commit 6f17581788 upstream.
gcc 7 complains:
drivers/net/wireless/intersil/p54/fwio.c: In function 'p54_scan':
drivers/net/wireless/intersil/p54/fwio.c:491:4: warning: 'memset' used with length equal to number of elements without multiplication by element size [-Wmemset-elt-size]
Fix that by passing the correct size to memset.
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Christian Lamparter <chunkeey@googlemail.com>
Cc: Kalle Valo <kvalo@codeaurora.org>
Cc: linux-wireless@vger.kernel.org
Cc: netdev@vger.kernel.org
Acked-by: Christian Lamparter <chunkeey@googlemail.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
[bwh: Backported to 3.16: adjust filename]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit bd7e31bbad upstream.
gcc-7 suggests that an expression using a bitwise not and a bitmask
on a 'bool' variable is better written using boolean logic:
drivers/media/rc/imon.c: In function 'imon_incoming_scancode':
drivers/media/rc/imon.c:1725:22: error: '~' on a boolean expression [-Werror=bool-operation]
ictx->pad_mouse = ~(ictx->pad_mouse) & 0x1;
^
drivers/media/rc/imon.c:1725:22: note: did you mean to use logical not?
I agree.
Fixes: 21677cfc56 ("V4L/DVB: ir-core: add imon driver")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit e843bb199b upstream.
Applying ++ to a bool is equivalent to setting it true, regardless of
its initial value (bools are not uint1_t). Hence the function
wl_get_vif_state_all can only ever return true/false. The only in-tree
caller uses its return value as a boolean. So update its return type,
and since the list traversal and bit testing have no side effects,
just return true immediately. Its return value tells if any vif is in
the specified state, so also rename it to brcmf_get_vif_state_any.
Reviewed-by: Arend van Spriel<arend@broadcom.com>
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 8234caed27 upstream.
The regmap_config struct may be const because it is not modified by the
driver and regmap_init() accepts pointer to const.
Replace doubled const in the arrays of clock names with proper const
pointer to const data. This fixes the warnings:
drivers/clk/clk-si5351.c:71:25: warning: duplicate const
drivers/clk/clk-si5351.c:74:25: warning: duplicate const
drivers/clk/clk-si5351.c:77:25: warning: duplicate const
drivers/clk/clk-si5351.c:80:25: warning: duplicate const
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Reviewed-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit be5136988e upstream.
There are certain places where the code uses .set mips32 or .set mips64
or .set arch=r4000. In preparation of MIPS R6 support, and in order to
use as less #ifdefs as possible, we define new macros to set similar
annotations for MIPS R6.
Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
[bwh: Backported to 3.16: We don't support MIPS R6 but I have applied a
commit that uses MIPS_ISA_LEVEL_RAW. Add the R2 definitions only.]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
This is based on upstream commit 10e840dfb0, which did not touch the
iio-trig-periodic-rtc driver because it has been removed upstream.
The following explanation comes from that commit:
These stand-alone trigger drivers were using iio_trigger_put()
where they should have been using iio_trigger_free(). The
iio_trigger_put() adds a module_put which is bad since they
never did a module_get.
In the sysfs driver, module_get/put's are used as triggers are
added & removed. This extra module_put() occurs on an error path
in the probe routine (probably rare).
In the bfin-timer & interrupt trigger drivers, the module resources
are not explicitly managed, so it's doing a put on something that
was never get'd. It occurs on the probe error path and on the
remove path (not so rare).
Tested with the sysfs trigger driver.
The bfin & interrupt drivers were build tested & inspected only.
This was build tested only.
Cc: Alison Schofield <amsfield22@gmail.com>
Cc: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit efdab99281 upstream.
syzkaller reported:
WARNING: CPU: 0 PID: 12927 at arch/x86/kernel/traps.c:780 do_debug+0x222/0x250
CPU: 0 PID: 12927 Comm: syz-executor Tainted: G OE 4.15.0-rc2+ #16
RIP: 0010:do_debug+0x222/0x250
Call Trace:
<#DB>
debug+0x3e/0x70
RIP: 0010:copy_user_enhanced_fast_string+0x10/0x20
</#DB>
_copy_from_user+0x5b/0x90
SyS_timer_create+0x33/0x80
entry_SYSCALL_64_fastpath+0x23/0x9a
The testcase sets a watchpoint (with perf_event_open) on a buffer that is
passed to timer_create() as the struct sigevent argument. In timer_create(),
copy_from_user()'s rep movsb triggers the BP. The testcase also sets
the debug registers for the guest.
However, KVM only restores host debug registers when the host has active
watchpoints, which triggers a race condition when running the testcase with
multiple threads. The guest's DR6.BS bit can escape to the host before
another thread invokes timer_create(), and do_debug() complains.
The fix is to respect do_debug()'s dr6 invariant when leaving KVM.
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 0538421343 upstream.
Starting from GCC 7.1, __gcov_exit is a new symbol expected to be
implemented in a profiling runtime.
