kernel-fxtec-pro1x/init/Kconfig
Ivaylo Georgiev 6f910c4e90 Merge android-4.19.31 (bb418a1) into msm-4.19
* refs/heads/tmp-bb418a1:
  Linux 4.19.31
  s390/setup: fix boot crash for machine without EDAT-1
  bcache: use (REQ_META|REQ_PRIO) to indicate bio for metadata
  KVM: nVMX: Ignore limit checks on VMX instructions using flat segments
  KVM: nVMX: Apply addr size mask to effective address for VMX instructions
  KVM: nVMX: Sign extend displacements of VMX instr's mem operands
  KVM: x86/mmu: Do not cache MMIO accesses while memslots are in flux
  KVM: x86/mmu: Detect MMIO generation wrap in any address space
  KVM: Call kvm_arch_memslots_updated() before updating memslots
  drm/amd/display: don't call dm_pp_ function from an fpu block
  drm/amd/powerplay: correct power reading on fiji
  drm/radeon/evergreen_cs: fix missing break in switch statement
  drm/fb-helper: generic: Fix drm_fbdev_client_restore()
  media: imx: csi: Stop upstream before disabling IDMA channel
  media: imx: csi: Disable CSI immediately after last EOF
  media: vimc: Add vimc-streamer for stream control
  media: uvcvideo: Avoid NULL pointer dereference at the end of streaming
  media: lgdt330x: fix lock status reporting
  media: imx: prpencvf: Stop upstream before disabling IDMA channel
  rcu: Do RCU GP kthread self-wakeup from softirq and interrupt
  tpm: Unify the send callback behaviour
  tpm/tpm_crb: Avoid unaligned reads in crb_recv()
  md: Fix failed allocation of md_register_thread
  perf intel-pt: Fix divide by zero when TSC is not available
  perf/x86/intel/uncore: Fix client IMC events return huge result
  perf intel-pt: Fix overlap calculation for padding
  perf auxtrace: Define auxtrace record alignment
  perf tools: Fix split_kallsyms_for_kcore() for trampoline symbols
  perf intel-pt: Fix CYC timestamp calculation after OVF
  x86/unwind/orc: Fix ORC unwind table alignment
  vt: perform safe console erase in the right order
  stable-kernel-rules.rst: add link to networking patch queue
  bcache: never writeback a discard operation
  PM / wakeup: Rework wakeup source timer cancellation
  svcrpc: fix UDP on servers with lots of threads
  NFSv4.1: Reinitialise sequence results before retransmitting a request
  nfsd: fix wrong check in write_v4_end_grace()
  nfsd: fix memory corruption caused by readdir
  nfsd: fix performance-limiting session calculation
  NFS: Don't recoalesce on error in nfs_pageio_complete_mirror()
  NFS: Fix an I/O request leakage in nfs_do_recoalesce
  NFS: Fix I/O request leakages
  cpcap-charger: generate events for userspace
  mfd: sm501: Fix potential NULL pointer dereference
  dm integrity: limit the rate of error messages
  dm: fix to_sector() for 32bit
  ipmi_si: fix use-after-free of resource->name
  arm64: KVM: Fix architecturally invalid reset value for FPEXC32_EL2
  arm64: debug: Ensure debug handlers check triggering exception level
  arm64: Fix HCR.TGE status for NMI contexts
  ARM: s3c24xx: Fix boolean expressions in osiris_dvs_notify
  powerpc/traps: Fix the message printed when stack overflows
  powerpc/traps: fix recoverability of machine check handling on book3s/32
  powerpc/hugetlb: Don't do runtime allocation of 16G pages in LPAR configuration
  powerpc/ptrace: Simplify vr_get/set() to avoid GCC warning
  powerpc: Fix 32-bit KVM-PR lockup and host crash with MacOS guest
  powerpc/powernv: Don't reprogram SLW image on every KVM guest entry/exit
  powerpc/83xx: Also save/restore SPRG4-7 during suspend
  powerpc/powernv: Make opal log only readable by root
  powerpc/wii: properly disable use of BATs when requested.
  powerpc/32: Clear on-stack exception marker upon exception return
  security/selinux: fix SECURITY_LSM_NATIVE_LABELS on reused superblock
  selinux: add the missing walk_size + len check in selinux_sctp_bind_connect
  jbd2: fix compile warning when using JBUFFER_TRACE
  jbd2: clear dirty flag when revoking a buffer from an older transaction
  serial: 8250_pci: Have ACCES cards that use the four port Pericom PI7C9X7954 chip use the pci_pericom_setup()
  serial: 8250_pci: Fix number of ports for ACCES serial cards
  serial: 8250_of: assume reg-shift of 2 for mrvl,mmp-uart
  serial: uartps: Fix stuck ISR if RX disabled with non-empty FIFO
  bpf: only test gso type on gso packets
  drm/i915: Relax mmap VMA check
  can: flexcan: FLEXCAN_IFLAG_MB: add () around macro argument
  gpio: pca953x: Fix dereference of irq data in shutdown
  media: i2c: ov5640: Fix post-reset delay
  i2c: tegra: fix maximum transfer size
  parport_pc: fix find_superio io compare code, should use equal test.
  intel_th: Don't reference unassigned outputs
  device property: Fix the length used in PROPERTY_ENTRY_STRING()
  kernel/sysctl.c: add missing range check in do_proc_dointvec_minmax_conv
  mm/memory.c: do_fault: avoid usage of stale vm_area_struct
  mm/vmalloc: fix size check for remap_vmalloc_range_partial()
  mm: hwpoison: fix thp split handing in soft_offline_in_use_page()
  dmaengine: usb-dmac: Make DMAC system sleep callbacks explicit
  usb: typec: tps6598x: handle block writes separately with plain-I2C adapters
  usb: chipidea: tegra: Fix missed ci_hdrc_remove_device()
  clk: ingenic: Fix doc of ingenic_cgu_div_info
  clk: ingenic: Fix round_rate misbehaving with non-integer dividers
  clk: samsung: exynos5: Fix kfree() of const memory on setting driver_override
  clk: samsung: exynos5: Fix possible NULL pointer exception on platform_device_alloc() failure
  clk: clk-twl6040: Fix imprecise external abort for pdmclk
  clk: uniphier: Fix update register for CPU-gear
  ext2: Fix underflow in ext2_max_size()
  cxl: Wrap iterations over afu slices inside 'afu_list_lock'
  IB/hfi1: Close race condition on user context disable and close
  PCI: dwc: skip MSI init if MSIs have been explicitly disabled
  PCI/DPC: Fix print AER status in DPC event handling
  PCI/ASPM: Use LTR if already enabled by platform
  ext4: fix crash during online resizing
  ext4: add mask of ext4 flags to swap
  ext4: update quota information while swapping boot loader inode
  ext4: cleanup pagecache before swap i_data
  ext4: fix check of inode in swap_inode_boot_loader
  cpufreq: pxa2xx: remove incorrect __init annotation
  cpufreq: tegra124: add missing of_node_put()
  cpufreq: kryo: Release OPP tables on module removal
  x86/kprobes: Prohibit probing on optprobe template code
  irqchip/brcmstb-l2: Use _irqsave locking variants in non-interrupt code
  irqchip/gic-v3-its: Avoid parsing _indirect_ twice for Device table
  libertas_tf: don't set URB_ZERO_PACKET on IN USB transfer
  soc: qcom: rpmh: Avoid accessing freed memory from batch API
  Btrfs: fix corruption reading shared and compressed extents after hole punching
  btrfs: ensure that a DUP or RAID1 block group has exactly two stripes
  Btrfs: setup a nofs context for memory allocation at __btrfs_set_acl
  Btrfs: setup a nofs context for memory allocation at btrfs_create_tree()
  m68k: Add -ffreestanding to CFLAGS
  ovl: Do not lose security.capability xattr over metadata file copy-up
  ovl: During copy up, first copy up data and then xattrs
  splice: don't merge into linked buffers
  fs/devpts: always delete dcache dentry-s in dput()
  scsi: qla2xxx: Fix LUN discovery if loop id is not assigned yet by firmware
  scsi: target/iscsi: Avoid iscsit_release_commands_from_conn() deadlock
  scsi: sd: Optimal I/O size should be a multiple of physical block size
  scsi: aacraid: Fix performance issue on logical drives
  scsi: virtio_scsi: don't send sc payload with tmfs
  s390/virtio: handle find on invalid queue gracefully
  s390/setup: fix early warning messages
  clocksource/drivers/arch_timer: Workaround for Allwinner A64 timer instability
  clocksource/drivers/exynos_mct: Clear timer interrupt when shutdown
  clocksource/drivers/exynos_mct: Move one-shot check from tick clear to ISR
  regulator: s2mpa01: Fix step values for some LDOs
  regulator: max77620: Initialize values for DT properties
  regulator: s2mps11: Fix steps for buck7, buck8 and LDO35
  spi: pxa2xx: Setup maximum supported DMA transfer length
  spi: ti-qspi: Fix mmap read when more than one CS in use
  netfilter: ipt_CLUSTERIP: fix warning unused variable cn
  mmc:fix a bug when max_discard is 0
  mmc: sdhci-esdhc-imx: fix HS400 timing issue
  ACPI / device_sysfs: Avoid OF modalias creation for removed device
  xen: fix dom0 boot on huge systems
  tracing/perf: Use strndup_user() instead of buggy open-coded version
  tracing: Do not free iter->trace in fail path of tracing_open_pipe()
  tracing: Use strncpy instead of memcpy for string keys in hist triggers
  CIFS: Fix read after write for files with read caching
  CIFS: Do not skip SMB2 message IDs on send failures
  CIFS: Do not reset lease state to NONE on lease break
  crypto: arm64/aes-ccm - fix bugs in non-NEON fallback routine
  crypto: arm64/aes-ccm - fix logical bug in AAD MAC handling
  crypto: x86/morus - fix handling chunked inputs and MAY_SLEEP
  crypto: x86/aesni-gcm - fix crash on empty plaintext
  crypto: x86/aegis - fix handling chunked inputs and MAY_SLEEP
  crypto: testmgr - skip crc32c context test for ahash algorithms
  crypto: skcipher - set CRYPTO_TFM_NEED_KEY if ->setkey() fails
  crypto: pcbc - remove bogus memcpy()s with src == dest
  crypto: morus - fix handling chunked inputs
  crypto: hash - set CRYPTO_TFM_NEED_KEY if ->setkey() fails
  crypto: arm64/crct10dif - revert to C code for short inputs
  crypto: arm64/aes-neonbs - fix returning final keystream block
  crypto: arm/crct10dif - revert to C code for short inputs
  crypto: aegis - fix handling chunked inputs
  crypto: aead - set CRYPTO_TFM_NEED_KEY if ->setkey() fails
  fix cgroup_do_mount() handling of failure exits
  libnvdimm: Fix altmap reservation size calculation
  libnvdimm/pmem: Honor force_raw for legacy pmem regions
  libnvdimm, pfn: Fix over-trim in trim_pfn_device()
  libnvdimm/label: Clear 'updating' flag after label-set update
  nfit/ars: Attempt short-ARS even in the no_init_ars case
  nfit/ars: Attempt a short-ARS whenever the ARS state is idle at boot
  acpi/nfit: Fix bus command validation
  nfit: acpi_nfit_ctl(): Check out_obj->type in the right place
  stm class: Prevent division by zero
  tmpfs: fix uninitialized return value in shmem_link
  selftests: fib_tests: sleep after changing carrier. again.
