP, Sun SPARC and UltraSPARC, Motorola 68000, PowerPC, PowerPC64, ARM, Hitachi SuperH, Cell, IBM S/390, MIPS, HP PA-RISC, Intel IA-64, DEC VAX, AMD x86-64 Xtensa, and ARC architectures. Linux is easily portable to most general-purpose 32- or 64-bit architectures as long as they have a paged memory management unit (PMMU) and a port of the GNU C compiler (gcc) (part of The GNU Compiler Collection, GCC). Linux has also been ported to a number of architectures without a PMMU, although functionality is then obviously somewhat limited. Linux has also been ported to itself. You can now run the kernel as a userspace application - this is called UserMode Linux (UML). Documentation ------------- - There is a lot of documentation available both in electronic form on the Internet and in books, both Linux-specific and pertaining to general UNIX questions. I'd recommend looking into the documentation subdirectories on any Linux FTP site for the LDP (Linux Documentation Project) books. This README is not meant to be documentation on the system: there are much better sources available. - There are various README files in the Documentation/ subdirectory: these typically contain kernel-specific installation notes for some drivers for example. See Documentation/00-INDEX for a list of what is contained in each file. Please read the :ref:`Documentation/process/changes.rst <changes>` file, as it contains information about the problems, which may result by upgrading your kernel. Installing the kernel source ---------------------------- - If you install the full sources, put the kernel tarball in a directory where you have permissions (e.g. your home directory) and unpack it:: xz -cd linux-4.X.tar.xz | tar xvf - Replace "X" with the version number of the latest kernel. Do NOT use the /usr/src/linux area! This area has a (usually incomplete) set of kernel headers that are used by the library header files. They should match the library, and not get messed up by whatever the kernel-du-jour happens to be. - You can also upgrade between 4.x releases by patching. Patches are distributed in the xz format. To install by patching, get all the newer patch files, enter the top level directory of the kernel source (linux-4.X) and execute:: xz -cd ../patch-4.x.xz | patch -p1 Replace "x" for all versions bigger than the version "X" of your current source tree, **in_order**, and you should be ok. You may want to remove the backup files (some-file-name~ or some-file-name.orig), and make sure that there are no failed patches (some-file-name# or some-file-name.rej). If there are, either you or I have made a mistake. Unlike patches for the 4.x kernels, patches for the 4.x.y kernels (also known as the -stable kernels) are not incremental but instead apply directly to the base 4.x kernel. For example, if your base kernel is 4.0 and you want to apply the 4.0.3 patch, you must not first apply the 4.0.1 and 4.0.2 patches. Similarly, if you are running kernel version 4.0.2 and want to jump to 4.0.3, you must first reverse the 4.0.2 patch (that is, patch -R) **before** applying the 4.0.3 patch. You can read more on this in :ref:`Documentation/process/applying-patches.rst <applying_patches>`. Alternatively, the script patch-kernel can be used to automate this process. It determines the current kernel version and applies any patches found:: linux/scripts/patch-kernel linux The first argument in the command above is the location of the kernel source. Patches are applied from the current directory, but an alternative directory can be specified as the second argument. - Make sure you have no stale .o files and dependencies lying around:: cd linux make mrproper You should now have the sources correctly installed. Software requirements --------------------- Compiling and running the 4.x kernels requires up-to-date versions of various software packages. Consult :ref:`Documentation/process/changes.rst <changes>` for the minimum version numbers required and how to get updates for these packages. Beware that using excessively old versions of these packages can cause indirect errors that are very difficult to track down, so don't assume that you can just update packages when obvious problems arise during build or operation. Build directory for the kernel ------------------------------ When compiling the kernel, all output files will per default be stored together with the kernel source code. Using the option ``make O=output/dir`` allows you to specify an alternate place for the output files (including .config). Example:: kernel source code: /usr/src/linux-4.X build directory: /home/name/build/kernel To configure and build the kernel, use:: cd /usr/src/linux-4.X make O=/home/name/build/kernel menuconfig make O=/home/name/build/kernel sudo make O=/home/name/build/kernel modules_install install Please note: If the ``O=output/dir`` option is used, then it must be used for all invocations of make. Configuring the kernel ---------------------- Do not skip this step even if you are only upgrading one minor version. New configuration options are added in each release, and odd problems will turn up if the configuration files are not set up as expected. If you want to carry your existing configuration