Refactor nfs4_call_sync_sequence() so it is used for NFSv4.0 now.
The RPC callouts will house transport blocking logic similar to
NFSv4.1 sessions.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
NFSv4.0 will have need for this functionality when I add the ability
to block NFSv4.0 traffic before migration recovery.
I'm not really clear on why nfs4_set_sequence_privileged() gets a
generic name, but nfs41_init_sequence() gets a minor
version-specific name.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Clean up: Both the NFSv4.0 and NFSv4.1 version of
nfs4_setup_sequence() are used only in fs/nfs/nfs4proc.c. No need
to keep global header declarations for either version.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Clean up: rename nfs41_call_sync_data for use as a data structure
common to all NFSv4 minor versions.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Clean up, since slot and sequence numbers are all unsigned anyway.
Among other things, squelch compiler warnings:
linux/fs/nfs/nfs4proc.c: In function ‘nfs4_setup_sequence’:
linux/fs/nfs/nfs4proc.c:703:2: warning: signed and unsigned type in
conditional expression [-Wsign-compare]
and
linux/fs/nfs/nfs4session.c: In function ‘nfs4_alloc_slot’:
linux/fs/nfs/nfs4session.c:151:31: warning: signed and unsigned type in
conditional expression [-Wsign-compare]
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
If an NFS client does
mkdir("dir");
fd = open("dir/file");
unlink("dir/file");
close(fd);
rmdir("dir");
then the asynchronous nature of the sillyrename operation means that
we can end up getting EBUSY for the rmdir() in the above test. Fix
that by ensuring that we wait for any in-progress sillyrenames
before sending the rmdir() to the server.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Commit 5ec16a8500 introduced a regression
that causes SECINFO to fail without actualy sending an RPC if:
1) the nfs_client's rpc_client was using KRB5i/p (now tried by default)
2) the current user doesn't have valid kerberos credentials
This situation is quite common - as of now a sec=sys mount would use
krb5i for the nfs_client's rpc_client and a user would hardly be faulted
for not having run kinit.
The solution is to use the machine cred when trying to use an integrity
protected auth flavor for SECINFO.
Older servers may not support using the machine cred or an integrity
protected auth flavor for SECINFO in every circumstance, so we fall back
to using the user's cred and the filesystem's auth flavor in this case.
We run into another problem when running against linux nfs servers -
they return NFS4ERR_WRONGSEC when using integrity auth flavor (unless the
mount is also that flavor) even though that is not a valid error for
SECINFO*. Even though it's against spec, handle WRONGSEC errors on SECINFO
by falling back to using the user cred and the filesystem's auth flavor.
Signed-off-by: Weston Andros Adamson <dros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Most of the time an error from the credops crvalidate function means the
server has sent us a garbage verifier. The gss_validate function is the
exception where there is an -EACCES case if the user GSS_context on the client
has expired.
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
We must avoid buffering a WRITE that is using a credential key (e.g. a GSS
context key) that is about to expire or has expired. We currently will
paint ourselves into a corner by returning success to the applciation
for such a buffered WRITE, only to discover that we do not have permission when
we attempt to flush the WRITE (and potentially associated COMMIT) to disk.
Use the RPC layer credential key timeout and expire routines which use a
a watermark, gss_key_expire_timeo. We test the key in nfs_file_write.
If a WRITE is using a credential with a key that will expire within
watermark seconds, flush the inode in nfs_write_end and send only
NFS_FILE_SYNC WRITEs by adding nfs_ctx_key_to_expire to nfs_need_sync_write.
Note that this results in single page NFS_FILE_SYNC WRITEs.
Signed-off-by: Andy Adamson <andros@netapp.com>
[Trond: removed a pr_warn_ratelimited() for now]
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
This patch provides the RPC layer helper functions to allow NFS to manage
data in the face of expired credentials - such as avoiding buffered WRITEs
and COMMITs when the gss context will expire before the WRITEs are flushed
and COMMITs are sent.
