simple_fill_super() is passed an array of tree_descr structures which
describe the files to create in the filesystem's root directory. Since
these arrays are never modified intentionally, they should be 'const' so
that they are placed in .rodata and benefit from memory protection.
This patch updates the function signature and all users, and also
constifies tree_descr.name.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Sorayukii <sorayukii69@gmail.com>
Eric Biggersauthored and Sorayukiicommited 2026-05-15 17:55:17 +07:00
* refs/heads/tmp-d47e38b:
Linux 4.9.174
media: v4l2: i2c: ov7670: Fix PLL bypass register values
x86/mce: Improve error message when kernel cannot recover, p2
selinux: never allow relabeling on context mounts
Input: snvs_pwrkey - initialize necessary driver data before enabling IRQ
scsi: RDMA/srpt: Fix a credit leak for aborted commands
staging: iio: adt7316: fix the dac write calculation
staging: iio: adt7316: fix the dac read calculation
staging: iio: adt7316: allow adt751x to use internal vref for all dacs
perf/x86/amd: Update generic hardware cache events for Family 17h
ARM: iop: don't use using 64-bit DMA masks
ARM: orion: don't use using 64-bit DMA masks
xsysace: Fix error handling in ace_setup
sh: fix multiple function definition build errors
hugetlbfs: fix memory leak for resv_map
net: hns: Fix WARNING when remove HNS driver with SMMU enabled
net: hns: Use NAPI_POLL_WEIGHT for hns driver
net: hns: fix KASAN: use-after-free in hns_nic_net_xmit_hw()
scsi: storvsc: Fix calculation of sub-channel count
scsi: core: add new RDAC LENOVO/DE_Series device
vfio/pci: use correct format characters
rtc: da9063: set uie_unsupported when relevant
debugfs: fix use-after-free on symlink traversal
jffs2: fix use-after-free on symlink traversal
net: stmmac: don't log oversized frames
net: stmmac: fix dropping of multi-descriptor RX frames
net: stmmac: don't overwrite discard_frame status
bonding: show full hw address in sysfs for slave entries
net/mlx5: E-Switch, Fix esw manager vport indication for more vport commands
igb: Fix WARN_ONCE on runtime suspend
batman-adv: Reduce tt_global hash refcnt only for removed entry
batman-adv: Reduce tt_local hash refcnt only for removed entry
batman-adv: Reduce claim hash refcnt only for removed entry
rtc: sh: Fix invalid alarm warning for non-enabled alarm
HID: debug: fix race condition with between rdesc_show() and device removal
HID: logitech: check the return value of create_singlethread_workqueue
nvme-loop: init nvmet_ctrl fatal_err_work when allocate
USB: core: Fix bug caused by duplicate interface PM usage counter
USB: core: Fix unterminated string returned by usb_string()
usb: usbip: fix isoc packet num validation in get_pipe
USB: w1 ds2490: Fix bug caused by improper use of altsetting array
USB: yurex: Fix protection fault after device removal
caif: reduce stack size with KASAN
arm64: mm: don't print out page table entries on EL0 faults
arm64: mm: print out correct page table entries
kasan: prevent compiler from optimizing away memset in tests
arm64: proc: Set PTE_NG for table entries to avoid traversing them twice
kasan: remove redundant initialization of variable 'real_size'
kasan: avoid -Wmaybe-uninitialized warning
kasan: add a prototype of task_struct to avoid warning
arm64: kasan: avoid bad virt_to_pfn()
x86/unwind: Disable KASAN checks for non-current tasks
mm/kasan: Switch to using __pa_symbol and lm_alias
x86/suspend: fix false positive KASAN warning on suspend/resume
net: phy: marvell: Fix buffer overrun with stats counters
bnxt_en: Improve multicast address setup logic.
packet: validate msg_namelen in send directly
ipv6: invert flowlabel sharing check in process and user mode
ipv6/flowlabel: wait rcu grace period before put_pid()
ipv4: ip_do_fragment: Preserve skb_iif during fragmentation
ALSA: line6: use dynamic buffers
ANDROID: cuttlefish 4.9: enable CONFIG_CRYPTO_AES_NI_INTEL=y
Change-Id: Ic2b4a8e559d993acfce1b5e963949dc297614f3a
Signed-off-by: Tengfei Fan <tengfeif@codeaurora.org>
[ Upstream commit 93b919da64c15b90953f96a536e5e61df896ca57 ]
symlink body shouldn't be freed without an RCU delay. Switch debugfs to
->destroy_inode() and use of call_rcu(); free both the inode and symlink
body in the callback. Similar to solution for bpf, only here it's even
more obvious that ->evict_inode() can be dropped.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Al Viroauthored and Greg Kroah-Hartmancommited 2019-05-08 07:19:10 +02:00
* refs/heads/tmp-fd5657a:
Linux 4.9.160
ax25: fix possible use-after-free
mISDN: fix a race in dev_expire_timer()
net/x25: do not hold the cpu too long in x25_new_lci()
btrfs: Remove false alert when fiemap range is smaller than on-disk extent
net: ipv4: use a dedicated counter for icmp_v4 redirect packets
net: stmmac: Fix a race in EEE enable callback
vxlan: test dev->flags & IFF_UP before calling netif_rx()
tcp: clear icsk_backoff in tcp_write_queue_purge()
net: Do not allocate page fragments that are not skb aligned
tcp: tcp_v4_err() should be more careful
net: Add header for usage of fls64()
vhost: correctly check the return value of translate_desc() in log_used()
sky2: Increase D3 delay again
net: stmmac: handle endianness in dwmac4_get_timestamp
net: phy: xgmiitorgmii: Support generic PHY status read
net: Fix for_each_netdev_feature on Big endian
hwmon: (lm80) Fix missing unlock on error in set_fan_div()
vsock: cope with memory allocation failure at socket creation time
net: fix IPv6 prefix route residue
Build break
FROMLIST: BACKPORT: overlayfs: override_creds=off option bypass creator_cred
Linux 4.9.159
Revert "scsi: aic94xx: fix module loading"
uapi/if_ether.h: move __UAPI_DEF_ETHHDR libc define
mm: stop leaking PageTables
pinctrl: msm: fix gpio-hog related boot issues
netfilter: nf_tables: fix mismatch in big-endian system
usb: dwc2: Remove unnecessary kfree
kaweth: use skb_cow_head() to deal with cloned skbs
ch9200: use skb_cow_head() to deal with cloned skbs
smsc95xx: Use skb_cow_head to deal with cloned skbs
drm/i915: Prevent a race during I915_GEM_MMAP ioctl with WC set
dm thin: fix bug where bio that overwrites thin block ignores FUA
x86/a.out: Clear the dump structure initially
signal: Restore the stop PTRACE_EVENT_EXIT
x86/platform/UV: Use efi_runtime_lock to serialise BIOS calls
tracing/uprobes: Fix output for multiple string arguments
alpha: Fix Eiger NR_IRQS to 128
alpha: fix page fault handling for r16-r18 targets
Input: elantech - enable 3rd button support on Fujitsu CELSIUS H780
Input: bma150 - register input device after setting private data
kvm: vmx: Fix entry number check for add_atomic_switch_msr()
ALSA: usb-audio: Fix implicit fb endpoint setup by quirk
ALSA: hda - Add quirk for HP EliteBook 840 G5
perf/x86: Add check_period PMU callback
perf/core: Fix impossible ring-buffer sizes warning
