fs: Add helper functions for permanently empty directories.
To ensure it is safe to mount proc and sysfs I need to check if
filesystems that are mounted on top of them are mounted on truly empty
directories. Given that some directories can gain entries over time,
knowing that a directory is empty right now is insufficient.
Therefore add supporting infrastructure for permantently empty
directories that proc and sysfs can use when they create mount points
for filesystems and fs_fully_visible can use to test for permanently
empty directories to ensure that nothing will be gained by mounting a
fresh copy of proc or sysfs.
Cc: stable@vger.kernel.org Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Limit the mounts fs_fully_visible considers to locked mounts.
Unlocked can always be unmounted so considering them adds hassle
but no security benefit.
Cc: stable@vger.kernel.org Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
The problem is almost exactly the same as the one fixed by feaff8e5b2cf.
We must take a reference to the struct file when running the LOCKU
compound to prevent the final fput from running until the operation is
complete.
Reported-by: Jean Spector <jean@primarydata.com> Signed-off-by: Jeff Layton <jeff.layton@primarydata.com> Cc: stable@vger.kernel.org Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Lars Poeschel [Thu, 25 Jun 2015 10:21:51 +0000 (12:21 +0200)]
watchdog: omap_wdt: early_enable module parameter
Add a early_enable module parameter to the omap_wdt that starts the
watchdog on module insertion. The default value is 0 which does not
start the watchdog - which also does not change the behavior if the
parameter is not given.
Signed-off-by: Lars Poeschel <poeschel@lemonage.de> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
Make each fuse device clone refer to a separate processing queue. The only
constraint on userspace code is that the request answer must be written to
the same device clone as it was read off.
Allow fuse device clones to refer to be distinguished. This patch just
adds the infrastructure by associating a separate "struct fuse_dev" with
each clone.
No longer need to call request_end() with the connection lock held. We
still protect the background counters and queue with fc->lock, so acquire
it if necessary.
When an unlocked request is aborted, it is moved from fpq->io to a private
list. Then, after unlocking fpq->lock, the private list is processed and
the requests are finished off.
To protect the private list, we need to mark the request with a flag, so if
in the meantime the request is unlocked the list is not corrupted.
Interrupt is only queued after the request has been sent to userspace.
This is either done in request_wait_answer() or fuse_dev_do_read()
depending on which state the request is in at the time of the interrupt.
If it's not yet sent, then queuing the interrupt is postponed until the
request is read. Otherwise (the request has already been read and is
waiting for an answer) the interrupt is queued immedidately.
We want to call queue_interrupt() without fc->lock protection, in which
case there can be a race between the two functions:
- neither of them queue the interrupt (thinking the other one has already
done it).
- both of them queue the interrupt
The first one is prevented by adding memory barriers, the second is
prevented by checking (under fiq->waitq.lock) if the interrupt has already
been queued.
The input queue contains normal requests (fc->pending), forgets
(fc->forget_*) and interrupts (fc->interrupts). There's also fc->waitq and
fc->fasync for waking up the readers of the fuse device when a request is
available.
The fc->reqctr is also moved to the input queue (assigned to the request
when the request is added to the input queue.
This patch just rearranges the fields, no functional change.
Use flags for representing the state in fuse_req. This is needed since
req->list will be protected by different locks in different states, hence
we'll want the state itself to be split into distinct bits, each protected
with the relevant lock in that state.
Only hold fc->lock over sections of request_wait_answer() that actually
need it. If wait_event_interruptible() returns zero, it means that the
request finished. Need to add memory barriers, though, to make sure that
all relevant data in the request is synchronized.
fc->conn_error is set once in FUSE_INIT reply and never cleared. Check it
in request allocation, there's no sense in doing all the preparation if
sending will surely fail.
fuse: account as waiting before queuing for background
Move accounting of fc->num_waiting to the point where the request actually
starts waiting. This is earlier than the current queue_request() for
background requests, since they might be waiting on the fc->bg_queue before
being queued on fc->pending.
request_end() expects fc->num_background and fc->active_background to have
been incremented, which is not the case in fuse_request_send_nowait()
failure path. So instead just call the ->end() callback (which is actually
set by all callers).