[akpm@linux-foundation.org: coding-style fixes]
[mliska@suse.cz: v2]
Link: http://lkml.kernel.org/r/e63a3c59-0149-c97e-4084-20ca8f146b26@suse.cz
Link: http://lkml.kernel.org/r/8c4084fa-3885-29fe-5fc4-0d4ca199c785@suse.cz
Signed-off-by: Martin Liska <mliska@suse.cz>
Acked-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 3e44c471a2 upstream.
Fix kernel gcov support for GCC 5.1. Similar to commit a992bf836f
("gcov: add support for GCC 4.9"), this patch takes into account the
existence of a new gcov counter (see gcc's gcc/gcov-counter.def.)
Firstly, it increments GCOV_COUNTERS (to 10), which makes the data
structure struct gcov_info compatible with GCC 5.1.
Secondly, a corresponding counter function __gcov_merge_icall_topn (Top N
value tracking for indirect calls) is included in base.c with the other
gcov counters unused for kernel profiling.
Signed-off-by: Lorenzo Stoakes <lstoakes@gmail.com>
Cc: Andrey Ryabinin <a.ryabinin@samsung.com>
Cc: Yuan Pengfei <coolypf@qq.com>
Tested-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Reviewed-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit c3883fe064 upstream.
This patch fixes an issue in drivers/hid/hid-input.c where values
outside of the logical range are not clamped when "null state" bit of
the input control is not set.
This was discussed on the lists [1] and this change stems from the fact
due to the ambiguity of the HID specification it might be appropriate to
follow Microsoft's own interpretation of the specification. As noted in
Microsoft's documentation [2] in the section titled "Required HID usages
for digitizers" it is noted that values reported outside the logical
range "will be considered as invalid data and the value will be changed
to the nearest boundary value (logical min/max)."
This patch fixes an issue where the (1292:4745) Innomedia INNEX
GENESIS/ATARI reports out of range values for its X and Y axis of the
DPad which, due to the null state bit being unset, are forwarded to
userspace as is. Now these values will get clamped to the logical range
before being forwarded to userspace. This device was also used to test
this patch.
This patch expands on commit 3f3752705d ("HID: reject input outside
logical range only if null state is set").
[1]: http://lkml.kernel.org/r/20170307131036.GA853@gaia.local
[2]: https://msdn.microsoft.com/en-us/library/windows/hardware/dn672278(v=vs.85).asp
Signed-off-by: Tomasz Kramkowski <tk@the-tk.com>
Acked-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 3f3752705d upstream.
This patch fixes an issue in drivers/hid/hid-input.c where USB HID
control null state flag is not checked upon rejecting inputs outside
logical minimum-maximum range. The check should be made according to USB
HID specification 1.11, section 6.2.2.5, p.31. The fix will resolve
issues with some game controllers, such as:
https://bugzilla.kernel.org/show_bug.cgi?id=68621
[tk@the-tk.com: shortened and fixed spelling in commit message]
Signed-off-by: Valtteri Heikkilä <rnd@nic.fi>
Signed-off-by: Tomasz Kramkowski <tk@the-tk.com>
Acked-By: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 9547837bdc upstream.
The (1292:4745) Innomedia INNEX GENESIS/ATARI adapter needs
HID_QUIRK_MULTI_INPUT to split the device up into two controllers
instead of inputs from both being merged into one.
Signed-off-by: Tomasz Kramkowski <tk@the-tk.com>
Acked-By: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 3b9b95363c upstream.
Per the documentation, use scnprintf instead of sprintf to ensure there
is never more than PAGE_SIZE bytes of trigger names put into the
buffer.
Signed-off-by: Nathan Sullivan <nathan.sullivan@ni.com>
Signed-off-by: Zach Brown <zach.brown@ni.com>
Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit b18cb64ead upstream.
This reverts more of:
b76437579d ("procfs: mark thread stack correctly in proc/<pid>/maps")
... which was partially reverted by:
65376df582 ("proc: revert /proc/<pid>/maps [stack:TID] annotation")
Originally, /proc/PID/task/TID/maps was the same as /proc/TID/maps.
In current kernels, /proc/PID/maps (or /proc/TID/maps even for
threads) shows "[stack]" for VMAs in the mm's stack address range.
In contrast, /proc/PID/task/TID/maps uses KSTK_ESP to guess the
target thread's stack's VMA. This is racy, probably returns garbage
and, on arches with CONFIG_TASK_INFO_IN_THREAD=y, is also crash-prone:
KSTK_ESP is not safe to use on tasks that aren't known to be running
ordinary process-context kernel code.
This patch removes the difference and just shows "[stack]" for VMAs
in the mm's stack range. This is IMO much more sensible -- the
actual "stack" address really is treated specially by the VM code,
and the current thread stack isn't even well-defined for programs
that frequently switch stacks on their own.