Input: elan_i2c - add ACPI ID for touchpad in Lenovo V330-15ISK
Revert "Input: elan_i2c - add ACPI ID for touchpad in ASUS Aspire F5-573G"
perf report: Include partial stacks unwound with libdw
cifs: Limit memory used by lock request calls to a page
gpio: pl061: handle failed allocations
ARM: dts: kirkwood: Fix polarity of GPIO fan lines
ARM: dts: da850-lcdk: Correct the sound card name
ARM: dts: da850-evm: Correct the sound card name
drm/bridge: tc358767: fix output H/V syncs
drm/bridge: tc358767: reject modes which require too much BW
drm/bridge: tc358767: fix initial DP0/1_SRCCTRL value
drm/bridge: tc358767: fix single lane configuration
drm/bridge: tc358767: add defines for DP1_SRCCTRL & PHY_2LANE
cpufreq: check if policy is inactive early in __cpufreq_get()
ACPI: NUMA: Use correct type for printing addresses on i386-PAE
bnx2x: disable GSO where gso_size is too big for hardware
net: create skb_gso_validate_mac_len()
ARM: fix the cockup in the previous patch
ARM: ensure that processor vtables is not lost after boot
ARM: spectre-v2: per-CPU vtables to work around big.Little systems
ARM: add PROC_VTABLE and PROC_TABLE macros
ARM: clean up per-processor check_bugs method call
ARM: split out processor lookup
ARM: make lookup_processor_type() non-__init
ARM: 8810/1: vfp: Fix wrong assignement to ufp_exc
ARM: 8797/1: spectre-v1.1: harden __copy_to_user
ARM: 8796/1: spectre-v1,v1.1: provide helpers for address sanitization
ARM: 8795/1: spectre-v1.1: use put_user() for __put_user()
ARM: 8794/1: uaccess: Prevent speculative use of the current addr_limit
ARM: 8793/1: signal: replace __put_user_error with __put_user
ARM: 8792/1: oabi-compat: copy oabi events using __copy_to_user()
ARM: 8791/1: vfp: use __copy_to_user() when saving VFP state
ARM: 8789/1: signal: copy registers using __copy_to_user()
uapi/if_ether.h: prevent redefinition of struct ethhdr
eeprom: at24: add support for 24c2048
dt-bindings: eeprom: at24: add "atmel,24c2048" compatible string
BACKPORT: userfaultfd: shmem/hugetlbfs: only allow to register VM_MAYWRITE vmas
ANDROID: cuttlefish_defconfig: Enable DEBUG_SET_MODULE_RONX
Linux 4.9.158
Revert "exec: load_script: don't blindly truncate shebang string"
Linux 4.9.157
batman-adv: Force mac header to start of data on xmit
batman-adv: Avoid WARN on net_device without parent in netns
xfrm: refine validation of template and selector families
libceph: avoid KEEPALIVE_PENDING races in ceph_con_keepalive()
Revert "cifs: In Kconfig CONFIG_CIFS_POSIX needs depends on legacy (insecure cifs)"
HID: debug: fix the ring buffer implementation
nfsd4: catch some false session retries
nfsd4: fix cached replies to solo SEQUENCE compounds
drm/vmwgfx: Return error code from vmw_execbuf_copy_fence_user
drm/vmwgfx: Fix setting of dma masks
drm/modes: Prevent division by zero htotal
mac80211: ensure that mgmt tx skbs have tailroom for encryption
ARM: tango: Improve ARCH_MULTIPLATFORM compatibility
ARM: iop32x/n2100: fix PCI IRQ mapping
MIPS: VDSO: Include $(ccflags-vdso) in o32,n32 .lds builds
MIPS: OCTEON: don't set octeon_dma_bar_type if PCI is disabled
mips: cm: reprime error cause
debugfs: fix debugfs_rename parameter checking
samples: mei: use /dev/mei0 instead of /dev/mei
misc: vexpress: Off by one in vexpress_syscfg_exec()
signal: Better detection of synchronous signals
signal: Always notice exiting tasks
iio: chemical: atlas-ph-sensor: correct IIO_TEMP values to millicelsius
mtd: rawnand: gpmi: fix MX28 bus master lockup problem
ANDROID: cuttlefish: enable CONFIG_NET_SCH_NETEM=y
Add XFRM-I to cuttlefish defconfigs
ANDROID: Move from clang r346389b to r349610.
Linux 4.9.156
ath9k: dynack: check da->enabled first in sampling routines
ath9k: dynack: make ewma estimation faster
perf/x86/intel: Delay memory deallocation until x86_pmu_dead_cpu()
IB/hfi1: Add limit test for RC/UC send via loopback
PCI: vmd: Free up IRQs on suspend path
oom, oom_reaper: do not enqueue same task twice
serial: fix race between flush_to_ldisc and tty_open
perf tests evsel-tp-sched: Fix bitwise operator
perf/core: Don't WARN() for impossible ring-buffer sizes
x86/MCE: Initialize mce.bank in the case of a fatal error in mce_no_way_out()
perf/x86/intel/uncore: Add Node ID mask
KVM: nVMX: unconditionally cancel preemption timer in free_nested (CVE-2019-7221)
kvm: fix kvm_ioctl_create_device() reference counting (CVE-2019-6974)
KVM: x86: work around leak of uninitialized stack contents (CVE-2019-7222)
scsi: aic94xx: fix module loading
usb: gadget: musb: fix short isoc packets with inventra dma
usb: gadget: udc: net2272: Fix bitwise and boolean operations
usb: phy: am335x: fix race condition in _probe
dmaengine: imx-dma: fix wrong callback invoke
dmaengine: bcm2835: Fix abort of transactions
dmaengine: bcm2835: Fix interrupt race on RT
fuse: handle zero sized retrieve correctly
fuse: decrement NR_WRITEBACK_TEMP on the right page
fuse: call pipe_buf_release() under pipe lock
ALSA: hda - Serialize codec registrations
ALSA: compress: Fix stop handling on compressed capture streams
enic: fix checksum validation for IPv6
net: dsa: slave: Don't propagate flag changes on down slave interfaces
net/mlx5e: Force CHECKSUM_UNNECESSARY for short ethernet frames
net: systemport: Fix WoL with password after deep sleep
rds: fix refcount bug in rds_sock_addref
skge: potential memory corruption in skge_get_regs()
rxrpc: bad unlock balance in rxrpc_recvmsg
net: dp83640: expire old TX-skb
dccp: fool proof ccid_hc_[rt]x_parse_options()
thermal: hwmon: inline helpers when CONFIG_THERMAL_HWMON is not set
exec: load_script: don't blindly truncate shebang string
fs/epoll: drop ovflist branch prediction
proc/sysctl: fix return error for proc_doulongvec_minmax()
kernel/hung_task.c: break RCU locks based on jiffies
HID: lenovo: Add checks to fix of_led_classdev_register
thermal: generic-adc: Fix adc to temp interpolation
block/swim3: Fix -EBUSY error when re-opening device after unmount
fsl/fman: Use GFP_ATOMIC in {memac,tgec}_add_hash_mac_address()
gdrom: fix a memory leak bug
isdn: hisax: hfc_pci: Fix a possible concurrency use-after-free bug in HFCPCI_l1hw()
ocfs2: don't clear bh uptodate for block read
scripts/decode_stacktrace: only strip base path when a prefix of the path
f2fs: fix sbi->extent_list corruption issue
niu: fix missing checks of niu_pci_eeprom_read
um: Avoid marking pages with "changed protection"
cifs: check ntwrk_buf_start for NULL before dereferencing it
MIPS: ralink: Select CONFIG_CPU_MIPSR2_IRQ_VI on MT7620/8
crypto: ux500 - Use proper enum in hash_set_dma_transfer
crypto: ux500 - Use proper enum in cryp_set_dma_transfer
seq_buf: Make seq_buf_puts() null-terminate the buffer
hwmon: (lm80) fix a missing check of bus read in lm80 probe
hwmon: (lm80) fix a missing check of the status of SMBus read
NFS: nfs_compare_mount_options always compare auth flavors.
