- 05 Oct, 2014 40 commits
-
-
Alex Deucher authored
commit 53beaa01 upstream. Use the new vga_switcheroo_fini_domain_pm_ops function to unregister the pm ops. Based on a patch from: Pali Rohár <pali.rohar@gmail.com> bug: https://bugzilla.kernel.org/show_bug.cgi?id=84431Reviewed-by:
Ben Skeggs <bskeggs@redhat.com> Signed-off-by:
Alex Deucher <alexander.deucher@amd.com> Cc: Ben Skeggs <bskeggs@redhat.com> Signed-off-by:
Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-
Alex Deucher authored
commit 766a53d0 upstream. Drivers should call this on unload to unregister pmops. Bug: https://bugzilla.kernel.org/show_bug.cgi?id=84431Reviewed-by:
Pali Rohár <pali.rohar@gmail.com> Cc: Ben Skeggs <bskeggs@redhat.com> Signed-off-by:
-
Cong Wang authored
commit 3577af70 upstream. We saw a kernel soft lockup in perf_remove_from_context(), it looks like the `perf` process, when exiting, could not go out of the retry loop. Meanwhile, the target process was forking a child. So either the target process should execute the smp function call to deactive the event (if it was running) or it should do a context switch which deactives the event. It seems we optimize out a context switch in perf_event_context_sched_out(), and what's more important, we still test an obsolete task pointer when retrying, so no one actually would deactive that event in this situation. Fix it directly by reloading the task pointer in perf_remove_from_context(). This should cure the above soft lockup. Signed-off-by:
Cong Wang <cwang@twopensource.com> Signed-off-by:
Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by:
Peter Zijlstra <peterz@infradead.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/1409696840-843-1-git-send-email-xiyou.wangcong@gmail.comSigned-off-by:
Ingo Molnar <mingo@kernel.org> Signed-off-by:
-
Matan Barak authored
commit a59c5850 upstream. When marsheling a user path to the kernel struct ib_sa_path, need to zero smac, dmac and set the vlan id to the "no vlan" value. Fixes: dd5f03be ("IB/core: Ethernet L2 attributes in verbs/cm structures") Reported-by:
Aleksey Senin <alekseys@mellanox.com> Signed-off-by:
Matan Barak <matanb@mellanox.com> Signed-off-by:
Or Gerlitz <ogerlitz@mellanox.com> Signed-off-by:
Roland Dreier <roland@purestorage.com> Signed-off-by:
-
Moni Shoua authored
commit f5c4834d upstream. When reading the IPv6 addresses from the net-device, make sure to avoid adding a duplicate entry to the GID table because of equality between the default GID we generate and the default IPv6 link-local address of the device. Fixes: acc4fccf ("IB/mlx4: Make sure GID index 0 is always occupied") Signed-off-by:
Moni Shoua <monis@mellanox.com> Signed-off-by:
-
Moni Shoua authored
commit e381835c upstream. When Ethernet netdev is not present for a port (e.g. when the link layer type of the port is InfiniBand) it's possible to dereference a null pointer when we do netdevice scanning. To fix that, we move a section of code that needs to run only when netdev is present to a proper if () statement. Fixes: ad4885d2 ("IB/mlx4: Build the port IBoE GID table properly under bonding") Reported-by:
Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by:
-
Mike Marciniszyn authored
commit 85cbb7c7 upstream. This particular reference count is not needed with the rcu protection, and the current code leaks a reference count, causing a hang in qib_qp_destroy(). Reviewed-by:
Dennis Dalessandro <dennis.dalessandro@intel.com> Signed-off-by:
Mike Marciniszyn <mike.marciniszyn@intel.com> Signed-off-by:
-
Al Viro authored
commit cfb2f9d5 upstream. Callers of d_splice_alias(dentry, inode) don't need iput(), neither on success nor on failure. Either the reference to inode is stored in a previously negative dentry, or it's dropped. In either case inode reference the caller used to hold is consumed. __gfs2_lookup() does iput() in case when d_splice_alias() has failed. Double iput() if we ever hit that. And gfs2_create_inode() ends up not only with double iput(), but with link count dropped to zero - on an inode it has just found in directory. Signed-off-by:
Al Viro <viro@zeniv.linux.org.uk> Signed-off-by:
Steven Whitehouse <swhiteho@redhat.com> Signed-off-by:
-
Richard Larocque authored