Reported-by: Jann Horn <jann@thejh.net>
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Linux API <linux-api@vger.kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tycho Andersen <tycho.andersen@canonical.com>
Link: http://lkml.kernel.org/r/3e678474ec14e0a0ec34c611016753eea2e1b8ba.1475257877.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
[bwh: Backported to 3.16: Squash in the earlier commits 58cb65487e
"proc/maps: make vm_is_stack() logic namespace-friendly" and
65376df582 "proc: revert /proc/<pid>/maps [stack:TID] annotation",
which would introduce build failures if applied separately.]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 41c73a49df upstream.
If the first allocation attempt using GFP_NOWAIT fails, drop the lock
and retry using GFP_NOIO allocation (lock is dropped because the
allocation can take some time).
Note that we won't do GFP_NOIO allocation when we loop for the second
time, because the lock shouldn't be dropped between __wait_for_free_buffer
and __get_unclaimed_buffer.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 9ea61cac0b upstream.
We've seen in-field reports showing _lots_ (18 in one case, 41 in
another) of tasks all sitting there blocked on:
mutex_lock+0x4c/0x68
dm_bufio_shrink_count+0x38/0x78
shrink_slab.part.54.constprop.65+0x100/0x464
shrink_zone+0xa8/0x198
In the two cases analyzed, we see one task that looks like this:
Workqueue: kverityd verity_prefetch_io
__switch_to+0x9c/0xa8
__schedule+0x440/0x6d8
schedule+0x94/0xb4
schedule_timeout+0x204/0x27c
schedule_timeout_uninterruptible+0x44/0x50
wait_iff_congested+0x9c/0x1f0
shrink_inactive_list+0x3a0/0x4cc
shrink_lruvec+0x418/0x5cc
shrink_zone+0x88/0x198
try_to_free_pages+0x51c/0x588
__alloc_pages_nodemask+0x648/0xa88
__get_free_pages+0x34/0x7c
alloc_buffer+0xa4/0x144
__bufio_new+0x84/0x278
dm_bufio_prefetch+0x9c/0x154
verity_prefetch_io+0xe8/0x10c
process_one_work+0x240/0x424
worker_thread+0x2fc/0x424
kthread+0x10c/0x114
...and that looks to be the one holding the mutex.
The problem has been reproduced on fairly easily:
0. Be running Chrome OS w/ verity enabled on the root filesystem
1. Pick test patch: http://crosreview.com/412360
2. Install launchBalloons.sh and balloon.arm from
http://crbug.com/468342
...that's just a memory stress test app.
3. On a 4GB rk3399 machine, run
nice ./launchBalloons.sh 4 900 100000
...that tries to eat 4 * 900 MB of memory and keep accessing.
4. Login to the Chrome web browser and restore many tabs
With that, I've seen printouts like:
DOUG: long bufio 90758 ms
...and stack trace always show's we're in dm_bufio_prefetch().
The problem is that we try to allocate memory with GFP_NOIO while
we're holding the dm_bufio lock. Instead we should be using
GFP_NOWAIT. Using GFP_NOIO can cause us to sleep while holding the
lock and that causes the above problems.
The current behavior explained by David Rientjes:
It will still try reclaim initially because __GFP_WAIT (or
__GFP_KSWAPD_RECLAIM) is set by GFP_NOIO. This is the cause of
contention on dm_bufio_lock() that the thread holds. You want to
pass GFP_NOWAIT instead of GFP_NOIO to alloc_buffer() when holding a
mutex that can be contended by a concurrent slab shrinker (if
count_objects didn't use a trylock, this pattern would trivially
deadlock).
This change significantly increases responsiveness of the system while
in this state. It makes a real difference because it unblocks kswapd.
In the bug report analyzed, kswapd was hung:
kswapd0 D ffffffc000204fd8 0 72 2 0x00000000
Call trace:
[<ffffffc000204fd8>] __switch_to+0x9c/0xa8
[<ffffffc00090b794>] __schedule+0x440/0x6d8
[<ffffffc00090bac0>] schedule+0x94/0xb4
[<ffffffc00090be44>] schedule_preempt_disabled+0x28/0x44
[<ffffffc00090d900>] __mutex_lock_slowpath+0x120/0x1ac
[<ffffffc00090d9d8>] mutex_lock+0x4c/0x68
[<ffffffc000708e7c>] dm_bufio_shrink_count+0x38/0x78
[<ffffffc00030b268>] shrink_slab.part.54.constprop.65+0x100/0x464
[<ffffffc00030dbd8>] shrink_zone+0xa8/0x198
[<ffffffc00030e578>] balance_pgdat+0x328/0x508
[<ffffffc00030eb7c>] kswapd+0x424/0x51c
[<ffffffc00023f06c>] kthread+0x10c/0x114
[<ffffffc000203dd0>] ret_from_fork+0x10/0x40
By unblocking kswapd memory pressure should be reduced.
Suggested-by: David Rientjes <rientjes@google.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit c3f4688a08 upstream.
This function sets req->r_locked_dir which is supposed to indicate to
ceph_fill_trace that the parent's i_rwsem is locked for write.
Unfortunately, there is no guarantee that the dir will be locked when
d_revalidate is called, so we really don't want ceph_fill_trace to do
any dcache manipulation from this context. Clear req->r_locked_dir since
it's clearly not safe to do that.