KVM: x86: svm: report MSR_IA32_MCG_EXT_CTL as unsupported
pinctrl: meson: meson8b: fix the GPIO function for the GPIOAO pins
pinctrl: meson: meson8: fix the GPIO function for the GPIOAO pins
fbdev: fbcon: Fix unregister crash when more than one framebuffer
igb: Fix an issue that PME is not enabled during runtime suspend
i40e: define proper net_device::neigh_priv_len
fbdev: fbmem: behave better with small rotated displays and many CPUs
video: clps711x-fb: release disp device node in probe()
drbd: Avoid Clang warning about pointless switch statment
drbd: skip spurious timeout (ping-timeo) when failing promote
drbd: disconnect, if the wrong UUIDs are attached on a connected peer
drbd: narrow rcu_read_lock in drbd_sync_handshake
cw1200: Fix concurrency use-after-free bugs in cw1200_hw_scan()
scsi: smartpqi: correct volume status
scsi: smartpqi: correct host serial num for ssa
Bluetooth: Fix unnecessary error message for HCI request completion
xfrm6_tunnel: Fix spi check in __xfrm6_tunnel_alloc_spi
mac80211: fix radiotap vendor presence bitmap handling
powerpc/uaccess: fix warning/error with access_ok()
arm64: KVM: Skip MMIO insn after emulation
perf probe: Fix unchecked usage of strncpy()
perf header: Fix unchecked usage of strncpy()
tty: serial: samsung: Properly set flags in autoCTS mode
memstick: Prevent memstick host from getting runtime suspended during card detection
ASoC: fsl: Fix SND_SOC_EUKREA_TLV320 build error on i.MX8M
ARM: pxa: avoid section mismatch warning
udf: Fix BUG on corrupted inode
i2c-axxia: check for error conditions first
cpuidle: big.LITTLE: fix refcount leak
clk: imx6sl: ensure MMDC CH0 handshake is bypassed
sata_rcar: fix deferred probing
iommu/arm-smmu-v3: Use explicit mb() when moving cons pointer
iommu/arm-smmu: Add support for qcom,smmu-v2 variant
mips: bpf: fix encoding bug for mm_srlv32_op
ARM: dts: Fix OMAP4430 SDP Ethernet startup
iommu/amd: Fix amd_iommu=force_isolation
clk: sunxi-ng: a33: Set CLK_SET_RATE_PARENT for all audio module clocks
timekeeping: Use proper seqcount initializer
usb: hub: delay hub autosuspend if USB3 port is still link training
smack: fix access permissions for keyring
media: DaVinci-VPBE: fix error handling in vpbe_initialize()
x86/fpu: Add might_fault() to user_insn()
ARM: dts: mmp2: fix TWSI2
arm64: ftrace: don't adjust the LR value
firmware/efi: Add NULL pointer checks in efivars API functions
Thermal: do not clear passive state during system sleep
nfsd4: fix crash on writing v4_end_grace before nfsd startup
soc: bcm: brcmstb: Don't leak device tree node reference
sunvdc: Do not spin in an infinite loop when vio_ldc_send() returns EAGAIN
f2fs: fix wrong return value of f2fs_acl_create
f2fs: move dir data flush to write checkpoint process
media: adv*/tc358743/ths8200: fill in min width/height/pixelclock
iio: accel: kxcjk1013: Add KIOX010A ACPI Hardware-ID
dmaengine: xilinx_dma: Remove __aligned attribute on zynqmp_dma_desc_ll
media: mtk-vcodec: Release device nodes in mtk_vcodec_init_enc_pm()
soc/tegra: Don't leak device tree node reference
perf tools: Add Hygon Dhyana support
modpost: validate symbol names also in find_elf_symbol
ARM: OMAP2+: hwmod: Fix some section annotations
staging: iio: ad7780: update voltage on read
staging:iio:ad2s90: Make probe handle spi_setup failure
ptp: check gettime64 return code in PTP_SYS_OFFSET ioctl
serial: fsl_lpuart: clear parity enable bit when disable parity
drm/vc4: ->x_scaling[1] should never be set to VC4_SCALING_NONE
powerpc/pseries: add of_node_put() in dlpar_detach_node()
x86/PCI: Fix Broadcom CNB20LE unintended sign extension (redux)
dlm: Don't swamp the CPU with callbacks queued during recovery
ARM: 8808/1: kexec:offline panic_smp_self_stop CPU
scsi: lpfc: Correct LCB RJT handling
ath9k: dynack: use authentication messages for 'late' ack
gpu: ipu-v3: image-convert: Prevent race between run and unprepare
ASoC: Intel: mrfld: fix uninitialized variable access
staging: iio: adc: ad7280a: handle error from __ad7280_read32()
drm/bufs: Fix Spectre v1 vulnerability
ANDROID: Turn xt_owner module on
ANDROID: Remove xt_qtaguid module from new kernels.
UPSTREAM: virt_wifi: fix error return code in virt_wifi_newlink()
ion: Disable ION_HEAP_TYPE_SYSTEM_CONTIG
ANDROID: arm64: lse: fix LSE atomics with LTO
Conflicts:
arch/arm/kernel/setup.c
drivers/iommu/arm-smmu.c
drivers/thermal/thermal_core.c
include/linux/sched.h
mm/memory.c
mm/oom_kill.c
net/netfilter/xt_qtaguid.c
Change-Id: I8629ac12c19fb9d63b21b21431afc300b4f1568d
Signed-off-by: jianzhou <jianzhou@codeaurora.org>
commit d88c93f090f708c18195553b352b9f205e65418f upstream.
debugfs_rename() needs to check that the dentries passed into it really
are valid, as sometimes they are not (i.e. if the return value of
another debugfs call is passed into this one.) So fix this up by
properly checking if the two parent directories are errors (they are
allowed to be NULL), and if the dentry to rename is not NULL or an
error.
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Currently, __debugfs_create_file allocates one struct debugfs_fsdata
instance for every file created. However, there are potentially many
debugfs file around, most of which are never touched by userspace.
Thus, defer the allocations to the first usage, i.e. to the first
debugfs_file_get().
