Instead of having all the sysctl handlers deal with user pointers, which
is rather hairy in terms of the BPF interaction, copy the input to and
from userspace in common code. This also means that the strings are
always NUL-terminated by the common code, making the API a little bit
safer.
As most handler just pass through the data to one of the common handlers
a lot of the changes are mechnical.
Change-Id: Ic71fd778e4cea58adc51d634d9e53c1f9f90cdf2
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Changes in 4.19.283
wifi: brcmfmac: slab-out-of-bounds read in brcmf_get_assoc_ies()
bluetooth: Perform careful capability checks in hci_sock_ioctl()
USB: serial: option: add UNISOC vendor and TOZED LT70C product
iio: adc: palmas_gpadc: fix NULL dereference on rmmod
ASoC: Intel: bytcr_rt5640: Add quirk for the Acer Iconia One 7 B1-750
stmmac: debugfs entry name is not be changed when udev rename device name.
USB: dwc3: fix runtime pm imbalance on unbind
perf sched: Cast PTHREAD_STACK_MIN to int as it may turn into sysconf(__SC_THREAD_STACK_MIN_VALUE)
staging: iio: resolver: ads1210: fix config mode
debugfs: regset32: Add Runtime PM support
xhci: fix debugfs register accesses while suspended
MIPS: fw: Allow firmware to pass a empty env
pwm: meson: Fix axg ao mux parents
ring-buffer: Sync IRQ works before buffer destruction
reiserfs: Add security prefix to xattr name in reiserfs_security_write()
KVM: nVMX: Emulate NOPs in L2, and PAUSE if it's not intercepted
i2c: omap: Fix standard mode false ACK readings
Revert "ubifs: dirty_cow_znode: Fix memleak in error handling path"
ubifs: Fix memleak when insert_old_idx() failed
ubi: Fix return value overwrite issue in try_write_vid_and_data()
ubifs: Free memory for tmpfile name
selinux: fix Makefile dependencies of flask.h
selinux: ensure av_permissions.h is built when needed
drm/rockchip: Drop unbalanced obj unref
drm/vgem: add missing mutex_destroy
drm/probe-helper: Cancel previous job before starting new one
EDAC, skx: Move debugfs node under EDAC's hierarchy
EDAC/skx: Fix overflows on the DRAM row address mapping arrays
ARM: dts: qcom: ipq4019: Fix the PCI I/O port range
media: bdisp: Add missing check for create_workqueue
media: uapi: add MEDIA_BUS_FMT_METADATA_FIXED media bus format.
media: av7110: prevent underflow in write_ts_to_decoder()
firmware: qcom_scm: Clear download bit during reboot
drm/msm/adreno: Defer enabling runpm until hw_init()
drm/msm/adreno: drop bogus pm_runtime_set_active()
x86/apic: Fix atomic update of offset in reserve_eilvt_offset()
media: dm1105: Fix use after free bug in dm1105_remove due to race condition
media: saa7134: fix use after free bug in saa7134_finidev due to race condition
media: rcar_fdp1: Fix the correct variable assignments
media: rcar_fdp1: Fix refcount leak in probe and remove function
media: rc: gpio-ir-recv: Fix support for wake-up
x86/ioapic: Don't return 0 from arch_dynirq_lower_bound()
arm64: kgdb: Set PSTATE.SS to 1 to re-enable single-step
debugobjects: Add percpu free pools
debugobjects: Move printk out of db->lock critical sections
debugobject: Prevent init race with static objects
wifi: ath6kl: minor fix for allocation size
wifi: ath9k: hif_usb: fix memory leak of remain_skbs
wifi: ath5k: fix an off by one check in ath5k_eeprom_read_freq_list()
wifi: ath6kl: reduce WARN to dev_dbg() in callback
tools: bpftool: Remove invalid \' json escape
scm: fix MSG_CTRUNC setting condition for SO_PASSSEC
vlan: partially enable SIOCSHWTSTAMP in container
net/packet: convert po->origdev to an atomic flag
net/packet: convert po->auxdata to an atomic flag
scsi: target: iscsit: Fix TAS handling during conn cleanup
scsi: megaraid: Fix mega_cmd_done() CMDID_INT_CMDS
rtlwifi: rtl_pci: Fix memory leak when hardware init fails
rtlwifi: Start changing RT_TRACE into rtl_dbg
rtlwifi: Replace RT_TRACE with rtl_dbg
wifi: rtlwifi: fix incorrect error codes in rtl_debugfs_set_write_rfreg()
wifi: rtlwifi: fix incorrect error codes in rtl_debugfs_set_write_reg()
bpftool: Fix bug for long instructions in program CFG dumps
crypto: drbg - make drbg_prepare_hrng() handle jent instantiation errors
crypto: drbg - Only fail when jent is unavailable in FIPS mode
md/raid10: fix leak of 'r10bio->remaining' for recovery
md/raid10: fix memleak for 'conf->bio_split'
md: update the optimal I/O size on reshape
md/raid10: fix memleak of md thread
wifi: iwlwifi: make the loop for card preparation effective
wifi: iwlwifi: mvm: check firmware response size
ixgbe: Allow flow hash to be set via ethtool
ixgbe: Enable setting RSS table to default values
netfilter: nf_tables: don't write table validation state without mutex
ipv4: Fix potential uninit variable access bug in __ip_make_skb()
Revert "Bluetooth: btsdio: fix use after free bug in btsdio_remove due to unfinished work"
netlink: Use copy_to_user() for optval in netlink_getsockopt().
net: amd: Fix link leak when verifying config failed
tcp/udp: Fix memleaks of sk and zerocopy skbs with TX timestamp.