  net: set static variable an initial value in atl2_probe()
  bnxt_en: Wait longer for the firmware message response to complete.
  bnxt_en: Fix typo in firmware message timeout logic.
  nfp: bpf: fix ALU32 high bits clearance bug
  nfp: bpf: fix code-gen bug on BPF_ALU | BPF_XOR | BPF_K
  net: thunderx: add nicvf_send_msg_to_pf result check for set_rx_mode_task
  net: thunderx: make CFG_DONE message to run through generic send-ack sequence
  bpf, lpm: fix lookup bug in map_delete_elem
  mac80211_hwsim: propagate genlmsg_reply return code
  phonet: fix building with clang
  ARCv2: don't assume core 0x54 has dual issue
  ARCv2: support manual regfile save on interrupts
  ARC: uacces: remove lp_start, lp_end from clobber list
  ARCv2: lib: memcpy: fix doing prefetchw outside of buffer
  ixgbe: fix older devices that do not support IXGBE_MRQC_L3L4TXSWEN
  tmpfs: fix link accounting when a tmpfile is linked in
  mm: handle lru_add_drain_all for UP properly
  net: marvell: mvneta: fix DMA debug warning
  ARM: tegra: Restore DT ABI on Tegra124 Chromebooks
  arm64: Relax GIC version check during early boot
  ARM: dts: armada-xp: fix Armada XP boards NAND description
  qed: Fix iWARP syn packet mac address validation.
  qed: Fix iWARP buffer size provided for syn packet processing.
  ASoC: topology: free created components in tplg load error
  mailbox: bcm-flexrm-mailbox: Fix FlexRM ring flush timeout issue
  xfrm: Fix inbound traffic via XFRM interfaces across network namespaces
  net: mv643xx_eth: disable clk on error path in mv643xx_eth_shared_probe()
  qmi_wwan: apply SET_DTR quirk to Sierra WP7607
  pinctrl: meson: meson8b: fix the sdxc_a data 1..3 pins
  net: dsa: bcm_sf2: Do not assume DSA master supports WoL
  net: systemport: Fix reception of BPDUs
  scsi: libiscsi: Fix race between iscsi_xmit_task and iscsi_complete_task
  keys: Fix dependency loop between construction record and auth key
  assoc_array: Fix shortcut creation
  ARM: 8835/1: dma-mapping: Clear DMA ops on teardown
  af_key: unconditionally clone on broadcast
  bpf: fix lockdep false positive in stackmap
  bpf: only adjust gso_size on bytestream protocols
  ARM: 8824/1: fix a migrating irq bug when hotplug cpu
  esp: Skip TX bytes accounting when sending from a request socket
  clk: sunxi: A31: Fix wrong AHB gate number
  kallsyms: Handle too long symbols in kallsyms.c
  clk: sunxi-ng: v3s: Fix TCON reset de-assert bit
  Input: st-keyscan - fix potential zalloc NULL dereference
  auxdisplay: ht16k33: fix potential user-after-free on module unload
  i2c: bcm2835: Clear current buffer pointers and counts after a transfer
  i2c: cadence: Fix the hold bit setting
  net: hns: Fix object reference leaks in hns_dsaf_roce_reset()
  mm: page_alloc: fix ref bias in page_frag_alloc() for 1-byte allocs
  x86/CPU: Add Icelake model number
  net: dsa: bcm_sf2: potential array overflow in bcm_sf2_sw_suspend()
  scsi: qla2xxx: Fix panic from use after free in qla2x00_async_tm_cmd
  Revert "mm: use early_pfn_to_nid in page_ext_init"
  mm/gup: fix gup_pmd_range() for dax
  NFS: Don't use page_file_mapping after removing the page
  xprtrdma: Make sure Send CQ is allocated on an existing compvec
  floppy: check_events callback should not return a negative number
  ipvs: fix dependency on nf_defrag_ipv6
  blk-mq: insert rq with DONTPREP to hctx dispatch list when requeue
  netfilter: compat: initialize all fields in xt_init
  mac80211: Fix Tx aggregation session tear down with ITXQs
  mac80211: call drv_ibss_join() on restart
  Input: matrix_keypad - use flush_delayed_work()
  Input: ps2-gpio - flush TX work when closing port
  Input: cap11xx - switch to using set_brightness_blocking()
  ARM: OMAP2+: fix lack of timer interrupts on CPU1 after hotplug
  ASoC: samsung: Prevent clk_get_rate() calls in atomic context
  KVM: arm64: Forbid kprobing of the VHE world-switch code
  KVM: arm/arm64: vgic: Always initialize the group of private IRQs
  arm/arm64: KVM: Don't panic on failure to properly reset system registers
  arm/arm64: KVM: Allow a VCPU to fully reset itself
  KVM: arm/arm64: Reset the VCPU without preemption and vcpu state loaded
  ASoC: rsnd: fixup rsnd_ssi_master_clk_start() user count check
  ASoC: dapm: fix out-of-bounds accesses to DAPM lookup tables
  ARM: OMAP2+: Variable "reg" in function omap4_dsi_mux_pads() could be uninitialized
  ARM: dts: Configure clock parent for pwm vibra
  Input: pwm-vibra - stop regulator after disabling pwm, not before
  Input: pwm-vibra - prevent unbalanced regulator
  s390/dasd: fix using offset into zero size array error
  arm64: dts: rockchip: fix graph_port warning on rk3399 bob kevin and excavator
  KVM: arm/arm64: vgic: Make vgic_dist->lpi_list_lock a raw_spinlock
  clocksource: timer-ti-dm: Fix pwm dmtimer usage of fck reparenting
  ASoC: rt5682: Correct the setting while select ASRC clk for AD/DA filter
  gpu: ipu-v3: Fix CSI offsets for imx53
  drm/imx: imx-ldb: add missing of_node_puts
  gpu: ipu-v3: Fix i.MX51 CSI control registers offset
  drm/imx: ignore plane updates on disabled crtcs
  crypto: rockchip - update new iv to device in multiple operations
  crypto: rockchip - fix scatterlist nents error
  crypto: ahash - fix another early termination in hash walk
  crypto: cfb - remove bogus memcpy() with src == dest
  crypto: cfb - add missing 'chunksize' property
  crypto: ccree - don't copy zero size ciphertext
  crypto: ccree - unmap buffer before copying IV
  crypto: ccree - fix free of unallocated mlli buffer
  crypto: caam - fix DMA mapping of stack memory
  crypto: caam - fixed handling of sg list
  crypto: ccree - fix missing break in switch statement
  crypto: caam - fix hash context DMA unmap size
  stm class: Fix an endless loop in channel allocation
  mei: bus: move hw module get/put to probe/release
  mei: hbm: clean the feature flags on link reset
  iio: adc: exynos-adc: Fix NULL pointer exception on unbind
  ASoC: codecs: pcm186x: Fix energysense SLEEP bit
  ASoC: codecs: pcm186x: fix wrong usage of DECLARE_TLV_DB_SCALE()
  ASoC: fsl_esai: fix register setting issue in RIGHT_J mode
  9p/net: fix memory leak in p9_client_create
  9p: use inode->i_lock to protect i_size_write() under 32-bit
  media: videobuf2-v4l2: drop WARN_ON in vb2_warn_zero_bytesused()
  ANDROID: cuttlefish_defconfig: Enable CONFIG_INPUT_MOUSEDEV
  FROMLIST: psi: introduce psi monitor
  FROMLIST: refactor header includes to allow kthread.h inclusion in psi_types.h
  FROMLIST: psi: track changed states
  FROMLIST: psi: split update_stats into parts
  FROMLIST: psi: rename psi fields in preparation for psi trigger addition
  FROMLIST: psi: make psi_enable static
  FROMLIST: psi: introduce state_mask to represent stalled psi states
  ANDROID: cuttlefish_defconfig: Enable CONFIG_PSI
  UPSTREAM: kernel: cgroup: add poll file operation
  UPSTREAM: fs: kernfs: add poll file operation
  UPSTREAM: psi: avoid divide-by-zero crash inside virtual machines
  UPSTREAM: psi: clarify the Kconfig text for the default-disable option
  UPSTREAM: psi: fix aggregation idle shut-off
  UPSTREAM: psi: fix reference to kernel commandline enable
  UPSTREAM: psi: make disabling/enabling easier for vendor kernels
  UPSTREAM: kernel/sched/psi.c: simplify cgroup_move_task()
  UPSTREAM: psi: cgroup support
  UPSTREAM: psi: pressure stall information for CPU, memory, and IO
  UPSTREAM: sched: introduce this_rq_lock_irq()
  UPSTREAM: sched: sched.h: make rq locking and clock functions available in stats.h
  UPSTREAM: sched: loadavg: make calc_load_n() public
  BACKPORT: sched: loadavg: consolidate LOAD_INT, LOAD_FRAC, CALC_LOAD
  UPSTREAM: delayacct: track delays from thrashing cache pages
  UPSTREAM: mm: workingset: tell cache transitions from workingset thrashing

Conflicts:
	arch/arm/kernel/irq.c
	drivers/scsi/sd.c
	include/linux/sched.h
	init/Kconfig
	kernel/sched/Makefile
	kernel/sched/sched.h
	kernel/workqueue.c
	sound/soc/soc-dapm.c

Change-Id: Ia2dcc01c712134c57037ca6788d51172f66bcd93
Signed-off-by: Ivaylo Georgiev <irgeorgiev@codeaurora.org>
2019-04-05 01:06:22 -07:00

2128 lines
67 KiB
Text

config DEFCONFIG_LIST
string
depends on !UML
option defconfig_list
default "/lib/modules/$(shell,uname -r)/.config"
default "/etc/kernel-config"
default "/boot/config-$(shell,uname -r)"
default ARCH_DEFCONFIG
default "arch/$(ARCH)/defconfig"
config CC_IS_GCC
def_bool $(success,$(CC) --version | head -n 1 | grep -q gcc)
config GCC_VERSION
int
default $(shell,$(srctree)/scripts/gcc-version.sh -p $(CC) | sed 's/^0*//') if CC_IS_GCC
default 0
config CC_IS_CLANG
def_bool $(success,$(CC) --version | head -n 1 | grep -q clang)
config CLANG_VERSION
int
default $(shell,$(srctree)/scripts/clang-version.sh $(CC))
config CONSTRUCTORS
bool
depends on !UML
config IRQ_WORK
bool
config BUILDTIME_EXTABLE_SORT
bool
config THREAD_INFO_IN_TASK
bool
help
Select this to move thread_info off the stack into task_struct. To
make this work, an arch will need to remove all thread_info fields
except flags and fix any runtime bugs.