A dentry's ->d_fsdata starts out to point to the "real", user provided
fops. After a debugfs_fsdata instance has been allocated (and the real
fops pointer has been moved over into its ->real_fops member),
->d_fsdata is changed to point to it from then on. The two cases are
distinguished by setting BIT(0) for the real fops case.
struct debugfs_fsdata's foremost purpose is to track active users and to
make debugfs_remove() block until they are done. Since no debugfs_fsdata
instance means no active users, make debugfs_remove() return immediately
in this case.
Take care of possible races between debugfs_file_get() and
debugfs_remove(): either debugfs_remove() must see a debugfs_fsdata
instance and thus wait for possible active users or debugfs_file_get() must
see a dead dentry and return immediately.
Make a dentry's ->d_release(), i.e. debugfs_release_dentry(), check whether
->d_fsdata is actually a debugfs_fsdata instance before kfree()ing it.
Similarly, make debugfs_real_fops() check whether ->d_fsdata is actually
a debugfs_fsdata instance before returning it, otherwise emit a warning.
The set of possible error codes returned from debugfs_file_get() has grown
from -EIO to -EIO and -ENOMEM. Make open_proxy_open() and full_proxy_open()
pass the -ENOMEM onwards to their callers.
Change-Id: I978318e95910338b8a6d4da66c273f72bde864cc
Signed-off-by: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Git-commit: 7d39bc50c47b3f8ed0e1a9d671ecb9ec02f10a2d
Git-repo: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Signed-off-by: Tingwei Zhang <tingwei@codeaurora.org>
Nicolai Stangeauthored and Gerrit - the friendly Code Review servercommited 2018-06-13 01:08:49 -07:00
The current implementation of debugfs_real_fops() relies on a
debugfs_fsdata instance to be installed at ->d_fsdata.
With future patches introducing lazy allocation of these, this requirement
will be guaranteed to be fullfilled only inbetween a
debugfs_file_get()/debugfs_file_put() pair.
The full proxies' fops implemented by debugfs happen to be the only
offenders. Fix them up by moving their debugfs_real_fops() calls past those
to debugfs_file_get().
full_proxy_release() is special as it doesn't invoke debugfs_file_get() at
all. Leave it alone for now.
Change-Id: I77c899614d317a581dea72c96583cd9f55f97930
Signed-off-by: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Git-commit: 154b9d7512ae012aca7b4e90af67a72419ad1941
Git-repo: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Signed-off-by: Tingwei Zhang <tingwei@codeaurora.org>
Nicolai Stangeauthored and Gerrit - the friendly Code Review servercommited 2018-06-13 01:08:13 -07:00
Convert all calls to the now obsolete debugfs_use_file_start() and
debugfs_use_file_finish() from the debugfs core itself to the new
debugfs_file_get() and debugfs_file_put() API.
Change-Id: I335bdb5050297b561281c51f840a81097e8ea88a
Fixes: 49d200deaa ("debugfs: prevent access to removed files' private data")
Signed-off-by: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Git-commit: 69d29f9e6a53559895e6f785f6cf72daa738f132
Git-repo: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Signed-off-by: Tingwei Zhang <tingwei@codeaurora.org>
Nicolai Stangeauthored and Gerrit - the friendly Code Review servercommited 2018-06-13 01:02:52 -07:00
Currently, debugfs_real_fops() is annotated with a
__must_hold(&debugfs_srcu) sparse annotation.
With the conversion of the SRCU based protection of users against
concurrent file removals to a per-file refcount based scheme, this becomes
wrong.
Drop this annotation.
Change-Id: I959c9b4519965132794e48ddb2e160ea130ff2fd
Signed-off-by: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Git-commit: 055ab8e3e3d52e005d2047b14ce63551b3a8b8b5
Git-repo: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Signed-off-by: Tingwei Zhang <tingwei@codeaurora.org>
Nicolai Stangeauthored and Gerrit - the friendly Code Review servercommited 2018-06-13 00:40:57 -07:00
Since commit 49d200deaa ("debugfs: prevent access to removed files'
private data"), accesses to a file's private data are protected from
concurrent removal by covering all file_operations with a SRCU read section
and sychronizing with those before returning from debugfs_remove() by means
of synchronize_srcu().
As pointed out by Johannes Berg, there are debugfs files with forever
blocking file_operations. Their corresponding SRCU read side sections would
block any debugfs_remove() forever as well, even unrelated ones. This
results in a livelock. Because a remover can't cancel any indefinite
blocking within foreign files, this is a problem.
Resolve this by introducing support for more granular protection on a
per-file basis.
This is implemented by introducing an 'active_users' refcount_t to the
per-file struct debugfs_fsdata state. At file creation time, it is set to
one and a debugfs_remove() will drop that initial reference. The new
debugfs_file_get() and debugfs_file_put(), intended to be used in place of
former debugfs_use_file_start() and debugfs_use_file_finish(), increment
and decrement it respectively. Once the count drops to zero,
debugfs_file_put() will signal a completion which is possibly being waited
for from debugfs_remove().
Thus, as long as there is a debugfs_file_get() not yet matched by a
corresponding debugfs_file_put() around, debugfs_remove() will block.
Actual users of debugfs_use_file_start() and -finish() will get converted
to the new debugfs_file_get() and debugfs_file_put() by followup patches.
Change-Id: I8240a7e8f45bc2003c78a49369282f4d49f82171
Fixes: 49d200deaa ("debugfs: prevent access to removed files' private data")
Reported-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Git-commit: e9117a5a4bf65d8e99f060d356a04d27a60b436d
Git-repo: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
[tingwei@codeaurora.org: Add refcount.h to resolve compile error]
Signed-off-by: Tingwei Zhang <tingwei@codeaurora.org>
Nicolai Stangeauthored and Tingwei Zhangcommited 2018-06-13 15:25:39 +08:00
Currently, the user provided fops, "real_fops", are stored directly into
->d_fsdata.
In order to be able to store more per-file state and thus prepare for more
granular file removal protection, wrap the real_fops into a dynamically
allocated container struct, debugfs_fsdata.
A struct debugfs_fsdata gets allocated at file creation and freed from the
newly intoduced ->d_release().
Finally, move the implementation of debugfs_real_fops() out of the public
debugfs header such that struct debugfs_fsdata's declaration can be kept
private.
Change-Id: I830f6018c3bc2af6511a07ca8248d216077a924e
Signed-off-by: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Git-commit: 7c8d469877b16d2c1cecf101a0abb7b218db85bc
Git-repo: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
Signed-off-by: Tingwei Zhang <tingwei@codeaurora.org>
Nicolai Stangeauthored and Tingwei Zhangcommited 2018-06-12 19:20:38 +08:00
commit 49d31c2f389acfe83417083e1208422b4091cd9e upstream.
take_dentry_name_snapshot() takes a safe snapshot of dentry name;
if the name is a short one, it gets copied into caller-supplied
structure, otherwise an extra reference to external name is grabbed
(those are never modified). In either case the pointer to stable
string is stored into the same structure.
dentry must be held by the caller of take_dentry_name_snapshot(),
but may be freely dropped afterwards - the snapshot will stay
until destroyed by release_dentry_name_snapshot().
Intended use:
struct name_snapshot s;
take_dentry_name_snapshot(&s, dentry);
...
access s.name
...
release_dentry_name_snapshot(&s);
Replaces fsnotify_oldname_...(), gets used in fsnotify to obtain the name
to pass down with event.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Al Viroauthored and Greg Kroah-Hartmancommited 2017-08-06 18:59:43 -07:00
commit 93faccbbfa958a9668d3ab4e30f38dd205cee8d8 upstream.