pstore: Revert pmsg_lock back to a normal mutex
usb: host: xhci-rcar: remove leftover quirk handling
fpga: bridge: fix kernel-doc parameter description
usb: gadget: udc: renesas_usb3: Fix use after free bug in renesas_usb3_remove due to race condition
linux/vt_buffer.h: allow either builtin or modular for macros
spi: qup: fix PM reference leak in spi_qup_remove()
spi: qup: Don't skip cleanup in remove's error path
spi: fsl-spi: Fix CPM/QE mode Litte Endian
vmci_host: fix a race condition in vmci_host_poll() causing GPF
of: Fix modalias string generation
ia64: mm/contig: fix section mismatch warning/error
ia64: salinfo: placate defined-but-not-used warning
mtd: spi-nor: cadence-quadspi: Make driver independent of flash geometry
mtd: spi-nor: cadence-quadspi: Don't initialize rx_dma_complete on failure
mtd: spi-nor: cadence-quadspi: Handle probe deferral while requesting DMA channel
spi: cadence-quadspi: fix suspend-resume implementations
uapi/linux/const.h: prefer ISO-friendly __typeof__
sh: sq: Fix incorrect element size for allocating bitmap buffer
usb: chipidea: fix missing goto in `ci_hdrc_probe`
tty: serial: fsl_lpuart: adjust buffer length to the intended size
serial: 8250: Add missing wakeup event reporting
staging: rtl8192e: Fix W_DISABLE# does not work after stop/start
spmi: Add a check for remove callback when removing a SPMI driver
macintosh/windfarm_smu_sat: Add missing of_node_put()
powerpc/mpc512x: fix resource printk format warning
powerpc/wii: fix resource printk format warnings
powerpc/sysdev/tsi108: fix resource printk format warnings
macintosh: via-pmu-led: requires ATA to be set
powerpc/rtas: use memmove for potentially overlapping buffer copy
perf/core: Fix hardlockup failure caused by perf throttle
RDMA/rdmavt: Delete unnecessary NULL check
RDMA/mlx4: Prevent shift wrapping in set_user_sq_size()
power: supply: generic-adc-battery: fix unit scaling
clk: add missing of_node_put() in "assigned-clocks" property parsing
IB/hfi1: Fix SDMA mmu_rb_node not being evicted in LRU order
NFSv4.1: Always send a RECLAIM_COMPLETE after establishing lease
SUNRPC: remove the maximum number of retries in call_bind_status
RDMA/mlx5: Use correct device num_ports when modify DC
openrisc: Properly store r31 to pt_regs on unhandled exceptions
pwm: mtk-disp: Don't check the return code of pwmchip_remove()
pwm: mtk-disp: Adjust the clocks to avoid them mismatch
pwm: mtk-disp: Disable shadow registers before setting backlight values
phy: tegra: xusb: Add missing tegra_xusb_port_unregister for usb2_port and ulpi_port
dmaengine: at_xdmac: do not enable all cyclic channels
parisc: Fix argument pointer in real64_call_asm()
nilfs2: do not write dirty data after degenerating to read-only
nilfs2: fix infinite loop in nilfs_mdt_get_block()
md/raid10: fix null-ptr-deref in raid10_sync_request
wifi: rtl8xxxu: RTL8192EU always needs full init
clk: rockchip: rk3399: allow clk_cifout to force clk_cifout_src to reparent
btrfs: scrub: reject unsupported scrub flags
s390/dasd: fix hanging blockdevice after request requeue
dm integrity: call kmem_cache_destroy() in dm_integrity_init() error path
dm flakey: fix a crash with invalid table line
dm ioctl: fix nested locking in table_clear() to remove deadlock concern
perf auxtrace: Fix address filter entire kernel size
debugobject: Ensure pool refill (again)
netfilter: nf_tables: deactivate anonymous set from preparation phase
nohz: Add TICK_DEP_BIT_RCU
tick/nohz: Fix cpu_is_hotpluggable() by checking with nohz subsystem
ipmi: Fix SSIF flag requests
ipmi: Fix how the lower layers are told to watch for messages
ipmi_ssif: Rename idle state and check
ipmi: fix SSIF not responding under certain cond.
dm verity: skip redundant verity_handle_err() on I/O errors
dm verity: fix error handling for check_at_most_once on FEC
kernel/relay.c: fix read_pos error when multiple readers
relayfs: fix out-of-bounds access in relay_file_read
sit: update dev->needed_headroom in ipip6_tunnel_bind_dev()
net: dsa: mv88e6xxx: Add missing watchdog ops for 6320 family
net: dsa: mv88e6xxx: add mv88e6321 rsvd2cpu
writeback: fix call of incorrect macro
net/sched: act_mirred: Add carrier check
rxrpc: Fix hard call timeout units
af_packet: Don't send zero-byte data in packet_sendmsg_spkt().
drm/amdgpu: Add amdgpu_gfx_off_ctrl function
drm/amdgpu: Put enable gfx off feature to a delay thread
drm/amdgpu: Add command to override the context priority.
drm/amdgpu: add a missing lock for AMDGPU_SCHED
ALSA: caiaq: input: Add error handling for unsupported input methods in `snd_usb_caiaq_input_init`
virtio_net: split free_unused_bufs()
virtio_net: suppress cpu stall when free_unused_bufs
perf vendor events power9: Remove UTF-8 characters from JSON files
perf map: Delete two variable initialisations before null pointer checks in sort__sym_from_cmp()
perf symbols: Fix return incorrect build_id size in elf_read_build_id()
btrfs: fix btrfs_prev_leaf() to not return the same key twice
btrfs: print-tree: parent bytenr must be aligned to sector size
cifs: fix pcchunk length type in smb2_copychunk_range
platform/x86: touchscreen_dmi: Add info for the Dexp Ursus KX210i
sh: math-emu: fix macro redefined warning
sh: init: use OF_EARLY_FLATTREE for early init
sh: nmi_debug: fix return value of __setup handler
ARM: dts: exynos: fix WM8960 clock name in Itop Elite
ARM: dts: s5pv210: correct MIPI CSIS clock name
drm/panel: otm8009a: Set backlight parent to panel device
HID: wacom: Set a default resolution for older tablets
ext4: fix WARNING in mb_find_extent
ext4: avoid a potential slab-out-of-bounds in ext4_group_desc_csum
ext4: improve error recovery code paths in __ext4_remount()
ext4: add bounds checking in get_max_inline_xattr_value_size()
ext4: bail out of ext4_xattr_ibody_get() fails for any reason
ext4: remove a BUG_ON in ext4_mb_release_group_pa()
ext4: fix invalid free tracking in ext4_xattr_move_to_block()
tty: Prevent writing chars during tcsetattr TCSADRAIN/FLUSH
serial: 8250: Fix serial8250_tx_empty() race with DMA Tx
drbd: correctly submit flush bio on barrier
PCI: pciehp: Use down_read/write_nested(reset_lock) to fix lockdep errors
PCI: pciehp: Fix AB-BA deadlock between reset_lock and device_lock
printk: declare printk_deferred_{enter,safe}() in include/linux/printk.h
mm/page_alloc: fix potential deadlock on zonelist_update_seq seqlock
Linux 4.19.283
Change-Id: Id2f95d527f356c874a9e01e57f1d816b9fa34e8b
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
commit 85e3e7fbbb720b9897fba9a99659e31cbd1c082e upstream.
[This patch implements subset of original commit 85e3e7fbbb72 ("printk:
remove NMI tracking") where commit 1007843a9190 ("mm/page_alloc: fix
potential deadlock on zonelist_update_seq seqlock") depends on, for
commit 3d36424b3b58 ("mm/page_alloc: fix race condition between
build_all_zonelists and page allocation") was backported to stable.]
All NMI contexts are handled the same as the safe context: store the
message and defer printing. There is no need to have special NMI
context tracking for this. Using in_nmi() is enough.
There are several parts of the kernel that are manually calling into
the printk NMI context tracking in order to cause general printk
deferred printing:
arch/arm/kernel/smp.c
arch/powerpc/kexec/crash.c
kernel/trace/trace.c
For arm/kernel/smp.c and powerpc/kexec/crash.c, provide a new
function pair printk_deferred_enter/exit that explicitly achieves the
same objective.
For ftrace, remove the printk context manipulation completely. It was
added in commit 03fc7f9c99 ("printk/nmi: Prevent deadlock when
accessing the main log buffer in NMI"). The purpose was to enforce
storing messages directly into the ring buffer even in NMI context.
It really should have only modified the behavior in NMI context.
There is no need for a special behavior any longer. All messages are
always stored directly now. The console deferring is handled
transparently in vprintk().
Signed-off-by: John Ogness <john.ogness@linutronix.de>
[pmladek@suse.com: Remove special handling in ftrace.c completely.