One subtle change that will be needed is to use try_get_task_stack()
and put_task_stack() in save_thread_stack_tsk() and get_wchan().
menu "General setup"
config BROKEN
bool
config BROKEN_ON_SMP
bool
depends on BROKEN || !SMP
default y
config INIT_ENV_ARG_LIMIT
int
default 32 if !UML
default 128 if UML
help
Maximum of each of the number of arguments and environment
variables passed to init from the kernel command line.
config COMPILE_TEST
bool "Compile also drivers which will not load"
depends on !UML
default n
help
Some drivers can be compiled on a different platform than they are
intended to be run on. Despite they cannot be loaded there (or even
when they load they cannot be used due to missing HW support),
developers still, opposing to distributors, might want to build such
drivers to compile-test them.
If you are a developer and want to build everything available, say Y
here. If you are a user/distributor, say N here to exclude useless
drivers to be distributed.
config LOCALVERSION
string "Local version - append to kernel release"
help
Append an extra string to the end of your kernel version.
This will show up when you type uname, for example.
The string you set here will be appended after the contents of
any files with a filename matching localversion* in your
object and source tree, in that order. Your total string can
be a maximum of 64 characters.
config LOCALVERSION_AUTO
bool "Automatically append version information to the version string"
default y
depends on !COMPILE_TEST
help
This will try to automatically determine if the current tree is a
release tree by looking for git tags that belong to the current
top of tree revision.
A string of the format -gxxxxxxxx will be added to the localversion
if a git-based tree is found. The string generated by this will be
appended after any matching localversion* files, and after the value
set in CONFIG_LOCALVERSION.
(The actual string used here is the first eight characters produced
by running the command:
$ git rev-parse --verify HEAD
which is done within the script "scripts/setlocalversion".)
config BUILD_SALT
string "Build ID Salt"
default ""
help
The build ID is used to link binaries and their debug info. Setting
this option will use the value in the calculation of the build id.
This is mostly useful for distributions which want to ensure the
build is unique between builds. It's safe to leave the default.
config HAVE_KERNEL_GZIP
bool
config HAVE_KERNEL_BZIP2
bool
config HAVE_KERNEL_LZMA
bool
config HAVE_KERNEL_XZ
bool
config HAVE_KERNEL_LZO
bool
config HAVE_KERNEL_LZ4
bool
config HAVE_KERNEL_UNCOMPRESSED
bool
choice
prompt "Kernel compression mode"
default KERNEL_GZIP
depends on HAVE_KERNEL_GZIP || HAVE_KERNEL_BZIP2 || HAVE_KERNEL_LZMA || HAVE_KERNEL_XZ || HAVE_KERNEL_LZO || HAVE_KERNEL_LZ4 || HAVE_KERNEL_UNCOMPRESSED
help
The linux kernel is a kind of self-extracting executable.
Several compression algorithms are available, which differ
in efficiency, compression and decompression speed.
Compression speed is only relevant when building a kernel.
Decompression speed is relevant at each boot.
If you have any problems with bzip2 or lzma compressed
kernels, mail me (Alain Knaff) <alain@knaff.lu>. (An older
version of this functionality (bzip2 only), for 2.4, was
supplied by Christian Ludwig)
High compression options are mostly useful for users, who
are low on disk space (embedded systems), but for whom ram
size matters less.
If in doubt, select 'gzip'
config KERNEL_GZIP
bool "Gzip"
depends on HAVE_KERNEL_GZIP
help
The old and tried gzip compression. It provides a good balance
between compression ratio and decompression speed.
config KERNEL_BZIP2
bool "Bzip2"
depends on HAVE_KERNEL_BZIP2
help
Its compression ratio and speed is intermediate.
Decompression speed is slowest among the choices. The kernel
size is about 10% smaller with bzip2, in comparison to gzip.
Bzip2 uses a large amount of memory. For modern kernels you
will need at least 8MB RAM or more for booting.
config KERNEL_LZMA
bool "LZMA"
depends on HAVE_KERNEL_LZMA
help
This compression algorithm's ratio is best. Decompression speed
is between gzip and bzip2. Compression is slowest.
The kernel size is about 33% smaller with LZMA in comparison to gzip.
config KERNEL_XZ
bool "XZ"
depends on HAVE_KERNEL_XZ
help
XZ uses the LZMA2 algorithm and instruction set specific
BCJ filters which can improve compression ratio of executable
code. The size of the kernel is about 30% smaller with XZ in
comparison to gzip. On architectures for which there is a BCJ
filter (i386, x86_64, ARM, IA-64, PowerPC, and SPARC), XZ
will create a few percent smaller kernel than plain LZMA.
The speed is about the same as with LZMA: The decompression
speed of XZ is better than that of bzip2 but worse than gzip
and LZO. Compression is slow.
config KERNEL_LZO
bool "LZO"
depends on HAVE_KERNEL_LZO
help
Its compression ratio is the poorest among the choices. The kernel
size is about 10% bigger than gzip; however its speed
(both compression and decompression) is the fastest.
config KERNEL_LZ4
bool "LZ4"
depends on HAVE_KERNEL_LZ4
help
LZ4 is an LZ77-type compressor with a fixed, byte-oriented encoding.
A preliminary version of LZ4 de/compression tool is available at
<https://code.google.com/p/lz4/>.
Its compression ratio is worse than LZO. The size of the kernel
is about 8% bigger than LZO. But the decompression speed is
faster than LZO.
config KERNEL_UNCOMPRESSED
bool "None"
depends on HAVE_KERNEL_UNCOMPRESSED
help
Produce uncompressed kernel image. This option is usually not what
you want. It is useful for debugging the kernel in slow simulation
environments, where decompressing and moving the kernel is awfully
slow. This option allows early boot code to skip the decompressor
and jump right at uncompressed kernel image.
endchoice
config DEFAULT_HOSTNAME
string "Default hostname"
default "(none)"
help
This option determines the default system hostname before userspace
calls sethostname(2). The kernel traditionally uses "(none)" here,
but you may wish to use a different default here to make a minimal
system more usable with less configuration.
#
# For some reason microblaze and nios2 hard code SWAP=n. Hopefully we can
# add proper SWAP support to them, in which case this can be remove.
#
config ARCH_NO_SWAP
bool
config SWAP
bool "Support for paging of anonymous memory (swap)"
depends on MMU && BLOCK && !ARCH_NO_SWAP
default y
help
This option allows you to choose whether you want to have support
for so called swap devices or swap files in your kernel that are
used to provide more virtual memory than the actual RAM present
in your computer. If unsure say Y.
config SYSVIPC
bool "System V IPC"
---help---
Inter Process Communication is a suite of library functions and
system calls which let processes (running programs) synchronize and
exchange information. It is generally considered to be a good thing,
and some programs won't run unless you say Y here. In particular, if
you want to run the DOS emulator dosemu under Linux (read the
DOSEMU-HOWTO, available from <http://www.tldp.org/docs.html#howto>),
you'll need to say Y here.
You can find documentation about IPC with "info ipc" and also in
section 6.4 of the Linux Programmer's Guide, available from
<http://www.tldp.org/guides.html>.
config SYSVIPC_SYSCTL
bool
depends on SYSVIPC
depends on SYSCTL
default y
config POSIX_MQUEUE
bool "POSIX Message Queues"
depends on NET
---help---
POSIX variant of message queues is a part of IPC. In POSIX message
queues every message has a priority which decides about succession
of receiving it by a process. If you want to compile and run
programs written e.g. for Solaris with use of its POSIX message
queues (functions mq_*) say Y here.
POSIX message queues are visible as a filesystem called 'mqueue'
and can be mounted somewhere if you want to do filesystem
operations on message queues.
If unsure, say Y.
config POSIX_MQUEUE_SYSCTL
bool
depends on POSIX_MQUEUE
depends on SYSCTL
default y
config CROSS_MEMORY_ATTACH
bool "Enable process_vm_readv/writev syscalls"
depends on MMU
default y
help
Enabling this option adds the system calls process_vm_readv and
process_vm_writev which allow a process with the correct privileges
to directly read from or write to another process' address space.
See the man page for more details.
config USELIB
bool "uselib syscall"
def_bool ALPHA || M68K || SPARC || X86_32 || IA32_EMULATION
help
This option enables the uselib syscall, a system call used in the
dynamic linker from libc5 and earlier. glibc does not use this
system call. If you intend to run programs built on libc5 or
earlier, you may need to enable this syscall. Current systems
running glibc can safely disable this.
config AUDIT
bool "Auditing support"
depends on NET
help
Enable auditing infrastructure that can be used with another
kernel subsystem, such as SELinux (which requires this for
logging of avc messages output). Does not do system-call
auditing without CONFIG_AUDITSYSCALL.
config HAVE_ARCH_AUDITSYSCALL
bool
config AUDITSYSCALL
bool "Enable system-call auditing support"
depends on AUDIT && HAVE_ARCH_AUDITSYSCALL
default y if SECURITY_SELINUX
help
Enable low-overhead system-call auditing infrastructure that
can be used independently or with another kernel subsystem,
such as SELinux.
config AUDIT_WATCH
def_bool y
depends on AUDITSYSCALL
select FSNOTIFY
config AUDIT_TREE
def_bool y
depends on AUDITSYSCALL
select FSNOTIFY
source "kernel/irq/Kconfig"
source "kernel/time/Kconfig"
source "kernel/Kconfig.preempt"
menu "CPU/Task time and stats accounting"
config VIRT_CPU_ACCOUNTING
bool
choice
prompt "Cputime accounting"
default TICK_CPU_ACCOUNTING if !PPC64
default VIRT_CPU_ACCOUNTING_NATIVE if PPC64
# Kind of a stub config for the pure tick based cputime accounting
config TICK_CPU_ACCOUNTING
bool "Simple tick based cputime accounting"
depends on !S390 && !NO_HZ_FULL
help
This is the basic tick based cputime accounting that maintains
statistics about user, system and idle time spent on per jiffies
granularity.