These helper functions enable checking the expiration of an underlying
credential key for a generic rpc credential, e.g. the gss_cred gss context
gc_expiry which for Kerberos is set to the remaining TGT lifetime.
A new rpc_authops key_timeout is only defined for the generic auth.
A new rpc_credops crkey_to_expire is only defined for the generic cred.
A new rpc_credops crkey_timeout is only defined for the gss cred.
Set a credential key expiry watermark, RPC_KEY_EXPIRE_TIMEO set to 240 seconds
as a default and can be set via a module parameter as we need to ensure there
is time for any dirty data to be flushed.
If key_timeout is called on a credential with an underlying credential key that
will expire within watermark seconds, we set the RPC_CRED_KEY_EXPIRE_SOON
flag in the generic_cred acred so that the NFS layer can clean up prior to
key expiration.
Checking a generic credential's underlying credential involves a cred lookup.
To avoid this lookup in the normal case when the underlying credential has
a key that is valid (before the watermark), a notify flag is set in
the generic credential the first time the key_timeout is called. The
generic credential then stops checking the underlying credential key expiry, and
the underlying credential (gss_cred) match routine then checks the key
expiration upon each normal use and sets a flag in the associated generic
credential only when the key expiration is within the watermark.
This in turn signals the generic credential key_timeout to perform the extra
credential lookup thereafter.
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
The NFS layer needs to know when a key has expired.
This change also returns -EKEYEXPIRED to the application, and the informative
"Key has expired" error message is displayed. The user then knows that
credential renewal is required.
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
This change sets the PCI devices' initial DMA capabilities
conservatively and promotes them at the request of the driver,
as opposed to assuming advanced DMA capabilities. The old design
runs the risk of breaking drivers that assume default capabilities.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
Should check the return value of kzalloc first to avoid the null pointer.
Then can dereference the non-null pointer to access the fields of struct
resource.
Signed-off-by: Wang Sheng-Hui <shhuiw@gmail.com>
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
This was really only useful for TILE64 when we mapped the
kernel data with small pages. Now we use a huge page and we
really don't want to map different parts of the kernel
data in different ways.
We retain the __write_once name in case we want to bring
it back to life at some point in the future.
Note that this change uncovered a latent bug where the
"smp_topology" variable happened to always be aligned mod 8
so we could store two "int" values at once, but when we
eliminated __write_once it ended up only aligned mod 4.
Fix with an explicit annotation.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
This chip is no longer being actively developed for (it was superceded
by the TILEPro64 in 2008), and in any case the existing compiler and
toolchain in the community do not support it. It's unlikely that the
kernel works with TILE64 at this point as the configuration has not been
tested in years. The support is also awkward as it requires maintaining
a significant number of ifdefs. So, just remove it altogether.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
The definisions of __ffs(), __fls(), and ffs() for tile are almost same
as asm-generic/bitops-*.h. The only difference is that it is defined
as __always_inline or inline. So this switches to use those headers.
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com> [moved #includes to end]
There's no need to make up new ways of computing the addresses
of the Tilera hypervisor APIs; just use the standard method
of relying on the symbols to provide the addresses.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
It was bombed away because it was previously marked as __devinit,
but it should be an __init function.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
If we wait until after including a bunch of other files, we
will have generated so much warning spew that it's hard to
notice the error about using the wrong compiler.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
It isn't used any more by us now that the generic kernel build
offers DEBUG_INFO_REDUCED, so just get rid of it.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
We use virt_to_pte(NULL, va) a lot, which isn't very obvious.
I added virt_to_kpte(va) as a more obvious wrapper function,
that also validates the va as being a kernel adddress.