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20210715193359.25946-5-john.ogness@linutronix.de
[penguin-kernel: Copy only printk_deferred_{enter,safe}() definition ]
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Changes in 4.19.134
perf: Make perf able to build with latest libbfd
net: rmnet: fix lower interface leak
genetlink: remove genl_bind
ipv4: fill fl4_icmp_{type,code} in ping_v4_sendmsg
l2tp: remove skb_dst_set() from l2tp_xmit_skb()
llc: make sure applications use ARPHRD_ETHER
net: Added pointer check for dst->ops->neigh_lookup in dst_neigh_lookup_skb
net_sched: fix a memory leak in atm_tc_init()
net: usb: qmi_wwan: add support for Quectel EG95 LTE modem
tcp: fix SO_RCVLOWAT possible hangs under high mem pressure
tcp: make sure listeners don't initialize congestion-control state
tcp: md5: add missing memory barriers in tcp_md5_do_add()/tcp_md5_hash_key()
tcp: md5: do not send silly options in SYNCOOKIES
tcp: md5: refine tcp_md5_do_add()/tcp_md5_hash_key() barriers
tcp: md5: allow changing MD5 keys in all socket states
cgroup: fix cgroup_sk_alloc() for sk_clone_lock()
cgroup: Fix sock_cgroup_data on big-endian.
sched: consistently handle layer3 header accesses in the presence of VLANs
vlan: consolidate VLAN parsing code and limit max parsing depth
drm/msm: fix potential memleak in error branch
drm/exynos: fix ref count leak in mic_pre_enable
m68k: nommu: register start of the memory with memblock
m68k: mm: fix node memblock init
arm64/alternatives: use subsections for replacement sequences
tpm_tis: extra chip->ops check on error path in tpm_tis_core_init
gfs2: read-only mounts should grab the sd_freeze_gl glock
i2c: eg20t: Load module automatically if ID matches
arm64/alternatives: don't patch up internal branches
iio:magnetometer:ak8974: Fix alignment and data leak issues
iio:humidity:hdc100x Fix alignment and data leak issues
iio: magnetometer: ak8974: Fix runtime PM imbalance on error
iio: mma8452: Add missed iio_device_unregister() call in mma8452_probe()
iio: pressure: zpa2326: handle pm_runtime_get_sync failure
iio:humidity:hts221 Fix alignment and data leak issues
iio:pressure:ms5611 Fix buffer element alignment
iio:health:afe4403 Fix timestamp alignment and prevent data leak.
spi: fix initial SPI_SR value in spi-fsl-dspi
spi: spi-fsl-dspi: Fix lockup if device is shutdown during SPI transfer
net: dsa: bcm_sf2: Fix node reference count
of: of_mdio: Correct loop scanning logic
Revert "usb/ohci-platform: Fix a warning when hibernating"
Revert "usb/xhci-plat: Set PM runtime as active on resume"
Revert "usb/ehci-platform: Set PM runtime as active on resume"
net: sfp: add support for module quirks
net: sfp: add some quirks for GPON modules
HID: quirks: Remove ITE 8595 entry from hid_have_special_driver
ARM: at91: pm: add quirk for sam9x60's ulp1
scsi: sr: remove references to BLK_DEV_SR_VENDOR, leave it enabled
ALSA: usb-audio: Create a registration quirk for Kingston HyperX Amp (0951:16d8)
doc: dt: bindings: usb: dwc3: Update entries for disabling SS instances in park mode
mmc: sdhci: do not enable card detect interrupt for gpio cd type
ALSA: usb-audio: Rewrite registration quirk handling
ACPI: video: Use native backlight on Acer Aspire 5783z
ALSA: usb-audio: Add registration quirk for Kingston HyperX Cloud Alpha S
Input: mms114 - add extra compatible for mms345l
ACPI: video: Use native backlight on Acer TravelMate 5735Z
ALSA: usb-audio: Add registration quirk for Kingston HyperX Cloud Flight S
iio:health:afe4404 Fix timestamp alignment and prevent data leak.
phy: sun4i-usb: fix dereference of pointer phy0 before it is null checked
arm64: dts: meson: add missing gxl rng clock
spi: spi-sun6i: sun6i_spi_transfer_one(): fix setting of clock rate
usb: gadget: udc: atmel: fix uninitialized read in debug printk
staging: comedi: verify array index is correct before using it
Revert "thermal: mediatek: fix register index error"
ARM: dts: socfpga: Align L2 cache-controller nodename with dtschema
regmap: debugfs: Don't sleep while atomic for fast_io regmaps
copy_xstate_to_kernel: Fix typo which caused GDB regression
apparmor: ensure that dfa state tables have entries
perf stat: Zero all the 'ena' and 'run' array slot stats for interval mode
soc: qcom: rpmh: Update dirty flag only when data changes
soc: qcom: rpmh: Invalidate SLEEP and WAKE TCSes before flushing new data
soc: qcom: rpmh-rsc: Clear active mode configuration for wake TCS
soc: qcom: rpmh-rsc: Allow using free WAKE TCS for active request
mtd: rawnand: marvell: Use nand_cleanup() when the device is not yet registered
mtd: rawnand: marvell: Fix probe error path
mtd: rawnand: timings: Fix default tR_max and tCCS_min timings
mtd: rawnand: brcmnand: fix CS0 layout
mtd: rawnand: oxnas: Keep track of registered devices
mtd: rawnand: oxnas: Unregister all devices on error
mtd: rawnand: oxnas: Release all devices in the _remove() path
slimbus: core: Fix mismatch in of_node_get/put
HID: magicmouse: do not set up autorepeat
HID: quirks: Always poll Obins Anne Pro 2 keyboard
HID: quirks: Ignore Simply Automated UPB PIM
ALSA: line6: Perform sanity check for each URB creation
ALSA: line6: Sync the pending work cancel at disconnection
ALSA: usb-audio: Fix race against the error recovery URB submission
ALSA: hda/realtek - change to suitable link model for ASUS platform
ALSA: hda/realtek - Enable Speaker for ASUS UX533 and UX534
USB: c67x00: fix use after free in c67x00_giveback_urb
usb: dwc2: Fix shutdown callback in platform
usb: chipidea: core: add wakeup support for extcon
usb: gadget: function: fix missing spinlock in f_uac1_legacy
USB: serial: iuu_phoenix: fix memory corruption
USB: serial: cypress_m8: enable Simply Automated UPB PIM
USB: serial: ch341: add new Product ID for CH340
USB: serial: option: add GosunCn GM500 series
USB: serial: option: add Quectel EG95 LTE modem
virt: vbox: Fix VBGL_IOCTL_VMMDEV_REQUEST_BIG and _LOG req numbers to match upstream
virt: vbox: Fix guest capabilities mask check
virtio: virtio_console: add missing MODULE_DEVICE_TABLE() for rproc serial
serial: mxs-auart: add missed iounmap() in probe failure and remove
ovl: inode reference leak in ovl_is_inuse true case.