If unsure, say Y.
config VIRT_CPU_ACCOUNTING_NATIVE
bool "Deterministic task and CPU time accounting"
depends on HAVE_VIRT_CPU_ACCOUNTING && !NO_HZ_FULL
select VIRT_CPU_ACCOUNTING
help
Select this option to enable more accurate task and CPU time
accounting. This is done by reading a CPU counter on each
kernel entry and exit and on transitions within the kernel
between system, softirq and hardirq state, so there is a
small performance impact. In the case of s390 or IBM POWER > 5,
this also enables accounting of stolen time on logically-partitioned
systems.
config VIRT_CPU_ACCOUNTING_GEN
bool "Full dynticks CPU time accounting"
depends on HAVE_CONTEXT_TRACKING
depends on HAVE_VIRT_CPU_ACCOUNTING_GEN
select VIRT_CPU_ACCOUNTING
select CONTEXT_TRACKING
help
Select this option to enable task and CPU time accounting on full
dynticks systems. This accounting is implemented by watching every
kernel-user boundaries using the context tracking subsystem.
The accounting is thus performed at the expense of some significant
overhead.
For now this is only useful if you are working on the full
dynticks subsystem development.
If unsure, say N.
endchoice
config IRQ_TIME_ACCOUNTING
bool "Fine granularity task level IRQ time accounting"
depends on HAVE_IRQ_TIME_ACCOUNTING && !VIRT_CPU_ACCOUNTING_NATIVE
help
Select this option to enable fine granularity task irq time
accounting. This is done by reading a timestamp on each
transitions between softirq and hardirq state, so there can be a
small performance impact.
If in doubt, say N here.
config SCHED_WALT
bool "Support window based load tracking"
depends on SMP
help
This feature will allow the scheduler to maintain a tunable window
based set of metrics for tasks and runqueues. These metrics can be
used to guide task placement as well as task frequency requirements
for cpufreq governors.
config HAVE_SCHED_AVG_IRQ
def_bool y
depends on IRQ_TIME_ACCOUNTING || PARAVIRT_TIME_ACCOUNTING
depends on SMP
config BSD_PROCESS_ACCT
bool "BSD Process Accounting"
depends on MULTIUSER
help
If you say Y here, a user level program will be able to instruct the
kernel (via a special system call) to write process accounting
information to a file: whenever a process exits, information about
that process will be appended to the file by the kernel. The
information includes things such as creation time, owning user,
command name, memory usage, controlling terminal etc. (the complete
list is in the struct acct in <file:include/linux/acct.h>). It is
up to the user level program to do useful things with this
information. This is generally a good idea, so say Y.
config BSD_PROCESS_ACCT_V3
bool "BSD Process Accounting version 3 file format"
depends on BSD_PROCESS_ACCT
default n
help
If you say Y here, the process accounting information is written
in a new file format that also logs the process IDs of each
process and its parent. Note that this file format is incompatible
with previous v0/v1/v2 file formats, so you will need updated tools
for processing it. A preliminary version of these tools is available
at <http://www.gnu.org/software/acct/>.
config TASKSTATS
bool "Export task/process statistics through netlink"
depends on NET
depends on MULTIUSER
default n
help
Export selected statistics for tasks/processes through the
generic netlink interface. Unlike BSD process accounting, the
statistics are available during the lifetime of tasks/processes as
responses to commands. Like BSD accounting, they are sent to user
space on task exit.
Say N if unsure.
config TASK_DELAY_ACCT
bool "Enable per-task delay accounting"
depends on TASKSTATS
select SCHED_INFO
help
Collect information on time spent by a task waiting for system
resources like cpu, synchronous block I/O completion and swapping
in pages. Such statistics can help in setting a task's priorities
relative to other tasks for cpu, io, rss limits etc.
Say N if unsure.
config TASK_XACCT
bool "Enable extended accounting over taskstats"
depends on TASKSTATS
help
Collect extended task accounting data and send the data
to userland for processing over the taskstats interface.
Say N if unsure.
config TASK_IO_ACCOUNTING
bool "Enable per-task storage I/O accounting"
depends on TASK_XACCT
help
Collect information on the number of bytes of storage I/O which this
task has caused.
Say N if unsure.
config PSI
bool "Pressure stall information tracking"
help
Collect metrics that indicate how overcommitted the CPU, memory,
and IO capacity are in the system.
If you say Y here, the kernel will create /proc/pressure/ with the
pressure statistics files cpu, memory, and io. These will indicate
the share of walltime in which some or all tasks in the system are
delayed due to contention of the respective resource.
In kernels with cgroup support, cgroups (cgroup2 only) will
have cpu.pressure, memory.pressure, and io.pressure files,
which aggregate pressure stalls for the grouped tasks only.
For more details see Documentation/accounting/psi.txt.
Say N if unsure.
config PSI_DEFAULT_DISABLED
bool "Require boot parameter to enable pressure stall information tracking"
default n
depends on PSI
help
If set, pressure stall information tracking will be disabled
per default but can be enabled through passing psi=1 on the
kernel commandline during boot.
This feature adds some code to the task wakeup and sleep
paths of the scheduler. The overhead is too low to affect
common scheduling-intense workloads in practice (such as
webservers, memcache), but it does show up in artificial
scheduler stress tests, such as hackbench.
If you are paranoid and not sure what the kernel will be
used for, say Y.
Say N if unsure.
endmenu # "CPU/Task time and stats accounting"
config CPU_ISOLATION
bool "CPU isolation"
depends on SMP || COMPILE_TEST
default y
help
Make sure that CPUs running critical tasks are not disturbed by
any source of "noise" such as unbound workqueues, timers, kthreads...
Unbound jobs get offloaded to housekeeping CPUs. This is driven by
the "isolcpus=" boot parameter.
Say Y if unsure.
source "kernel/rcu/Kconfig"
config BUILD_BIN2C
bool
default n
config IKCONFIG
tristate "Kernel .config support"
select BUILD_BIN2C
---help---
This option enables the complete Linux kernel ".config" file
contents to be saved in the kernel. It provides documentation
of which kernel options are used in a running kernel or in an
on-disk kernel. This information can be extracted from the kernel
image file with the script scripts/extract-ikconfig and used as
input to rebuild the current kernel or to build another kernel.
It can also be extracted from a running kernel by reading
/proc/config.gz if enabled (below).
config IKCONFIG_PROC
bool "Enable access to .config through /proc/config.gz"
depends on IKCONFIG && PROC_FS
---help---
This option enables access to the kernel configuration file
through /proc/config.gz.
config LOG_BUF_SHIFT
int "Kernel log buffer size (16 => 64KB, 17 => 128KB)"
range 12 25
default 17
depends on PRINTK
help
Select the minimal kernel log buffer size as a power of 2.
The final size is affected by LOG_CPU_MAX_BUF_SHIFT config
parameter, see below. Any higher size also might be forced
by "log_buf_len" boot parameter.
Examples:
17 => 128 KB
16 => 64 KB
15 => 32 KB
14 => 16 KB
13 => 8 KB
12 => 4 KB
config CONSOLE_FLUSH_ON_HOTPLUG
bool "Enable console flush configurable in hot plug code path"
depends on HOTPLUG_CPU
def_bool n
help
In cpu hot plug path console lock acquire and release causes the
console to flush. If console lock is not free hot plug latency
increases. So make console flush configurable in hot plug path
and default disabled to help in cpu hot plug latencies.
config LOG_CPU_MAX_BUF_SHIFT
int "CPU kernel log buffer size contribution (13 => 8 KB, 17 => 128KB)"
depends on SMP
range 0 21
default 12 if !BASE_SMALL
default 0 if BASE_SMALL
depends on PRINTK
help
This option allows to increase the default ring buffer size
according to the number of CPUs. The value defines the contribution
of each CPU as a power of 2. The used space is typically only few
lines however it might be much more when problems are reported,
e.g. backtraces.
The increased size means that a new buffer has to be allocated and
the original static one is unused. It makes sense only on systems
with more CPUs. Therefore this value is used only when the sum of
contributions is greater than the half of the default kernel ring
buffer as defined by LOG_BUF_SHIFT. The default values are set
so that more than 64 CPUs are needed to trigger the allocation.
Also this option is ignored when "log_buf_len" kernel parameter is
used as it forces an exact (power of two) size of the ring buffer.
The number of possible CPUs is used for this computation ignoring
hotplugging making the computation optimal for the worst case
scenario while allowing a simple algorithm to be used from bootup.
Examples shift values and their meaning:
17 => 128 KB for each CPU
16 => 64 KB for each CPU
15 => 32 KB for each CPU
14 => 16 KB for each CPU
13 => 8 KB for each CPU
12 => 4 KB for each CPU
config PRINTK_SAFE_LOG_BUF_SHIFT
int "Temporary per-CPU printk log buffer size (12 => 4KB, 13 => 8KB)"
range 10 21
default 13
depends on PRINTK
help
Select the size of an alternate printk per-CPU buffer where messages
printed from usafe contexts are temporary stored. One example would
be NMI messages, another one - printk recursion. The messages are
copied to the main log buffer in a safe context to avoid a deadlock.
The value defines the size as a power of 2.
Those messages are rare and limited. The largest one is when
a backtrace is printed. It usually fits into 4KB. Select
8KB if you want to be on the safe side.