To support unprivileged users mounting filesystems two permission
checks have to be performed: a test to see if the user allowed to
create a mount in the mount namespace, and a test to see if
the user is allowed to access the specified filesystem.
The automount case is special in that mounting the original filesystem
grants permission to mount the sub-filesystems, to any user who
happens to stumble across the their mountpoint and satisfies the
ordinary filesystem permission checks.
Attempting to handle the automount case by using override_creds
almost works. It preserves the idea that permission to mount
the original filesystem is permission to mount the sub-filesystem.
Unfortunately using override_creds messes up the filesystems
ordinary permission checks.
Solve this by being explicit that a mount is a submount by introducing
vfs_submount, and using it where appropriate.
vfs_submount uses a new mount internal mount flags MS_SUBMOUNT, to let
sget and friends know that a mount is a submount so they can take appropriate
action.
sget and sget_userns are modified to not perform any permission checks
on submounts.
follow_automount is modified to stop using override_creds as that
has proven problemantic.
do_mount is modified to always remove the new MS_SUBMOUNT flag so
that we know userspace will never by able to specify it.
autofs4 is modified to stop using current_real_cred that was put in
there to handle the previous version of submount permission checking.
cifs is modified to pass the mountpoint all of the way down to vfs_submount.
debugfs is modified to pass the mountpoint all of the way down to
trace_automount by adding a new parameter. To make this change easier
a new typedef debugfs_automount_t is introduced to capture the type of
the debugfs automount function.
Fixes: 069d5ac9ae ("autofs: Fix automounts by using current_real_cred()->uid")
Fixes: aeaa4a79ff ("fs: Call d_automount with the filesystems creds")
Reviewed-by: Trond Myklebust <trond.myklebust@primarydata.com>
Reviewed-by: Seth Forshee <seth.forshee@canonical.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Eric W. Biedermanauthored and Greg Kroah-Hartmancommited 2017-03-15 10:02:44 +08:00
Pull more vfs updates from Al Viro:
">rename2() work from Miklos + current_time() from Deepa"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
fs: Replace current_fs_time() with current_time()
fs: Replace CURRENT_TIME_SEC with current_time() for inode timestamps
fs: Replace CURRENT_TIME with current_time() for inode timestamps
fs: proc: Delete inode time initializations in proc_alloc_inode()
vfs: Add current_time() api
vfs: add note about i_op->rename changes to porting
fs: rename "rename2" i_op to "rename"
vfs: remove unused i_op->rename
fs: make remaining filesystems use .rename2
libfs: support RENAME_NOREPLACE in simple_rename()
fs: support RENAME_NOREPLACE for local filesystems
ncpfs: fix unused variable warning
current_fs_time() uses struct super_block* as an argument.
As per Linus's suggestion, this is changed to take struct
inode* as a parameter instead. This is because the function
is primarily meant for vfs inode timestamps.
Also the function was renamed as per Arnd's suggestion.
Change all calls to current_fs_time() to use the new
current_time() function instead. current_fs_time() will be
deleted.
Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Deepa Dinamaniauthored and Al Virocommited 2016-09-27 21:06:22 -04:00
The result was being ignored and 0 was always returned.
Return the actual result instead.
Signed-off-by: Eric Engestrom <eric.engestrom@imgtec.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Eric Engestromauthored and Greg Kroah-Hartmancommited 2016-09-27 12:45:57 +02:00
This is trivial to do:
- add flags argument to simple_rename()
- check if flags doesn't have any other than RENAME_NOREPLACE
- assign simple_rename() to .rename2 instead of .rename
Filesystems converted:
hugetlbfs, ramfs, bpf.
Debugfs uses simple_rename() to implement debugfs_rename(), which is for
debugfs instances to rename files internally, not for userspace filesystem
access. For this case pass zero flags to simple_rename().
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Alexei Starovoitov <ast@kernel.org>
This patch introduces an accessor which can be used
by the users of debugfs (drivers, fs, ...) to get the
original file_operations struct. It also removes the
REAL_FOPS_DEREF macro in file.c and converts the code
to use the public version.
Previously, REAL_FOPS_DEREF was only available within
the file.c of debugfs. But having a public getter
available for debugfs users is important as some
drivers (carl9170 and b43) use the pointer of the
original file_operations in conjunction with container_of()
within their debugfs implementations.
Reviewed-by: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: Christian Lamparter <chunkeey@gmail.com>
Cc: stable <stable@vger.kernel.org> # 4.7+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Christian Lamparterauthored and Greg Kroah-Hartmancommited 2016-09-21 12:13:31 +02:00
debugfs_create_file_unsafe() is declared twice in exactly the same
manner each: once in fs/debugfs/internal.h and once in
include/linux/debugfs.h
All files that include the former also include the latter and thus,
the declaration in fs/debugfs/internal.h is superfluous.
Remove it.
Signed-off-by: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Nicolai Stangeauthored and Greg Kroah-Hartmancommited 2016-08-31 15:08:10 +02:00
Debugfs' open_proxy_open(), the ->open() installed at all inodes created
through debugfs_create_file_unsafe(),
- grabs a reference to the original file_operations instance passed to
debugfs_create_file_unsafe() via fops_get(),
- installs it at the file's ->f_op by means of replace_fops()
- and calls fops_put() on it.
Since the semantics of replace_fops() are such that the reference's
ownership is transferred, the subsequent fops_put() will result in a double
release when the file is eventually closed.
Currently, this is not an issue since fops_put() basically does a
module_put() on the file_operations' ->owner only and there don't exist any
modules calling debugfs_create_file_unsafe() yet. This is expected to
change in the future though, c.f. commit c646880814 ("debugfs: add
support for self-protecting attribute file fops").
Remove the call to fops_put() from open_proxy_open().
Fixes: 9fd4dcece4 ("debugfs: prevent access to possibly dead
file_operations at file open")
Signed-off-by: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Nicolai Stangeauthored and Greg Kroah-Hartmancommited 2016-06-15 04:56:35 -07:00
Debugfs' full_proxy_open(), the ->open() installed at all inodes created
through debugfs_create_file(),
- grabs a reference to the original struct file_operations instance passed
to debugfs_create_file(),
- dynamically allocates a proxy struct file_operations instance wrapping
the original
- and installs this at the file's ->f_op.
Afterwards, it calls the original ->open() and passes its return value back
to the VFS layer.
Now, if that return value indicates failure, the VFS layer won't ever call
->release() and thus, neither the reference to the original file_operations
nor the memory for the proxy file_operations will get released, i.e. both
are leaked.
Upon failure of the original fops' ->open(), undo the proxy installation.
That is:
- Set the struct file ->f_op to what it had been when full_proxy_open()
was entered.
- Drop the reference to the original file_operations.
- Free the memory holding the proxy file_operations.
Fixes: 49d200deaa ("debugfs: prevent access to removed files' private
data")
Signed-off-by: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Nicolai Stangeauthored and Greg Kroah-Hartmancommited 2016-06-15 04:56:35 -07:00
Starting with 4.1 the tracing subsystem has its own filesystem
which is automounted in the tracing subdirectory of debugfs.