What we really want to know with d_revalidate is whether the dentry
still points to the same inode. ceph_fill_trace installs a pointer to
the inode in req->r_target_inode, so we can just compare that to
d_inode(dentry) to see if it's the same one after the lookup.
Also, since we aren't generally interested in the parent here, we can
switch to using a GETATTR to hint that to the MDS, which also means that
we only need to reserve one cap.
Finally, just remove the d_unhashed check. That's really outside the
purview of a filesystem's d_revalidate. If the thing became unhashed
while we're checking it, then that's up to the VFS to handle anyway.
Fixes: 200fd27c8f ("ceph: use lookup request to revalidate dentry")
Link: http://tracker.ceph.com/issues/18041
Reported-by: Donatas Abraitis <donatas.abraitis@gmail.com>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Reviewed-by: "Yan, Zheng" <zyan@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Cc: Bryan Henderson <bryanh@giraffe-data.com>
[bwh: Backported to 3.16: s/d_really_is_(positive|negative)/d_is_\1/ since
we don't have to consider overlayfs]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 200fd27c8f upstream.
If dentry has no lease, ceph_d_revalidate() previously return 0.
This causes VFS to invalidate the dentry and create a new dentry
for later lookup. Invalidating a dentry also detach any underneath
mount points. So mount point inside cephfs can disapear mystically
(even the mount point is not modified by other hosts).
The fix is using lookup request to revalidate dentry without lease.
This can partly solve the mount points disapear issue (as long as
the mount point is not modified by other hosts)
Signed-off-by: Yan, Zheng <zyan@redhat.com>
Cc: Bryan Henderson <bryanh@giraffe-data.com>
[bwh: Backported to 3.16: Add the ceph_security_xattr_wanted() function]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit ad608fbcf1 upstream.
The event subscriptions are added to the subscribed event list while
holding a spinlock, but that lock is subsequently released while still
accessing the subscription object. This makes it possible to unsubscribe
the event --- and freeing the subscription object's memory --- while
the subscription object is simultaneously accessed.
Prevent this by adding a mutex to serialise the event subscription and
unsubscription. This also gives a guarantee to the callback ops that the
add op has returned before the del op is called.
This change also results in making the elems field less special:
subscriptions are only added to the event list once they are fully
initialised.
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Hans Verkuil <hans.verkuil@cisco.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Fixes: c3b5b0241f ("V4L/DVB: V4L: Events: Add backend")
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 096a020a9e upstream.
There were some curly braces intended here.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit d472b3a6cf upstream.
skb_shinfo() can change when calling __pskb_pull_tail(): Don't cache
its return value.
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Wei Liu <wei.liu2@citrix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 4c0d7cd5c8 upstream.
RCU pathwalk relies upon the assumption that anything that changes
->d_inode of a dentry will invalidate its ->d_seq. That's almost
true - the one exception is that the final dput() of already unhashed
dentry does *not* touch ->d_seq at all. Unhashing does, though,
so for anything we'd found by RCU dcache lookup we are fine.
Unfortunately, we can *start* with an unhashed dentry or jump into
it.
We could try and be careful in the (few) places where that could
happen. Or we could just make the final dput() invalidate the damn
thing, unhashed or not. The latter is much simpler and easier to
backport, so let's do it that way.
Reported-by: "Dae R. Jeong" <threeearcat@gmail.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 550dce01dd upstream.
There is a lot of duplication between dentry_unlink_inode() and dentry_iput().
The only real difference is that dentry_unlink_inode() bumps ->d_seq and
dentry_iput() doesn't. The argument of the latter is known to have been
unhashed, so anybody who might've found it in RCU lookup would already be
doomed to a ->d_seq mismatch. And we want to avoid pointless smp_rmb() there.
This patch makes dentry_unlink_inode() bump ->d_seq only for hashed dentries.
It's safe (d_delete() calls that sucker only if we are holding the only
reference to dentry, so rehash is not going to happen) and it allows
to use dentry_unlink_inode() in __dentry_kill() and get rid of dentry_iput().
The interesting question here is profiling; it *is* a hot path, and extra
conditional jumps in there might or might not be painful.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit a528aca7f3 upstream.
Games with ordering and barriers are way too brittle. Just
bump ->d_seq before and after updating ->d_inode and ->d_flags
type bits, so that verifying ->d_seq would guarantee they are
coherent.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 4bf46a2726 upstream.
Impose ordering on accesses of d_inode and d_flags to avoid the need to do
this:
if (!dentry->d_inode || d_is_negative(dentry)) {
when this:
if (d_is_negative(dentry)) {
should suffice.
This check is especially problematic if a dentry can have its type field set
to something other than DENTRY_MISS_TYPE when d_inode is NULL (as in
unionmount).
What we really need to do is stick a write barrier between setting d_inode and
setting d_flags and a read barrier between reading d_flags and reading
d_inode.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
[bwh: Backported to 3.16:
- Use ACCESS_ONCE() instead of {READ,WRITE}_ONCE()
- There's no DCACHE_FALLTHRU flag]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 119e1ef80e upstream.