Examples:
17 => 128 KB for each CPU
16 => 64 KB for each CPU
15 => 32 KB for each CPU
14 => 16 KB for each CPU
13 => 8 KB for each CPU
12 => 4 KB for each CPU
#
# Architectures with an unreliable sched_clock() should select this:
#
config HAVE_UNSTABLE_SCHED_CLOCK
bool
config GENERIC_SCHED_CLOCK
bool
#
# For architectures that want to enable the support for NUMA-affine scheduler
# balancing logic:
#
config ARCH_SUPPORTS_NUMA_BALANCING
bool
#
# For architectures that prefer to flush all TLBs after a number of pages
# are unmapped instead of sending one IPI per page to flush. The architecture
# must provide guarantees on what happens if a clean TLB cache entry is
# written after the unmap. Details are in mm/rmap.c near the check for
# should_defer_flush. The architecture should also consider if the full flush
# and the refill costs are offset by the savings of sending fewer IPIs.
config ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
bool
#
# For architectures that know their GCC __int128 support is sound
#
config ARCH_SUPPORTS_INT128
bool
# For architectures that (ab)use NUMA to represent different memory regions
# all cpu-local but of different latencies, such as SuperH.
#
config ARCH_WANT_NUMA_VARIABLE_LOCALITY
bool
config NUMA_BALANCING
bool "Memory placement aware NUMA scheduler"
depends on ARCH_SUPPORTS_NUMA_BALANCING
depends on !ARCH_WANT_NUMA_VARIABLE_LOCALITY
depends on SMP && NUMA && MIGRATION
help
This option adds support for automatic NUMA aware memory/task placement.
The mechanism is quite primitive and is based on migrating memory when
it has references to the node the task is running on.
This system will be inactive on UMA systems.
config NUMA_BALANCING_DEFAULT_ENABLED
bool "Automatically enable NUMA aware memory/task placement"
default y
depends on NUMA_BALANCING
help
If set, automatic NUMA balancing will be enabled if running on a NUMA
machine.
menuconfig CGROUPS
bool "Control Group support"
select KERNFS
help
This option adds support for grouping sets of processes together, for
use with process control subsystems such as Cpusets, CFS, memory
controls or device isolation.
See
- Documentation/scheduler/sched-design-CFS.txt (CFS)
- Documentation/cgroup-v1/ (features for grouping, isolation
and resource control)
Say N if unsure.
if CGROUPS
config PAGE_COUNTER
bool
config MEMCG
bool "Memory controller"
select PAGE_COUNTER
select EVENTFD
help
Provides control over the memory footprint of tasks in a cgroup.
config MEMCG_SWAP
bool "Swap controller"
depends on MEMCG && SWAP
help
Provides control over the swap space consumed by tasks in a cgroup.
config MEMCG_SWAP_ENABLED
bool "Swap controller enabled by default"
depends on MEMCG_SWAP
default y
help
Memory Resource Controller Swap Extension comes with its price in
a bigger memory consumption. General purpose distribution kernels
which want to enable the feature but keep it disabled by default
and let the user enable it by swapaccount=1 boot command line
parameter should have this option unselected.
For those who want to have the feature enabled by default should
select this option (if, for some reason, they need to disable it
then swapaccount=0 does the trick).
config MEMCG_KMEM
bool
depends on MEMCG && !SLOB
default y
config BLK_CGROUP
bool "IO controller"
depends on BLOCK
default n
---help---
Generic block IO controller cgroup interface. This is the common
cgroup interface which should be used by various IO controlling
policies.
Currently, CFQ IO scheduler uses it to recognize task groups and
control disk bandwidth allocation (proportional time slice allocation)
to such task groups. It is also used by bio throttling logic in
block layer to implement upper limit in IO rates on a device.
This option only enables generic Block IO controller infrastructure.
One needs to also enable actual IO controlling logic/policy. For
enabling proportional weight division of disk bandwidth in CFQ, set
CONFIG_CFQ_GROUP_IOSCHED=y; for enabling throttling policy, set
CONFIG_BLK_DEV_THROTTLING=y.
See Documentation/cgroup-v1/blkio-controller.txt for more information.
config DEBUG_BLK_CGROUP
bool "IO controller debugging"
depends on BLK_CGROUP
default n
---help---
Enable some debugging help. Currently it exports additional stat
files in a cgroup which can be useful for debugging.
config CGROUP_WRITEBACK
bool
depends on MEMCG && BLK_CGROUP
default y
menuconfig CGROUP_SCHED
bool "CPU controller"
default n
help
This feature lets CPU scheduler recognize task groups and control CPU
bandwidth allocation to such task groups. It uses cgroups to group
tasks.
if CGROUP_SCHED
config FAIR_GROUP_SCHED
bool "Group scheduling for SCHED_OTHER"
depends on CGROUP_SCHED
default CGROUP_SCHED
config CFS_BANDWIDTH
bool "CPU bandwidth provisioning for FAIR_GROUP_SCHED"
depends on FAIR_GROUP_SCHED
default n
help
This option allows users to define CPU bandwidth rates (limits) for
tasks running within the fair group scheduler. Groups with no limit
set are considered to be unconstrained and will run with no
restriction.
See Documentation/scheduler/sched-bwc.txt for more information.
config RT_GROUP_SCHED
bool "Group scheduling for SCHED_RR/FIFO"
depends on CGROUP_SCHED
default n
help
This feature lets you explicitly allocate real CPU bandwidth
to task groups. If enabled, it will also make it impossible to
schedule realtime tasks for non-root users until you allocate
realtime bandwidth for them.
See Documentation/scheduler/sched-rt-group.txt for more information.
endif #CGROUP_SCHED
config CGROUP_PIDS
bool "PIDs controller"
help
Provides enforcement of process number limits in the scope of a
cgroup. Any attempt to fork more processes than is allowed in the
cgroup will fail. PIDs are fundamentally a global resource because it
is fairly trivial to reach PID exhaustion before you reach even a
conservative kmemcg limit. As a result, it is possible to grind a
system to halt without being limited by other cgroup policies. The
PIDs controller is designed to stop this from happening.
It should be noted that organisational operations (such as attaching
to a cgroup hierarchy will *not* be blocked by the PIDs controller),
since the PIDs limit only affects a process's ability to fork, not to
attach to a cgroup.
config CGROUP_RDMA
bool "RDMA controller"
help
Provides enforcement of RDMA resources defined by IB stack.
It is fairly easy for consumers to exhaust RDMA resources, which
can result into resource unavailability to other consumers.
RDMA controller is designed to stop this from happening.
Attaching processes with active RDMA resources to the cgroup
hierarchy is allowed even if can cross the hierarchy's limit.
config CGROUP_FREEZER
bool "Freezer controller"
help
Provides a way to freeze and unfreeze all tasks in a
cgroup.
This option affects the ORIGINAL cgroup interface. The cgroup2 memory
controller includes important in-kernel memory consumers per default.
If you're using cgroup2, say N.
config CGROUP_HUGETLB
bool "HugeTLB controller"
depends on HUGETLB_PAGE
select PAGE_COUNTER
default n
help
Provides a cgroup controller for HugeTLB pages.
When you enable this, you can put a per cgroup limit on HugeTLB usage.
The limit is enforced during page fault. Since HugeTLB doesn't
support page reclaim, enforcing the limit at page fault time implies
that, the application will get SIGBUS signal if it tries to access
HugeTLB pages beyond its limit. This requires the application to know
beforehand how much HugeTLB pages it would require for its use. The
control group is tracked in the third page lru pointer. This means
that we cannot use the controller with huge page less than 3 pages.
config CPUSETS
bool "Cpuset controller"
depends on SMP
help
This option will let you create and manage CPUSETs which
allow dynamically partitioning a system into sets of CPUs and
Memory Nodes and assigning tasks to run only within those sets.
This is primarily useful on large SMP or NUMA systems.
Say N if unsure.
config PROC_PID_CPUSET
bool "Include legacy /proc/<pid>/cpuset file"
depends on CPUSETS
default y
config CGROUP_DEVICE
bool "Device controller"
help
Provides a cgroup controller implementing whitelists for
devices which a process in the cgroup can mknod or open.
config CGROUP_CPUACCT
bool "Simple CPU accounting controller"
help
Provides a simple controller for monitoring the
total CPU consumed by the tasks in a cgroup.
config CGROUP_PERF
bool "Perf controller"
depends on PERF_EVENTS
help
This option extends the perf per-cpu mode to restrict monitoring
to threads which belong to the cgroup specified and run on the
designated cpu.
Say N if unsure.
config CGROUP_BPF
bool "Support for eBPF programs attached to cgroups"
depends on BPF_SYSCALL
select SOCK_CGROUP_DATA
help
Allow attaching eBPF programs to a cgroup using the bpf(2)
syscall command BPF_PROG_ATTACH.
In which context these programs are accessed depends on the type
of attachment. For instance, programs that are attached using
BPF_CGROUP_INET_INGRESS will be executed on the ingress path of
inet sockets.
config CGROUP_DEBUG
bool "Debug controller"
default n
depends on DEBUG_KERNEL
help
This option enables a simple controller that exports
debugging information about the cgroups framework. This
controller is for control cgroup debugging only. Its
interfaces are not stable.
Say N.
config SOCK_CGROUP_DATA
bool
default n
endif # CGROUPS
config SCHED_CORE_CTL
bool "QTI Core Control"
depends on SMP && SCHED_WALT
help
This options enables the core control functionality in
the scheduler. Core control automatically offline and
online cores based on cpu load and utilization.
If unsure, say N here.
menuconfig NAMESPACES
bool "Namespaces support" if EXPERT
depends on MULTIUSER
default !EXPERT
help
Provides the way to make tasks work with different objects using
the same id. For example same IPC id may refer to different objects
or same user id or pid may refer to different tasks when used in
different namespaces.
if NAMESPACES
config UTS_NS
bool "UTS namespace"
default y
help
In this namespace tasks see different info provided with the
uname() system call
config IPC_NS
bool "IPC namespace"
depends on (SYSVIPC || POSIX_MQUEUE)
default y
help
In this namespace tasks work with IPC ids which correspond to
different IPC objects in different namespaces.
config USER_NS
bool "User namespace"
default n
help
This allows containers, i.e. vservers, to use user namespaces
to provide different user info for different servers.
When user namespaces are enabled in the kernel it is
recommended that the MEMCG option also be enabled and that
user-space use the memory control groups to limit the amount
of memory a memory unprivileged users can use.
If unsure, say N.
config PID_NS
bool "PID Namespaces"
default y
help
Support process id namespaces. This allows having multiple
processes with the same pid as long as they are in different
pid namespaces. This is a building block of containers.
config NET_NS
bool "Network namespace"
depends on NET
default y
help
Allow user space to create what appear to be multiple instances
of the network stack.
endif # NAMESPACES
config CHECKPOINT_RESTORE
bool "Checkpoint/restore support"
select PROC_CHILDREN
default n
help
Enables additional kernel features in a sake of checkpoint/restore.