And, I fixed the semantics of virt_to_pte() so that we handle
the pud and pmd the same way, and we now document the fact that
we handle the final pte level differently.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
Allow enabling frame pointer support; this makes it easier to hook
into the various kernel features that claim they require it without
having to add Kconfig conditionals everywhere (a la mips, ppc, s390,
and microblaze). When enabled, it basically eliminates leaf functions
as such, and stops optimizing tail and sibling calls. It adds around
3% to the size of the kernel when enabled.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
Newer hypervisors have an API for reporting per-cpu statistics
information. This change allows seeing that information via
/sys/devices/system/cpu/cpuN/hv_stats file for each core.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
Enter kernel debugger at boot with:
--hvd UART_1=1 --hvx kgdbwait --hvx kgdboc=ttyS1,115200
or at runtime with:
echo ttyS1,115200 > /sys/module/kgdboc/parameters/kgdboc
echo g > /proc/sysrq-trigger
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
The TILE-Gx chip includes an on-chip UART. This change adds support
for using the UART from within the kernel. The UART shim has more
functionality than is exposed here, but to keep the kernel code and
binary simpler, this is a subset of the full API designed to enable
a standard Linux tty serial driver only.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
The existing code relied on the hardware definition (<arch/chip.h>)
to specify how much VA and PA space was available. It's convenient
to allow customizing this for some configurations, so provide symbols
MAX_PA_WIDTH and MAX_VA_WIDTH in <asm/page.h> that can be modified
if desired.
Additionally, move away from the MEM_XX_INTRPT nomenclature to
define the start of various regions within the VA space. In fact
the cleaner symbol is, for example, MEM_SV_START, to indicate the
start of the area used for supervisor code; the actual address of the
interrupt vectors is not as important, and can be changed if desired.
As part of this change, convert from "intrpt1" nomenclature (which
built in the old privilege-level 1 model) to a simple "intrpt".
Also strip out some tilepro-specific code supporting modifying the
PL the kernel could run at, since we don't actually support using
different PLs in tilepro, only tilegx.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
Technically, user privilege is anything less than kernel
privilege. We modify the existing user_mode() macro to have
this semantic (and use it in a couple of places it wasn't being
used before), and add an IS_KERNEL_EX1() macro to the assembly
code as well.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
Pull tty/serial driver patches from Greg KH:
"Here's the big tty/serial driver pull request for 3.12-rc1.
Lots of n_tty reworks to resolve some very long-standing issues,
removing the 3-4 different locks that were taken for every character.
This code has been beaten on for a long time in linux-next with no
reported regressions.
Other than that, a range of serial and tty driver updates and
revisions. Full details in the shortlog"
* tag 'tty-3.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (226 commits)
hvc_xen: Remove unnecessary __GFP_ZERO from kzalloc
serial: imx: initialize the local variable
tty: ar933x_uart: add device tree support and binding documentation
tty: ar933x_uart: allow to build the driver as a module
ARM: dts: msm: Update uartdm compatible strings
devicetree: serial: Document msm_serial bindings
serial: unify serial bindings into a single dir
serial: fsl-imx-uart: Cleanup duplicate device tree binding
tty: ar933x_uart: use config_enabled() macro to clean up ifdefs
tty: ar933x_uart: remove superfluous assignment of ar933x_uart_driver.nr
tty: ar933x_uart: use the clk API to get the uart clock
tty: serial: cpm_uart: Adding proper request of GPIO used by cpm_uart driver
serial: sirf: fix the amount of serial ports
serial: sirf: define macro for some magic numbers of USP
serial: icom: move array overflow checks earlier
TTY: amiserial, remove unnecessary platform_set_drvdata()
serial: st-asc: remove unnecessary platform_set_drvdata()
msm_serial: Send more than 1 character on the console w/ UARTDM
msm_serial: Add support for non-GSBI UARTDM devices
msm_serial: Switch clock consumer strings and simplify code
...
Pull staging tree merge from Greg KH:
"Here's the bit staging tree pull request for 3.12-rc1.
Lots of staging driver updates, and fixes. Lustre is finally enabled
in the build, and lots of cleanup started happening in it. There's a
new wireless driver in here, and 2 new TTY drivers, which cause the
overall lines added/removed to be quite large on the "added" side.