__legitimize_mnt() has two problems - one is that in case of success
the check of mount_lock is not ordered wrt preceding increment of
refcount, making it possible to have successful __legitimize_mnt()
on one CPU just before the otherwise final mntpu() on another,
with __legitimize_mnt() not seeing mntput() taking the lock and
mntput() not seeing the increment done by __legitimize_mnt().
Solved by a pair of barriers.
Another is that failure of __legitimize_mnt() on the second
read_seqretry() leaves us with reference that'll need to be
dropped by caller; however, if that races with final mntput()
we can end up with caller dropping rcu_read_lock() and doing
mntput() to release that reference - with the first mntput()
having freed the damn thing just as rcu_read_lock() had been
dropped. Solution: in "do mntput() yourself" failure case
grab mount_lock, check if MNT_DOOMED has been set by racing
final mntput() that has missed our increment and if it has -
undo the increment and treat that as "failure, caller doesn't
need to drop anything" case.
It's not easy to hit - the final mntput() has to come right
after the first read_seqretry() in __legitimize_mnt() *and*
manage to miss the increment done by __legitimize_mnt() before
the second read_seqretry() in there. The things that are almost
impossible to hit on bare hardware are not impossible on SMP
KVM, though...
Reported-by: Oleg Nesterov <oleg@redhat.com>
Fixes: 48a066e72d ("RCU'd vsfmounts")
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
[bwh: Backported to 3.16: __legitimize_mnt() has not been split out
from legitimize_mnt(). Adjust the added return statement and
comments accordingly.]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 9ea0a46ca2 upstream.
mntput_no_expire() does the calculation of total refcount under mount_lock;
unfortunately, the decrement (as well as all increments) are done outside
of it, leading to false positives in the "are we dropping the last reference"
test. Consider the following situation:
* mnt is a lazy-umounted mount, kept alive by two opened files. One
of those files gets closed. Total refcount of mnt is 2. On CPU 42
mntput(mnt) (called from __fput()) drops one reference, decrementing component
* After it has looked at component #0, the process on CPU 0 does
mntget(), incrementing component #0, gets preempted and gets to run again -
on CPU 69. There it does mntput(), which drops the reference (component #69)
and proceeds to spin on mount_lock.
* On CPU 42 our first mntput() finishes counting. It observes the
decrement of component #69, but not the increment of component #0. As the
result, the total it gets is not 1 as it should've been - it's 0. At which
point we decide that vfsmount needs to be killed and proceed to free it and
shut the filesystem down. However, there's still another opened file
on that filesystem, with reference to (now freed) vfsmount, etc. and we are
screwed.
It's not a wide race, but it can be reproduced with artificial slowdown of
the mnt_get_count() loop, and it should be easier to hit on SMP KVM setups.
Fix consists of moving the refcount decrement under mount_lock; the tricky
part is that we want (and can) keep the fast case (i.e. mount that still
has non-NULL ->mnt_ns) entirely out of mount_lock. All places that zero
mnt->mnt_ns are dropping some reference to mnt and they call synchronize_rcu()
before that mntput(). IOW, if mntput() observes (under rcu_read_lock())
a non-NULL ->mnt_ns, it is guaranteed that there is another reference yet to
be dropped.
Reported-by: Jann Horn <jannh@google.com>
Tested-by: Jann Horn <jannh@google.com>
Fixes: 48a066e72d ("RCU'd vsfmounts")
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
[bwh: Backported to 3.16: Use ACCESS_ONCE() instead of READ_ONCE()]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 61ef4b07fc upstream.
The shift of 'cwnd' with '(now - hc->tx_lsndtime) / hc->tx_rto' value
can lead to undefined behavior [1].
In order to fix this use a gradual shift of the window with a 'while'
loop, similar to what tcp_cwnd_restart() is doing.
When comparing delta and RTO there is a minor difference between TCP
and DCCP, the last one also invokes dccp_cwnd_restart() and reduces
'cwnd' if delta equals RTO. That case is preserved in this change.
[1]:
[40850.963623] UBSAN: Undefined behaviour in net/dccp/ccids/ccid2.c:237:7
[40851.043858] shift exponent 67 is too large for 32-bit type 'unsigned int'
[40851.127163] CPU: 3 PID: 15940 Comm: netstress Tainted: G W E 4.18.0-rc7.x86_64 #1
...