Prior to this debugfs could be bind mounted in a cloned mount
namespace, but if tracefs has been mounted under debugfs this
now fails because there is a locked child mount. This creates
a regression for container software which bind mounts debugfs
to satisfy the assumption of some userspace software.
In other pseudo filesystems such as proc and sysfs we're already
creating mountpoints like this in such a way that no dirents can
be created in the directories, allowing them to be exceptions to
some MNT_LOCKED tests. In fact we're already do this for the
tracefs mountpoint in sysfs.
Do the same in debugfs_create_automount(), since the intention
here is clearly to create a mountpoint. This fixes the regression,
as locked child mounts on permanently empty directories do not
cause a bind mount to fail.
Cc: stable@vger.kernel.org # v4.1+
Signed-off-by: Seth Forshee <seth.forshee@canonical.com>
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Seth Forsheeauthored and Greg Kroah-Hartmancommited 2016-04-12 15:01:53 -07:00
The struct file_operations u32_array_fops associated with files created
through debugfs_create_u32_array() has been lifetime aware already:
everything needed for subsequent operation is copied to a ->f_private
buffer at file opening time in u32_array_open(). Now, ->open() is always
protected against file removal issues by the debugfs core.
There is no need for the debugfs core to wrap the u32_array_fops
with a file lifetime managing proxy.
Make debugfs_create_u32_array() create its files in non-proxying operation
mode by means of debugfs_create_file_unsafe().
Signed-off-by: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Nicolai Stangeauthored and Greg Kroah-Hartmancommited 2016-04-12 14:14:21 -07:00
Currently, the struct file_operations fops_blob associated with files
created through the debugfs_create_blob() helpers are not file
lifetime aware.
Thus, a lifetime managing proxy is created around fops_blob each time such
a file is opened which is an unnecessary waste of resources.
Implement file lifetime management for the fops_bool file_operations.
Namely, make read_file_blob() safe gainst file removals by means of
debugfs_use_file_start() and debugfs_use_file_finish().
Make debugfs_create_blob() create its files in non-proxying operation mode
by means of debugfs_create_file_unsafe().
Signed-off-by: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Nicolai Stangeauthored and Greg Kroah-Hartmancommited 2016-04-12 14:14:21 -07:00
Currently, the struct file_operations fops_bool associated with files
created through the debugfs_create_bool() helpers are not file
lifetime aware.
Thus, a lifetime managing proxy is created around fops_bool each time such
a file is opened which is an unnecessary waste of resources.
Implement file lifetime management for the fops_bool file_operations.
Namely, make debugfs_read_file_bool() and debugfs_write_file_bool() safe
against file removals by means of debugfs_use_file_start() and
debugfs_use_file_finish().
Make debugfs_create_bool() create its files in non-proxying operation mode
through debugfs_create_mode_unsafe().
Finally, purge debugfs_create_mode() as debugfs_create_bool() had been its
last user.
Signed-off-by: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Nicolai Stangeauthored and Greg Kroah-Hartmancommited 2016-04-12 14:14:21 -07:00
Currently, the struct file_operations associated with the integer attribute
style files created through the debugfs_create_*() helpers are not file
lifetime aware as they are defined by means of DEFINE_SIMPLE_ATTRIBUTE().
Thus, a lifetime managing proxy is created around the original fops each
time such a file is opened which is an unnecessary waste of resources.
Migrate all usages of DEFINE_SIMPLE_ATTRIBUTE() within debugfs itself
to DEFINE_DEBUGFS_ATTRIBUTE() in order to implement file lifetime managing
within the struct file_operations thus defined.
Introduce the debugfs_create_mode_unsafe() helper, analogous to
debugfs_create_mode(), but distinct in that it creates the files in
non-proxying operation mode through debugfs_create_file_unsafe().
Feed all struct file_operations migrated to DEFINE_DEBUGFS_ATTRIBUTE()
into debugfs_create_mode_unsafe() instead of former debugfs_create_mode().
Signed-off-by: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Nicolai Stangeauthored and Greg Kroah-Hartmancommited 2016-04-12 14:14:21 -07:00
In order to protect them against file removal issues, debugfs_create_file()
creates a lifetime managing proxy around each struct file_operations
handed in.
In cases where this struct file_operations is able to manage file lifetime
by itself already, the proxy created by debugfs is a waste of resources.
The most common class of struct file_operations given to debugfs are those
defined by means of the DEFINE_SIMPLE_ATTRIBUTE() macro.
Introduce a DEFINE_DEBUGFS_ATTRIBUTE() macro to allow any
struct file_operations of this class to be easily made file lifetime aware
and thus, to be operated unproxied.
Specifically, introduce debugfs_attr_read() and debugfs_attr_write()
which wrap simple_attr_read() and simple_attr_write() under the protection
of a debugfs_use_file_start()/debugfs_use_file_finish() pair.
Make DEFINE_DEBUGFS_ATTRIBUTE() set the defined struct file_operations'
->read() and ->write() members to these wrappers.
Export debugfs_create_file_unsafe() in order to allow debugfs users to
create their files in non-proxying operation mode.
Signed-off-by: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Nicolai Stangeauthored and Greg Kroah-Hartmancommited 2016-04-12 14:14:21 -07:00
Upon return of debugfs_remove()/debugfs_remove_recursive(), it might
still be attempted to access associated private file data through
previously opened struct file objects. If that data has been freed by
the caller of debugfs_remove*() in the meanwhile, the reading/writing
process would either encounter a fault or, if the memory address in
question has been reassigned again, unrelated data structures could get
overwritten.
However, since debugfs files are seldomly removed, usually from module
exit handlers only, the impact is very low.
Currently, there are ~1000 call sites of debugfs_create_file() spread
throughout the whole tree and touching all of those struct file_operations
in order to make them file removal aware by means of checking the result of
debugfs_use_file_start() from within their methods is unfeasible.
Instead, wrap the struct file_operations by a lifetime managing proxy at
file open:
- In debugfs_create_file(), the original fops handed in has got stashed
away in ->d_fsdata already.
- In debugfs_create_file(), install a proxy file_operations factory,
debugfs_full_proxy_file_operations, at ->i_fop.
This proxy factory has got an ->open() method only. It carries out some
lifetime checks and if successful, dynamically allocates and sets up a new
struct file_operations proxy at ->f_op. Afterwards, it forwards to the
->open() of the original struct file_operations in ->d_fsdata, if any.
The dynamically set up proxy at ->f_op has got a lifetime managing wrapper
set for each of the methods defined in the original struct file_operations
in ->d_fsdata.
Its ->release()er frees the proxy again and forwards to the original
->release(), if any.
In order not to mislead the VFS layer, it is strictly necessary to leave
those fields blank in the proxy that have been NULL in the original
struct file_operations also, i.e. aren't supported. This is why there is a
need for dynamically allocated proxies. The choice made not to allocate a
proxy instance for every dentry at file creation, but for every
struct file object instantiated thereof is justified by the expected usage
pattern of debugfs, namely that in general very few files get opened more
than once at a time.
The wrapper methods set in the struct file_operations implement lifetime
managing by means of the SRCU protection facilities already in place for
debugfs:
They set up a SRCU read side critical section and check whether the dentry
is still alive by means of debugfs_use_file_start(). If so, they forward
the call to the original struct file_operation stored in ->d_fsdata, still
under the protection of the SRCU read side critical section.