ovl: relax WARN_ON() when decoding lower directory file handle
ovl: fix unneeded call to ovl_change_flags()
fuse: Fix parameter for FS_IOC_{GET,SET}FLAGS
Revert "zram: convert remaining CLASS_ATTR() to CLASS_ATTR_RO()"
mei: bus: don't clean driver pointer
Input: i8042 - add Lenovo XiaoXin Air 12 to i8042 nomux list
uio_pdrv_genirq: fix use without device tree and no interrupt
timer: Prevent base->clk from moving backward
timer: Fix wheel index calculation on last level
MIPS: Fix build for LTS kernel caused by backporting lpj adjustment
riscv: use 16KB kernel stack on 64-bit
hwmon: (emc2103) fix unable to change fan pwm1_enable attribute
powerpc/book3s64/pkeys: Fix pkey_access_permitted() for execute disable pkey
intel_th: pci: Add Jasper Lake CPU support
intel_th: pci: Add Tiger Lake PCH-H support
intel_th: pci: Add Emmitsburg PCH support
intel_th: Fix a NULL dereference when hub driver is not loaded
dmaengine: fsl-edma: Fix NULL pointer exception in fsl_edma_tx_handler
misc: atmel-ssc: lock with mutex instead of spinlock
thermal/drivers/cpufreq_cooling: Fix wrong frequency converted from power
arm64: ptrace: Override SPSR.SS when single-stepping is enabled
arm64: ptrace: Consistently use pseudo-singlestep exceptions
arm64: compat: Ensure upper 32 bits of x0 are zero on syscall return
sched: Fix unreliable rseq cpu_id for new tasks
sched/fair: handle case of task_h_load() returning 0
genirq/affinity: Handle affinity setting on inactive interrupts correctly
printk: queue wake_up_klogd irq_work only if per-CPU areas are ready
libceph: don't omit recovery_deletes in target_copy()
rxrpc: Fix trace string
spi: sprd: switch the sequence of setting WDG_LOAD_LOW and _HIGH
Linux 4.19.134
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
Change-Id: Ieeb9e03f4a2d51aeebe3a3eadd9c1b93a26088a0
commit ab6f762f0f53162d41497708b33c9a3236d3609e upstream.
printk_deferred(), similarly to printk_safe/printk_nmi, does not
immediately attempt to print a new message on the consoles, avoiding
calls into non-reentrant kernel paths, e.g. scheduler or timekeeping,
which potentially can deadlock the system.
Those printk() flavors, instead, rely on per-CPU flush irq_work to print
messages from safer contexts. For same reasons (recursive scheduler or
timekeeping calls) printk() uses per-CPU irq_work in order to wake up
user space syslog/kmsg readers.
However, only printk_safe/printk_nmi do make sure that per-CPU areas
have been initialised and that it's safe to modify per-CPU irq_work.
This means that, for instance, should printk_deferred() be invoked "too
early", that is before per-CPU areas are initialised, printk_deferred()
will perform illegal per-CPU access.
Lech Perczak [0] reports that after commit 1b710b1b10ef ("char/random:
silence a lockdep splat with printk()") user-space syslog/kmsg readers
are not able to read new kernel messages.
The reason is printk_deferred() being called too early (as was pointed
out by Petr and John).
Fix printk_deferred() and do not queue per-CPU irq_work before per-CPU
areas are initialized.
Link: https://lore.kernel.org/lkml/aa0732c6-5c4e-8a8b-a1c1-75ebe3dca05b@camlintechnologies.com/
Reported-by: Lech Perczak <l.perczak@camlintechnologies.com>
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Tested-by: Jann Horn <jannh@google.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: John Ogness <john.ogness@linutronix.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
We can't modify the original linux_banner symbol due to ramdump parsing
dependencies. So add an additional symbol pointer that just points at
it. This way ABI monitoring won't care about the value and
modules can still access the banner value.
Signed-off-by: Will McVicker <willmcvicker@google.com>
Bug: 154586724
Bug: 154345163
Test: compile
Change-Id: I65678e02467b8754824a7527270a725741394fe3
This variable can have its ABI intentionally changed by anybody building
on a different hostname etc. so it does not make sense to monitor it as
a C string. Make linux_banner a C pointer so it is checked for presence
but not for length.
Bug: 154345163
Signed-off-by: Alistair Delva <adelva@google.com>
Change-Id: I932e7c2ca1a1bd6d730462249005515c71771ed8
The commit 719f6a7040 ("printk: Use the main logbuf in NMI
when logbuf_lock is available") brought back the possible deadlocks
in printk() and NMI.
The check of logbuf_lock is done only in printk_nmi_enter() to prevent
mixed output. But another CPU might take the lock later, enter NMI, and:
+ Both NMIs might be serialized by yet another lock, for example,
the one in nmi_cpu_backtrace().
+ The other CPU might get stopped in NMI, see smp_send_stop()
in panic().
The only safe solution is to use trylock when storing the message
into the main log-buffer. It might cause reordering when some lines
go to the main lock buffer directly and others are delayed via
the per-CPU buffer. It means that it is not useful in general.
This patch replaces the problematic NMI deferred context with NMI
direct context. It can be used to mark a code that might produce
many messages in NMI and the risk of losing them is more critical
than problems with eventual reordering.
The context is then used when dumping trace buffers on oops. It was
the primary motivation for the original fix. Also the reordering is
even smaller issue there because some traces have their own time stamps.
Finally, nmi_cpu_backtrace() need not longer be serialized because
it will always us the per-CPU buffers again.
Fixes: 719f6a7040 ("printk: Use the main logbuf in NMI when logbuf_lock is available")
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/20180627142028.11259-1-pmladek@suse.com
To: Steven Rostedt <rostedt@goodmis.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Cc: linux-kernel@vger.kernel.org
Cc: stable@vger.kernel.org
Acked-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
The goal of passing the "quiet" option to the kernel is for the kernel
to be quiet unless something really is wrong.
Sofar passing quiet has been (mostly) equivalent to passing
loglevel=4 on the kernel commandline. Which means to show any messages
with a level of KERN_ERR or higher severity on the console.
In practice this often does not result in a quiet boot though, since
there are many false-positive or otherwise harmless error messages printed,
defeating the purpose of the quiet option. Esp. the ACPICA code is really
bad wrt this, but there are plenty of others too.
This commit makes CONSOLE_LOGLEVEL_QUIET configurable.
This for example will allow distros which want quiet to really mean quiet
to set CONSOLE_LOGLEVEL_QUIET so that only messages with a higher severity
then KERN_ERR (CRIT, ALERT, EMERG) get printed, avoiding an endless game
of whack-a-mole silencing harmless error messages.
Link: http://lkml.kernel.org/r/20180619115726.3098-1-hdegoede@redhat.com
To: Petr Mladek <pmladek@suse.com>
To: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Cc: Hans de Goede <hdegoede@redhat.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Pull printk updates from Petr Mladek:
- print the warning about dropped messages on consoles on a separate
line. It makes it more legible.
- one typo fix and small code clean up.
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk:
added new line symbol after warning about dropped messages
printk: fix typo in printk_safe.c
printk: simplify no_printk()
Building kallsyms fails without CONFIG_PRINTK due to a missing
declaration:
kernel/kallsyms.c: In function 'kallsyms_show_value':
kernel/kallsyms.c:670:10: error: 'kptr_restrict' undeclared (first use in this function); did you mean 'keyring_restrict'?
This moves the declaration outside of the #ifdef guard, the definition
is already available without CONFIG_PRINTK.
Fixes: c0f3ea1589 ("stop using '%pK' for /proc/kallsyms pointer values")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
[ I clearly need to start doing "allnoconfig" builds too, or just have a
test branch for the 0day robot - Linus ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.
By default all files without license information are under the default
license of the kernel, which is GPL version 2.
Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.
This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.
How this work was done:
Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,
Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.
The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.
The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.
Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if <5
lines).
All documentation files were explicitly excluded.
The following heuristics were used to determine which SPDX license
identifiers to apply.
- when both scanners couldn't find any license traces, file was
considered to have no license information in it, and the top level
COPYING file license applied.