The current pmd_huge() and pud_huge() functions simply check if the table
bit is not set and reports the entries as huge in that case. This is
counter-intuitive as a clear pmd/pud cannot also be a huge pmd/pud, and
it is inconsistent with at least arm and x86.
To prevent others from making the same mistake as me in looking at code
that calls these functions and to fix an issue with KVM on arm64 that
causes memory corruption due to incorrect page reference counting
resulting from this mistake, let's change the behavior.
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org> Reviewed-by: Steve Capper <steve.capper@linaro.org> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Fixes: 084bd29810a5 ("ARM64: mm: HugeTLB support.") Cc: <stable@vger.kernel.org> # 3.11+ Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Bjorn Andersson [Fri, 26 Jun 2015 21:47:21 +0000 (14:47 -0700)]
hwspinlock: qcom: Correct msb in regmap_field
msb of the regmap_field was mistakenly given the value 32, to set all bits
in the regmap update mask; although incorrect this worked until 921cc294,
where the mask calculation was corrected.
Thomas Gleixner [Wed, 1 Jul 2015 07:57:35 +0000 (09:57 +0200)]
time: Remove development rules from Kbuild/Makefile
time.o gets rebuilt unconditionally due to a leftover Makefile rule
which was placed there for development purposes.
Remove it along with the commented out always rule in the toplevel
Kbuild file.
Fixes: 0a227985d4a9 'time: Move timeconst.h into include/generated'
Reported-by; Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Nicholas Mc Guire <der.herr@hofr.at>
Joerg Roedel [Tue, 30 Jun 2015 06:56:11 +0000 (08:56 +0200)]
iommu/amd: Introduce protection_domain_init() function
This function contains the common parts between the
initialization of dma_ops_domains and usual protection
domains. This also fixes a long-standing bug which was
uncovered by recent changes, in which the api_lock was not
initialized for dma_ops_domains.
Reported-by: George Wang <xuw2015@gmail.com> Tested-by: George Wang <xuw2015@gmail.com> Signed-off-by: Joerg Roedel <jroedel@suse.de>
Pull arch/tile updates from Chris Metcalf:
"These are a grab bag of changes to improve debugging and respond to a
variety of issues raised on LKML over the last couple of months"
* git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile:
tile: avoid a "label not used" warning in do_page_fault()
tile: vdso: use raw_read_seqcount_begin() in vdso
tile: force CONFIG_TILEGX if ARCH != tilepro
tile: improve stack backtrace
tile: fix "odd fault" warning for stack backtraces
tile: set up initial stack top to honor STACK_TOP_DELTA
tile: support delivering NMIs for multicore backtrace
drivers/tty/hvc/hvc_tile.c: properly return -EAGAIN
tile: add <asm/word-at-a-time.h> and enable support functions
tile: use READ_ONCE() in arch_spin_is_locked()
tile: modify arch_spin_unlock_wait() semantics
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux
Pull more s390 updates from Martin Schwidefsky:
"There is one larger patch for the AP bus code to make it work with the
longer reset periods of the latest crypto cards.
A new default configuration, a naming cleanup for SMP and a few fixes"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
s390/kdump: fix compile for !SMP
s390/kdump: fix nosmt kernel parameter
s390: new default configuration
s390/smp: cleanup core vs. cpu in the SCLP interface
s390/smp: fix sigp cpu detection loop
s390/zcrypt: Fixed reset and interrupt handling of AP queues
s390/kdump: fix REGSET_VX_LOW vector register ELF notes
s390/bpf: Fix backward jumps
Merge branch 'for-next' of git://git.samba.org/sfrench/cifs-2.6
Pull CIFS/SMB3 updates from Steve French:
"Includes two bug fixes, as well as (minimal) support for the new
protocol dialect (SMB3.1.1), and support for two ioctls including
reflink (duplicate extents) file copy and set integrity"
* 'for-next' of git://git.samba.org/sfrench/cifs-2.6:
cifs: Unset CIFS_MOUNT_POSIX_PATHS flag when following dfs mounts
Update negotiate protocol for SMB3.11 dialect
Add ioctl to set integrity
Add Get/Set Integrity Information structure definitions
Add reflink copy over SMB3.11 with new FSCTL_DUPLICATE_EXTENTS
Add SMB3.11 mount option synonym for new dialect
add struct FILE_STANDARD_INFO
Make dialect negotiation warning message easier to read
Add defines and structs for smb3.1 dialect
Allow parsing vers=3.11 on cifs mount
client MUST ignore EncryptionKeyLength if CAP_EXTENDED_SECURITY is set
Merge tag 'xfs-for-linus-4.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/dgc/linux-xfs
Pul xfs updates from Dave Chinner:
"There's a couple of small API changes to the core DAX code which
required small changes to the ext2 and ext4 code bases, but otherwise
everything is within the XFS codebase.