This SRCU read side critical section prevents any pending debugfs_remove()
and friends to return to their callers. Since a file's private data must
only be freed after the return of debugfs_remove(), the ongoing proxied
call is guarded against any file removal race.
If, on the other hand, the initial call to debugfs_use_file_start() detects
that the dentry is dead, the wrapper simply returns -EIO and does not
forward the call. Note that the ->poll() wrapper is special in that its
signature does not allow for the return of arbitrary -EXXX values and thus,
POLLHUP is returned here.
In order not to pollute debugfs with wrapper definitions that aren't ever
needed, I chose not to define a wrapper for every struct file_operations
method possible. Instead, a wrapper is defined only for the subset of
methods which are actually set by any debugfs users.
Currently, these are:
->llseek()
->read()
->write()
->unlocked_ioctl()
->poll()
The ->release() wrapper is special in that it does not protect the original
->release() in any way from dead files in order not to leak resources.
Thus, any ->release() handed to debugfs must implement file lifetime
management manually, if needed.
For only 33 out of a total of 434 releasers handed in to debugfs, it could
not be verified immediately whether they access data structures that might
have been freed upon a debugfs_remove() return in the meanwhile.
Export debugfs_use_file_start() and debugfs_use_file_finish() in order to
allow any ->release() to manually implement file lifetime management.
For a set of common cases of struct file_operations implemented by the
debugfs_core itself, future patches will incorporate file lifetime
management directly within those in order to allow for their unproxied
operation. Rename the original, non-proxying "debugfs_create_file()" to
"debugfs_create_file_unsafe()" and keep it for future internal use by
debugfs itself. Factor out code common to both into the new
__debugfs_create_file().
Signed-off-by: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Nicolai Stangeauthored and Greg Kroah-Hartmancommited 2016-04-12 14:14:21 -07:00
Nothing prevents a dentry found by path lookup before a return of
__debugfs_remove() to actually get opened after that return. Now, after
the return of __debugfs_remove(), there are no guarantees whatsoever
regarding the memory the corresponding inode's file_operations object
had been kept in.
Since __debugfs_remove() is seldomly invoked, usually from module exit
handlers only, the race is hard to trigger and the impact is very low.
A discussion of the problem outlined above as well as a suggested
solution can be found in the (sub-)thread rooted at
http://lkml.kernel.org/g/20130401203445.GA20862@ZenIV.linux.org.uk
("Yet another pipe related oops.")
Basically, Greg KH suggests to introduce an intermediate fops and
Al Viro points out that a pointer to the original ones may be stored in
->d_fsdata.
Follow this line of reasoning:
- Add SRCU as a reverse dependency of DEBUG_FS.
- Introduce a srcu_struct object for the debugfs subsystem.
- In debugfs_create_file(), store a pointer to the original
file_operations object in ->d_fsdata.
- Make debugfs_remove() and debugfs_remove_recursive() wait for a
SRCU grace period after the dentry has been delete()'d and before they
return to their callers.
- Introduce an intermediate file_operations object named
"debugfs_open_proxy_file_operations". It's ->open() functions checks,
under the protection of a SRCU read lock, whether the dentry is still
alive, i.e. has not been d_delete()'d and if so, tries to acquire a
reference on the owning module.
On success, it sets the file object's ->f_op to the original
file_operations and forwards the ongoing open() call to the original
->open().
- For clarity, rename the former debugfs_file_operations to
debugfs_noop_file_operations -- they are in no way canonical.
The choice of SRCU over "normal" RCU is justified by the fact, that the
former may also be used to protect ->i_private data from going away
during the execution of a file's readers and writers which may (and do)
sleep.
Finally, introduce the fs/debugfs/internal.h header containing some
declarations internal to the debugfs implementation.
Signed-off-by: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Nicolai Stangeauthored and Greg Kroah-Hartmancommited 2016-04-12 14:14:21 -07:00
CURRENT_TIME macro is not appropriate for filesystems as it
doesn't use the right granularity for filesystem timestamps.
Use current_fs_time() instead.
Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Deepa Dinamaniauthored and Greg Kroah-Hartmancommited 2016-03-29 10:11:44 -07:00
parallel to mutex_{lock,unlock,trylock,is_locked,lock_nested},
inode_foo(inode) being mutex_foo(&inode->i_mutex).
Please, use those for access to ->i_mutex; over the coming cycle
->i_mutex will become rwsem, with ->lookup() done with it held
only shared.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
In debugfs' start_creating(), we pin the file system to safely access
its root. When we failed to create a file, we unpin the file system via
failed_creating() to release the mount count and eventually the reference
of the vfsmount.
However, when we run into an error during lookup_one_len() when still
in start_creating(), we only release the parent's mutex but not so the
reference on the mount. Looks like it was done in the past, but after
splitting portions of __create_file() into start_creating() and
end_creating() via 190afd81e4 ("debugfs: split the beginning and the
end of __create_file() off"), this seemed missed. Noticed during code
review.
Fixes: 190afd81e4 ("debugfs: split the beginning and the end of __create_file() off")
Cc: stable@vger.kernel.org # v4.0+
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Daniel Borkmannauthored and Al Virocommited 2015-11-11 02:04:44 -05:00
Add debugfs_create_ulong() for the users of type 'unsigned long'. These
will be 32 bits long on a 32 bit machine and 64 bits long on a 64 bit
machine.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Viresh Kumarauthored and Greg Kroah-Hartmancommited 2015-10-18 10:14:39 -07:00
There aren't any read-only or write-only bool file ops, but there
is a caller of debugfs_create_bool() that calls it with mode
equal to 0400. This leads to the possibility of userspace
modifying the file, so let's use the newly created
debugfs_create_mode() helper here to fix this.
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Stephen Boydauthored and Greg Kroah-Hartmancommited 2015-10-17 22:09:03 -07:00
There aren't any read-only or write-only size_t file ops, but there
is a caller of debugfs_create_size_t() that calls it with mode
equal to 0400. This leads to the possibility of userspace
modifying the file, so let's use the newly created
debugfs_create_mode() helper here to fix this.
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Stephen Boydauthored and Greg Kroah-Hartmancommited 2015-10-17 22:09:03 -07:00
There aren't any read-only or write-only x64 file ops, but there
is a caller of debugfs_create_x64() that calls it with mode equal
to S_IRUGO. This leads to the possibility of userspace modifying
the file, so let's use the newly created debugfs_create_mode()
helper here to fix this.
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Stephen Boydauthored and Greg Kroah-Hartmancommited 2015-10-17 22:09:03 -07:00
The code that creates debugfs file with different file ops based
on the file mode is duplicated in each debugfs_create_*() API.
Consolidate that code into debugfs_create_mode(), that takes
three file ops structures so that we don't have to keep
copy/pasting that logic.
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Stephen Boydauthored and Greg Kroah-Hartmancommited 2015-10-17 22:09:03 -07:00
According to commit a59d6293e5 ("debugfs: change parameter check in
debugfs_remove() functions"), this is meant to make cleanup easier for
callers. In that case it ought to be documented.