For non */uapi/* files that summary was:
SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 11139
and resulted in the first patch in this series.
If that file was a */uapi/* path one, it was "GPL-2.0 WITH
Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was:
SPDX license identifier # files
---------------------------------------------------|-------
GPL-2.0 WITH Linux-syscall-note 930
and resulted in the second patch in this series.
- if a file had some form of licensing information in it, and was one
of the */uapi/* ones, it was denoted with the Linux-syscall-note if
any GPL family license was found in the file or had no licensing in
it (per prior point). Results summary:
SPDX license identifier # files
---------------------------------------------------|------
GPL-2.0 WITH Linux-syscall-note 270
GPL-2.0+ WITH Linux-syscall-note 169
((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21
((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17
LGPL-2.1+ WITH Linux-syscall-note 15
GPL-1.0+ WITH Linux-syscall-note 14
((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5
LGPL-2.0+ WITH Linux-syscall-note 4
LGPL-2.1 WITH Linux-syscall-note 3
((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3
((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1
and that resulted in the third patch in this series.
- when the two scanners agreed on the detected license(s), that became
the concluded license(s).
- when there was disagreement between the two scanners (one detected a
license but the other didn't, or they both detected different
licenses) a manual inspection of the file occurred.
- In most cases a manual inspection of the information in the file
resulted in a clear resolution of the license that should apply (and
which scanner probably needed to revisit its heuristics).
- When it was not immediately clear, the license identifier was
confirmed with lawyers working with the Linux Foundation.
- If there was any question as to the appropriate license identifier,
the file was flagged for further research and to be revisited later
in time.
In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.
Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights. The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.
Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.
In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.
Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
- a full scancode scan run, collecting the matched texts, detected
license ids and scores
- reviewing anything where there was a license detected (about 500+
files) to ensure that the applied SPDX license was correct
- reviewing anything where there was no detection but the patch license
was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
SPDX license was correct
This produced a worksheet with 20 files needing minor correction. This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.
These .csv files were then reviewed by Greg. Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected. This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.) Finally Greg ran the script using the .csv files to
generate the patches.
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Patch series "kexec/fadump: remove dependency with CONFIG_KEXEC and
reuse crashkernel parameter for fadump", v4.
Traditionally, kdump is used to save vmcore in case of a crash. Some
architectures like powerpc can save vmcore using architecture specific
support instead of kexec/kdump mechanism. Such architecture specific
support also needs to reserve memory, to be used by dump capture kernel.
crashkernel parameter can be a reused, for memory reservation, by such
architecture specific infrastructure.
This patchset removes dependency with CONFIG_KEXEC for crashkernel
parameter and vmcoreinfo related code as it can be reused without kexec
support. Also, crashkernel parameter is reused instead of
fadump_reserve_mem to reserve memory for fadump.
The first patch moves crashkernel parameter parsing and vmcoreinfo
related code under CONFIG_CRASH_CORE instead of CONFIG_KEXEC_CORE. The
second patch reuses the definitions of append_elf_note() & final_note()
functions under CONFIG_CRASH_CORE in IA64 arch code. The third patch
removes dependency on CONFIG_KEXEC for firmware-assisted dump (fadump)
in powerpc. The next patch reuses crashkernel parameter for reserving
memory for fadump, instead of the fadump_reserve_mem parameter. This
has the advantage of using all syntaxes crashkernel parameter supports,
for fadump as well. The last patch updates fadump kernel documentation
about use of crashkernel parameter.
This patch (of 5):
Traditionally, kdump is used to save vmcore in case of a crash. Some
architectures like powerpc can save vmcore using architecture specific
support instead of kexec/kdump mechanism. Such architecture specific
support also needs to reserve memory, to be used by dump capture kernel.
crashkernel parameter can be a reused, for memory reservation, by such
architecture specific infrastructure.
But currently, code related to vmcoreinfo and parsing of crashkernel
parameter is built under CONFIG_KEXEC_CORE. This patch introduces
CONFIG_CRASH_CORE and moves the above mentioned code under this config,
allowing code reuse without dependency on CONFIG_KEXEC. There is no
functional change with this patch.
Link: http://lkml.kernel.org/r/149035338104.6881.4550894432615189948.stgit@hbathini.in.ibm.com
Signed-off-by: Hari Bathini <hbathini@linux.vnet.ibm.com>
Acked-by: Dave Young <dyoung@redhat.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch extends the idea of NMI per-cpu buffers to regions
that may cause recursive printk() calls and possible deadlocks.
Namely, printk() can't handle printk calls from schedule code
or printk() calls from lock debugging code (spin_dump() for instance);
because those may be called with `sem->lock' already taken or any
other `critical' locks (p->pi_lock, etc.). An example of deadlock
can be
vprintk_emit()
console_unlock()
up() << raw_spin_lock_irqsave(&sem->lock, flags);
wake_up_process()
try_to_wake_up()
ttwu_queue()
ttwu_activate()
activate_task()
enqueue_task()
enqueue_task_fair()
cfs_rq_of()
task_of()
WARN_ON_ONCE(!entity_is_task(se))
vprintk_emit()
console_trylock()
down_trylock()
raw_spin_lock_irqsave(&sem->lock, flags)
^^^^ deadlock
and some other cases.
Just like in NMI implementation, the solution uses a per-cpu
`printk_func' pointer to 'redirect' printk() calls to a 'safe'
callback, that store messages in a per-cpu buffer and flushes
them back to logbuf buffer later.
Usage example:
printk()
printk_safe_enter_irqsave(flags)
//
// any printk() call from here will endup in vprintk_safe(),
// that stores messages in a special per-CPU buffer.
//
printk_safe_exit_irqrestore(flags)
The 'redirection' mechanism, though, has been reworked, as suggested
by Petr Mladek. Instead of using a per-cpu @print_func callback we now
keep a per-cpu printk-context variable and call either default or nmi
vprintk function depending on its value. printk_nmi_entrer/exit and
printk_safe_enter/exit, thus, just set/celar corresponding bits in
printk-context functions.
The patch only adds printk_safe support, we don't use it yet.
Link: http://lkml.kernel.org/r/20161227141611.940-4-sergey.senozhatsky@gmail.com
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Tejun Heo <tj@kernel.org>
Cc: Calvin Owens <calvinowens@fb.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Peter Hurley <peter@hurleysoftware.com>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Add a configuration option to set the default console loglevel. This
is, as before, still possible to override at runtime through bootargs
(loglevel=<x>), sysrq and /proc/printk.
There are cases where adding additional arguments on the commandline is
impractical, and changing the default for the kernel when being built
makes more sense. Provide such a method here, for those who choose to
do so.
Also, while touching this code, clarify the difference between
MESSAGE_LOGLEVEL_DEFAULT and CONSOLE_LOGLEVEL_DEFAULT.
Link: http://lkml.kernel.org/r/1479676829-30031-1-git-send-email-olof@lixom.net
Signed-off-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit 4bcc595ccd ("printk: reinstate KERN_CONT for printing
continuation lines") allows to define more message headers for a single
message. The motivation is that continuous lines might get mixed.
Therefore it make sense to define the right log level for every piece of
a cont line.
The current btrfs_printk() macros do not support continuous lines at the
moment. But better be prepared for a custom messages and avoid
potential "lvl" buffer overflow.
This patch iterates over the entire message header. It is interested
only into the message level like the original code.