This update contains:
- A new sparse on-disk inode record format to allow small extents to
be used for inode allocation when free space is fragmented.
- DAX support. This includes minor changes to the DAX core code to
fix problems with lock ordering and bufferhead mapping abuse.
- transaction commit interface cleanup
- removal of various unnecessary XFS specific type definitions
- cleanup and optimisation of freelist preparation before allocation
* tag 'xfs-for-linus-4.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/dgc/linux-xfs: (49 commits)
xfs: don't truncate attribute extents if no extents exist
xfs: clean up XFS_MIN_FREELIST macros
xfs: sanitise error handling in xfs_alloc_fix_freelist
xfs: factor out free space extent length check
xfs: xfs_alloc_fix_freelist() can use incore perag structures
xfs: remove xfs_caddr_t
xfs: use void pointers in log validation helpers
xfs: return a void pointer from xfs_buf_offset
xfs: remove inst_t
xfs: remove __psint_t and __psunsigned_t
xfs: fix remote symlinks on V5/CRC filesystems
xfs: fix xfs_log_done interface
xfs: saner xfs_trans_commit interface
xfs: remove the flags argument to xfs_trans_cancel
xfs: pass a boolean flag to xfs_trans_free_items
xfs: switch remaining xfs_trans_dup users to xfs_trans_roll
xfs: check min blks for random debug mode sparse allocations
xfs: fix sparse inodes 32-bit compile failure
xfs: add initial DAX support
xfs: add DAX IO path support
...
Merge branch 'for-linus-4.2' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs
Pull btrfs updates from Chris Mason:
"Outside of our usual batch of fixes, this integrates the subvolume
quota updates that Qu Wenruo from Fujitsu has been working on for a
few releases now. He gets an extra gold star for making btrfs smaller
this time, and fixing a number of quota corners in the process.
Dave Sterba tested and integrated Anand Jain's sysfs improvements.
Outside of exporting a symbol (ack'd by Greg) these are all internal
to btrfs and it's mostly cleanups and fixes. Anand also attached some
of our sysfs objects to our internal device management structs instead
of an object off the super block. It will make device management
easier overall and it's a better fit for how the sysfs files are used.
None of the existing sysfs files are moved around.
Thanks for all the fixes everyone"
* 'for-linus-4.2' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (87 commits)
btrfs: delayed-ref: double free in btrfs_add_delayed_tree_ref()
Btrfs: Check if kobject is initialized before put
lib: export symbol kobject_move()
Btrfs: sysfs: add support to show replacing target in the sysfs
Btrfs: free the stale device
Btrfs: use received_uuid of parent during send
Btrfs: fix use-after-free in btrfs_replay_log
btrfs: wait for delayed iputs on no space
btrfs: qgroup: Make snapshot accounting work with new extent-oriented qgroup.
btrfs: qgroup: Add the ability to skip given qgroup for old/new_roots.
btrfs: ulist: Add ulist_del() function.
btrfs: qgroup: Cleanup the old ref_node-oriented mechanism.
btrfs: qgroup: Switch self test to extent-oriented qgroup mechanism.
btrfs: qgroup: Switch to new extent-oriented qgroup mechanism.
btrfs: qgroup: Switch rescan to new mechanism.
btrfs: qgroup: Add new qgroup calculation function btrfs_qgroup_account_extents().
btrfs: backref: Add special time_seq == (u64)-1 case for btrfs_find_all_roots().
btrfs: qgroup: Add new function to record old_roots.
btrfs: qgroup: Record possible quota-related extent for qgroup.
btrfs: qgroup: Add function qgroup_update_counters().
