linux-toradex.git/kernel, branch v4.4.129

resource: fix integer overflow at reallocation

2018-04-24T07:32:05+00:00

commit 60bb83b81169820c691fbfa33a6a4aef32aa4b0b upstream.

We've got a bug report indicating a kernel panic at booting on an x86-32
system, and it turned out to be the invalid PCI resource assigned after
reallocation.  __find_resource() first aligns the resource start address
and resets the end address with start+size-1 accordingly, then checks
whether it's contained.  Here the end address may overflow the integer,
although resource_contains() still returns true because the function
validates only start and end address.  So this ends up with returning an
invalid resource (start > end).

There was already an attempt to cover such a problem in the commit
47ea91b4052d ("Resource: fix wrong resource window calculation"), but
this case is an overseen one.

This patch adds the validity check of the newly calculated resource for
avoiding the integer overflow problem.

Bugzilla: http://bugzilla.opensuse.org/show_bug.cgi?id=1086739
Link: http://lkml.kernel.org/r/s5hpo37d5l8.wl-tiwai@suse.de
Fixes: 23c570a67448 ("resource: ability to resize an allocated resource")
Signed-off-by: Takashi Iwai 
Reported-by: Michael Henders 
Tested-by: Michael Henders 
Reviewed-by: Andrew Morton 
Cc: Ram Pai 
Cc: Bjorn Helgaas 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

futex: Remove requirement for lock_page() in get_futex_key()

2018-04-13T17:50:24+00:00

commit 65d8fc777f6dcfee12785c057a6b57f679641c90 upstream.

When dealing with key handling for shared futexes, we can drastically reduce
the usage/need of the page lock. 1) For anonymous pages, the associated futex
object is the mm_struct which does not require the page lock. 2) For inode
based, keys, we can check under RCU read lock if the page mapping is still
valid and take reference to the inode. This just leaves one rare race that
requires the page lock in the slow path when examining the swapcache.

Additionally realtime users currently have a problem with the page lock being
contended for unbounded periods of time during futex operations.

Task A
     get_futex_key()
     lock_page()
    ---> preempted

Now any other task trying to lock that page will have to wait until
task A gets scheduled back in, which is an unbound time.

With this patch, we pretty much have a lockless futex_get_key().

Experiments show that this patch can boost/speedup the hashing of shared
futexes with the perf futex benchmarks (which is good for measuring such
change) by up to 45% when there are high (> 100) thread counts on a 60 core
Westmere. Lower counts are pretty much in the noise range or less than 10%,
but mid range can be seen at over 30% overall throughput (hash ops/sec).
This makes anon-mem shared futexes much closer to its private counterpart.

Signed-off-by: Mel Gorman 
[ Ported on top of thp refcount rework, changelog, comments, fixes. ]
Signed-off-by: Davidlohr Bueso 
Reviewed-by: Thomas Gleixner 
Cc: Chris Mason 
Cc: Darren Hart 
Cc: Hugh Dickins 
Cc: Linus Torvalds 
Cc: Mel Gorman 
Cc: Peter Zijlstra 
Cc: Sebastian Andrzej Siewior 
Cc: dave@stgolabs.net
Link: http://lkml.kernel.org/r/1455045314-8305-3-git-send-email-dave@stgolabs.net
Signed-off-by: Ingo Molnar 
Signed-off-by: Chenbo Feng 
Signed-off-by: Greg Kroah-Hartman

perf/core: Correct event creation with PERF_FORMAT_GROUP

2018-04-13T17:50:19+00:00

[ Upstream commit ba5213ae6b88fb170c4771fef6553f759c7d8cdd ]

Andi was asking about PERF_FORMAT_GROUP vs inherited events, which led
to the discovery of a bug from commit:

  3dab77fb1bf8 ("perf: Rework/fix the whole read vs group stuff")

 -       PERF_SAMPLE_GROUP                       = 1U << 4,
 +       PERF_SAMPLE_READ                        = 1U << 4,

 -       if (attr->inherit && (attr->sample_type & PERF_SAMPLE_GROUP))
 +       if (attr->inherit && (attr->read_format & PERF_FORMAT_GROUP))

is a clear fail :/

While this changes user visible behaviour; it was previously possible
to create an inherited event with PERF_SAMPLE_READ; this is deemed
acceptible because its results were always incorrect.