The IIO driver updates are also coming through here, as they are tied
to the staging iio drivers"
* tag 'staging-3.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging: (942 commits)
staging: dwc2: make dwc2_core_params documentation more complete
staging: dwc2: validate the value for phy_utmi_width
staging: dwc2: interpret all hwcfg and related register at init time
staging: dwc2: properly mask the GRXFSIZ register
staging: dwc2: remove redundant register reads
staging: dwc2: re-use hptxfsiz variable
staging: dwc2: simplify debug output in dwc_hc_init
staging: dwc2: add missing shift
staging: dwc2: simplify register shift expressions
staging: dwc2: only read the snpsid register once
staging: dwc2: unshift non-bool register value constants
staging: dwc2: fix off-by-one in check for max_packet_count parameter
staging: dwc2: remove specific fifo size constants
Staging:BCM:DDRInit.c:Renaming __FUNCTION__
staging: bcm: remove Version.h file.
staging: rtl8188eu: off by one in rtw_set_802_11_add_wep()
staging: r8188eu: copying one byte too much
staging: rtl8188eu: || vs && typo
staging: r8188eu: off by one bugs
staging: crystalhd: Resolve sparse 'different base types' warnings.
...
Pull driver core patches from Greg KH:
"Here's the big driver core pull request for 3.12-rc1.
Lots of tiny changes here fixing up the way sysfs attributes are
created, to try to make drivers simpler, and fix a whole class race
conditions with creations of device attributes after the device was
announced to userspace.
All the various pieces are acked by the different subsystem
maintainers"
* tag 'driver-core-3.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (119 commits)
firmware loader: fix pending_fw_head list corruption
drivers/base/memory.c: introduce help macro to_memory_block
dynamic debug: line queries failing due to uninitialized local variable
sysfs: sysfs_create_groups returns a value.
debugfs: provide debugfs_create_x64() when disabled
rbd: convert bus code to use bus_groups
firmware: dcdbas: use binary attribute groups
sysfs: add sysfs_create/remove_groups for when SYSFS is not enabled
driver core: add #include <linux/sysfs.h> to core files.
HID: convert bus code to use dev_groups
Input: serio: convert bus code to use drv_groups
Input: gameport: convert bus code to use drv_groups
driver core: firmware: use __ATTR_RW()
driver core: core: use DEVICE_ATTR_RO
driver core: bus: use DRIVER_ATTR_WO()
driver core: create write-only attribute macros for devices and drivers
sysfs: create __ATTR_WO()
driver-core: platform: convert bus code to use dev_groups
workqueue: convert bus code to use dev_groups
MEI: convert bus code to use dev_groups
...
Pull char/misc patches from Greg KH:
"Here is the big char/misc driver pull request for 3.12-rc1
Lots of driver updates all over the char/misc tree, full details in
the shortlog"
* tag 'char-misc-3.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (62 commits)
drivers: uio: Kconfig: add MMU dependancy for UIO
drivers: uio: Add driver for Humusoft MF624 DAQ PCI card
drivers: uio_pdrv_genirq: use dev_get_platdata()
drivers: uio_pruss: use dev_get_platdata()
drivers: uio_dmem_genirq: use dev_get_platdata()
drivers: parport: Kconfig: exclude h8300 for PARPORT_PC
drivers: misc: ti-st: fix potential race if st_kim_start fails
Drivers: hv: vmbus: Do not attempt to negoatiate a new version prematurely
misc: vmw_balloon: Remove braces to fix build for clang.
Drivers: hv: vmbus: Fix a bug in the handling of channel offers
vme: vme_ca91cx42.c: fix to pass correct device identity to free_irq()
VMCI: Add support for virtual IOMMU
VMCI: Remove non-blocking/pinned queuepair support
uio: uio_pruss: remove unnecessary platform_set_drvdata()
parport: amiga: remove unnecessary platform_set_drvdata()
vme: vme_vmivme7805.c: add missing __iomem annotation
vme: vme_ca91cx42.c: add missing __iomem annotation
vme: vme_tsi148.c: add missing __iomem annotation
drivers/misc/hpilo: Correct panic when an AUX iLO is detected
uio: drop unused vma_count member in uio_device struct
...