This patch also introduces PRINTK_MAX_SINGLE_HEADER_LEN. Three bytes
are enough for the message level header at the moment. But it used to
be three, see the commit 04d2c8c83d ("printk: convert the format for
KERN_<LEVEL> to a 2 byte pattern").
Also I fixed the default ratelimit level. It looked very strange when it
was different from the default log level.
[pmladek@suse.com: Fix a check of the valid message level]
Link: http://lkml.kernel.org/r/20161111183236.GD2145@dhcp128.suse.cz
Link: http://lkml.kernel.org/r/1478695291-12169-4-git-send-email-pmladek@suse.com
Signed-off-by: Petr Mladek <pmladek@suse.com>
Acked-by: David Sterba <dsterba@suse.com>
Cc: Joe Perches <joe@perches.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: Jaroslav Kysela <perex@perex.cz>
Cc: Takashi Iwai <tiwai@suse.com>
Cc: Chris Mason <clm@fb.com>
Cc: Josef Bacik <jbacik@fb.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Long long ago the kernel log buffer was a buffered stream of bytes, very
much like stdio in user space. It supported log levels by scanning the
stream and noticing the log level markers at the beginning of each line,
but if you wanted to print a partial line in multiple chunks, you just
did multiple printk() calls, and it just automatically worked.
Except when it didn't, and you had very confusing output when different
lines got all mixed up with each other. Then you got fragment lines
mixing with each other, or with non-fragment lines, because it was
traditionally impossible to tell whether a printk() call was a
continuation or not.
To at least help clarify the issue of continuation lines, we added a
KERN_CONT marker back in 2007 to mark continuation lines:
4749252776 ("printk: add KERN_CONT annotation").
That continuation marker was initially an empty string, and didn't
actuall make any semantic difference. But it at least made it possible
to annotate the source code, and have check-patch notice that a printk()
didn't need or want a log level marker, because it was a continuation of
a previous line.
To avoid the ambiguity between a continuation line that had that
KERN_CONT marker, and a printk with no level information at all, we then
in 2009 made KERN_CONT be a real log level marker which meant that we
could now reliably tell the difference between the two cases.
5fd29d6ccb ("printk: clean up handling of log-levels and newlines")
and we could take advantage of that to make sure we didn't mix up
continuation lines with lines that just didn't have any loglevel at all.
Then, in 2012, the kernel log buffer was changed to be a "record" based
log, where each line was a record that has a loglevel and a timestamp.
You can see the beginning of that conversion in commits
e11fea92e1 ("kmsg: export printk records to the /dev/kmsg interface")
7ff9554bb5 ("printk: convert byte-buffer to variable-length record buffer")
with a number of follow-up commits to fix some painful fallout from that
conversion. Over all, it took a couple of months to sort out most of
it. But the upside was that you could have concurrent readers (and
writers) of the kernel log and not have lines with mixed output in them.
And one particular pain-point for the record-based kernel logging was
exactly the fragmentary lines that are generated in smaller chunks. In
order to still log them as one recrod, the continuation lines need to be
attached to the previous record properly.
However the explicit continuation record marker that is actually useful
for this exact case was actually removed in aroundm the same time by commit
61e99ab8e3 ("printk: remove the now unnecessary "C" annotation for KERN_CONT")
due to the incorrect belief that KERN_CONT wasn't meaningful. The
ambiguity between "is this a continuation line" or "is this a plain
printk with no log level information" was reintroduced, and in fact
became an even bigger pain point because there was now the whole
record-level merging of kernel messages going on.
This patch reinstates the KERN_CONT as a real non-empty string marker,
so that the ambiguity is fixed once again.
But it's not a plain revert of that original removal: in the four years
since we made KERN_CONT an empty string again, not only has the format
of the log level markers changed, we've also had some usage changes in
this area.
For example, some ACPI code seems to use KERN_CONT _together_ with a log
level, and now uses both the KERN_CONT marker and (for example) a
KERN_INFO marker to show that it's an informational continuation of a
line.
Which is actually not a bad idea - if the continuation line cannot be
attached to its predecessor, without the log level information we don't
know what log level to assign to it (and we traditionally just assigned
it the default loglevel). So having both a log level and the KERN_CONT
marker is not necessarily a bad idea, but it does mean that we need to
actually iterate over potentially multiple markers, rather than just a
single one.
Also, since KERN_CONT was still conceptually needed, and encouraged, but
didn't actually _do_ anything, we've also had the reverse problem:
rather than having too many annotations it has too few, and there is bit
rot with code that no longer marks the continuation lines with the
KERN_CONT marker.
So this patch not only re-instates the non-empty KERN_CONT marker, it
also fixes up the cases of bit-rot I noticed in my own logs.
There are probably other cases where KERN_CONT will be needed to be
added, either because it is new code that never dealt with the need for
KERN_CONT, or old code that has bitrotted without anybody noticing.
That said, we should strive to avoid the need for KERN_CONT. It does
result in real problems for logging, and should generally not be seen as
a good feature. If we some day can get rid of the feature entirely,
because nobody does any fragmented printk calls, that would be lovely.
But until that point, let's at mark the code that relies on the hacky
multi-fragment kernel printk's. Not only does it avoid the ambiguity,
it also annotates code as "maybe this would be good to fix some day".
(That said, particularly during single-threaded bootup, the downsides of
KERN_CONT are very limited. Things get much hairier when you have
multiple threads going on and user level reading and writing logs too).
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This reverts commit 874f9c7da9.
Geert Uytterhoeven reports:
"This change seems to have an (unintendent?) side-effect.
Before, pr_*() calls without a trailing newline characters would be
printed with a newline character appended, both on the console and in
the output of the dmesg command.
After this commit, no new line character is appended, and the output
of the next pr_*() call of the same type may be appended, like in:
- Truncating RAM at 0x0000000040000000-0x00000000c0000000 to -0x0000000070000000
- Ignoring RAM at 0x0000000200000000-0x0000000240000000 (!CONFIG_HIGHMEM)
+ Truncating RAM at 0x0000000040000000-0x00000000c0000000 to -0x0000000070000000Ignoring RAM at 0x0000000200000000-0x0000000240000000 (!CONFIG_HIGHMEM)"
Joe Perches says:
"No, that is not intentional.
The newline handling code inside vprintk_emit is a bit involved and
for now I suggest a revert until this has all the same behavior as
earlier"
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Requested-by: Joe Perches <joe@perches.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add a "printk.devkmsg" kernel command line parameter which controls how
userspace writes into /dev/kmsg. It has three options:
* ratelimit - ratelimit logging from userspace.
* on - unlimited logging from userspace
* off - logging from userspace gets ignored
The default setting is to ratelimit the messages written to it.
This changes the kernel default setting of "on" to "ratelimit" and we do
that because we want to keep userspace spamming /dev/kmsg to sane
levels. This is especially moot when a small kernel log buffer wraps
around and messages get lost. So the ratelimiting setting should be a
sane setting where kernel messages should have a bit higher chance of
survival from all the spamming.
It additionally does not limit logging to /dev/kmsg while the system is
booting if we haven't disabled it on the command line.
Furthermore, we can control the logging from a lower priority sysctl
interface - kernel.printk_devkmsg.
That interface will succeed only if printk.devkmsg *hasn't* been
supplied on the command line. If it has, then printk.devkmsg is a
one-time setting which remains for the duration of the system lifetime.