Reported-by: Andi Kleen 
Signed-off-by: Peter Zijlstra (Intel) 
Cc: Alexander Shishkin 
Cc: Arnaldo Carvalho de Melo 
Cc: Jiri Olsa 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Stephane Eranian 
Cc: Thomas Gleixner 
Cc: Vince Weaver 
Fixes:  3dab77fb1bf8 ("perf: Rework/fix the whole read vs group stuff")
Link: http://lkml.kernel.org/r/20170530094512.dy2nljns2uq7qa3j@hirez.programming.kicks-ass.net
Signed-off-by: Ingo Molnar 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

sched/numa: Use down_read_trylock() for the mmap_sem

2018-04-13T17:50:09+00:00

[ Upstream commit 8655d5497735b288f8a9b458bd22e7d1bf95bb61 ]

A customer has reported a soft-lockup when running an intensive
memory stress test, where the trace on multiple CPU's looks like this:

 RIP: 0010:[]
  [] native_queued_spin_lock_slowpath+0x10e/0x190
...
 Call Trace:
  [] queued_spin_lock_slowpath+0x7/0xa
  [] change_protection_range+0x3b1/0x930
  [] change_prot_numa+0x18/0x30
  [] task_numa_work+0x1fe/0x310
  [] task_work_run+0x72/0x90

Further investigation showed that the lock contention here is pmd_lock().

The task_numa_work() function makes sure that only one thread is let to perform
the work in a single scan period (via cmpxchg), but if there's a thread with
mmap_sem locked for writing for several periods, multiple threads in
task_numa_work() can build up a convoy waiting for mmap_sem for read and then
all get unblocked at once.

This patch changes the down_read() to the trylock version, which prevents the
build up. For a workload experiencing mmap_sem contention, it's probably better
to postpone the NUMA balancing work anyway. This seems to have fixed the soft
lockups involving pmd_lock(), which is in line with the convoy theory.

Signed-off-by: Vlastimil Babka 
Signed-off-by: Peter Zijlstra (Intel) 
Acked-by: Rik van Riel 
Acked-by: Mel Gorman 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Link: http://lkml.kernel.org/r/20170515131316.21909-1-vbabka@suse.cz
Signed-off-by: Ingo Molnar 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

pidns: disable pid allocation if pid_ns_prepare_proc() is failed in alloc_pid()

2018-04-13T17:50:03+00:00

[ Upstream commit 8896c23d2ef803f1883fea73117a435925c2b4c4 ]

alloc_pidmap() advances pid_namespace::last_pid.  When first pid
allocation fails, then next created process will have pid 2 and
pid_ns_prepare_proc() won't be called.  So, pid_namespace::proc_mnt will
never be initialized (not to mention that there won't be a child
reaper).

I saw crash stack of such case on kernel 3.10:

    BUG: unable to handle kernel NULL pointer dereference at (null)
    IP: proc_flush_task+0x8f/0x1b0
    Call Trace:
        release_task+0x3f/0x490
        wait_consider_task.part.10+0x7ff/0xb00
        do_wait+0x11f/0x280
        SyS_wait4+0x7d/0x110

We may fix this by restore of last_pid in 0 or by prohibiting of futher
allocations.  Since there was a similar issue in Oleg Nesterov's commit
314a8ad0f18a ("pidns: fix free_pid() to handle the first fork failure").
and it was fixed via prohibiting allocation, let's follow this way, and
do the same.

Link: http://lkml.kernel.org/r/149201021004.4863.6762095011554287922.stgit@localhost.localdomain
Signed-off-by: Kirill Tkhai 
Acked-by: Cyrill Gorcunov 
Cc: Andrei Vagin 
Cc: Andreas Gruenbacher 
Cc: Kees Cook 
Cc: Michael Kerrisk 
Cc: Al Viro 
Cc: Oleg Nesterov 
Cc: Paul Moore 
Cc: Eric Biederman 
Cc: Andy Lutomirski 
Cc: Ingo Molnar 
Cc: Serge Hallyn 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

audit: add tty field to LOGIN event

2018-04-08T09:51:57+00:00

commit db0a6fb5d97afe01fd9c47d37c6daa82d4d4001d upstream.