to a new version with minimal work, use ``make oldconfig``, which will only ask you for the answers to new questions. - Alternative configuration commands are:: "make config" Plain text interface. "make menuconfig" Text based color menus, radiolists & dialogs. "make nconfig" Enhanced text based color menus. "make xconfig" Qt based configuration tool. "make gconfig" GTK+ based configuration tool. "make oldconfig" Default all questions based on the contents of your existing ./.config file and asking about new config symbols. "make olddefconfig" Like above, but sets new symbols to their default values without prompting. "make defconfig" Create a ./.config file by using the default symbol values from either arch/$ARCH/defconfig or arch/$ARCH/configs/${PLATFORM}_defconfig, depending on the architecture. "make ${PLATFORM}_defconfig" Create a ./.config file by using the default symbol values from arch/$ARCH/configs/${PLATFORM}_defconfig. Use "make help" to get a list of all available platforms of your architecture. "make allyesconfig" Create a ./.config file by setting symbol values to 'y' as much as possible. "make allmodconfig" Create a ./.config file by setting symbol values to 'm' as much as possible. "make allnoconfig" Create a ./.config file by setting symbol values to 'n' as much as possible. "make randconfig" Create a ./.config file by setting symbol values to random values. "make localmodconfig" Create a config based on current config and loaded modules (lsmod). Disables any module option that is not needed for the loaded modules. To create a localmodconfig for another machine, store the lsmod of that machine into a file and pass it in as a LSMOD parameter. target$ lsmod > /tmp/mylsmod target$ scp /tmp/mylsmod host:/tmp host$ make LSMOD=/tmp/mylsmod localmodconfig The above also works when cross compiling. "make localyesconfig" Similar to localmodconfig, except it will convert all module options to built in (=y) options. "make kvmconfig" Enable additional options for kvm guest kernel support. "make xenconfig" Enable additional options for xen dom0 guest kernel support. "make tinyconfig" Configure the tiniest possible kernel. You can find more information on using the Linux kernel config tools in Documentation/kbuild/kconfig.txt. - NOTES on ``make config``: - Having unnecessary drivers will make the kernel bigger, and can under some circumstances lead to problems: probing for a nonexistent controller card may confuse your other controllers. - A kernel with math-emulation compiled in will still use the coprocessor if one is present: the math emulation will just never get used in that case. The kernel will be slightly larger, but will work on different machines regardless of whether they have a math coprocessor or not. - The "kernel hacking" configuration details usually result in a bigger or slower kernel (or both), and can even make the kernel less stable by configuring some routines to actively try to break bad code to find kernel problems (kmalloc()). Thus you should probably answer 'n' to the questions for "development", "experimental", or "debugging" features. Compiling the kernel -------------------- - Make sure you have at least gcc 3.2 available. For more information, refer to :ref:`Documentation/process/changes.rst <changes>`. Please note that you can still run a.out user programs with this kernel. - Do a ``make`` to create a compressed kernel image. It is also possible to do ``make install`` if you have lilo installed to suit the kernel makefiles, but you may want to check your particular lilo setup first. To do the actual install, you have to be root, but none of the normal build should require that. Don't take the name of root in vain. - If you configured any of the parts of the kernel as ``modules``, you will also have to do ``make modules_install``. - Verbose kernel compile/build output: Normally, the kernel build system runs in a fairly quiet mode (but not totally silent). However, sometimes you or other kernel developers need to see compile, link, or other commands exactly as they are executed. For this, use "verbose" build mode. This is done by passing ``V=1`` to the ``make`` command, e.g.:: make V=1 all To have the build system also tell the reason for the rebuild of each target, use ``V=2``. The default is ``V=0``. - Keep a backup kernel handy in case something goes wrong. This is especially true for the development releases, since each new release contains new code which has not been debugged. Make sure you keep a backup of the modules corresponding to that kernel, as well. If you are installing a new kernel with the same version number as your working kernel, make a backup of your modules directory before you do a ``make modules_install``. Alternatively, before compiling, use the kernel config option "LOCALVERSION" to append a unique suffix to the regular kernel version. LOCALVERSION can be set in the "General Setup" menu. - In order to boot your new kernel, you'll need to copy the kernel image (e.g. .../linux/arch/x86/boot/bzImage after compilation) to the place where your regular bootable kernel is found. - Booting a kernel directly from a floppy without the assistance of a bootloader such as LILO, is no