In particular it adds auxiliary prctl codes to setup process text,
data and heap segment sizes, and a few additional /proc filesystem
entries.
If unsure, say N here.
config SCHED_AUTOGROUP
bool "Automatic process group scheduling"
select CGROUPS
select CGROUP_SCHED
select FAIR_GROUP_SCHED
help
This option optimizes the scheduler for common desktop workloads by
automatically creating and populating task groups. This separation
of workloads isolates aggressive CPU burners (like build jobs) from
desktop applications. Task group autogeneration is currently based
upon task session.
config SCHED_TUNE
bool "Boosting for CFS tasks (EXPERIMENTAL)"
depends on SMP
help
This option enables support for task classification using a new
cgroup controller, schedtune. Schedtune allows tasks to be given
a boost value and marked as latency-sensitive or not. This option
provides the "schedtune" controller.
This new controller:
1. allows only a two layers hierarchy, where the root defines the
system-wide boost value and its direct childrens define each one a
different "class of tasks" to be boosted with a different value
2. supports up to 16 different task classes, each one which could be
configured with a different boost value
Latency-sensitive tasks are not subject to energy-aware wakeup
task placement. The boost value assigned to tasks is used to
influence task placement and CPU frequency selection (if
utilization-driven frequency selection is in use).
If unsure, say N.
config SYSFS_DEPRECATED
bool "Enable deprecated sysfs features to support old userspace tools"
depends on SYSFS
default n
help
This option adds code that switches the layout of the "block" class
devices, to not show up in /sys/class/block/, but only in
/sys/block/.
This switch is only active when the sysfs.deprecated=1 boot option is
passed or the SYSFS_DEPRECATED_V2 option is set.
This option allows new kernels to run on old distributions and tools,
which might get confused by /sys/class/block/. Since 2007/2008 all
major distributions and tools handle this just fine.
Recent distributions and userspace tools after 2009/2010 depend on
the existence of /sys/class/block/, and will not work with this
option enabled.
Only if you are using a new kernel on an old distribution, you might
need to say Y here.
config SYSFS_DEPRECATED_V2
bool "Enable deprecated sysfs features by default"
default n
depends on SYSFS
depends on SYSFS_DEPRECATED
help
Enable deprecated sysfs by default.
See the CONFIG_SYSFS_DEPRECATED option for more details about this
option.
Only if you are using a new kernel on an old distribution, you might
need to say Y here. Even then, odds are you would not need it
enabled, you can always pass the boot option if absolutely necessary.
config RELAY
bool "Kernel->user space relay support (formerly relayfs)"
select IRQ_WORK
help
This option enables support for relay interface support in
certain file systems (such as debugfs).
It is designed to provide an efficient mechanism for tools and
facilities to relay large amounts of data from kernel space to
user space.
If unsure, say N.
config BLK_DEV_INITRD
bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support"
help
The initial RAM filesystem is a ramfs which is loaded by the
boot loader (loadlin or lilo) and that is mounted as root
before the normal boot procedure. It is typically used to
load modules needed to mount the "real" root file system,
etc. See <file:Documentation/admin-guide/initrd.rst> for details.
If RAM disk support (BLK_DEV_RAM) is also included, this
also enables initial RAM disk (initrd) support and adds
15 Kbytes (more on some other architectures) to the kernel size.
If unsure say Y.
if BLK_DEV_INITRD
source "usr/Kconfig"
endif
choice
prompt "Compiler optimization level"
default CC_OPTIMIZE_FOR_PERFORMANCE
config CC_OPTIMIZE_FOR_PERFORMANCE
bool "Optimize for performance"
help
This is the default optimization level for the kernel, building
with the "-O2" compiler flag for best performance and most
helpful compile-time warnings.
config CC_OPTIMIZE_FOR_SIZE
bool "Optimize for size"
help
Enabling this option will pass "-Os" instead of "-O2" to
your compiler resulting in a smaller kernel.
If unsure, say N.
endchoice
config HAVE_LD_DEAD_CODE_DATA_ELIMINATION
bool
help
This requires that the arch annotates or otherwise protects
its external entry points from being discarded. Linker scripts
must also merge .text.*, .data.*, and .bss.* correctly into
output sections. Care must be taken not to pull in unrelated
sections (e.g., '.text.init'). Typically '.' in section names
is used to distinguish them from label names / C identifiers.
config LD_DEAD_CODE_DATA_ELIMINATION
bool "Dead code and data elimination (EXPERIMENTAL)"
depends on HAVE_LD_DEAD_CODE_DATA_ELIMINATION
depends on EXPERT
depends on !(FUNCTION_TRACER && CC_IS_GCC && GCC_VERSION < 40800)
depends on $(cc-option,-ffunction-sections -fdata-sections)
depends on $(ld-option,--gc-sections)
help
Enable this if you want to do dead code and data elimination with
the linker by compiling with -ffunction-sections -fdata-sections,
and linking with --gc-sections.
This can reduce on disk and in-memory size of the kernel
code and static data, particularly for small configs and
on small systems. This has the possibility of introducing
silently broken kernel if the required annotations are not
present. This option is not well tested yet, so use at your
own risk.
config SYSCTL
bool
config ANON_INODES
bool
config HAVE_UID16
bool
config SYSCTL_EXCEPTION_TRACE
bool
help
Enable support for /proc/sys/debug/exception-trace.
config SYSCTL_ARCH_UNALIGN_NO_WARN
bool
help
Enable support for /proc/sys/kernel/ignore-unaligned-usertrap
Allows arch to define/use @no_unaligned_warning to possibly warn
about unaligned access emulation going on under the hood.
config SYSCTL_ARCH_UNALIGN_ALLOW
bool
help
Enable support for /proc/sys/kernel/unaligned-trap
Allows arches to define/use @unaligned_enabled to runtime toggle
the unaligned access emulation.
see arch/parisc/kernel/unaligned.c for reference
config HAVE_PCSPKR_PLATFORM
bool
# interpreter that classic socket filters depend on
config BPF
bool
menuconfig EXPERT
bool "Configure standard kernel features (expert users)"
# Unhide debug options, to make the on-by-default options visible
select DEBUG_KERNEL
help
This option allows certain base kernel options and settings
to be disabled or tweaked. This is for specialized
environments which can tolerate a "non-standard" kernel.
Only use this if you really know what you are doing.
config UID16
bool "Enable 16-bit UID system calls" if EXPERT
depends on HAVE_UID16 && MULTIUSER
default y
help
This enables the legacy 16-bit UID syscall wrappers.
config MULTIUSER
bool "Multiple users, groups and capabilities support" if EXPERT
default y
help
This option enables support for non-root users, groups and
capabilities.
If you say N here, all processes will run with UID 0, GID 0, and all
possible capabilities. Saying N here also compiles out support for
system calls related to UIDs, GIDs, and capabilities, such as setuid,
setgid, and capset.
If unsure, say Y here.
config SGETMASK_SYSCALL
bool "sgetmask/ssetmask syscalls support" if EXPERT
def_bool PARISC || M68K || PPC || MIPS || X86 || SPARC || MICROBLAZE || SUPERH
---help---
sys_sgetmask and sys_ssetmask are obsolete system calls
no longer supported in libc but still enabled by default in some
architectures.
If unsure, leave the default option here.
config SYSFS_SYSCALL
bool "Sysfs syscall support" if EXPERT
default y
---help---
sys_sysfs is an obsolete system call no longer supported in libc.
Note that disabling this option is more secure but might break
compatibility with some systems.
If unsure say Y here.
config SYSCTL_SYSCALL
bool "Sysctl syscall support" if EXPERT
depends on PROC_SYSCTL
default n
select SYSCTL
---help---
sys_sysctl uses binary paths that have been found challenging
to properly maintain and use. The interface in /proc/sys
using paths with ascii names is now the primary path to this
information.
Almost nothing using the binary sysctl interface so if you are
trying to save some space it is probably safe to disable this,
making your kernel marginally smaller.
If unsure say N here.
config FHANDLE
bool "open by fhandle syscalls" if EXPERT
select EXPORTFS
default y
help
If you say Y here, a user level program will be able to map
file names to handle and then later use the handle for
different file system operations. This is useful in implementing
userspace file servers, which now track files using handles instead
of names. The handle would remain the same even if file names
get renamed. Enables open_by_handle_at(2) and name_to_handle_at(2)
syscalls.
config POSIX_TIMERS
bool "Posix Clocks & timers" if EXPERT
default y
help
This includes native support for POSIX timers to the kernel.
Some embedded systems have no use for them and therefore they
can be configured out to reduce the size of the kernel image.
When this option is disabled, the following syscalls won't be
available: timer_create, timer_gettime: timer_getoverrun,
timer_settime, timer_delete, clock_adjtime, getitimer,
setitimer, alarm. Furthermore, the clock_settime, clock_gettime,
clock_getres and clock_nanosleep syscalls will be limited to
CLOCK_REALTIME, CLOCK_MONOTONIC and CLOCK_BOOTTIME only.
If unsure say y.
config PRINTK
default y
bool "Enable support for printk" if EXPERT
select IRQ_WORK
help
This option enables normal printk support. Removing it
eliminates most of the message strings from the kernel image
and makes the kernel more or less silent. As this makes it
very difficult to diagnose system problems, saying N here is
strongly discouraged.
config PRINTK_NMI
def_bool y
depends on PRINTK
depends on HAVE_NMI
config BUG
bool "BUG() support" if EXPERT
default y
help
Disabling this option eliminates support for BUG and WARN, reducing
the size of your kernel image and potentially quietly ignoring
numerous fatal conditions. You should only consider disabling this
option for embedded systems with no facilities for reporting errors.
Just say Y.
config ELF_CORE
depends on COREDUMP
default y
bool "Enable ELF core dumps" if EXPERT
help
Enable support for generating core dumps. Disabling saves about 4k.
config PCSPKR_PLATFORM
bool "Enable PC-Speaker support" if EXPERT
depends on HAVE_PCSPKR_PLATFORM
select I8253_LOCK
default y
help
This option allows to disable the internal PC-Speaker
support, saving some memory.
config BASE_FULL
default y
bool "Enable full-sized data structures for core" if EXPERT
help
Disabling this option reduces the size of miscellaneous core
kernel data structures. This saves memory on small machines,
but may reduce performance.
config FUTEX
bool "Enable futex support" if EXPERT
default y
imply RT_MUTEXES
help
Disabling this option will cause the kernel to be built without
support for "fast userspace mutexes". The resulting kernel may not
run glibc-based applications correctly.
config FUTEX_PI
bool
depends on FUTEX && RT_MUTEXES
default y
config HAVE_FUTEX_CMPXCHG
bool
depends on FUTEX
help
Architectures should select this if futex_atomic_cmpxchg_inatomic()
is implemented and always working. This removes a couple of runtime
checks.
config EPOLL
bool "Enable eventpoll support" if EXPERT
default y
select ANON_INODES
help
Disabling this option will cause the kernel to be built without
support for epoll family of system calls.
config SIGNALFD
bool "Enable signalfd() system call" if EXPERT
select ANON_INODES
default y
help
Enable the signalfd() system call that allows to receive signals
on a file descriptor.