...
Merge branch 'for-linus' of git://git.kernel.dk/linux-block
Pull more block layer patches from Jens Axboe:
"A few later arrivers that I didn't fold into the first pull request,
so we had a chance to run some testing. This contains:
- NVMe:
- Set of fixes from Keith
- 4.4 and earlier gcc build fix from Andrew
- small set of xen-blk{back,front} fixes from Bob Liu.
- warnings fix for bogus inline statement in I_BDEV() from Geert.
- error code fixup for SG_IO ioctl from Paolo Bonzini"
* 'for-linus' of git://git.kernel.dk/linux-block:
drivers/block/nvme-core.c: fix build with gcc-4.4.4
bdi: Remove "inline" keyword from exported I_BDEV() implementation
block: fix bogus EFAULT error from SG_IO ioctl
NVMe: Fix filesystem deadlock on removal
NVMe: Failed controller initialization fixes
NVMe: Unify controller probe and resume
NVMe: Don't use fake status on cancelled command
NVMe: Fix device cleanup on initialization failure
drivers: xen-blkfront: only talk_to_blkback() when in XenbusStateInitialising
xen/block: add multi-page ring support
driver: xen-blkfront: move talk_to_blkback to a more suitable place
drivers: xen-blkback: delay pending_req allocation to connect_ring
genalloc: rename of_get_named_gen_pool() to of_gen_pool_get()
To be consistent with other kernel interface namings, rename
of_get_named_gen_pool() to of_gen_pool_get(). In the original function
name "_named" suffix references to a device tree property, which contains
a phandle to a device and the corresponding device driver is assumed to
register a gen_pool object.
Due to a weak relation and to avoid any confusion (e.g. in future
possible scenario if gen_pool objects are named) the suffix is removed.
[sfr@canb.auug.org.au: crypto/marvell/cesa - fix up for of_get_named_gen_pool() rename] Signed-off-by: Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com> Cc: Nicolas Ferre <nicolas.ferre@atmel.com> Cc: Philipp Zabel <p.zabel@pengutronix.de> Cc: Shawn Guo <shawn.guo@linaro.org> Cc: Sascha Hauer <kernel@pengutronix.de> Cc: Alexandre Belloni <alexandre.belloni@free-electrons.com> Cc: Russell King <linux@arm.linux.org.uk> Cc: Mauro Carvalho Chehab <mchehab@osg.samsung.com> Cc: Vinod Koul <vinod.koul@intel.com> Cc: Takashi Iwai <tiwai@suse.de> Cc: Jaroslav Kysela <perex@perex.cz> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Boris BREZILLON <boris.brezillon@free-electrons.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
genalloc: rename dev_get_gen_pool() to gen_pool_get()
To be consistent with other genalloc interface namings, rename
dev_get_gen_pool() to gen_pool_get(). The original omitted "dev_" prefix
is removed, since it points to argument type of the function, and so it
does not bring any useful information.
[akpm@linux-foundation.org: update arch/arm/mach-socfpga/pm.c] Signed-off-by: Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com> Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com> Cc: Philipp Zabel <p.zabel@pengutronix.de> Cc: Shawn Guo <shawn.guo@linaro.org> Cc: Sascha Hauer <kernel@pengutronix.de> Cc: Alexandre Belloni <alexandre.belloni@free-electrons.com> Cc: Russell King <linux@arm.linux.org.uk> Cc: Mauro Carvalho Chehab <mchehab@osg.samsung.com> Cc: Vinod Koul <vinod.koul@intel.com> Cc: Takashi Iwai <tiwai@suse.de> Cc: Jaroslav Kysela <perex@perex.cz> Cc: Mark Brown <broonie@kernel.org> Cc: Nicolas Ferre <nicolas.ferre@atmel.com> Cc: Alan Tull <atull@opensource.altera.com> Cc: Dinh Nguyen <dinguyen@opensource.altera.com> Cc: Kevin Hilman <khilman@linaro.org> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Josh Triplett [Tue, 30 Jun 2015 22:00:00 +0000 (15:00 -0700)]
x86: opt into HAVE_COPY_THREAD_TLS, for both 32-bit and 64-bit
For 32-bit userspace on a 64-bit kernel, this requires modifying
stub32_clone to actually swap the appropriate arguments to match
CONFIG_CLONE_BACKWARDS, rather than just leaving the C argument for tls
broken.