[40851.377176] Call Trace:
[40851.408503] dump_stack+0xf1/0x17b
[40851.451331] ? show_regs_print_info+0x5/0x5
[40851.503555] ubsan_epilogue+0x9/0x7c
[40851.548363] __ubsan_handle_shift_out_of_bounds+0x25b/0x2b4
[40851.617109] ? __ubsan_handle_load_invalid_value+0x18f/0x18f
[40851.686796] ? xfrm4_output_finish+0x80/0x80
[40851.739827] ? lock_downgrade+0x6d0/0x6d0
[40851.789744] ? xfrm4_prepare_output+0x160/0x160
[40851.845912] ? ip_queue_xmit+0x810/0x1db0
[40851.895845] ? ccid2_hc_tx_packet_sent+0xd36/0x10a0 [dccp]
[40851.963530] ccid2_hc_tx_packet_sent+0xd36/0x10a0 [dccp]
[40852.029063] dccp_xmit_packet+0x1d3/0x720 [dccp]
[40852.086254] dccp_write_xmit+0x116/0x1d0 [dccp]
[40852.142412] dccp_sendmsg+0x428/0xb20 [dccp]
[40852.195454] ? inet_dccp_listen+0x200/0x200 [dccp]
[40852.254833] ? sched_clock+0x5/0x10
[40852.298508] ? sched_clock+0x5/0x10
[40852.342194] ? inet_create+0xdf0/0xdf0
[40852.388988] sock_sendmsg+0xd9/0x160
...
Fixes: 113ced1f52 ("dccp ccid-2: Perform congestion-window validation")
Signed-off-by: Alexey Kodanev <alexey.kodanev@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 455f05ecd2 upstream.
syzbot reported that we reinitialize an active delayed
work in vsock_stream_connect():
ODEBUG: init active (active state 0) object type: timer_list hint:
delayed_work_timer_fn+0x0/0x90 kernel/workqueue.c:1414
WARNING: CPU: 1 PID: 11518 at lib/debugobjects.c:329
debug_print_object+0x16a/0x210 lib/debugobjects.c:326
The pattern is apparently wrong, we should only initialize
the dealyed work once and could repeatly schedule it. So we
have to move out the initializations to allocation side.
And to avoid confusion, we can split the shared dwork
into two, instead of re-using the same one.
Fixes: d021c34405 ("VSOCK: Introduce VM Sockets")
Reported-by: <syzbot+8a9b1bd330476a4f3db6@syzkaller.appspotmail.com>
Cc: Andy king <acking@vmware.com>
Cc: Stefan Hajnoczi <stefanha@redhat.com>
Cc: Jorgen Hansen <jhansen@vmware.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 4576cd469d upstream.
TPACKET_V3 stores variable length frames in fixed length blocks.
Blocks must be able to store a block header, optional private space
and at least one minimum sized frame.
Frames, even for a zero snaplen packet, store metadata headers and
optional reserved space.
In the block size bounds check, ensure that the frame of the
chosen configuration fits. This includes sockaddr_ll and optional
tp_reserve.
Syzbot was able to construct a ring with insuffient room for the
sockaddr_ll in the header of a zero-length frame, triggering an
out-of-bounds write in dev_parse_header.
Convert the comparison to less than, as zero is a valid snap len.
This matches the test for minimum tp_frame_size immediately below.
Fixes: f6fb8f100b ("af-packet: TPACKET_V3 flexible buffer implementation.")
Fixes: eb73190f4f ("net/packet: refine check for priv area size")
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 90bad5e05b upstream.
Since mountpoint crossing can happen without leaving lazy mode,
root dentries do need the same protection against having their
memory freed without RCU delay as everything else in the tree.
It's partially hidden by RCU delay between detaching from the
mount tree and dropping the vfsmount reference, but the starting
point of pathwalk can be on an already detached mount, in which
case umount-caused RCU delay has already passed by the time the
lazy pathwalk grabs rcu_read_lock(). If the starting point
happens to be at the root of that vfsmount *and* that vfsmount
covers the entire filesystem, we get trouble.
Fixes: 48a066e72d ("RCU'd vsfmounts")
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 91874ecf32 upstream.
It's legal to have 64 groups for netlink_sock.
As user-supplied nladdr->nl_groups is __u32, it's possible to subscribe
only to first 32 groups.
The check for correctness of .bind() userspace supplied parameter
is done by applying mask made from ngroups shift. Which broke Android
as they have 64 groups and the shift for mask resulted in an overflow.
Fixes: 61f4b23769 ("netlink: Don't shift with UB on nlk->ngroups")
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Cc: netdev@vger.kernel.org
Reported-and-Tested-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit f664e37dcc upstream.
If 'session' is not NULL and is not a PPP pseudo-wire, then we fail to
drop the reference taken by l2tp_session_get().
Fixes: ecd012e45a ("l2tp: filter out non-PPP sessions in pppol2tp_tunnel_ioctl()")
Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Backported to 3.16: Also call session->deref in both cases]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 1214fd7b49 upstream.
Surround scsi_execute() calls with scsi_autopm_get_device() and
scsi_autopm_put_device(). Note: removing sr_mutex protection from the
scsi_cd_get() and scsi_cd_put() calls is safe because the purpose of
sr_mutex is to serialize cdrom_*() calls.
This patch avoids that complaints similar to the following appear in the
kernel log if runtime power management is enabled:
INFO: task systemd-udevd:650 blocked for more than 120 seconds.
