Pull timer fixes from Thomas Gleixner:
"Two oneliners addressing NOHZ failures:
- Use a bitmask to check for the pending timer softirq and not the
bit number. The existing code using the bit number checked for
the wrong bit, which caused timers to either expire late or stop
completely.
- Make the nohz evaluation on interrupt exit more robust. The
existing code did not re-arm the hardware when interrupting a
running softirq in task context (ksoftirqd or tail of
local_bh_enable()), which caused timers to either expire late
or stop completely"
* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
nohz: Fix missing tick reprogram when interrupting an inline softirq
nohz: Fix local_timer_softirq_pending()
The full nohz tick is reprogrammed in irq_exit() only if the exit is not in
a nesting interrupt. This stands as an optimization: whether a hardirq or a
softirq is interrupted, the tick is going to be reprogrammed when necessary
at the end of the inner interrupt, with even potential new updates on the
timer queue.
When soft interrupts are interrupted, it's assumed that they are executing
on the tail of an interrupt return. In that case tick_nohz_irq_exit() is
called after softirq processing to take care of the tick reprogramming.
But the assumption is wrong: softirqs can be processed inline as well, ie:
outside of an interrupt, like in a call to local_bh_enable() or from
ksoftirqd.
Inline softirqs don't reprogram the tick once they are done, as opposed to
interrupt tail softirq processing. So if a tick interrupts an inline
softirq processing, the next timer will neither be reprogrammed from the
interrupting tick's irq_exit() nor after the interrupted softirq
processing. This situation may leave the tick unprogrammed while timers are
armed.
To fix this, simply keep reprogramming the tick even if a softirq has been
interrupted. That can be optimized further, but for now correctness is more
important.
Note that new timers enqueued in nohz_full mode after a softirq gets
interrupted will still be handled just fine through self-IPIs triggered by
the timer code.
Reported-by: Anna-Maria Gleixner <anna-maria@linutronix.de>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Anna-Maria Gleixner <anna-maria@linutronix.de>
Cc: stable@vger.kernel.org # 4.14+
Link: https://lkml.kernel.org/r/1533303094-15855-1-git-send-email-frederic@kernel.org
The support of force threading interrupts which are set up with both a
primary and a threaded handler wreckaged the setup of regular requested
threaded interrupts (primary handler == NULL).
The reason is that it does not check whether the primary handler is set to
the default handler which wakes the handler thread. Instead it replaces the
thread handler with the primary handler as it would do with force threaded
interrupts which have been requested via request_irq(). So both the primary
and the thread handler become the same which then triggers the warnon that
the thread handler tries to wakeup a not configured secondary thread.
Fortunately this only happens when the driver omits the IRQF_ONESHOT flag
when requesting the threaded interrupt, which is normaly caught by the
sanity checks when force irq threading is disabled.
Fix it by skipping the force threading setup when a regular threaded
interrupt is requested. As a consequence the interrupt request which lacks
the IRQ_ONESHOT flag is rejected correctly instead of silently wreckaging
it.
Fixes: 2a1d3ab898 ("genirq: Handle force threading of irqs with primary and thread handler")
Reported-by: Kurt Kanzenbach <kurt.kanzenbach@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Kurt Kanzenbach <kurt.kanzenbach@linutronix.de>
Cc: stable@vger.kernel.org
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Merge tag 'audit-pr-20180731' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit
Pull audit fix from Paul Moore:
"A single small audit fix to guard against memory allocation failures
when logging information about a kernel module load.
It's small, easy to understand, and self-contained; while nothing is
zero risk, this should be pretty low"
* tag 'audit-pr-20180731' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit:
audit: fix potential null dereference 'context->module.name'
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
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20180731161358.29472-1-anna-maria@linutronix.de
Pull networking fixes from David Miller:
"Several smallish fixes, I don't think any of this requires another -rc
but I'll leave that up to you:
1) Don't leak uninitialzed bytes to userspace in xfrm_user, from Eric
Dumazet.
2) Route leak in xfrm_lookup_route(), from Tommi Rantala.
3) Premature poll() returns in AF_XDP, from Björn Töpel.
4) devlink leak in netdevsim, from Jakub Kicinski.
5) Don't BUG_ON in fib_compute_spec_dst, the condition can
legitimately happen. From Lorenzo Bianconi.
6) Fix some spectre v1 gadgets in generic socket code, from Jeremy
Cline.