Pull USB patches from Greg KH:
"Here's the big USB driver pull request for 3.12-rc1
Lots of USB driver fixes and updates. Nothing major, just the normal
xhci, gadget, and other driver changes. Full details in the shortlog"
* tag 'usb-3.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb: (352 commits)
usbcore: fix incorrect type in assignment in descriptors_changed()
usbcore: compare and release one bos descriptor in usb_reset_and_verify_device()
ehci: remove debugging statement with ehci statistics in ehci_stop()
ehci: remove duplicate debug_async_open() prototype in ehci-dbg.c
ehci: enable debugging code when CONFIG_DYNAMIC_DEBUG is set
ehci: remove ehci_vdbg() verbose debugging statements
Documentation sysfs-bus-usb: Document which files are used by libusb
Documentation sysfs-bus-usb: Document the speed file used by libusb
Documentation sysfs-bus-usb: Move files with known users to stable
USB: fix build error when CONFIG_PM_SLEEP isn't enabled
usb: r8a66597-hcd: use platform_{get,set}_drvdata()
usb: phy-tegra-usb: use platform_{get,set}_drvdata()
usb: acm gadget: Null termintate strings table
dma: cppi41: off by one in desc_to_chan()
xhci: Fix warning introduced by disabling runtime PM.
dev-core: fix build break when DEBUG is enabled
USB: OHCI: Allow runtime PM without system sleep
usb: ohci-at91: remove unnecessary dev_set_drvdata()
usb: renesas_usbhs: use platform_{get,set}_drvdata()
usb: fotg210-udc: use platform_{get,set}_drvdata()
...
Debugfs was setup in NTB to only have a single debugfs directory. This
resulted in the leaking of debugfs directories and files when multiple
NTB devices were present, due to each device stomping on the variables
containing the previous device's values (thus preventing them from being
freed on cleanup). Correct this by creating a secondary directory of
the PCI BDF for each device present, and nesting the previously existing
information in those directories.
Signed-off-by: Jon Mason <jon.mason@intel.com>
We remove some debug code in relocate_kernel_64.S that made raw
calls to the hv_console_putc Tilera hypervisor API, since everything
should funnel through the early_hv_write() API.
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>
Due to ambiguous documentation, the USD/DSD identification is backward
when compared to the setting in BIOS. Correct the bits to match the
BIOS setting.
Signed-off-by: Jon Mason <jon.mason@intel.com>
The NTB Xeon hardware has 16 scratch pad registers and 16 back-to-back
scratch pad registers. Correct the #define to represent this and update
the variable names to reflect their usage.
Signed-off-by: Jon Mason <jon.mason@intel.com>
If an error is encountered in ntb_device_setup, it is possible that the
spci_cmd isn't populated. Writes to the offset can result in a NULL
pointer dereference. This issue is easily encountered by running in
NTB-RP mode, as it currently is not supported and will generate an
error. To get around this issue, return if an error is encountered
prior to attempting to write to the spci_cmd offset.
Signed-off-by: Jon Mason <jon.mason@intel.com>
Pull first batch of s390 updates from Martin Schwidefsky:
"The most interesting change is that Martin converted s390 to generic
hardirqs. Which means that all current architectures have been
converted and that CONFIG_GENERIC_HARDIRQS can be removed. Martin
prepared a patch for that already (see genirq branch), but the best
time to merge that is probably at the end of the merge window / begin
of -rc1.
Another patch converts s390 to software referenced bits instead of
relying on the reference bit in the storage key. Therefore s390
doesn't use storage keys anymore, except for kvm.
Besides that we have improvements, cleanups and fixes in PCI, DASD and
all over the place."