Patch co-authored by Josh Triplett and Thiago Macieira.
Signed-off-by: Josh Triplett <josh@joshtriplett.org> Acked-by: Andy Lutomirski <luto@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Thiago Macieira <thiago.macieira@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Joe Perches [Tue, 30 Jun 2015 21:59:39 +0000 (14:59 -0700)]
MAINTAINERS: update sound soc intel patterns
Commit 2106241a6803 ("ASoC: Intel: create common folder and move common
files in") moved the files around. Update the patterns.
Signed-off-by: Joe Perches <joe@perches.com> Cc: Jie Yang <yang.jie@intel.com> Acked-by: Jie Yang <yang.jie@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Antonio Ospite [Tue, 30 Jun 2015 21:59:03 +0000 (14:59 -0700)]
printk: improve the description of /dev/kmsg line format
The comment about /dev/kmsg does not mention the additional values which
may actually be exported, fix that.
Also move up the part of the comment instructing the users to ignore these
additional values, this way the reading is more fluent and logically
compact.
Signed-off-by: Antonio Ospite <ao2@ao2.it> Cc: Joe Perches <joe@perches.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
do_device_access() takes a separate parameter to indicate the direction of
data transfer, which it used to use to select the appropriate function out
of sg_pcopy_{to,from}_buffer(). However these two functions now have
So this patch makes it bypass these wrappers and call the underlying
function sg_copy_buffer() directly; this has the same calling style as
do_device_access() i.e. a separate direction-of-transfer parameter and no
pointers-to-const, so skipping the wrappers not only eliminates the
warning, it also make the code simpler :)
[akpm@linux-foundation.org: fix very broken build] Signed-off-by: Dave Gordon <david.s.gordon@intel.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Cc: James Bottomley <James.Bottomley@HansenPartnership.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Dave Gordon [Tue, 30 Jun 2015 21:58:54 +0000 (14:58 -0700)]
lib/scatterlist: mark input buffer parameters as 'const'
The 'buf' parameter of sg(p)copy_from_buffer() can and should be
const-qualified, although because of the shared implementation of
_to_buffer() and _from_buffer(), we have to cast this away internally.
This means that callers who have a 'const' buffer containing the data to
be copied to the sg-list no longer have to cast away the const-ness
themselves. It also enables improved coverage by code analysis tools.
Signed-off-by: Dave Gordon <david.s.gordon@intel.com> Cc: Akinobu Mita <akinobu.mita@gmail.com> Cc: "Martin K. Petersen" <martin.petersen@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Dave Gordon [Tue, 30 Jun 2015 21:58:52 +0000 (14:58 -0700)]
lib/scatterlist.c: fix kerneldoc for sg_pcopy_{to,from}_buffer()
The kerneldoc for the functions doesn't match the code; the last two
parameters (buflen, skip) have been transposed, which is confusing,
especially as they're both integral types and the compiler won't warn
about swapping them.
These functions and the kerneldoc were introduced in commit: df642cea lib/scatterlist: introduce sg_pcopy_from_buffer() ...
Author: Akinobu Mita <akinobu.mita@gmail.com>
Date: Mon Jul 8 16:01:54 2013 -0700
The only difference between sg_pcopy_{from,to}_buffer() and
sg_copy_{from,to}_buffer() is an additional argument that
specifies the number of bytes to skip the SG list before
copying.
The functions have the extra argument at the end, but the kerneldoc
lists it in penultimate position.