Signed-off-by: Ulf Magnusson <ulfalizer@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Ulf Magnussonauthored and Greg Kroah-Hartmancommited 2015-10-04 11:36:07 +01:00
Its a bit odd that debugfs_create_bool() takes 'u32 *' as an argument,
when all it needs is a boolean pointer.
It would be better to update this API to make it accept 'bool *'
instead, as that will make it more consistent and often more convenient.
Over that bool takes just a byte.
That required updates to all user sites as well, in the same commit
updating the API. regmap core was also using
debugfs_{read|write}_file_bool(), directly and variable types were
updated for that to be bool as well.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Mark Brown <broonie@kernel.org>
Acked-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Viresh Kumarauthored and Greg Kroah-Hartmancommited 2015-10-04 11:36:07 +01:00
The file read/write functions for bools have no special dependencies
on debugfs internals and are sufficiently non-trivial to be worth
exporting so clients can re-use the implementation.
Signed-off-by: Richard Fitzgerald <rf@opensource.wolfsonmicro.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
Richard Fitzgeraldauthored and Mark Browncommited 2015-07-20 18:44:50 +01:00
Pull more vfs updates from Al Viro:
"Assorted VFS fixes and related cleanups (IMO the most interesting in
that part are f_path-related things and Eric's descriptor-related
stuff). UFS regression fixes (it got broken last cycle). 9P fixes.
fs-cache series, DAX patches, Jan's file_remove_suid() work"
[ I'd say this is much more than "fixes and related cleanups". The
file_table locking rule change by Eric Dumazet is a rather big and
fundamental update even if the patch isn't huge. - Linus ]
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (49 commits)
9p: cope with bogus responses from server in p9_client_{read,write}
p9_client_write(): avoid double p9_free_req()
9p: forgetting to cancel request on interrupted zero-copy RPC
dax: bdev_direct_access() may sleep
block: Add support for DAX reads/writes to block devices
dax: Use copy_from_iter_nocache
dax: Add block size note to documentation
fs/file.c: __fget() and dup2() atomicity rules
fs/file.c: don't acquire files->file_lock in fd_install()
fs:super:get_anon_bdev: fix race condition could cause dev exceed its upper limitation
vfs: avoid creation of inode number 0 in get_next_ino
namei: make set_root_rcu() return void
make simple_positive() public
ufs: use dir_pages instead of ufs_dir_pages()
pagemap.h: move dir_pages() over there
remove the pointless include of lglock.h
fs: cleanup slight list_entry abuse
xfs: Correctly lock inode when removing suid and file capabilities
fs: Call security_ops->inode_killpriv on truncate
fs: Provide function telling whether file_remove_privs() will do anything
...
Pull user namespace updates from Eric Biederman:
"Long ago and far away when user namespaces where young it was realized
that allowing fresh mounts of proc and sysfs with only user namespace
permissions could violate the basic rule that only root gets to decide
if proc or sysfs should be mounted at all.
Some hacks were put in place to reduce the worst of the damage could
be done, and the common sense rule was adopted that fresh mounts of
proc and sysfs should allow no more than bind mounts of proc and
sysfs. Unfortunately that rule has not been fully enforced.
There are two kinds of gaps in that enforcement. Only filesystems
mounted on empty directories of proc and sysfs should be ignored but
the test for empty directories was insufficient. So in my tree
directories on proc, sysctl and sysfs that will always be empty are
created specially. Every other technique is imperfect as an ordinary
directory can have entries added even after a readdir returns and
shows that the directory is empty. Special creation of directories
for mount points makes the code in the kernel a smidge clearer about
it's purpose. I asked container developers from the various container
projects to help test this and no holes were found in the set of mount
points on proc and sysfs that are created specially.
This set of changes also starts enforcing the mount flags of fresh
mounts of proc and sysfs are consistent with the existing mount of
proc and sysfs. I expected this to be the boring part of the work but
unfortunately unprivileged userspace winds up mounting fresh copies of
proc and sysfs with noexec and nosuid clear when root set those flags
on the previous mount of proc and sysfs. So for now only the atime,
read-only and nodev attributes which userspace happens to keep
consistent are enforced. Dealing with the noexec and nosuid
attributes remains for another time.
This set of changes also addresses an issue with how open file
descriptors from /proc/<pid>/ns/* are displayed. Recently readlink of
/proc/<pid>/fd has been triggering a WARN_ON that has not been
meaningful since it was added (as all of the code in the kernel was
converted) and is not now actively wrong.
There is also a short list of issues that have not been fixed yet that
I will mention briefly.
It is possible to rename a directory from below to above a bind mount.
At which point any directory pointers below the renamed directory can
be walked up to the root directory of the filesystem. With user
namespaces enabled a bind mount of the bind mount can be created
allowing the user to pick a directory whose children they can rename
to outside of the bind mount. This is challenging to fix and doubly
so because all obvious solutions must touch code that is in the
performance part of pathname resolution.
As mentioned above there is also a question of how to ensure that
developers by accident or with purpose do not introduce exectuable
files on sysfs and proc and in doing so introduce security regressions
in the current userspace that will not be immediately obvious and as
such are likely to require breaking userspace in painful ways once
they are recognized"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
vfs: Remove incorrect debugging WARN in prepend_path
mnt: Update fs_fully_visible to test for permanently empty directories
sysfs: Create mountpoints with sysfs_create_mount_point
sysfs: Add support for permanently empty directories to serve as mount points.
kernfs: Add support for always empty directories.
proc: Allow creating permanently empty directories that serve as mount points
sysctl: Allow creating permanently empty directories that serve as mountpoints.
fs: Add helper functions for permanently empty directories.
vfs: Ignore unlocked mounts in fs_fully_visible
mnt: Modify fs_fully_visible to deal with locked ro nodev and atime
mnt: Refactor the logic for mounting sysfs and proc in a user namespace
This allows for better documentation in the code and
it allows for a simpler and fully correct version of
fs_fully_visible to be written.
The mount points converted and their filesystems are:
/sys/hypervisor/s390/ s390_hypfs
/sys/kernel/config/ configfs
/sys/kernel/debug/ debugfs
/sys/firmware/efi/efivars/ efivarfs
/sys/fs/fuse/connections/ fusectl
/sys/fs/pstore/ pstore
/sys/kernel/tracing/ tracefs
/sys/fs/cgroup/ cgroup
/sys/kernel/security/ securityfs
/sys/fs/selinux/ selinuxfs
/sys/fs/smackfs/ smackfs
Cc: stable@vger.kernel.org
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Eric W. Biedermancommited 2015-07-01 10:36:47 -05:00
Eric Biggers
authored and
Sorayukii
commited 
Tengfei Fan
commited 
Al Viro
authored and
Greg Kroah-Hartman
commited 
jianzhou
commited 
Nicolai Stange
authored and
Gerrit - the friendly Code Review server
commited 
Tingwei Zhang
commited 
Eric W. Biederman
authored and
Linus Torvalds
commited 
Deepa Dinamani
authored and
Eric Engestrom
authored and
Miklos Szeredi
commited 
Christian Lamparter
authored and
Seth Forshee
authored and
Roman Pen
authored and
Daniel Borkmann
authored and
Viresh Kumar
authored and
Stephen Boyd
authored and
Ulf Magnusson
authored and
Richard Fitzgerald
authored and
Mark Brown
commited