If unsure, say Y.
config TIMERFD
bool "Enable timerfd() system call" if EXPERT
select ANON_INODES
default y
help
Enable the timerfd() system call that allows to receive timer
events on a file descriptor.
If unsure, say Y.
config EVENTFD
bool "Enable eventfd() system call" if EXPERT
select ANON_INODES
default y
help
Enable the eventfd() system call that allows to receive both
kernel notification (ie. KAIO) or userspace notifications.
If unsure, say Y.
config SHMEM
bool "Use full shmem filesystem" if EXPERT
default y
depends on MMU
help
The shmem is an internal filesystem used to manage shared memory.
It is backed by swap and manages resource limits. It is also exported
to userspace as tmpfs if TMPFS is enabled. Disabling this
option replaces shmem and tmpfs with the much simpler ramfs code,
which may be appropriate on small systems without swap.
config AIO
bool "Enable AIO support" if EXPERT
default y
help
This option enables POSIX asynchronous I/O which may by used
by some high performance threaded applications. Disabling
this option saves about 7k.
config ADVISE_SYSCALLS
bool "Enable madvise/fadvise syscalls" if EXPERT
default y
help
This option enables the madvise and fadvise syscalls, used by
applications to advise the kernel about their future memory or file
usage, improving performance. If building an embedded system where no
applications use these syscalls, you can disable this option to save
space.
config MEMBARRIER
bool "Enable membarrier() system call" if EXPERT
default y
help
Enable the membarrier() system call that allows issuing memory
barriers across all running threads, which can be used to distribute
the cost of user-space memory barriers asymmetrically by transforming
pairs of memory barriers into pairs consisting of membarrier() and a
compiler barrier.
If unsure, say Y.
config KALLSYMS
bool "Load all symbols for debugging/ksymoops" if EXPERT
default y
help
Say Y here to let the kernel print out symbolic crash information and
symbolic stack backtraces. This increases the size of the kernel
somewhat, as all symbols have to be loaded into the kernel image.
config KALLSYMS_ALL
bool "Include all symbols in kallsyms"
depends on DEBUG_KERNEL && KALLSYMS
help
Normally kallsyms only contains the symbols of functions for nicer
OOPS messages and backtraces (i.e., symbols from the text and inittext
sections). This is sufficient for most cases. And only in very rare
cases (e.g., when a debugger is used) all symbols are required (e.g.,
names of variables from the data sections, etc).
This option makes sure that all symbols are loaded into the kernel
image (i.e., symbols from all sections) in cost of increased kernel
size (depending on the kernel configuration, it may be 300KiB or
something like this).
Say N unless you really need all symbols.
config KALLSYMS_ABSOLUTE_PERCPU
bool
depends on KALLSYMS
default X86_64 && SMP
config KALLSYMS_BASE_RELATIVE
bool
depends on KALLSYMS
default !IA64
help
Instead of emitting them as absolute values in the native word size,
emit the symbol references in the kallsyms table as 32-bit entries,
each containing a relative value in the range [base, base + U32_MAX]
or, when KALLSYMS_ABSOLUTE_PERCPU is in effect, each containing either
an absolute value in the range [0, S32_MAX] or a relative value in the
range [base, base + S32_MAX], where base is the lowest relative symbol
address encountered in the image.
On 64-bit builds, this reduces the size of the address table by 50%,
but more importantly, it results in entries whose values are build
time constants, and no relocation pass is required at runtime to fix
up the entries based on the runtime load address of the kernel.
# end of the "standard kernel features (expert users)" menu
# syscall, maps, verifier
config BPF_SYSCALL
bool "Enable bpf() system call"
select ANON_INODES
select BPF
select IRQ_WORK
default n
help
Enable the bpf() system call that allows to manipulate eBPF
programs and maps via file descriptors.
config BPF_JIT_ALWAYS_ON
bool "Permanently enable BPF JIT and remove BPF interpreter"
depends on BPF_SYSCALL && HAVE_EBPF_JIT && BPF_JIT
help
Enables BPF JIT and removes BPF interpreter to avoid
speculative execution of BPF instructions by the interpreter
config USERFAULTFD
bool "Enable userfaultfd() system call"
select ANON_INODES
depends on MMU
help
Enable the userfaultfd() system call that allows to intercept and
handle page faults in userland.
config ARCH_HAS_MEMBARRIER_CALLBACKS
bool
config ARCH_HAS_MEMBARRIER_SYNC_CORE
bool
config RSEQ
bool "Enable rseq() system call" if EXPERT
default y
depends on HAVE_RSEQ
select MEMBARRIER
help
Enable the restartable sequences system call. It provides a
user-space cache for the current CPU number value, which
speeds up getting the current CPU number from user-space,
as well as an ABI to speed up user-space operations on
per-CPU data.
If unsure, say Y.
config DEBUG_RSEQ
default n
bool "Enabled debugging of rseq() system call" if EXPERT
depends on RSEQ && DEBUG_KERNEL
help
Enable extra debugging checks for the rseq system call.
If unsure, say N.
config EMBEDDED
bool "Embedded system"
option allnoconfig_y
select EXPERT
help
This option should be enabled if compiling the kernel for
an embedded system so certain expert options are available
for configuration.
config HAVE_PERF_EVENTS
bool
help
See tools/perf/design.txt for details.
config PERF_USE_VMALLOC
bool
help
See tools/perf/design.txt for details
config PC104
bool "PC/104 support" if EXPERT
help
Expose PC/104 form factor device drivers and options available for
selection and configuration. Enable this option if your target
machine has a PC/104 bus.
menu "Kernel Performance Events And Counters"
config PERF_EVENTS
bool "Kernel performance events and counters"
default y if PROFILING
depends on HAVE_PERF_EVENTS
select ANON_INODES
select IRQ_WORK
select SRCU
help
Enable kernel support for various performance events provided
by software and hardware.
Software events are supported either built-in or via the
use of generic tracepoints.
Most modern CPUs support performance events via performance
counter registers. These registers count the number of certain
types of hw events: such as instructions executed, cachemisses
suffered, or branches mis-predicted - without slowing down the
kernel or applications. These registers can also trigger interrupts
when a threshold number of events have passed - and can thus be
used to profile the code that runs on that CPU.
The Linux Performance Event subsystem provides an abstraction of
these software and hardware event capabilities, available via a
system call and used by the "perf" utility in tools/perf/. It
provides per task and per CPU counters, and it provides event
capabilities on top of those.
Say Y if unsure.
config PERF_USER_SHARE
bool "Perf event sharing with user-space"
help
Say yes here to enable the user-space sharing of events. The events
can be shared among other user-space events or with kernel created
events that has the same config and type event attributes.
Say N if unsure.
config DEBUG_PERF_USE_VMALLOC
default n
bool "Debug: use vmalloc to back perf mmap() buffers"
depends on PERF_EVENTS && DEBUG_KERNEL && !PPC
select PERF_USE_VMALLOC
help
Use vmalloc memory to back perf mmap() buffers.
Mostly useful for debugging the vmalloc code on platforms
that don't require it.
Say N if unsure.
endmenu
config VM_EVENT_COUNTERS
default y
bool "Enable VM event counters for /proc/vmstat" if EXPERT
help
VM event counters are needed for event counts to be shown.
This option allows the disabling of the VM event counters
on EXPERT systems. /proc/vmstat will only show page counts
if VM event counters are disabled.
config SLUB_DEBUG
default y
bool "Enable SLUB debugging support" if EXPERT
depends on SLUB && SYSFS
help
SLUB has extensive debug support features. Disabling these can
result in significant savings in code size. This also disables
SLUB sysfs support. /sys/slab will not exist and there will be
no support for cache validation etc.
config SLUB_MEMCG_SYSFS_ON
default n
bool "Enable memcg SLUB sysfs support by default" if EXPERT
depends on SLUB && SYSFS && MEMCG
help
SLUB creates a directory under /sys/kernel/slab for each
allocation cache to host info and debug files. If memory
cgroup is enabled, each cache can have per memory cgroup
caches. SLUB can create the same sysfs directories for these
caches under /sys/kernel/slab/CACHE/cgroup but it can lead
to a very high number of debug files being created. This is
controlled by slub_memcg_sysfs boot parameter and this
config option determines the parameter's default value.
config COMPAT_BRK
bool "Disable heap randomization"
default y
help
Randomizing heap placement makes heap exploits harder, but it
also breaks ancient binaries (including anything libc5 based).
This option changes the bootup default to heap randomization
disabled, and can be overridden at runtime by setting
/proc/sys/kernel/randomize_va_space to 2.
On non-ancient distros (post-2000 ones) N is usually a safe choice.
choice
prompt "Choose SLAB allocator"
default SLUB
help
This option allows to select a slab allocator.
config SLAB
bool "SLAB"
select HAVE_HARDENED_USERCOPY_ALLOCATOR
help
The regular slab allocator that is established and known to work
well in all environments. It organizes cache hot objects in
per cpu and per node queues.
config SLUB
bool "SLUB (Unqueued Allocator)"
select HAVE_HARDENED_USERCOPY_ALLOCATOR
help
SLUB is a slab allocator that minimizes cache line usage
instead of managing queues of cached objects (SLAB approach).
Per cpu caching is realized using slabs of objects instead
of queues of objects. SLUB can use memory efficiently
and has enhanced diagnostics. SLUB is the default choice for
a slab allocator.
config SLOB
depends on EXPERT
bool "SLOB (Simple Allocator)"
help
SLOB replaces the stock allocator with a drastically simpler
allocator. SLOB is generally more space efficient but
does not perform as well on large systems.
endchoice
config SLAB_MERGE_DEFAULT
bool "Allow slab caches to be merged"
default y
help
For reduced kernel memory fragmentation, slab caches can be
merged when they share the same size and other characteristics.