longer supported. If you boot Linux from the hard drive, chances are you use LILO, which uses the kernel image as specified in the file /etc/lilo.conf. The kernel image file is usually /vmlinuz, /boot/vmlinuz, /bzImage or /boot/bzImage. To use the new kernel, save a copy of the old image and copy the new image over the old one. Then, you MUST RERUN LILO to update the loading map! If you don't, you won't be able to boot the new kernel image. Reinstalling LILO is usually a matter of running /sbin/lilo. You may wish to edit /etc/lilo.conf to specify an entry for your old kernel image (say, /vmlinux.old) in case the new one does not work. See the LILO docs for more information. After reinstalling LILO, you should be all set. Shutdown the system, reboot, and enjoy! If you ever need to change the default root device, video mode, ramdisk size, etc. in the kernel image, use the ``rdev`` program (or alternatively the LILO boot options when appropriate). No need to recompile the kernel to change these parameters. - Reboot with the new kernel and enjoy. If something goes wrong ----------------------- - If you have problems that seem to be due to kernel bugs, please check the file MAINTAINERS to see if there is a particular person associated with the part of the kernel that you are having trouble with. If there isn't anyone listed there, then the second best thing is to mail them to me (torvalds@linux-foundation.org), and possibly to any other relevant mailing-list or to the newsgroup. - In all bug-reports, *please* tell what kernel you are talking about, how to duplicate the problem, and what your setup is (use your common sense). If the problem is new, tell me so, and if the problem is old, please try to tell me when you first noticed it. - If the bug results in a message like:: unable to handle kernel paging request at address C0000010 Oops: 0002 EIP: 0010:XXXXXXXX eax: xxxxxxxx ebx: xxxxxxxx ecx: xxxxxxxx edx: xxxxxxxx esi: xxxxxxxx edi: xxxxxxxx ebp: xxxxxxxx ds: xxxx es: xxxx fs: xxxx gs: xxxx Pid: xx, process nr: xx xx xx xx xx xx xx xx xx xx xx or similar kernel debugging information on your screen or in your system log, please duplicate it *exactly*. The dump may look incomprehensible to you, but it does contain information that may help debugging the problem. The text above the dump is also important: it tells something about why the kernel dumped code (in the above example, it's due to a bad kernel pointer). More information on making sense of the dump is in Documentation/admin-guide/bug-hunting.rst - If you compiled the kernel with CONFIG_KALLSYMS you can send the dump as is, otherwise you will have to use the ``ksymoops`` program to make sense of the dump (but compiling with CONFIG_KALLSYMS is usually preferred). This utility can be downloaded from https://www.kernel.org/pub/linux/utils/kernel/ksymoops/ . Alternatively, you can do the dump lookup by hand: - In debugging dumps like the above, it helps enormously if you can look up what the EIP value means. The hex value as such doesn't help me or anybody else very much: it will depend on your particular kernel setup. What you should do is take the hex value from the EIP line (ignore the ``0010:``), and look it up in the kernel namelist to see which kernel function contains the offending address. To find out the kernel function name, you'll need to find the system binary associated with the kernel that exhibited the symptom. This is the file 'linux/vmlinux'. To extract the namelist and match it against the EIP from the kernel crash, do:: nm vmlinux | sort | less This will give you a list of kernel addresses sorted in ascending order, from which it is simple to find the function that contains the offending address. Note that the address given by the kernel debugging messages will not necessarily match exactly with the function addresses (in fact, that is very unlikely), so you can't just 'grep' the list: the list will, however, give you the starting point of each kernel function, so by looking for the function that has a starting address lower than the one you are searching for but is followed by a function with a higher address you will find the one you want. In fact, it may be a good idea to include a bit of "context" in your problem report, giving a few lines around the interesting one. If you for some reason cannot do the above (you have a pre-compiled kernel image or similar), telling me as much about your setup as possible will help. Please read the :ref:`admin-guide/reporting-bugs.rst <reportingbugs>` document for details. - Alternatively, you can use gdb on a running kernel. (read-only; i.e. you cannot change values or set break points.) To do this, first compile the kernel with -g; edit arch/x86/Makefile appropriately, then do a ``make clean``. You'll also need to enable CONFIG_PROC_FS (via ``make config``). After you've rebooted with the new kernel, do ``gdb vmlinux /proc/kcore``. You can now use all the usual gdb commands. The command to look up the point where your system crashed is ``l *0xXXXXXXXX``. (Replace the XXXes with the EIP value.) gdb'ing a non-running kernel currently fails because ``gdb`` (wrongly) disregards the starting offset for which the kernel is compiled.