7) Don't allow user to bind to out of range multicast groups, from
Dmitry Safonov with a follow-up by Dmitry Safonov.
8) Fix metrics leak in fib6_drop_pcpu_from(), from Sabrina Dubroca"
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (41 commits)
netlink: Don't shift with UB on nlk->ngroups
net/ipv6: fix metrics leak
xen-netfront: wait xenbus state change when load module manually
can: ems_usb: Fix memory leak on ems_usb_disconnect()
openvswitch: meter: Fix setting meter id for new entries
netlink: Do not subscribe to non-existent groups
NET: stmmac: align DMA stuff to largest cache line length
tcp_bbr: fix bw probing to raise in-flight data for very small BDPs
net: socket: Fix potential spectre v1 gadget in sock_is_registered
net: socket: fix potential spectre v1 gadget in socketcall
net: mdio-mux: bcm-iproc: fix wrong getter and setter pair
ipv4: remove BUG_ON() from fib_compute_spec_dst
enic: handle mtu change for vf properly
net: lan78xx: fix rx handling before first packet is send
nfp: flower: fix port metadata conversion bug
bpf: use GFP_ATOMIC instead of GFP_KERNEL in bpf_parse_prog()
bpf: fix bpf_skb_load_bytes_relative pkt length check
perf build: Build error in libbpf missing initialization
net: ena: Fix use of uninitialized DMA address bits field
bpf: btf: Use exact btf value_size match in map_check_btf()
...
The variable 'context->module.name' may be null pointer when
kmalloc return null, so it's better to check it before using
to avoid null dereference.
Another one more thing this patch does is using kstrdup instead
of (kmalloc + strcpy), and signal a lost record via audit_log_lost.
Cc: stable@vger.kernel.org # 4.11
Signed-off-by: Yi Wang <wang.yi59@zte.com.cn>
Reviewed-by: Jiang Biao <jiang.biao2@zte.com.cn>
Reviewed-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
Pull scheduler fixes from Ingo Molnar:
"Misc fixes:
- a deadline scheduler related bug fix which triggered a kernel
warning
- an RT_RUNTIME_SHARE fix
- a stop_machine preemption fix
- a potential NULL dereference fix in sched_domain_debug_one()"
* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched/rt: Restore rt_runtime after disabling RT_RUNTIME_SHARE
sched/deadline: Update rq_clock of later_rq when pushing a task
stop_machine: Disable preemption after queueing stopper threads
sched/topology: Check variable group before dereferencing it
Pull locking fixes from Ingo Molnar:
"A paravirt UP-patching fix, and an I2C MUX driver lockdep warning fix"
* 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
locking/pvqspinlock/x86: Use LOCK_PREFIX in __pv_queued_spin_unlock() assembly code
i2c/mux, locking/core: Annotate the nested rt_mutex usage
locking/rtmutex: Allow specifying a subclass for nested locking
Daniel Borkmann says:
====================
pull-request: bpf 2018-07-28
The following pull-request contains BPF updates for your *net* tree.
The main changes are:
1) API fixes for libbpf's BTF mapping of map key/value types in order
to make them compatible with iproute2's BPF_ANNOTATE_KV_PAIR()
markings, from Martin.
2) Fix AF_XDP to not report POLLIN prematurely by using the non-cached
consumer pointer of the RX queue, from Björn.
3) Fix __xdp_return() to check for NULL pointer after the rhashtable
lookup that retrieves the allocator object, from Taehee.
4) Fix x86-32 JIT to adjust ebp register in prologue and epilogue
by 4 bytes which got removed from overall stack usage, from Wang.
5) Fix bpf_skb_load_bytes_relative() length check to use actual
packet length, from Daniel.
6) Fix uninitialized return code in libbpf bpf_perf_event_read_simple()
handler, from Thomas.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Merge misc fixes from Andrew Morton:
"11 fixes"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
kvm, mm: account shadow page tables to kmemcg
zswap: re-check zswap_is_full() after do zswap_shrink()
include/linux/eventfd.h: include linux/errno.h
mm: fix vma_is_anonymous() false-positives
mm: use vma_init() to initialize VMAs on stack and data segments
mm: introduce vma_init()
mm: fix exports that inadvertently make put_page() EXPORT_SYMBOL_GPL
ipc/sem.c: prevent queue.status tearing in semop
mm: disallow mappings that conflict for devm_memremap_pages()
kasan: only select SLUB_DEBUG with SYSFS=y
delayacct: fix crash in delayacct_blkio_end() after delayacct init failure
- Fix double free when the reg() call fails in event_trigger_callback()
- Fix anomoly of snapshot causing tracing_on flag to change
- Add selftest to test snapshot and tracing_on affecting each other
- Fix setting of tracepoint flag on error that prevents probes from
being deleted.