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (32 commits)
s390/pci: use virtual memory for iommu bitmap
s390/cio: fix unlocked access of global bitmap
s390/pci: update function handle after resume from hibernate
s390/pci: try harder to modify a function
s390/pci: split lpf
s390/hibernate: add early resume function
s390/pci: add recover sysfs knob
s390/pci: use claim_resource
s390/pci/hotplug: convert to be builtin only
s390/mm: implement software referenced bits
s390/dasd: fix statistics for recovered requests
s390/tx: allow program interruption filtering in user space
s390/pgtable: fix mprotect for single-threaded KVM guests
s390/time: return with irqs disabled from psw_idle
s390/kprobes: add support for compare and branch instructions
s390/switch_to: fix save_access_regs() / restore_access_regs()
s390/bitops: fix inline assembly constraints
s390/dasd: enable raw_track_access reads without direct I/O
s390/mm: introduce ptep_flush_lazy helper
s390/time: clock comparator revalidation
...
Pull m68k updates from Geert Uytterhoeven:
"Summary:
- Kill harmless warning messages when running a multi-platform kernel
on Atari
- Correct virt/phys mixups that didn't actually hurt due to identity
mappings"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/geert/linux-m68k:
m68k/atari: ARAnyM - Always use physical addresses in NatFeat calls
m68k: Ignore disabled HSYNC interrupt on Atari for irqs_disabled()
Pull hwmon updates from Guenter Roeck:
- new driver for HTU21D (humidity sensor)
- add support for Fam16h (Kabini) to k10temp
- add support for NCT6102D/6106D and NCT6791D to nct6775 driver
- add support for ADS1115 to ads1015 driver
- add support for hibernate to w83627ehf and nct6775 drivers
- some minor cleanups
* tag 'hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging:
hwmon: (htu21) Add Measurement Specialties HTU21D support
hwmon: Change my email address.
hwmon: (k10temp) Add support for Fam16h (Kabini)
hwmon: (adt7462) ADT7462_REG_VOLT_MAX() should return 0
hwmon: (ads1015) Add support for ADS1115
hwmon: (w83627ehf) Add support for hibernate
hwmon: (nct6775) Add support for hibernate
hwmon: use dev_get_platdata()
hwmon: (nct6775) Fix size of data->temp array
hwmon: (nct6775) Avoid using device platform data outside probe function
hwmon: (nct6775) Add support for NCT6791D
hwmon: (nct6775) Add support for beep attributes
hwmon: (nct6775) Add support for critical low/high temperature limits on NCT6106
hwmon: (nct6775) Add support for NCT6102D/6106D
hwmon: (nct6775) Support two SuperIO chips in the same system
hwmon: (nct6775) Allocate attributes dynamically from templates
hwmon: (coretemp) Atom CPUs don't support TjMax; no warning needed
The check if the queue is full and adding current to the wait queue of
pending msgsnd() operations (ss_add()) must be atomic.
Otherwise:
- the thread that performs msgsnd() finds a full queue and decides to
sleep.
- the thread that performs msgrcv() first reads all messages from the
queue and then sleeps, because the queue is empty.
- the msgrcv() calls do not perform any wakeups, because the msgsnd()
task has not yet called ss_add().
- then the msgsnd()-thread first calls ss_add() and then sleeps.
Net result: msgsnd() and msgrcv() both sleep forever.
Observed with msgctl08 from ltp with a preemptible kernel.
Fix: Call ipc_lock_object() before performing the check.
The patch also moves security_msg_queue_msgsnd() under ipc_lock_object:
- msgctl(IPC_SET) explicitely mentions that it tries to expunge any
pending operations that are not allowed anymore with the new
permissions. If security_msg_queue_msgsnd() is called without locks,
then there might be races.
- it makes the patch much simpler.
Reported-and-tested-by: Vineet Gupta <Vineet.Gupta1@synopsys.com>
Acked-by: Rik van Riel <riel@redhat.com>
Cc: stable@vger.kernel.org # for 3.11
Signed-off-by: Manfred Spraul <manfred@colorfullife.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