The tty field was missing from AUDIT_LOGIN events.

Refactor code to create a new function audit_get_tty(), using it to
replace the call in audit_log_task_info() and to add it to
audit_log_set_loginuid().  Lock and bump the kref to protect it, adding
audit_put_tty() alias to decrement it.

Signed-off-by: Richard Guy Briggs 
Signed-off-by: Paul Moore 
Signed-off-by: Greg Kroah-Hartman

genirq: Use cpumask_available() for check of cpumask variable

2018-04-08T09:51:57+00:00

commit d170fe7dd992b313d4851ae5ab77ee7a51ed8c72 upstream.

This fixes the following clang warning when CONFIG_CPUMASK_OFFSTACK=n:

kernel/irq/manage.c:839:28: error: address of array
'desc->irq_common_data.affinity' will always evaluate to 'true'
[-Werror,-Wpointer-bool-conversion]

Signed-off-by: Matthias Kaehlcke 
Cc: Grant Grundler 
Cc: Rusty Russell 
Cc: Greg Hackmann 
Cc: Michael Davidson 
Cc: Andrew Morton 
Link: http://lkml.kernel.org/r/20170412182030.83657-2-mka@chromium.org
Signed-off-by: Thomas Gleixner 
Cc: Nathan Chancellor 
Signed-off-by: Greg Kroah-Hartman

kprobes/x86: Fix to set RWX bits correctly before releasing trampoline

2018-04-08T09:51:56+00:00

commit c93f5cf571e7795f97d49ef51b766cf25e328545 upstream.

Fix kprobes to set(recover) RWX bits correctly on trampoline
buffer before releasing it. Releasing readonly page to
module_memfree() crash the kernel.

Without this fix, if kprobes user register a bunch of kprobes
in function body (since kprobes on function entry usually
use ftrace) and unregister it, kernel hits a BUG and crash.

Link: http://lkml.kernel.org/r/149570868652.3518.14120169373590420503.stgit@devbox

Signed-off-by: Masami Hiramatsu 
Fixes: d0381c81c2f7 ("kprobes/x86: Set kprobes pages read-only")
Signed-off-by: Steven Rostedt (VMware) 
Cc: Ben Hutchings 
Signed-off-by: Greg Kroah-Hartman

perf/hwbp: Simplify the perf-hwbp code, fix documentation

2018-04-08T09:51:56+00:00

commit f67b15037a7a50c57f72e69a6d59941ad90a0f0f upstream.

Annoyingly, modify_user_hw_breakpoint() unnecessarily complicates the
modification of a breakpoint - simplify it and remove the pointless
local variables.

Also update the stale Docbook while at it.

Signed-off-by: Linus Torvalds 
Acked-by: Thomas Gleixner 
Cc: 
Cc: Alexander Shishkin 
Cc: Andy Lutomirski 
Cc: Arnaldo Carvalho de Melo 
Cc: Frederic Weisbecker 
Cc: Jiri Olsa 
Cc: Peter Zijlstra 
Cc: Stephane Eranian 
Cc: Vince Weaver 
Signed-off-by: Ingo Molnar 
Signed-off-by: Greg Kroah-Hartman

Revert "genirq: Use irqd_get_trigger_type to compare the trigger type for shared IRQs"

2018-03-31T16:12:32+00:00

This reverts commit 9d0273bb1c4b645817eccfe5c5975ea29add3300 which is
commit 382bd4de61827dbaaf5fb4fb7b1f4be4a86505e7 upstream.

It causes too many problems with the stable tree, and would require too
many other things to be backported, so just revert it.

Reported-by: Guenter Roeck 
Cc: Thomas Gleixner 
Cc: Hans de Goede 
Cc: Marc Zyngier 
Cc: Thomas Gleixner 
Cc: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman