Guenter Roeck f25191bb32 cdrom: Fix race condition in cdrom_sysctl_register ... The following traceback is sometimes seen when booting an image in qemu: [ 54.608293] cdrom: Uniform CD-ROM driver Revision: 3.20 [ 54.611085] Fusion MPT base driver 3.04.20 [ 54.611877] Copyright (c) 1999-2008 LSI Corporation [ 54.616234] Fusion MPT SAS Host driver 3.04.20 [ 54.635139] sysctl duplicate entry: /dev/cdrom//info [ 54.639578] CPU: 0 PID: 266 Comm: kworker/u4:5 Not tainted 5.0.0-rc5 #1 [ 54.639578] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015 [ 54.641273] Workqueue: events_unbound async_run_entry_fn [ 54.641273] Call Trace: [ 54.641273] dump_stack+0x67/0x90 [ 54.641273] __register_sysctl_table+0x50b/0x570 [ 54.641273] ? rcu_read_lock_sched_held+0x6f/0x80 [ 54.641273] ? kmem_cache_alloc_trace+0x1c7/0x1f0 [ 54.646814] __register_sysctl_paths+0x1c8/0x1f0 [ 54.646814] cdrom_sysctl_register.part.7+0xc/0x5f [ 54.646814] register_cdrom.cold.24+0x2a/0x33 [ 54.646814] sr_probe+0x4bd/0x580 [ 54.646814] ? __driver_attach+0xd0/0xd0 [ 54.646814] really_probe+0xd6/0x260 [ 54.646814] ? __driver_attach+0xd0/0xd0 [ 54.646814] driver_probe_device+0x4a/0xb0 [ 54.646814] ? __driver_attach+0xd0/0xd0 [ 54.646814] bus_for_each_drv+0x73/0xc0 [ 54.646814] __device_attach+0xd6/0x130 [ 54.646814] bus_probe_device+0x9a/0xb0 [ 54.646814] device_add+0x40c/0x670 [ 54.646814] ? __pm_runtime_resume+0x4f/0x80 [ 54.646814] scsi_sysfs_add_sdev+0x81/0x290 [ 54.646814] scsi_probe_and_add_lun+0x888/0xc00 [ 54.646814] ? scsi_autopm_get_host+0x21/0x40 [ 54.646814] __scsi_add_device+0x116/0x130 [ 54.646814] ata_scsi_scan_host+0x93/0x1c0 [ 54.646814] async_run_entry_fn+0x34/0x100 [ 54.646814] process_one_work+0x237/0x5e0 [ 54.646814] worker_thread+0x37/0x380 [ 54.646814] ? rescuer_thread+0x360/0x360 [ 54.646814] kthread+0x118/0x130 [ 54.646814] ? kthread_create_on_node+0x60/0x60 [ 54.646814] ret_from_fork+0x3a/0x50 The only sensible explanation is that cdrom_sysctl_register() is called twice, once from the module init function and once from register_cdrom(). cdrom_sysctl_register() is not mutex protected and may happily execute twice if the second call is made before the first call is complete. Use a static atomic to ensure that the function is executed exactly once. Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Jens Axboe <axboe@kernel.dk>		2019-02-08 06:46:59 -07:00
..
accessibility	…
acpi	acpi/nfit: Fix command-supported detection	2019-01-21 09:58:31 -08:00
amba	…
android	binderfs: switch from d_add() to d_instantiate()	2019-01-22 12:25:54 +01:00
ata	SCSI fixes on 20190125	2019-01-26 15:03:43 -08:00
atm	atm: he: fix sign-extension overflow on large shift	2019-01-17 11:27:00 -08:00
auxdisplay	auxdisplay: charlcd: fix x/y command parsing	2018-12-21 21:27:21 +01:00
base	regmap: Fixes for v5.0	2019-01-19 07:17:19 +12:00
bcma	…
block	mtip32xx: ѕtop abusing the managed resource APIs	2019-01-31 12:50:12 -07:00
bluetooth	Bluetooth: hci_bcm: Handle specific unknown packets after firmware loading	2018-12-19 13:43:42 +01:00
bus	ARM: SoC driver updates	2018-12-31 17:32:35 -08:00
cdrom	cdrom: Fix race condition in cdrom_sysctl_register	2019-02-08 06:46:59 -07:00
char	Char/Misc driver fixes for 5.0-rc4	2019-01-25 13:03:34 -10:00
clk	clk: socfpga: stratix10: fix naming convention for the fixed-clocks	2019-01-15 12:58:38 -08:00
clocksource	arch/csky patches for 4.21-rc1	2019-01-05 09:50:07 -08:00
connector	…
cpufreq	Merge branches 'pm-cpuidle', 'pm-cpufreq' and 'pm-sleep'	2019-01-11 10:09:51 +01:00
cpuidle	powerpc updates for 4.21	2018-12-27 10:43:24 -08:00
crypto	Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6	2019-01-19 05:48:43 +12:00
dax	mm, devm_memremap_pages: fix shutdown handling	2018-12-28 12:11:47 -08:00
dca	…
devfreq	…
dio	…
dma	cross-tree: phase out dma_zalloc_coherent()	2019-01-08 07:58:37 -05:00
dma-buf	drivers/dma-buf/udmabuf.c: convert to use vm_fault_t	2019-01-04 13:13:46 -08:00
edac	EDAC, altera: Fix S10 persistent register offset	2019-01-24 17:13:59 +01:00
eisa	…
extcon	…
firewire	scsi: communicate max segment size to the DMA mapping code	2019-01-22 20:40:59 -05:00
firmware	arm64 fixes for -rc1	2019-01-05 11:28:39 -08:00
fmc	…
fpga	Remove 'type' argument from access_ok() function	2019-01-03 18:57:57 -08:00
fsi	…
gnss	…
gpio	gpio: pca953x: Make symbol 'pca953x_i2c_regmap' static	2019-01-11 09:16:40 +01:00
gpu	Merge tag 'drm-msm-fixes-2019-01-24' of git://people.freedesktop.org/~robclark/linux into drm-fixes	2019-01-25 07:45:00 +10:00
hid	HID: core: simplify active collection tracking	2019-01-16 14:29:48 +01:00
hsi	…
hv	vmbus: fix subchannel removal	2019-01-09 19:20:31 -05:00
hwmon	hwmon: (tmp421) Correct the misspelling of the tmp442 compatible attribute in OF device ID table	2019-01-17 12:54:52 -08:00
hwspinlock	hwspinlock: fix return value check in stm32_hwspinlock_probe()	2019-01-03 11:42:10 -08:00
hwtracing	intel_th: msu: Fix an off-by-one in attribute store	2018-12-19 20:21:06 +01:00
i2c	i2c: tegra: Fix Maximum transfer size	2019-01-11 00:15:04 +01:00
i3c	i3c: master: Fix an error checking typo in 'cdns_i3c_master_probe()'	2019-01-22 13:56:37 +01:00
ide	ide: fix a typo in the settings proc file name	2019-01-22 15:08:12 +13:00
idle	…
iio	- New Device Support	2019-01-15 06:24:36 +12:00
infiniband	First 5.0 rc pull request	2019-01-18 17:17:20 +12:00
input	Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input	2019-01-27 09:07:03 -08:00
iommu	IOMMU Fix for Linux v5.0-rc3	2019-01-22 07:27:17 +13:00
ipack	…
irqchip	irqchip updates for 5.0-rc3	2019-01-18 23:32:29 +01:00
isdn	isdn: avm: Fix string plus integer warning from Clang	2019-01-19 10:01:03 -08:00
leds	leds: lp5523: fix a missing check of return value of lp55xx_read	2019-01-17 22:27:39 +01:00
lightnvm	lightnvm: pblk: fix use-after-free bug	2018-12-22 14:45:35 -07:00
macintosh	Remove 'type' argument from access_ok() function	2019-01-03 18:57:57 -08:00
mailbox	mailbox: tegra-hsp: Use device-managed registration API	2018-12-21 22:31:26 -06:00
mcb	…
md	raid1: simplify raid1_error function	2019-02-04 10:37:11 -08:00
media	media: vim2m: only cancel work if it is for right context	2019-01-16 11:13:25 -05:00
memory	ARM: SoC: late updates	2019-01-05 11:30:37 -08:00
memstick	MMC core:	2018-12-28 16:52:18 -08:00
message	scsi: flip the default on use_clustering	2018-12-18 23:13:12 -05:00
mfd	- New Device Support	2019-01-15 06:24:36 +12:00
misc	Char/Misc driver fixes for 5.0-rc4	2019-01-25 13:03:34 -10:00
mmc	MMC host:	2019-01-25 13:07:03 -10:00
mtd	mtd: rawnand: denali: get ->setup_data_interface() working again	2019-01-18 10:27:01 +01:00
mux	…
net	qed: Revert error handling changes.	2019-01-25 15:32:28 -08:00
nfc	…
ntb	cross-tree: phase out dma_zalloc_coherent()	2019-01-08 07:58:37 -05:00
nubus	…
nvdimm	libnvdimm/security: Require nvdimm_security_setup_events() to succeed	2019-01-21 09:57:43 -08:00
nvme	nvme: remove the .stop_ctrl callout	2019-02-04 15:41:25 +01:00
nvmem	…
of	OF: properties: add missing of_node_put	2019-01-16 12:49:53 -06:00
opp	cpufreq: scpi/scmi: Fix freeing of dynamic OPPs	2019-01-04 12:19:40 +01:00
oprofile	…
parisc	Kconfig file consolidation for v4.21	2018-12-29 13:40:29 -08:00
parport	…
pci	pci-v5.0-fixes-2	2019-01-19 07:26:16 +12:00
pcmcia	Included in this update:	2019-01-05 11:23:17 -08:00
perf	drivers/perf: hisi: Fixup one DDRC PMU register offset	2019-01-04 10:13:27 +00:00
phy	USB/PHY fixes for 5.0-rc4	2019-01-25 12:57:09 -10:00
pinctrl	Pin control bulk changes for the v4.21 kernel cycle:	2019-01-01 13:19:16 -08:00
platform	platform/x86: apple-gmux: Make PCI dependency explicit	2019-01-15 23:17:16 +01:00
pnp	Remove 'type' argument from access_ok() function	2019-01-03 18:57:57 -08:00
power	power supply and reset changes for the v4.21 series	2018-12-28 20:22:45 -08:00
powercap	…
pps	Kconfig updates for v4.21	2018-12-29 13:03:29 -08:00
ps3	…
ptp	ptp: check that rsv field is zero in struct ptp_sys_offset_extended	2019-01-08 16:22:56 -05:00
pwm	pwm: imx: Add ipg clock operation	2018-12-24 12:06:56 +01:00
rapidio	cross-tree: phase out dma_zalloc_coherent()	2019-01-08 07:58:37 -05:00
ras	treewide: surround Kconfig file paths with double quotes	2018-12-22 00:25:54 +09:00
regulator	Merge remote-tracking branch 'regulator/topic/coupled' into regulator-next	2018-12-21 13:43:35 +00:00
remoteproc	virtio: don't allocate vqs when names[i] = NULL	2019-01-14 20:15:19 -05:00
reset	reset: uniphier-glue: Add AHCI reset control support in glue layer	2019-01-07 16:38:51 +01:00
rpmsg	…
rtc	RTC for 4.21	2019-01-01 13:24:31 -08:00
s390	s390 update with bug fixes for 5.0-rc4	2019-01-24 08:58:01 +13:00
sbus	Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-next	2018-12-26 10:32:18 -08:00
scsi	SCSI fixes on 20190125	2019-01-26 15:03:43 -08:00
sfi	…
sh	…
siox	…
slimbus	…
sn	…
soc	Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net	2019-01-16 05:13:36 +12:00
soundwire	…
spi	cross-tree: phase out dma_zalloc_coherent()	2019-01-08 07:58:37 -05:00
spmi	…
ssb	…
staging	staging: android: ion: Support cpu access during dma_buf_detach	2019-01-22 11:38:09 +01:00
target	scsi: tcmu: fix use after free	2019-01-22 20:54:00 -05:00
tc	…
tee	OP-TEE dynamic shm log message	2018-12-31 13:06:30 -08:00
thermal	Merge branch 'for-rc' of git://git.kernel.org/pub/scm/linux/kernel/git/rzhang/linux	2019-01-23 16:23:41 +13:00
thunderbolt	…
tty	serial: fsl_lpuart: fix maximum acceptable baud rate with over-sampling	2019-01-22 09:32:08 +01:00
uio	Char/Misc driver patches for 4.21-rc1	2018-12-28 20:54:57 -08:00
usb	USB-serial fixes for 5.0-rc3	2019-01-18 12:58:20 +01:00
uwb	…
vfio	vfio-pci/nvlink2: Fix ancient gcc warnings	2019-01-23 08:20:43 -07:00
vhost	Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net	2019-01-21 12:52:31 +13:00
video	TTY/Serial driver fixes for 5.0-rc4	2019-01-25 12:58:40 -10:00
virt	…
virtio	virtio-balloon: tweak config_changed implementation	2019-01-14 20:15:20 -05:00
visorbus	…
vlynq	…
vme	…
w1	treewide: surround Kconfig file paths with double quotes	2018-12-22 00:25:54 +09:00
watchdog	watchdog: tqmx86: Fix a couple IS_ERR() vs NULL bugs	2019-01-07 10:10:35 +01:00
xen	arm64/xen: fix xen-swiotlb cache flushing	2019-01-23 22:14:56 +01:00
zorro	…
Kconfig	Kconfig file consolidation for v4.21	2018-12-29 13:40:29 -08:00
Makefile	…