Signed-off-by: Dave Gordon <david.s.gordon@intel.com> Reviewed-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: "Martin K. Petersen" <martin.petersen@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Davidlohr Bueso [Tue, 30 Jun 2015 21:58:48 +0000 (14:58 -0700)]
ipc,sysv: return -EINVAL upon incorrect id/seqnum
In ipc_obtain_object_check we return -EIDRM when a bogus sequence number
is detected via ipc_checkid, while the ipc manpages state the following
return codes for such errors:
EIDRM <ID> points to a removed identifier.
EINVAL Invalid <ID> value, or unaligned, etc.
EIDRM should only be returned upon a RMID call (->deleted check), and thus
return EINVAL for wrong seq. This difference in semantics has also caused
real bugs, ie: https://bugzilla.redhat.com/show_bug.cgi?id=246509
Davidlohr Bueso [Tue, 30 Jun 2015 21:58:45 +0000 (14:58 -0700)]
ipc,sysv: make return -EIDRM when racing with RMID consistent
The ipc_lock helper is used by all forms of sysv ipc to acquire the ipc
object's spinlock. Upon error (bogus identifier), we always return
-EINVAL, whether the problem be in the idr path or because we raced with a
task performing RMID. For the later, however, all ipc related manpages,
state the that for:
EIDRM <ID> points to a removed identifier.
And return:
EINVAL Invalid <ID> value, or unaligned, etc.
Which (EINVAL) should only return once the ipc resource is deleted. For
all types of ipc this is done immediately upon a RMID command. However,
shared memory behaves slightly different as it can merely mark a segment
for deletion, and delay the actual freeing until there are no more active
consumers. Per shmctl(IPC_RMID) manpage:
""
Mark the segment to be destroyed. The segment will only actually
be destroyed after the last process detaches it (i.e., when the
shm_nattch member of the associated structure shmid_ds is zero).
""
Unlike ipc_lock, paths that behave "correctly", at least per the manpage,
involve controlling the ipc resource via *ctl(), doing the exact same
validity check as ipc_lock after right acquiring the spinlock:
if (!ipc_valid_object()) {
err = -EIDRM;
goto out_unlock;
}
Thus make ipc_lock consistent with the rest of ipc code and return -EIDRM
in ipc_lock when !ipc_valid_object().
Davidlohr Bueso [Tue, 30 Jun 2015 21:58:39 +0000 (14:58 -0700)]
ipc,msg: provide barrier pairings for lockless receive
We currently use a full barrier on the sender side to to avoid receiver
tasks disappearing on us while still performing on the sender side wakeup.
We lack however, the proper CPU-CPU interactions pairing on the receiver
side which busy-waits for the message. Similarly, we do not need a full
smp_mb, and can relax the semantics for the writer and reader sides of the
message. This is safe as we are only ordering loads and stores to r_msg.
And in both smp_wmb and smp_rmb, there are no stores after the calls
_anyway_.
This obviously applies for pipelined_send and expunge_all, for EIRDM when
destroying a queue.
Akinobu Mita [Tue, 30 Jun 2015 21:58:30 +0000 (14:58 -0700)]
arc: use for_each_sg()
This replaces the plain loop over the sglist array with for_each_sg()
macro which consists of sg_next() function calls. Since arc doesn't
select ARCH_HAS_SG_CHAIN, it is not necessary to use for_each_sg() in
order to loop over each sg element. But this can help find problems with
drivers that do not properly initialize their sg tables when
CONFIG_DEBUG_SG is enabled.
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Acked-by: Vineet Gupta <vgupta@synopsys.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Josh Triplett [Tue, 30 Jun 2015 21:58:27 +0000 (14:58 -0700)]
devpts: if initialization failed, don't crash when opening /dev/ptmx
If devpts failed to initialize, it would store an ERR_PTR in the global
devpts_mnt. A subsequent open of /dev/ptmx would call devpts_new_index,
which would dereference devpts_mnt and crash.
Avoid storing invalid values in devpts_mnt; leave it NULL instead. Make
both devpts_new_index and devpts_pty_new fail gracefully with ENODEV in
that case, which then becomes the return value to the userspace open call
on /dev/ptmx.
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