Not tainted 4.18.0-rc7-dbg+ #1
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
systemd-udevd D28176 650 513 0x00000104
Call Trace:
__schedule+0x444/0xfe0
schedule+0x4e/0xe0
schedule_preempt_disabled+0x18/0x30
__mutex_lock+0x41c/0xc70
mutex_lock_nested+0x1b/0x20
__blkdev_get+0x106/0x970
blkdev_get+0x22c/0x5a0
blkdev_open+0xe9/0x100
do_dentry_open.isra.19+0x33e/0x570
vfs_open+0x7c/0xd0
path_openat+0x6e3/0x1120
do_filp_open+0x11c/0x1c0
do_sys_open+0x208/0x2d0
__x64_sys_openat+0x59/0x70
do_syscall_64+0x77/0x230
entry_SYSCALL_64_after_hwframe+0x49/0xbe
Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com>
Cc: Maurizio Lombardi <mlombard@redhat.com>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Cc: Alan Stern <stern@rowland.harvard.edu>
Tested-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
[bwh: Backported to 3.16:
- Update one extra "goto out" in sr_block_ioctl() and delete the unused
label
- Adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 80d20d35af upstream.
local_timer_softirq_pending() checks whether the timer softirq is
pending with: local_softirq_pending() & TIMER_SOFTIRQ.
This is wrong because TIMER_SOFTIRQ is the softirq number and not a
bitmask. So the test checks for the wrong bit.
Use BIT(TIMER_SOFTIRQ) instead.
Fixes: 5d62c183f9 ("nohz: Prevent a timer interrupt storm in tick_nohz_stop_sched_tick()")
Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Daniel Bristot de Oliveira <bristot@redhat.com>
Acked-by: Frederic Weisbecker <frederic@kernel.org>
Cc: bigeasy@linutronix.de
Cc: peterz@infradead.org
Link: https://lkml.kernel.org/r/20180731161358.29472-1-anna-maria@linutronix.de
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit d512584780 upstream.
Anatoly reports another squashfs fuzzing issue, where the decompression
parameters themselves are in a compressed block.
This causes squashfs_read_data() to be called in order to read the
decompression options before the decompression stream having been set
up, making squashfs go sideways.
Reported-by: Anatoly Trosinenko <anatoly.trosinenko@gmail.com>
Acked-by: Phillip Lougher <phillip.lougher@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 61f4b23769 upstream.
On i386 nlk->ngroups might be 32 or 0. Which leads to UB, resulting in
hang during boot.
Check for 0 ngroups and use (unsigned long long) as a type to shift.
Fixes: 7acf9d4237 ("netlink: Do not subscribe to non-existent groups").
Reported-by: kernel test robot <rong.a.chen@intel.com>
Signed-off-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 7acf9d4237 upstream.
Make ABI more strict about subscribing to group > ngroups.
Code doesn't check for that and it looks bogus.
(one can subscribe to non-existing group)
Still, it's possible to bind() to all possible groups with (-1)
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Cc: netdev@vger.kernel.org
Signed-off-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 89da619bc1 upstream.
Kernel panic when with high memory pressure, calltrace looks like,
PID: 21439 TASK: ffff881be3afedd0 CPU: 16 COMMAND: "java"
#0 [ffff881ec7ed7630] machine_kexec at ffffffff81059beb
#1 [ffff881ec7ed7690] __crash_kexec at ffffffff81105942
#2 [ffff881ec7ed7760] crash_kexec at ffffffff81105a30
#3 [ffff881ec7ed7778] oops_end at ffffffff816902c8
#4 [ffff881ec7ed77a0] no_context at ffffffff8167ff46
#5 [ffff881ec7ed77f0] __bad_area_nosemaphore at ffffffff8167ffdc
#6 [ffff881ec7ed7838] __node_set at ffffffff81680300
#7 [ffff881ec7ed7860] __do_page_fault at ffffffff8169320f
#8 [ffff881ec7ed78c0] do_page_fault at ffffffff816932b5
#9 [ffff881ec7ed78f0] page_fault at ffffffff8168f4c8
[exception RIP: _raw_spin_lock_irqsave+47]
RIP: ffffffff8168edef RSP: ffff881ec7ed79a8 RFLAGS: 00010046
RAX: 0000000000000246 RBX: ffffea0019740d00 RCX: ffff881ec7ed7fd8
RDX: 0000000000020000 RSI: 0000000000000016 RDI: 0000000000000008
RBP: ffff881ec7ed79a8 R8: 0000000000000246 R9: 000000000001a098
R10: ffff88107ffda000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000008 R14: ffff881ec7ed7a80 R15: ffff881be3afedd0
ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018
It happens in the pagefault and results in double pagefault
during compacting pages when memory allocation fails.
Analysed the vmcore, the page leads to second pagefault is corrupted
with _mapcount=-256, but private=0.
It's caused by the race between migration and ballooning, and lock
missing in virtballoon_migratepage() of virtio_balloon driver.
This patch fix the bug.
Fixes: e22504296d ("virtio_balloon: introduce migration primitives to balloon pages")
Signed-off-by: Jiang Biao <jiang.biao2@zte.com.cn>
Signed-off-by: Huang Chong <huang.chong@zte.com.cn>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 72c05f32f4 upstream.
ems_usb_probe() allocates memory for dev->tx_msg_buffer, but there
is no its deallocation in ems_usb_disconnect().