This "locking" of the setting is to prevent userspace from changing the
logging on us through sysctl(2).
This patch is based on previous patches from Linus and Steven.
[bp@suse.de: fixes]
Link: http://lkml.kernel.org/r/20160719072344.GC25563@nazgul.tnic
Link: http://lkml.kernel.org/r/20160716061745.15795-3-bp@alien8.de
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Dave Young <dyoung@redhat.com>
Cc: Franck Bui <fbui@suse.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Using functions instead of macros can reduce overall code size by
eliminating unnecessary "KERN_SOH<digit>" prefixes from format strings.
defconfig x86-64:
$ size vmlinux*
text data bss dec hex filename
10193570 4331464 1105920 15630954 ee826a vmlinux.new
10192623 4335560 1105920 15634103 ee8eb7 vmlinux.old
As the return value are unimportant and unused in the kernel tree, these
new functions return void.
Miscellanea:
- change pr_<level> macros to call new __pr_<level> functions
- change vprintk_nmi and vprintk_default to add LOGLEVEL_<level> argument
[akpm@linux-foundation.org: fix LOGLEVEL_INFO, per Joe]
Link: http://lkml.kernel.org/r/e16cc34479dfefcae37c98b481e6646f0f69efc3.1466718827.git.joe@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In NMI context, printk() messages are stored into per-CPU buffers to
avoid a possible deadlock. They are normally flushed to the main ring
buffer via an IRQ work. But the work is never called when the system
calls panic() in the very same NMI handler.
This patch tries to flush NMI buffers before the crash dump is
generated. In this case it does not risk a double release and bails out
when the logbuf_lock is already taken. The aim is to get the messages
into the main ring buffer when possible. It makes them better
accessible in the vmcore.
Then the patch tries to flush the buffers second time when other CPUs
are down. It might be more aggressive and reset logbuf_lock. The aim
is to get the messages available for the consequent kmsg_dump() and
console_flush_on_panic() calls.
The patch causes vprintk_emit() to be called even in NMI context again.
But it is done via printk_deferred() so that the console handling is
skipped. Consoles use internal locks and we could not prevent a
deadlock easily. They are explicitly called later when the crash dump
is not generated, see console_flush_on_panic().
Signed-off-by: Petr Mladek <pmladek@suse.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Daniel Thompson <daniel.thompson@linaro.org>
Cc: David Miller <davem@davemloft.net>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jiri Kosina <jkosina@suse.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
printk() takes some locks and could not be used a safe way in NMI
context.
The chance of a deadlock is real especially when printing stacks from
all CPUs. This particular problem has been addressed on x86 by the
commit a9edc88093 ("x86/nmi: Perform a safe NMI stack trace on all
CPUs").
The patchset brings two big advantages. First, it makes the NMI
backtraces safe on all architectures for free. Second, it makes all NMI
messages almost safe on all architectures (the temporary buffer is
limited. We still should keep the number of messages in NMI context at
minimum).
Note that there already are several messages printed in NMI context:
WARN_ON(in_nmi()), BUG_ON(in_nmi()), anything being printed out from MCE
handlers. These are not easy to avoid.
This patch reuses most of the code and makes it generic. It is useful
for all messages and architectures that support NMI.
The alternative printk_func is set when entering and is reseted when
leaving NMI context. It queues IRQ work to copy the messages into the
main ring buffer in a safe context.
__printk_nmi_flush() copies all available messages and reset the buffer.
Then we could use a simple cmpxchg operations to get synchronized with
writers. There is also used a spinlock to get synchronized with other
flushers.
We do not longer use seq_buf because it depends on external lock. It
would be hard to make all supported operations safe for a lockless use.
It would be confusing and error prone to make only some operations safe.
The code is put into separate printk/nmi.c as suggested by Steven
Rostedt. It needs a per-CPU buffer and is compiled only on
architectures that call nmi_enter(). This is achieved by the new
HAVE_NMI Kconfig flag.
The are MN10300 and Xtensa architectures. We need to clean up NMI
handling there first. Let's do it separately.
The patch is heavily based on the draft from Peter Zijlstra, see
https://lkml.org/lkml/2015/6/10/327
[arnd@arndb.de: printk-nmi: use %zu format string for size_t]
[akpm@linux-foundation.org: min_t->min - all types are size_t here]
Signed-off-by: Petr Mladek <pmladek@suse.com>
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Jan Kara <jack@suse.cz>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk> [arm part]
Cc: Daniel Thompson <daniel.thompson@linaro.org>
Cc: Jiri Kosina <jkosina@suse.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: David Miller <davem@davemloft.net>
Cc: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently, pr_debug and pr_devel will not elide function call arguments
appearing in calls to the no_printk for these macros. This is because
all side effects must be honored before proceeding to the 0-value
assignment in no_printk.
The behavior is contrary to documentation found in the CodingStyle and
the header file where these functions are declared.
This patch corrects that behavior by shunting out the call to no_printk
completely. The format string is still checked by gcc for correctness,
but no code seems to be emitted in common cases.
[akpm@linux-foundation.org: remove braces, per Joe]
Fixes: 5264f2f75d ("include/linux/printk.h: use and neaten no_printk")
Signed-off-by: Aaron Conole <aconole@redhat.com>
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Joe Perches <joe@perches.com>
Cc: Jason Baron <jbaron@akamai.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
print_hex_dump_debug() is likely supposed to be analogous to pr_debug() or
dev_dbg() & friends. Currently it will adhere to dynamic debug, but will
not stub out prints if CONFIG_DEBUG is not set. Let's make it do the
right thing, because I am tired of having my dmesg buffer full of hex
dumps on production systems.
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The other two implementations of pr_debug_ratelimited include pr_fmt,
along with every other pr_* function. But pr_debug_ratelimited forgot to
add it with the CONFIG_DYNAMIC_DEBUG implementation.
This patch unifies the behavior.
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Using __printf attributes helps to detect several format string issues
at compile time (even though -Wformat-security is currently disabled in
Makefile). For example it can detect when formatting a pointer as a
number, like the issue fixed in commit a3fa71c40f ("wl18xx: show
rx_frames_per_rates as an array as it really is"), or when the arguments
do not match the format string, c.f. for example commit 5ce1aca814
("reiserfs: fix __RASSERT format string").
To prevent similar bugs in the future, add a __printf attribute to every
function prototype which needs one in include/linux/ and lib/. These
functions were mostly found by using gcc's -Wsuggest-attribute=format
flag.
Signed-off-by: Nicolas Iooss <nicolas.iooss_linux@m4x.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Felipe Balbi <balbi@ti.com>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patchset updates netconsole so that it can emit messages with the
same header as used in /dev/kmsg which gives neconsole receiver full log
information which enables things like structured logging and detection
of lost messages.
This patch (of 7):
devkmsg_read() uses 8k buffer and assumes that the formatted output
message won't overrun which seems safe given LOG_LINE_MAX, the current use
of dict and the escaping method being used; however, we're planning to use
devkmsg formatting wider and accounting for the buffer size properly isn't
that complicated.