commit 474e941b upstream. Locks the k_itimer's it_lock member when handling the alarm timer's expiry callback. The regular posix timers defined in posix-timers.c have this lock held during timout processing because their callbacks are routed through posix_timer_fn(). The alarm timers follow a different path, so they ought to grab the lock somewhere else. Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@kernel.org> Cc: Richard Cochran <richardcochran@gmail.com> Cc: Prarit Bhargava <prarit@redhat.com> Cc: Sharvil Nanavati <sharvil@google.com> Signed-off-by:
Richard Larocque <rlarocque@google.com> Signed-off-by:
John Stultz <john.stultz@linaro.org> Signed-off-by:
-
Richard Larocque authored
commit 265b81d2 upstream. Avoids sending a signal to alarm timers created with sigev_notify set to SIGEV_NONE by checking for that special case in the timeout callback. The regular posix timers avoid sending signals to SIGEV_NONE timers by not scheduling any callbacks for them in the first place. Although it would be possible to do something similar for alarm timers, it's simpler to handle this as a special case in the timeout. Prior to this patch, the alarm timer would ignore the sigev_notify value and try to deliver signals to the process anyway. Even worse, the sanity check for the value of sigev_signo is skipped when SIGEV_NONE was specified, so the signal number could be bogus. If sigev_signo was an unitialized value (as it often would be if SIGEV_NONE is used), then it's hard to predict which signal will be sent. Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@kernel.org> Cc: Richard Cochran <richardcochran@gmail.com> Cc: Prarit Bhargava <prarit@redhat.com> Cc: Sharvil Nanavati <sharvil@google.com> Signed-off-by:
-
Richard Larocque authored
commit e86fea76 upstream. Returns the time remaining for an alarm timer, rather than the time at which it is scheduled to expire. If the timer has already expired or it is not currently scheduled, the it_value's members are set to zero. This new behavior matches that of the other posix-timers and the POSIX specifications. This is a change in user-visible behavior, and may break existing applications. Hopefully, few users rely on the old incorrect behavior. Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@kernel.org> Cc: Richard Cochran <richardcochran@gmail.com> Cc: Prarit Bhargava <prarit@redhat.com> Cc: Sharvil Nanavati <sharvil@google.com> Signed-off-by:
-
John David Anglin authored
commit d26a7730 upstream. In spite of what the GCC manual says, the -mfast-indirect-calls has never been supported in the 64-bit parisc compiler. Indirect calls have always been done using function descriptors irrespective of the -mfast-indirect-calls option. Recently, it was noticed that a function descriptor was always requested when the -mfast-indirect-calls option was specified. This caused problems when the option was used in application code and doesn't make any sense because the whole point of the option is to avoid using a function descriptor for indirect calls. Fixing this broke 64-bit kernel builds. I will fix GCC but for now we need the attached change. This results in the same kernel code as before. Signed-off-by:
John David Anglin <dave.anglin@bell.net> Signed-off-by:
Helge Deller <deller@gmx.de> Signed-off-by:
-
Guy Martin authored
commit 89206491 upstream. The current LWS cas only works correctly for 32bit. The new LWS allows for CAS operations of variable size. Signed-off-by:
Guy Martin <gmsoft@tuxicoman.be> Signed-off-by:
-
Al Viro authored
commit 7bd88377 upstream. return the value instead, and have path_init() do the assignment. Broken by "vfs: Fix absolute RCU path walk failures due to uninitialized seq number", which was Cc-stable with 2.6.38+ as destination. This one should go where it went. To avoid dummy value returned in case when root is already set (it would do no harm, actually, since the only caller that doesn't ignore the return value is guaranteed to have nd->root *not* set, but it's more obvious that way), lift the check into callers. And do the same to set_root(), to keep them in sync. Signed-off-by:
-
Michael Ellerman authored
commit 78e05b14 upstream. Similar to the previous commit which described why we need to add a barrier to arch_spin_is_locked(), we have a similar problem with spin_unlock_wait(). We need a barrier on entry to ensure any spinlock we have previously taken is visibly locked prior to the load of lock->slock. It's also not clear if spin_unlock_wait() is intended to have ACQUIRE semantics. For now be conservative and add a barrier on exit to give it ACQUIRE semantics. Signed-off-by:
Michael Ellerman <mpe@ellerman.id.au> Signed-off-by:
Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by:
-
Michael Ellerman authored
commit 51d7d520 upstream. The kernel defines the function spin_is_locked(), which can be used to check if a spinlock is currently locked. Using spin_is_locked() on a lock you don't hold is obviously racy. That is, even though you may observe that the lock is unlocked, it may become locked at any time. There is (at least) one exception to that, which is if two locks are used as a pair, and the holder of each checks the status of the other before doing any update. Assuming *A and *B are two locks, and *COUNTER is a shared non-atomic value: The first CPU does: spin_lock(*A) if spin_is_locked(*B) # nothing else smp_mb() LOAD r = *COUNTER r++ STORE *COUNTER = r spin_unlock(*A) And the second CPU does: spin_lock(*B) if spin_is_locked(*A) # nothing else smp_mb() LOAD r = *COUNTER r++ STORE *COUNTER = r spin_unlock(*B) Although this is a strange locking construct, it should work. It seems to be understood, but not documented, that spin_is_locked() is not a memory barrier, so in the examples above and below the caller inserts its own memory barrier before acting on the result of spin_is_locked(). For now we assume spin_is_locked() is implemented as below, and we break it out in our examples: bool spin_is_locked(*LOCK) { LOAD l = *LOCK return l.locked } Our intuition is that there should be no problem even if the two code sequences run simultaneously such as: CPU 0 CPU 1 ================================================== spin_lock(*A) spin_lock(*B) LOAD b = *B LOAD a = *A if b.locked # true if a.locked # true # nothing # nothing spin_unlock(*A) spin_unlock(*B) If one CPU gets the lock before the other then it will do the update and the other CPU will back off: CPU 0 CPU 1 ================================================== spin_lock(*A) LOAD b = *B spin_lock(*B) if b.locked # false LOAD a = *A else if a.locked # true smp_mb() # nothing LOAD r1 = *COUNTER spin_unlock(*B) r1++ STORE *COUNTER = r1 spin_unlock(*A) However in reality spin_lock() itself is not indivisible. On powerpc we implement it as a load-and-reserve and store-conditional. Ignoring the retry logic for the lost reservation case, it boils down to: spin_lock(*LOCK) { LOAD l = *LOCK l.locked = true STORE *LOCK = l ACQUIRE_BARRIER } The ACQUIRE_BARRIER is required to give spin_lock() ACQUIRE semantics as defined in memory-barriers.txt: This acts as a one-way permeable barrier. It guarantees that all memory operations after the ACQUIRE operation will appear to happen after the ACQUIRE operation with respect to the other components of the system. On modern powerpc systems we use lwsync for ACQUIRE_BARRIER. lwsync is also know as "lightweight sync", or "sync 1". As described in Power ISA v2.07 section B.2.1.1, in this scenario the lwsync is not the barrier itself. It instead causes the LOAD of *LOCK to act as the barrier, preventing any loads or stores in the locked region from occurring prior to the load of *LOCK. Whether this behaviour is in accordance with the definition of ACQUIRE semantics in memory-barriers.txt is open to discussion, we may switch to a different barrier in future. What this means in practice is that the following can occur: CPU 0 CPU 1 ================================================== LOAD a = *A LOAD b = *B a.locked = true b.locked = true LOAD b = *B LOAD a = *A STORE *A = a STORE *B = b if b.locked # false if a.locked # false else else smp_mb() smp_mb() LOAD r1 = *COUNTER LOAD r2 = *COUNTER r1++ r2++ STORE *COUNTER = r1 STORE *COUNTER = r2 # Lost update spin_unlock(*A) spin_unlock(*B) That is, the load of *B can occur prior to the store that makes *A visibly locked. And similarly for CPU 1. The result is both CPUs hold their lock and believe the other lock is unlocked. The easiest fix for this is to add a full memory barrier to the start of spin_is_locked(), so adding to our previous definition would give us: bool spin_is_locked(*LOCK) { smp_mb() LOAD l = *LOCK return l.locked } The new barrier orders the store to the lock we are locking vs the load of the other lock: CPU 0 CPU 1 ================================================== LOAD a = *A LOAD b = *B a.locked = true b.locked = true STORE *A = a STORE *B = b smp_mb() smp_mb() LOAD b = *B LOAD a = *A if b.locked # true if a.locked # true # nothing # nothing spin_unlock(*A) spin_unlock(*B) Although the above example is theoretical, there is code similar to this example in sem_lock() in ipc/sem.c. This commit in addition to the next commit appears to be a fix for crashes we are seeing in that code where we believe this race happens in practice. Signed-off-by:
-
Anton Blanchard authored
commit 85101af1 upstream. ABIv2 kernels are failing to backtrace through the kernel. An example: 39.30% readseek2_proce [kernel.kallsyms] [k] find_get_entry | --- find_get_entry __GI___libc_read The problem is in valid_next_sp() where we check that the new stack pointer is at least STACK_FRAME_OVERHEAD below the previous one. ABIv1 has a minimum stack frame size of 112 bytes consisting of 48 bytes and 64 bytes of parameter save area. ABIv2 changes that to 32 bytes with no paramter save area. STACK_FRAME_OVERHEAD is in theory the minimum stack frame size, but we over 240 uses of it, some of which assume that it includes space for the parameter area. We need to work through all our stack defines and rationalise them but let's fix perf now by creating STACK_FRAME_MIN_SIZE and using in valid_next_sp(). This fixes the issue: 30.64% readseek2_proce [kernel.kallsyms] [k] find_get_entry | --- find_get_entry pagecache_get_page generic_file_read_iter new_sync_read vfs_read sys_read syscall_exit __GI___libc_read Reported-by:
Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by:
Anton Blanchard <anton@samba.org> Signed-off-by:
-
Arend van Spriel authored
commit 87c47903 upstream. The firmware notifies about interface changes through the IF event which has a NO_IF flag that means host can ignore the event. This behaviour was introduced in the driver by: commit 2ee8382f Author: Arend van Spriel <arend@broadcom.com> Date: Sat Aug 10 12:27:24 2013 +0200 brcmfmac: ignore IF event if firmware indicates it It turns out that the IF event for the P2P_DEVICE also has this flag set, but the event should not be ignored in this scenario. The mentioned commit caused a regression in 3.12 kernel in creation of the P2P_DEVICE interface. Reviewed-by:
Hante Meuleman <meuleman@broadcom.com> Reviewed-by:
Franky (Zhenhui) Lin <frankyl@broadcom.com> Reviewed-by:
Daniel (Deognyoun) Kim <dekim@broadcom.com> Reviewed-by:
Pieter-Paul Giesberts <pieterpg@broadcom.com> Signed-off-by:
Arend van Spriel <arend@broadcom.com> Signed-off-by:
John W. Linville <linville@tuxdriver.com> Signed-off-by:
-
Wanpeng Li authored
commit 03bd4e1f upstream. The following bug can be triggered by hot adding and removing a large number of xen domain0's vcpus repeatedly: BUG: unable to handle kernel NULL pointer dereference at 0000000000000004 IP: [..] find_busiest_group PGD 5a9d5067 PUD 13067 PMD 0 Oops: 0000 [#3] SMP [...] Call Trace: load_balance ? _raw_spin_unlock_irqrestore idle_balance __schedule schedule schedule_timeout ? lock_timer_base schedule_timeout_uninterruptible msleep lock_device_hotplug_sysfs online_store dev_attr_store sysfs_write_file vfs_write SyS_write system_call_fastpath Last level cache shared mask is built during CPU up and the build_sched_domain() routine takes advantage of it to setup the sched domain CPU topology. However, llc_shared_mask is not released during CPU disable, which leads to an invalid sched domainCPU topology. This patch fix it by releasing the llc_shared_mask correctly during CPU disable. Yasuaki also reported that this can happen on real hardware: https://lkml.org/lkml/2014/7/22/1018 His case is here: == Here is an example on my system. My system has 4 sockets and each socket has 15 cores and HT is enabled. In this case, each core of sockes is numbered as follows: | CPU# Socket#0 | 0-14 , 60-74 Socket#1 | 15-29, 75-89 Socket#2 | 30-44, 90-104 Socket#3 | 45-59, 105-119 Then llc_shared_mask of CPU#30 has 0x3fff80000001fffc0000000. It means that last level cache of Socket#2 is shared with CPU#30-44 and 90-104. When hot-removing socket#2 and #3, each core of sockets is numbered as follows: | CPU# Socket#0 | 0-14 , 60-74 Socket#1 | 15-29, 75-89 But llc_shared_mask is not cleared. So llc_shared_mask of CPU#30 remains having 0x3fff80000001fffc0000000. After that, when hot-adding socket#2 and #3, each core of sockets is numbered as follows: | CPU# Socket#0 | 0-14 , 60-74 Socket#1 | 15-29, 75-89 Socket#2 | 30-59 Socket#3 | 90-119 Then llc_shared_mask of CPU#30 becomes 0x3fff8000fffffffc0000000. It means that last level cache of Socket#2 is shared with CPU#30-59 and 90-104. So the mask has the wrong value. Signed-off-by:
Wanpeng Li <wanpeng.li@linux.intel.com> Tested-by:
Linn Crosetto <linn@hp.com> Reviewed-by:
Borislav Petkov <bp@suse.de> Reviewed-by:
Toshi Kani <toshi.kani@hp.com> Reviewed-by:
Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Cc: David Rientjes <rientjes@google.com> Cc: Prarit Bhargava <prarit@redhat.com> Cc: Steven Rostedt <srostedt@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1411547885-48165-1-git-send-email-wanpeng.li@linux.intel.comSigned-off-by:
-
Peter Feiner authored
commit dbab31aa upstream. This fixes the same bug as b43790ee ("mm: softdirty: don't forget to save file map softdiry bit on unmap") and 9aed8614 ("mm/memory.c: don't forget to set softdirty on file mapped fault") where the return value of pte_*mksoft_dirty was being ignored. To be sure that no other pte/pmd "mk" function return values were being ignored, I annotated the functions in arch/x86/include/asm/pgtable.h with __must_check and rebuilt. The userspace effect of this bug is that the softdirty mark might be lost if a file mapped pte get zapped. Signed-off-by:
Peter Feiner <pfeiner@google.com> Acked-by:
Cyrill Gorcunov <gorcunov@openvz.org> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Jamie Liu <jamieliu@google.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by:
-
David Rientjes authored
commit d4a5fca5 upstream. Since commit 45906855 ("mm/sl[aou]b: Common alignment code"), the "ralign" automatic variable in __kmem_cache_create() may be used as uninitialized. The proper alignment defaults to BYTES_PER_WORD and can be overridden by SLAB_RED_ZONE or the alignment specified by the caller. This fixes https://bugzilla.kernel.org/show_bug.cgi?id=85031Signed-off-by:
David Rientjes <rientjes@google.com> Reported-by:
Andrei Elovikov <a.elovikov@gmail.com> Acked-by:
Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by:
-
Joseph Qi authored
commit 5760a97c upstream. There is a deadlock case which reported by Guozhonghua: https://oss.oracle.com/pipermail/ocfs2-devel/2014-September/010079.html This case is caused by &res->spinlock and &dlm->master_lock misordering in different threads. It was introduced by commit 8d400b81 ("ocfs2/dlm: Clean up refmap helpers"). Since lockres is new, it doesn't not require the &res->spinlock. So remove it. Fixes: 8d400b81 ("ocfs2/dlm: Clean up refmap helpers") Signed-off-by:
Joseph Qi <joseph.qi@huawei.com> Reviewed-by:
joyce.xue <xuejiufei@huawei.com> Reported-by:
Guozhonghua <guozhonghua@h3c.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Mark Fasheh <mfasheh@suse.com> Signed-off-by:
-
Andreas Rohner authored
commit 56d7acc7 upstream. This bug leads to reproducible silent data loss, despite the use of msync(), sync() and a clean unmount of the file system. It is easily reproducible with the following script: ----------------[BEGIN SCRIPT]-------------------- mkfs.nilfs2 -f /dev/sdb mount /dev/sdb /mnt dd if=/dev/zero bs=1M count=30 of=/mnt/testfile umount /mnt mount /dev/sdb /mnt CHECKSUM_BEFORE="$(md5sum /mnt/testfile)" /root/mmaptest/mmaptest /mnt/testfile 30 10 5 sync CHECKSUM_AFTER="$(md5sum /mnt/testfile)" umount /mnt mount /dev/sdb /mnt CHECKSUM_AFTER_REMOUNT="$(md5sum /mnt/testfile)" umount /mnt echo "BEFORE MMAP:\t$CHECKSUM_BEFORE" echo "AFTER MMAP:\t$CHECKSUM_AFTER" echo "AFTER REMOUNT:\t$CHECKSUM_AFTER_REMOUNT" ----------------[END SCRIPT]-------------------- The mmaptest tool looks something like this (very simplified, with error checking removed): ----------------[BEGIN mmaptest]-------------------- data = mmap(NULL, file_size - file_offset, PROT_READ | PROT_WRITE, MAP_SHARED, fd, file_offset); for (i = 0; i < write_count; ++i) { memcpy(data + i * 4096, buf, sizeof(buf)); msync(data, file_size - file_offset, MS_SYNC)) } ----------------[END mmaptest]-------------------- The output of the script looks something like this: BEFORE MMAP: 281ed1d5ae50e8419f9b978aab16de83 /mnt/testfile AFTER MMAP: 6604a1c31f10780331a6850371b3a313 /mnt/testfile AFTER REMOUNT: 281ed1d5ae50e8419f9b978aab16de83 /mnt/testfile So it is clear, that the changes done using mmap() do not survive a remount. This can be reproduced a 100% of the time. The problem was introduced in commit 136e8770 ("nilfs2: fix issue of nilfs_set_page_dirty() for page at EOF boundary"). If the page was read with mpage_readpage() or mpage_readpages() for example, then it has no buffers attached to it. In that case page_has_buffers(page) in nilfs_set_page_dirty() will be false. Therefore nilfs_set_file_dirty() is never called and the pages are never collected and never written to disk. This patch fixes the problem by also calling nilfs_set_file_dirty() if the page has no buffers attached to it. [akpm@linux-foundation.org: s/PAGE_SHIFT/PAGE_CACHE_SHIFT/] Signed-off-by:
Andreas Rohner <andreas.rohner@gmx.net> Tested-by:
Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> Signed-off-by:
-
Andrey Vagin authored
commit 7e882481 upstream. Currently we handle only ENOSPC. In case of other errors the file_handle variable isn't filled properly and we will show a part of stack. Signed-off-by:
Andrey Vagin <avagin@openvz.org> Acked-by:
-
Andrey Vagin authored
commit 1fc98d11 upstream. MAX_HANDLE_SZ is equal to 128, but currently the size of pad is only 64 bytes, so exportfs_encode_inode_fh can return an error. Signed-off-by:
-
Rasmus Villemoes authored
commit acbbe6fb upstream. The C operator <= defines a perfectly fine total ordering on the set of values representable in a long. However, unlike its namesake in the integers, it is not translation invariant, meaning that we do not have "b <= c" iff "a+b <= a+c" for all a,b,c. This means that it is always wrong to try to boil down the relationship between two longs to a question about the sign of their difference, because the resulting relation [a LEQ b iff a-b <= 0] is neither anti-symmetric or transitive. The former is due to -LONG_MIN==LONG_MIN (take any two a,b with a-b = LONG_MIN; then a LEQ b and b LEQ a, but a != b). The latter can either be seen observing that x LEQ x+1 for all x, implying x LEQ x+1 LEQ x+2 ... LEQ x-1 LEQ x; or more directly with the simple example a=LONG_MIN, b=0, c=1, for which a-b < 0, b-c < 0, but a-c > 0. Note that it makes absolutely no difference that a transmogrying bijection has been applied before the comparison is done. In fact, had the obfuscation not been done, one could probably not observe the bug (assuming all values being compared always lie in one half of the address space, the mathematical value of a-b is always representable in a long). As it stands, one can easily obtain three file descriptors exhibiting the non-transitivity of kcmp(). Side note 1: I can't see that ensuring the MSB of the multiplier is set serves any purpose other than obfuscating the obfuscating code. Side note 2: #include <stdio.h> #include <stdlib.h> #include <string.h> #include <fcntl.h> #include <unistd.h> #include <assert.h> #include <sys/syscall.h> enum kcmp_type { KCMP_FILE, KCMP_VM, KCMP_FILES, KCMP_FS, KCMP_SIGHAND, KCMP_IO, KCMP_SYSVSEM, KCMP_TYPES, }; pid_t pid; int kcmp(pid_t pid1, pid_t pid2, int type, unsigned long idx1, unsigned long idx2) { return syscall(SYS_kcmp, pid1, pid2, type, idx1, idx2); } int cmp_fd(int fd1, int fd2) { int c = kcmp(pid, pid, KCMP_FILE, fd1, fd2); if (c < 0) { perror("kcmp"); exit(1); } assert(0 <= c && c < 3); return c; } int cmp_fdp(const void *a, const void *b) { static const int normalize[] = {0, -1, 1}; return normalize[cmp_fd(*(int*)a, *(int*)b)]; } #define MAX 100 /* This is plenty; I've seen it trigger for MAX==3 */ int main(int argc, char *argv[]) { int r, s, count = 0; int REL[3] = {0,0,0}; int fd[MAX]; pid = getpid(); while (count < MAX) { r = open("/dev/null", O_RDONLY); if (r < 0) break; fd[count++] = r; } printf("opened %d file descriptors\n", count); for (r = 0; r < count; ++r) { for (s = r+1; s < count; ++s) { REL[cmp_fd(fd[r], fd[s])]++; } } printf("== %d\t< %d\t> %d\n", REL[0], REL[1], REL[2]); qsort(fd, count, sizeof(fd[0]), cmp_fdp); memset(REL, 0, sizeof(REL)); for (r = 0; r < count; ++r) { for (s = r+1; s < count; ++s) { REL[cmp_fd(fd[r], fd[s])]++; } } printf("== %d\t< %d\t> %d\n", REL[0], REL[1], REL[2]); return (REL[0] + REL[2] != 0); } Signed-off-by:
Rasmus Villemoes <linux@rasmusvillemoes.dk> Reviewed-by:
-
Nicolas Iooss authored