This carries a risk of kernel heap overflows being able to
overwrite objects from merged caches (and more easily control
cache layout), which makes such heap attacks easier to exploit
by attackers. By keeping caches unmerged, these kinds of exploits
can usually only damage objects in the same cache. To disable
merging at runtime, "slab_nomerge" can be passed on the kernel
command line.
config SLAB_FREELIST_RANDOM
default n
depends on SLAB || SLUB
bool "SLAB freelist randomization"
help
Randomizes the freelist order used on creating new pages. This
security feature reduces the predictability of the kernel slab
allocator against heap overflows.
config SLAB_FREELIST_HARDENED
bool "Harden slab freelist metadata"
depends on SLUB
help
Many kernel heap attacks try to target slab cache metadata and
other infrastructure. This options makes minor performance
sacrifies to harden the kernel slab allocator against common
freelist exploit methods.
config SLUB_CPU_PARTIAL
default y
depends on SLUB && SMP
bool "SLUB per cpu partial cache"
help
Per cpu partial caches accellerate objects allocation and freeing
that is local to a processor at the price of more indeterminism
in the latency of the free. On overflow these caches will be cleared
which requires the taking of locks that may cause latency spikes.
Typically one would choose no for a realtime system.
config MMAP_ALLOW_UNINITIALIZED
bool "Allow mmapped anonymous memory to be uninitialized"
depends on EXPERT && !MMU
default n
help
Normally, and according to the Linux spec, anonymous memory obtained
from mmap() has its contents cleared before it is passed to
userspace. Enabling this config option allows you to request that
mmap() skip that if it is given an MAP_UNINITIALIZED flag, thus
providing a huge performance boost. If this option is not enabled,
then the flag will be ignored.
This is taken advantage of by uClibc's malloc(), and also by
ELF-FDPIC binfmt's brk and stack allocator.
Because of the obvious security issues, this option should only be
enabled on embedded devices where you control what is run in
userspace. Since that isn't generally a problem on no-MMU systems,
it is normally safe to say Y here.
See Documentation/nommu-mmap.txt for more information.
config SYSTEM_DATA_VERIFICATION
def_bool n
select SYSTEM_TRUSTED_KEYRING
select KEYS
select CRYPTO
select CRYPTO_RSA
select ASYMMETRIC_KEY_TYPE
select ASYMMETRIC_PUBLIC_KEY_SUBTYPE
select ASN1
select OID_REGISTRY
select X509_CERTIFICATE_PARSER
select PKCS7_MESSAGE_PARSER
help
Provide PKCS#7 message verification using the contents of the system
trusted keyring to provide public keys. This then can be used for
module verification, kexec image verification and firmware blob
verification.
config PROFILING
bool "Profiling support"
help
Say Y here to enable the extended profiling support mechanisms used
by profilers such as OProfile.
#
# Place an empty function call at each tracepoint site. Can be
# dynamically changed for a probe function.
#
config TRACEPOINTS
bool
endmenu # General setup
source "arch/Kconfig"
config RT_MUTEXES
bool
config BASE_SMALL
int
default 0 if BASE_FULL
default 1 if !BASE_FULL
menuconfig MODULES
bool "Enable loadable module support"
option modules
help
Kernel modules are small pieces of compiled code which can
be inserted in the running kernel, rather than being
permanently built into the kernel. You use the "modprobe"
tool to add (and sometimes remove) them. If you say Y here,
many parts of the kernel can be built as modules (by
answering M instead of Y where indicated): this is most
useful for infrequently used options which are not required
for booting. For more information, see the man pages for
modprobe, lsmod, modinfo, insmod and rmmod.
If you say Y here, you will need to run "make
modules_install" to put the modules under /lib/modules/
where modprobe can find them (you may need to be root to do
this).
If unsure, say Y.
if MODULES
config MODULE_FORCE_LOAD
bool "Forced module loading"
default n
help
Allow loading of modules without version information (ie. modprobe
--force). Forced module loading sets the 'F' (forced) taint flag and
is usually a really bad idea.
config MODULE_UNLOAD
bool "Module unloading"
help
Without this option you will not be able to unload any
modules (note that some modules may not be unloadable
anyway), which makes your kernel smaller, faster
and simpler. If unsure, say Y.
config MODULE_FORCE_UNLOAD
bool "Forced module unloading"
depends on MODULE_UNLOAD
help
This option allows you to force a module to unload, even if the
kernel believes it is unsafe: the kernel will remove the module
without waiting for anyone to stop using it (using the -f option to
rmmod). This is mainly for kernel developers and desperate users.
If unsure, say N.
config MODVERSIONS
bool "Module versioning support"
help
Usually, you have to use modules compiled with your kernel.
Saying Y here makes it sometimes possible to use modules
compiled for different kernels, by adding enough information
to the modules to (hopefully) spot any changes which would
make them incompatible with the kernel you are running. If
unsure, say N.
config MODULE_REL_CRCS
bool
depends on MODVERSIONS
config MODULE_SRCVERSION_ALL
bool "Source checksum for all modules"
help
Modules which contain a MODULE_VERSION get an extra "srcversion"
field inserted into their modinfo section, which contains a
sum of the source files which made it. This helps maintainers
see exactly which source was used to build a module (since
others sometimes change the module source without updating
the version). With this option, such a "srcversion" field
will be created for all modules. If unsure, say N.
config MODULE_SIG
bool "Module signature verification"
depends on MODULES
select SYSTEM_DATA_VERIFICATION
help
Check modules for valid signatures upon load: the signature
is simply appended to the module. For more information see
<file:Documentation/admin-guide/module-signing.rst>.
Note that this option adds the OpenSSL development packages as a
kernel build dependency so that the signing tool can use its crypto
library.
!!!WARNING!!! If you enable this option, you MUST make sure that the
module DOES NOT get stripped after being signed. This includes the
debuginfo strip done by some packagers (such as rpmbuild) and
inclusion into an initramfs that wants the module size reduced.
config MODULE_SIG_FORCE
bool "Require modules to be validly signed"
depends on MODULE_SIG
help
Reject unsigned modules or signed modules for which we don't have a
key. Without this, such modules will simply taint the kernel.
config MODULE_SIG_ALL
bool "Automatically sign all modules"
default y
depends on MODULE_SIG
help
Sign all modules during make modules_install. Without this option,
modules must be signed manually, using the scripts/sign-file tool.
comment "Do not forget to sign required modules with scripts/sign-file"
depends on MODULE_SIG_FORCE && !MODULE_SIG_ALL
choice
prompt "Which hash algorithm should modules be signed with?"
depends on MODULE_SIG
help
This determines which sort of hashing algorithm will be used during
signature generation. This algorithm _must_ be built into the kernel
directly so that signature verification can take place. It is not
possible to load a signed module containing the algorithm to check
the signature on that module.
config MODULE_SIG_SHA1
bool "Sign modules with SHA-1"
select CRYPTO_SHA1
config MODULE_SIG_SHA224
bool "Sign modules with SHA-224"
select CRYPTO_SHA256
config MODULE_SIG_SHA256
bool "Sign modules with SHA-256"
select CRYPTO_SHA256
config MODULE_SIG_SHA384
bool "Sign modules with SHA-384"
select CRYPTO_SHA512
config MODULE_SIG_SHA512
bool "Sign modules with SHA-512"
select CRYPTO_SHA512
endchoice
config MODULE_SIG_HASH
string
depends on MODULE_SIG
default "sha1" if MODULE_SIG_SHA1
default "sha224" if MODULE_SIG_SHA224
default "sha256" if MODULE_SIG_SHA256
default "sha384" if MODULE_SIG_SHA384
default "sha512" if MODULE_SIG_SHA512
config MODULE_COMPRESS
bool "Compress modules on installation"
depends on MODULES
help
Compresses kernel modules when 'make modules_install' is run; gzip or
xz depending on "Compression algorithm" below.
module-init-tools MAY support gzip, and kmod MAY support gzip and xz.
Out-of-tree kernel modules installed using Kbuild will also be
compressed upon installation.
Note: for modules inside an initrd or initramfs, it's more efficient
to compress the whole initrd or initramfs instead.
Note: This is fully compatible with signed modules.
If in doubt, say N.
choice
prompt "Compression algorithm"
depends on MODULE_COMPRESS
default MODULE_COMPRESS_GZIP
help
This determines which sort of compression will be used during
'make modules_install'.
GZIP (default) and XZ are supported.
config MODULE_COMPRESS_GZIP
bool "GZIP"
config MODULE_COMPRESS_XZ
bool "XZ"
endchoice
config TRIM_UNUSED_KSYMS
bool "Trim unused exported kernel symbols"
depends on MODULES && !UNUSED_SYMBOLS
help
The kernel and some modules make many symbols available for
other modules to use via EXPORT_SYMBOL() and variants. Depending
on the set of modules being selected in your kernel configuration,
many of those exported symbols might never be used.
This option allows for unused exported symbols to be dropped from
the build. In turn, this provides the compiler more opportunities
(especially when using LTO) for optimizing the code and reducing
binary size. This might have some security advantages as well.
If unsure, or if you need to build out-of-tree modules, say N.
endif # MODULES
config MODULES_TREE_LOOKUP
def_bool y
depends on PERF_EVENTS || TRACING || CFI_CLANG
config INIT_ALL_POSSIBLE
bool
help
Back when each arch used to define their own cpu_online_mask and
cpu_possible_mask, some of them chose to initialize cpu_possible_mask
with all 1s, and others with all 0s. When they were centralised,
it was better to provide this option than to break all the archs
and have several arch maintainers pursuing me down dark alleys.
source "block/Kconfig"
config PREEMPT_NOTIFIERS
bool
config PADATA
depends on SMP
bool
config ASN1
tristate
help
Build a simple ASN.1 grammar compiler that produces a bytecode output
that can be interpreted by the ASN.1 stream decoder and used to
inform it as to what tags are to be expected in a stream and what
functions to call on what tags.
source "kernel/Kconfig.locks"
config ARCH_HAS_SYNC_CORE_BEFORE_USERMODE
bool
# It may be useful for an architecture to override the definitions of the
# SYSCALL_DEFINE() and __SYSCALL_DEFINEx() macros in <linux/syscalls.h>
# and the COMPAT_ variants in <linux/compat.h>, in particular to use a
# different calling convention for syscalls. They can also override the
# macros for not-implemented syscalls in kernel/sys_ni.c and
# kernel/time/posix-stubs.c. All these overrides need to be available in
# <asm/syscall_wrapper.h>.
config ARCH_HAS_SYSCALL_WRAPPER
def_bool n