This patch defines CONSOLE_EXT_LOG_MAX as 8192 and updates devkmsg_read()
so that it limits output accordingly.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: David Miller <davem@davemloft.net>
Cc: Kay Sievers <kay@vrfy.org>
Reviewed-by: Petr Mladek <pmladek@suse.cz>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
KERN_CONT is nicely commented in kern_levels.h, but pr_cont() is now used
more often, and it lacks the comment stating what it is used for. It can
be confused as continuing the log level, but that is not its purpose. Its
purpose is to continue a line that had no newline enclosed. This should
be documented by pr_cont() as well.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Acked-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch makes hexdump return the number of bytes placed in the buffer
excluding trailing NUL. In the case of overflow it returns the desired
amount of bytes to produce the entire dump. Thus, it mimics snprintf().
This will be useful for users that would like to repeat with a bigger
buffer.
[akpm@linux-foundation.org: fix printk warning]
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull nmi-safe seq_buf printk update from Steven Rostedt:
"This code is a fork from the trace-3.19 pull as it needed the
trace_seq clean ups from that branch.
This code solves the issue of performing stack dumps from NMI context.
The issue is that printk() is not safe from NMI context as if the NMI
were to trigger when a printk() was being performed, the NMI could
deadlock from the printk() internal locks. This has been seen in
practice.
With lots of review from Petr Mladek, this code went through several
iterations, and we feel that it is now at a point of quality to be
accepted into mainline.
Here's what is contained in this patch set:
- Creates a "seq_buf" generic buffer utility that allows a descriptor
to be passed around where functions can write their own "printk()"
formatted strings into it. The generic version was pulled out of
the trace_seq() code that was made specifically for tracing.
- The seq_buf code was change to model the seq_file code. I have a
patch (not included for 3.19) that converts the seq_file.c code
over to use seq_buf.c like the trace_seq.c code does. This was
done to make sure that seq_buf.c is compatible with seq_file.c. I
may try to get that patch in for 3.20.
- The seq_buf.c file was moved to lib/ to remove it from being
dependent on CONFIG_TRACING.
- The printk() was updated to allow for a per_cpu "override" of the
internal calls. That is, instead of writing to the console, a call
to printk() may do something else. This made it easier to allow
the NMI to change what printk() does in order to call dump_stack()
without needing to update that code as well.
- Finally, the dump_stack from all CPUs via NMI code was converted to
use the seq_buf code. The caller to trigger the NMI code would
wait till all the NMIs finished, and then it would print the
seq_buf data to the console safely from a non NMI context
One added bonus is that this code also makes the NMI dump stack work
on PREEMPT_RT kernels. As printk() includes sleeping locks on
PREEMPT_RT, printk() only writes to console if the console does not
use any rt_mutex converted spin locks. Which a lot do"
* tag 'trace-seq-buf-3.19' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
x86/nmi: Fix use of unallocated cpumask_var_t
printk/percpu: Define printk_func when printk is not defined
x86/nmi: Perform a safe NMI stack trace on all CPUs
printk: Add per_cpu printk func to allow printk to be diverted
seq_buf: Move the seq_buf code to lib/
seq-buf: Make seq_buf_bprintf() conditional on CONFIG_BINARY_PRINTF
tracing: Add seq_buf_get_buf() and seq_buf_commit() helper functions
tracing: Have seq_buf use full buffer
seq_buf: Add seq_buf_can_fit() helper function
tracing: Add paranoid size check in trace_printk_seq()
tracing: Use trace_seq_used() and seq_buf_used() instead of len
tracing: Clean up tracing_fill_pipe_page()
seq_buf: Create seq_buf_used() to find out how much was written
tracing: Add a seq_buf_clear() helper and clear len and readpos in init
tracing: Convert seq_buf fields to be like seq_file fields
tracing: Convert seq_buf_path() to be like seq_path()
tracing: Create seq_buf layer in trace_seq
Eliminate the unlikely possibility of message interleaving for
early_printk/early_vprintk use.
early_vprintk can be done via the %pV extension so remove this
unnecessary function and change early_printk to have the equivalent
vprintk code.
All uses of early_printk already end with a newline so also remove the
unnecessary newline from the early_printk function.
Signed-off-by: Joe Perches <joe@perches.com>
Acked-by: Chris Metcalf <cmetcalf@tilera.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
To avoid include hell, the per_cpu variable printk_func was declared
in percpu.h. But it is only defined if printk is defined.
As users of printk may also use the printk_func variable, it needs to
be defined even if CONFIG_PRINTK is not.
Also add a printk.h include in percpu.h just to be safe.
Link: http://lkml.kernel.org/r/20141121183215.01ba539c@canb.auug.org.au
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Being able to divert printk to call another function besides the normal
logging is useful for such things like NMI handling. If some functions
are to be called from NMI that does printk() it is possible to lock up
the box if the nmi handler triggers when another printk is happening.
One example of this use is to perform a stack trace on all CPUs via NMI.
But if the NMI is to do the printk() it can cause the system to lock up.
By allowing the printk to be diverted to another function that can safely
record the printk output and then print it when it in a safe context
then NMIs will be safe to call these functions like show_regs().
Link: http://lkml.kernel.org/p/20140619213952.209176403@goodmis.org
Tested-by: Jiri Kosina <jkosina@suse.cz>
Acked-by: Jiri Kosina <jkosina@suse.cz>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Petr Mladek <pmladek@suse.cz>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Platforms like IBM Power Systems supports service processor
assisted dump. It provides interface to add memory region to
be captured when system is crashed.
During initialization/running we can add kernel memory region
to be collected.
Presently we don't have a way to get the log buffer base address
and size. This patch adds support to return log buffer address
and size.
Signed-off-by: Vasant Hegde <hegdevasant@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Andrew Morton <akpm@linux-foundation.org>
Commit a8fe19ebfb ("kernel/printk: use symbolic defines for console
loglevels") makes consistent use of symbolic values for printk() log
levels.
The naming scheme used is different from the one used for
DEFAULT_MESSAGE_LOGLEVEL though. Change that symbol name to be
MESSAGE_LOGLEVEL_DEFAULT for consistency. And because the value of that
symbol comes from a similarly-named config option, rename
CONFIG_DEFAULT_MESSAGE_LOGLEVEL as well.
Signed-off-by: Alex Elder <elder@linaro.org>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: Jan Kara <jack@suse.cz>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Petr Mladek <pmladek@suse.cz>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
... instead of naked numbers.
Stuff in sysrq.c used to set it to 8 which is supposed to mean above
default level so set it to DEBUG instead as we're terminating/killing all
tasks and we want to be verbose there.
Also, correct the check in x86_64_start_kernel which should be >= as
we're clearly issuing the string there for all debug levels, not only
the magical 10.
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Joe Perches <joe@perches.com>
Cc: Valdis Kletnieks <Valdis.Kletnieks@vt.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The pr_debug() and related debug print macros all differ from the normal
pr_XXX() macros, in that the normal ones print unconditionally, while
the debug macros are compiled out unless DEBUG is defined or
CONFIG_DYNAMIC_DEBUG is set. This isn't obvious, and the only way to
find this out is either to review the actual printk.h code or to read
CodingStyle, and the message there doesn't highlight the fact.
Change Documentation/CodingStyle to clearly indicate that pr_debug() and
related debug printing macros behave differently than all other pr_XXX()
macros, and attempt to clarify when and where the different debug
printing methods might be used.
Add short comment to printk.h above the pr_XXX() macros indicating that
while these macros print unconditionally, pr_debug() does not.
Signed-off-by: Dan Streetman <ddstreet@ieee.org>
Cc: Joe Perches <joe@perches.com>
Cc: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