commit c680e41b upstream. When calling epoll_ctl with operation EPOLL_CTL_DEL, structure epds is not initialized but ep_take_care_of_epollwakeup reads its event field. When this unintialized field has EPOLLWAKEUP bit set, a capability check is done for CAP_BLOCK_SUSPEND in ep_take_care_of_epollwakeup. This produces unexpected messages in the audit log, such as (on a system running SELinux): type=AVC msg=audit(1408212798.866:410): avc: denied { block_suspend } for pid=7754 comm="dbus-daemon" capability=36 scontext=unconfined_u:unconfined_r:unconfined_t tcontext=unconfined_u:unconfined_r:unconfined_t tclass=capability2 permissive=1 type=SYSCALL msg=audit(1408212798.866:410): arch=c000003e syscall=233 success=yes exit=0 a0=3 a1=2 a2=9 a3=7fffd4d66ec0 items=0 ppid=1 pid=7754 auid=1000 uid=0 gid=0 euid=0 suid=0 fsuid=0 egid=0 sgid=0 fsgid=0 tty=(none) ses=3 comm="dbus-daemon" exe="/usr/bin/dbus-daemon" subj=unconfined_u:unconfined_r:unconfined_t key=(null) ("arch=c000003e syscall=233 a1=2" means "epoll_ctl(op=EPOLL_CTL_DEL)") Remove use of epds in epoll_ctl when op == EPOLL_CTL_DEL. Fixes: 4d7e30d9 ("epoll: Add a flag, EPOLLWAKEUP, to prevent suspend while epoll events are ready") Signed-off-by:
Nicolas Iooss <nicolas.iooss_linux@m4x.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Arve Hjønnevåg <arve@android.com> Signed-off-by:
-
Johannes Berg authored
commit bb512ad0 upstream. This reverts commit 24aa11ab. That commit was wrong since it uses data that hasn't even been set up yet, but might be a hold-over from a previous connection. Additionally, it seems like a driver-specific workaround that shouldn't have been in mac80211 to start with. Fixes: 24aa11ab ("mac80211: disable uAPSD if all ACs are under ACM") Reviewed-by:
Luciano Coelho <luciano.coelho@intel.com> Signed-off-by:
Johannes Berg <johannes.berg@intel.com> Signed-off-by:
-
Felipe Balbi authored
commit dc99f16f upstream. We can't suspend the PHYs before dwc3_core_exit_mode() has been called, that's because the host and/or device sides might still need to communicate with the far end link partner. Fixes: 8ba007a9 (usb: dwc3: core: enable the USB2 and USB3 phy in probe) Suggested-by:
Alan Stern <stern@rowland.harvard.edu> Signed-off-by:
Felipe Balbi <balbi@ti.com> Signed-off-by:
-
Felipe Balbi authored
commit fed33afc upstream. Currently, we disable pm_runtime before all register accesses are done, this is dangerous and might lead to abort exceptions due to the driver trying to access a register which is clocked by a clock which was long gated. Fix that by moving pm_runtime_put_sync() and pm_runtime_disable() as the last thing we do before returning from our ->remove() method. Fixes: 72246da4 (usb: Introduce DesignWare USB3 DRD Driver) Signed-off-by:
-
Jens Axboe authored
commit 46f341ff upstream. Commit 2da78092 changed the locking from a mutex to a spinlock, so we now longer sleep in this context. But there was a leftover might_sleep() in there, which now triggers since we do the final free from an RCU callback. Get rid of it. Reported-by:
Pontus Fuchs <pontus.fuchs@gmail.com> Signed-off-by:
Jens Axboe <axboe@fb.com> Signed-off-by:
-
Trond Myklebust authored
commit 22fdcf02 upstream. This commit reverts the addition of lockdep checking to raw_seqcount_begin for the following reasons: 1) It violates the naming convention that raw_* functions should not do lockdep checks (a convention that is also followed by the other raw_*_seqcount_begin functions). 2) raw_seqcount_begin does not spin, so it can only be part of an ABBA deadlock in very special circumstances (for instance if a lock is held across the entire raw_seqcount_begin()+read_seqcount_retry() loop while also being taken inside the write_seqcount protected area). 3) It is causing false positives with some existing callers, and there is no non-lockdep alternative for those callers to use. None of the three existing callers (__d_lookup_rcu, netdev_get_name, and the NFS state code) appear to use the function in a manner that is ABBA deadlock prone. Fixes: 1ca7d67c: seqcount: Add lockdep functionality to seqcount/seqlock Signed-off-by:
Trond Myklebust <trond.myklebust@primarydata.com> Signed-off-by:
-
J. Bruce Fields authored
commit 7c17705e upstream. Nikita Yuschenko reported that booting a kernel with init=/bin/sh and then nfs mounting without portmap or rpcbind running using a busybox mount resulted in: # mount -t nfs 10.30.130.21:/opt /mnt svc: failed to register lockdv1 RPC service (errno 111). lockd_up: makesock failed, error=-111 Unable to handle kernel paging request for data at address 0x00000030 Faulting instruction address: 0xc055e65c Oops: Kernel access of bad area, sig: 11 [#1] MPC85xx CDS Modules linked in: CPU: 0 PID: 1338 Comm: mount Not tainted 3.10.44.cge #117 task: cf29cea0 ti: cf35c000 task.ti: cf35c000 NIP: c055e65c LR: c0566490 CTR: c055e648 REGS: cf35dad0 TRAP: 0300 Not tainted (3.10.44.cge) MSR: 00029000 <CE,EE,ME> CR: 22442488 XER: 20000000 DEAR: 00000030, ESR: 00000000 GPR00: c05606f4 cf35db80 cf29cea0 cf0ded80 cf0dedb8 00000001 1dec3086 00000000 GPR08: 00000000 c07b1640 00000007 1dec3086 22442482 100b9758 00000000 10090ae8 GPR16: 00000000 000186a5 00000000 00000000 100c3018 bfa46edc 100b0000 bfa46ef0 GPR24: cf386ae0 c07834f0 00000000 c0565f88 00000001 cf0dedb8 00000000 cf0ded80 NIP [c055e65c] call_start+0x14/0x34 LR [c0566490] __rpc_execute+0x70/0x250 Call Trace: [cf35db80] [00000080] 0x80 (unreliable) [cf35dbb0] [c05606f4] rpc_run_task+0x9c/0xc4 [cf35dbc0] [c0560840] rpc_call_sync+0x50/0xb8 [cf35dbf0] [c056ee90] rpcb_register_call+0x54/0x84 [cf35dc10] [c056f24c] rpcb_register+0xf8/0x10c [cf35dc70] [c0569e18] svc_unregister.isra.23+0x100/0x108 [cf35dc90] [c0569e38] svc_rpcb_cleanup+0x18/0x30 [cf35dca0] [c0198c5c] lockd_up+0x1dc/0x2e0 [cf35dcd0] [c0195348] nlmclnt_init+0x2c/0xc8 [cf35dcf0] [c015bb5c] nfs_start_lockd+0x98/0xec [cf35dd20] [c015ce6c] nfs_create_server+0x1e8/0x3f4 [cf35dd90] [c0171590] nfs3_create_server+0x10/0x44 [cf35dda0] [c016528c] nfs_try_mount+0x158/0x1e4 [cf35de20] [c01670d0] nfs_fs_mount+0x434/0x8c8 [cf35de70] [c00cd3bc] mount_fs+0x20/0xbc [cf35de90] [c00e4f88] vfs_kern_mount+0x50/0x104 [cf35dec0] [c00e6e0c] do_mount+0x1d0/0x8e0 [cf35df10] [c00e75ac] SyS_mount+0x90/0xd0 [cf35df40] [c000ccf4] ret_from_syscall+0x0/0x3c The addition of svc_shutdown_net() resulted in two calls to svc_rpcb_cleanup(); the second is no longer necessary and crashes when it calls rpcb_register_call with clnt=NULL. Reported-by:
Nikita Yushchenko <nyushchenko@dev.rtsoft.ru> Fixes: 679b033d "lockd: ensure we tear down any live sockets when socket creation fails during lockd_up" Acked-by:
Jeff Layton <jlayton@primarydata.com> Signed-off-by:
J. Bruce Fields <bfields@redhat.com> Signed-off-by:
-
Larry Finger authored
commit c6651716 upstream. The Sitecom WLA-2102 adapter uses this driver. Reported-by:
Nico Baggus <nico-linux@noci.xs4all.nl> Signed-off-by:
Larry Finger <Larry.Finger@lwfinger.net> Cc: Nico Baggus <nico-linux@noci.xs4all.nl> Signed-off-by:
-
Eliad Peller authored
commit a5fe8e76 upstream. alpha2 is defined as 2-chars array, but is used in multiple places as string (e.g. with nla_put_string calls), which might leak kernel data. Solve it by simply adding an extra char for the NULL terminator, making such operations safe. Signed-off-by:
Eliad Peller <eliadx.peller@intel.com> Signed-off-by:
-
Tejun Heo authored
commit 849f5169 upstream. If pcpu_map_pages() fails midway, it unmaps the already mapped pages. Currently, it doesn't flush tlb after the partial unmapping. This may be okay in most cases as the established mapping hasn't been used at that point but it can go wrong and when it goes wrong it'd be extremely difficult to track down. Flush tlb after the partial unmapping. Signed-off-by:
Tejun Heo <tj@kernel.org> Signed-off-by:
-
Tejun Heo authored
commit f0d27965 upstream. When pcpu_alloc_pages() fails midway, pcpu_free_pages() is invoked to free what has already been allocated. The invocation is across the whole requested range and pcpu_free_pages() will try to free all non-NULL pages; unfortunately, this is incorrect as pcpu_get_pages_and_bitmap(), unlike what its comment suggests, doesn't clear the pages array and thus the array may have entries from the previous invocations making the partial failure path free incorrect pages. Fix it by open-coding the partial freeing of the already allocated pages. Signed-off-by:
-
Honggang Li authored
commit 3189eddb upstream. Currently, only SMP system free the percpu allocation info. Uniprocessor system should free it too. For example, one x86 UML virtual machine with 256MB memory, UML kernel wastes one page memory. Signed-off-by:
Honggang Li <enjoymindful@gmail.com> Signed-off-by:
-
James Ralston authored
commit 6cad1376 upstream. This patch adds the IDE mode SATA Device IDs for the Intel 9 Series PCH. Signed-off-by:
James Ralston <james.d.ralston@intel.com> Signed-off-by:
-
Robert Coulson authored
commit 39c627a0 upstream. After the conversion rate is changed, the zbits are not updated, but should be, since they are used later in the set_temp function. Fixes: a50d9a4d ("hwmon: (ds1621) Fix temperature rounding operations") Reported-by:
Murat Ilsever <murat.ilsever@gmail.com> Signed-off-by:
Robert Coulson <rob.coulson@gmail.com> Signed-off-by:
Guenter Roeck <linux@roeck-us.net> Signed-off-by:
-