Found by Linux Driver Verification project (linuxtesting.org).
Signed-off-by: Anton Vasilyev <vasilyev@ispras.ru>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 01cfb7937a upstream.
Anatoly Trosinenko reports that a corrupted squashfs image can cause a
kernel oops. It turns out that squashfs can end up being confused about
negative fragment lengths.
The regular squashfs_read_data() does check for negative lengths, but
squashfs_read_metadata() did not, and the fragment size code just
blindly trusted the on-disk value. Fix both the fragment parsing and
the metadata reading code.
Reported-by: Anatoly Trosinenko <anatoly.trosinenko@gmail.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Phillip Lougher <phillip@squashfs.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit c8e8cd579b upstream.
'call' is a user-controlled value, so sanitize the array index after the
bounds check to avoid speculating past the bounds of the 'nargs' array.
Found with the help of Smatch:
net/socket.c:2508 __do_sys_socketcall() warn: potential spectre issue
'nargs' [r] (local cap)
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Jeremy Cline <jcline@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 9fc12023d6 upstream.
Remove BUG_ON() from fib_compute_spec_dst routine and check
in_dev pointer during flowi4 data structure initialization.
fib_compute_spec_dst routine can be run concurrently with device removal
where ip_ptr net_device pointer is set to NULL. This can happen
if userspace enables pkt info on UDP rx socket and the device
is removed while traffic is flowing
Fixes: 35ebf65e85 ("ipv4: Create and use fib_compute_spec_dst() helper")
Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 3e536e222f upstream.
There is a window for racing when printing directly to task->comm,
allowing other threads to see a non-terminated string. The vsnprintf
function fills the buffer, counts the truncated chars, then finally
writes the \0 at the end.
creator other
vsnprintf:
fill (not terminated)
count the rest trace_sched_waking(p):
... memcpy(comm, p->comm, TASK_COMM_LEN)
write \0
The consequences depend on how 'other' uses the string. In our case,
it was copied into the tracing system's saved cmdlines, a buffer of
adjacent TASK_COMM_LEN-byte buffers (note the 'n' where 0 should be):
crash-arm64> x/1024s savedcmd->saved_cmdlines | grep 'evenk'
0xffffffd5b3818640: "irq/497-pwr_evenkworker/u16:12"
...and a strcpy out of there would cause stack corruption:
[224761.522292] Kernel panic - not syncing: stack-protector:
Kernel stack is corrupted in: ffffff9bf9783c78
crash-arm64> kbt | grep 'comm\|trace_print_context'
#6 0xffffff9bf9783c78 in trace_print_context+0x18c(+396)
comm (char [16]) = "irq/497-pwr_even"
crash-arm64> rd 0xffffffd4d0e17d14 8
ffffffd4d0e17d14: 2f71726900000000 5f7277702d373934 ....irq/497-pwr_
ffffffd4d0e17d24: 726f776b6e657665 3a3631752f72656b evenkworker/u16:
ffffffd4d0e17d34: f9780248ff003231 cede60e0ffffff9b 12..H.x......`..
ffffffd4d0e17d44: cede60c8ffffffd4 00000fffffffffd4 .....`..........
The workaround in e09e28671 (use strlcpy in __trace_find_cmdline) was
likely needed because of this same bug.
Solved by vsnprintf:ing to a local buffer, then using set_task_comm().
This way, there won't be a window where comm is not terminated.
Link: http://lkml.kernel.org/r/20180726071539.188015-1-snild@sony.com
Fixes: bc0c38d139 ("ftrace: latency tracer infrastructure")
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Snild Dolkow <snild@sony.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 2519c1bbe3 upstream.
Commit 57ea2a34ad ("tracing/kprobes: Fix trace_probe flags on
enable_trace_kprobe() failure") added an if statement that depends on another
if statement that gcc doesn't see will initialize the "link" variable and
gives the warning:
"warning: 'link' may be used uninitialized in this function"
It is really a false positive, but to quiet the warning, and also to make
sure that it never actually is used uninitialized, initialize the "link"
variable to NULL and add an if (!WARN_ON_ONCE(!link)) where the compiler
thinks it could be used uninitialized.
Fixes: 57ea2a34ad ("tracing/kprobes: Fix trace_probe flags on enable_trace_kprobe() failure")
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
commit 15cc78644d upstream.
There was a case that triggered a double free in event_trigger_callback()
due to the called reg() function freeing the trigger_data and then it
getting freed again by the error return by the caller. The solution there
was to up the trigger_data ref count.
Code inspection found that event_enable_trigger_func() has the same issue,
but is not as easy to trigger (requires harder to trigger failures). It
needs to be solved slightly different as it needs more to clean up when the
reg() function fails.
Link: http://lkml.kernel.org/r/20180725124008.7008e586@gandalf.local.home
Fixes: 7862ad1846 ("tracing: Add 'enable_event' and 'disable_event' event trigger commands")
Reivewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