- Fix another possible double free that is similar to event_trigger_callback()
- Quiet a gcc warning of a false positive unused variable
- Fix crash of partial exposed task->comm to trace events
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Merge tag 'trace-v4.18-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing fixes from Steven Rostedt:
"Various fixes to the tracing infrastructure:
- Fix double free when the reg() call fails in
event_trigger_callback()
- Fix anomoly of snapshot causing tracing_on flag to change
- Add selftest to test snapshot and tracing_on affecting each other
- Fix setting of tracepoint flag on error that prevents probes from
being deleted.
- Fix another possible double free that is similar to
event_trigger_callback()
- Quiet a gcc warning of a false positive unused variable
- Fix crash of partial exposed task->comm to trace events"
* tag 'trace-v4.18-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
kthread, tracing: Don't expose half-written comm when creating kthreads
tracing: Quiet gcc warning about maybe unused link variable
tracing: Fix possible double free in event_enable_trigger_func()
tracing/kprobes: Fix trace_probe flags on enable_trace_kprobe() failure
selftests/ftrace: Add snapshot and tracing_on test case
ring_buffer: tracing: Inherit the tracing setting to next ring buffer
tracing: Fix double free of event_trigger_data
Not all VMAs allocated with vm_area_alloc(). Some of them allocated on
stack or in data segment.
The new helper can be use to initialize VMA properly regardless where it
was allocated.
Link: http://lkml.kernel.org/r/20180724121139.62570-2-kirill.shutemov@linux.intel.com
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit e763848843 ("mm: introduce MEMORY_DEVICE_FS_DAX and
CONFIG_DEV_PAGEMAP_OPS") added two EXPORT_SYMBOL_GPL() symbols, but
these symbols are required by the inlined put_page(), thus accidentally
making put_page() a GPL export only. This breaks OpenAFS (at least).
Mark them EXPORT_SYMBOL() instead.
Link: http://lkml.kernel.org/r/153128611970.2928.11310692420711601254.stgit@dwillia2-desk3.amr.corp.intel.com
Fixes: e763848843 ("mm: introduce MEMORY_DEVICE_FS_DAX and CONFIG_DEV_PAGEMAP_OPS")
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Reported-by: Joe Gorse <jhgorse@gmail.com>
Reported-by: John Hubbard <jhubbard@nvidia.com>
Tested-by: Joe Gorse <jhgorse@gmail.com>
Tested-by: John Hubbard <jhubbard@nvidia.com>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Mark Vitale <mvitale@sinenomine.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When pmem namespaces created are smaller than section size, this can
cause an issue during removal and gpf was observed:
general protection fault: 0000 1 SMP PTI
CPU: 36 PID: 3941 Comm: ndctl Tainted: G W 4.14.28-1.el7uek.x86_64 #2
task: ffff88acda150000 task.stack: ffffc900233a4000
RIP: 0010:__put_page+0x56/0x79
Call Trace:
devm_memremap_pages_release+0x155/0x23a
release_nodes+0x21e/0x260
devres_release_all+0x3c/0x48
device_release_driver_internal+0x15c/0x207
device_release_driver+0x12/0x14
unbind_store+0xba/0xd8
drv_attr_store+0x27/0x31
sysfs_kf_write+0x3f/0x46
kernfs_fop_write+0x10f/0x18b
__vfs_write+0x3a/0x16d
vfs_write+0xb2/0x1a1
SyS_write+0x55/0xb9
do_syscall_64+0x79/0x1ae
entry_SYSCALL_64_after_hwframe+0x3d/0x0
Add code to check whether we have a mapping already in the same section
and prevent additional mappings from being created if that is the case.
Link: http://lkml.kernel.org/r/152909478401.50143.312364396244072931.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Robert Elliott <elliott@hpe.com>
Cc: Jeff Moyer <jmoyer@redhat.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The current map_check_btf() in BPF_MAP_TYPE_ARRAY rejects
'> map->value_size' to ensure map_seq_show_elem() will not
access things beyond an array element.
Yonghong suggested that using '!=' is a more correct
check. The 8 bytes round_up on value_size is stored
in array->elem_size. Hence, using '!=' on map->value_size
is a proper check.
This patch also adds new tests to check the btf array
key type and value type. Two of these new tests verify
the btf's value_size (the change in this patch).
It also fixes two existing tests that wrongly encoded
a btf's type size (pprint_test) and the value_type_id (in one
of the raw_tests[]). However, that do not affect these two
BTF verification tests before or after this test changes.
These two tests mainly failed at array creation time after
this patch.
Fixes: a26ca7c982 ("bpf: btf: Add pretty print support to the basic arraymap")
Suggested-by: Yonghong Song <yhs@fb.com>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
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
Cc: stable@vger.kernel.org
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>
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.
Cc: stable@vger.kernel.org
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>
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
Cc: stable@vger.kernel.org
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>
If enable_trace_kprobe fails to enable the probe in enable_k(ret)probe
it returns an error, but does not unset the tp flags it set previously.
This results in a probe being considered enabled and failures like being
unable to remove the probe through kprobe_events file since probes_open()
expects every probe to be disabled.
Link: http://lkml.kernel.org/r/20180725102826.8300-1-asavkov@redhat.com
Link: http://lkml.kernel.org/r/20180725142038.4765-1-asavkov@redhat.com
Cc: Ingo Molnar <mingo@redhat.com>
Cc: stable@vger.kernel.org
Fixes: 41a7dd420c ("tracing/kprobes: Support ftrace_event_file base multibuffer")
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Artem Savkov <asavkov@redhat.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Maintain the tracing on/off setting of the ring_buffer when switching
to the trace buffer snapshot.
Taking a snapshot is done by swapping the backup ring buffer
(max_tr_buffer). But since the tracing on/off setting is defined
by the ring buffer, when swapping it, the tracing on/off setting
can also be changed. This causes a strange result like below:
/sys/kernel/debug/tracing # cat tracing_on
1
/sys/kernel/debug/tracing # echo 0 > tracing_on
/sys/kernel/debug/tracing # cat tracing_on
0
/sys/kernel/debug/tracing # echo 1 > snapshot
/sys/kernel/debug/tracing # cat tracing_on
1
/sys/kernel/debug/tracing # echo 1 > snapshot
/sys/kernel/debug/tracing # cat tracing_on
0
We don't touch tracing_on, but snapshot changes tracing_on
setting each time. This is an anomaly, because user doesn't know
that each "ring_buffer" stores its own tracing-enable state and
the snapshot is done by swapping ring buffers.
Link: http://lkml.kernel.org/r/153149929558.11274.11730609978254724394.stgit@devbox
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Tom Zanussi <tom.zanussi@linux.intel.com>
Cc: Hiraku Toyooka <hiraku.toyooka@cybertrust.co.jp>
Cc: stable@vger.kernel.org
Fixes: debdd57f51 ("tracing: Make a snapshot feature available from userspace")
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
[ Updated commit log and comment in the code ]
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Running the following:
# cd /sys/kernel/debug/tracing
# echo 500000 > buffer_size_kb
[ Or some other number that takes up most of memory ]
# echo snapshot > events/sched/sched_switch/trigger
Triggers the following bug:
------------[ cut here ]------------
kernel BUG at mm/slub.c:296!
invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC PTI
CPU: 6 PID: 6878 Comm: bash Not tainted 4.18.0-rc6-test+ #1066
Hardware name: Hewlett-Packard HP Compaq Pro 6300 SFF/339A, BIOS K01 v03.03 07/14/2016
RIP: 0010:kfree+0x16c/0x180
Code: 05 41 0f b6 72 51 5b 5d 41 5c 4c 89 d7 e9 ac b3 f8 ff 48 89 d9 48 89 da 41 b8 01 00 00 00 5b 5d 41 5c 4c 89 d6 e9 f4 f3 ff ff <0f> 0b 0f 0b 48 8b 3d d9 d8 f9 00 e9 c1 fe ff ff 0f 1f 40 00 0f 1f
RSP: 0018:ffffb654436d3d88 EFLAGS: 00010246
RAX: ffff91a9d50f3d80 RBX: ffff91a9d50f3d80 RCX: ffff91a9d50f3d80
RDX: 00000000000006a4 RSI: ffff91a9de5a60e0 RDI: ffff91a9d9803500
RBP: ffffffff8d267c80 R08: 00000000000260e0 R09: ffffffff8c1a56be
R10: fffff0d404543cc0 R11: 0000000000000389 R12: ffffffff8c1a56be
R13: ffff91a9d9930e18 R14: ffff91a98c0c2890 R15: ffffffff8d267d00
FS: 00007f363ea64700(0000) GS:ffff91a9de580000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055c1cacc8e10 CR3: 00000000d9b46003 CR4: 00000000001606e0
Call Trace:
event_trigger_callback+0xee/0x1d0
event_trigger_write+0xfc/0x1a0
__vfs_write+0x33/0x190
? handle_mm_fault+0x115/0x230
? _cond_resched+0x16/0x40
vfs_write+0xb0/0x190
ksys_write+0x52/0xc0
do_syscall_64+0x5a/0x160
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7f363e16ab50
Code: 73 01 c3 48 8b 0d 38 83 2c 00 f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 83 3d 79 db 2c 00 00 75 10 b8 01 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 1e e3 01 00 48 89 04 24
RSP: 002b:00007fff9a4c6378 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000009 RCX: 00007f363e16ab50
RDX: 0000000000000009 RSI: 000055c1cacc8e10 RDI: 0000000000000001
RBP: 000055c1cacc8e10 R08: 00007f363e435740 R09: 00007f363ea64700
R10: 0000000000000073 R11: 0000000000000246 R12: 0000000000000009
R13: 0000000000000001 R14: 00007f363e4345e0 R15: 00007f363e4303c0
Modules linked in: ip6table_filter ip6_tables snd_hda_codec_hdmi snd_hda_codec_realtek snd_hda_codec_generic snd_hda_intel snd_hda_codec snd_hwdep snd_hda_core snd_seq snd_seq_device i915 snd_pcm snd_timer i2c_i801 snd soundcore i2c_algo_bit drm_kms_helper
86_pkg_temp_thermal video kvm_intel kvm irqbypass wmi e1000e
---[ end trace d301afa879ddfa25 ]---
The cause is because the register_snapshot_trigger() call failed to
allocate the snapshot buffer, and then called unregister_trigger()
which freed the data that was passed to it. Then on return to the
function that called register_snapshot_trigger(), as it sees it
failed to register, it frees the trigger_data again and causes
a double free.
By calling event_trigger_init() on the trigger_data (which only ups
the reference counter for it), and then event_trigger_free() afterward,
the trigger_data would not get freed by the registering trigger function
as it would only up and lower the ref count for it. If the register
trigger function fails, then the event_trigger_free() called after it
will free the trigger data normally.
Link: http://lkml.kernel.org/r/20180724191331.738eb819@gandalf.local.home
Cc: stable@vger.kerne.org
Fixes: 93e31ffbf4 ("tracing: Add 'snapshot' event trigger command")
Reported-by: Masami Hiramatsu <mhiramat@kernel.org>
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
In function perf_event_parse_addr_filter(), the path::dentry of each struct
perf_addr_filter is left unassigned (as it should be) when the pattern
being parsed is related to kernel space. But in function
perf_addr_filter_match() the same dentries are given to d_inode() where
the value is not expected to be NULL, resulting in the following splat:
Unable to handle kernel NULL pointer dereference at virtual address 0000000000000058
pc : perf_event_mmap+0x2fc/0x5a0
lr : perf_event_mmap+0x2c8/0x5a0
Process uname (pid: 2860, stack limit = 0x000000001cbcca37)
Call trace:
perf_event_mmap+0x2fc/0x5a0
mmap_region+0x124/0x570
do_mmap+0x344/0x4f8
vm_mmap_pgoff+0xe4/0x110
vm_mmap+0x2c/0x40
elf_map+0x60/0x108
load_elf_binary+0x450/0x12c4
search_binary_handler+0x90/0x290
__do_execve_file.isra.13+0x6e4/0x858
sys_execve+0x3c/0x50
el0_svc_naked+0x30/0x34
This patch is fixing the problem by introducing a new check in function
perf_addr_filter_match() to see if the filter's dentry is NULL.
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: acme@kernel.org
Cc: miklos@szeredi.hu
Cc: namhyung@kernel.org
Cc: songliubraving@fb.com
Fixes: 9511bce9fe ("perf/core: Fix bad use of igrab()")
Link: http://lkml.kernel.org/r/1531782831-1186-1-git-send-email-mathieu.poirier@linaro.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Vince reported the perf_fuzzer giving various unwinder warnings and
Josh reported:
> Deja vu. Most of these are related to perf PEBS, similar to the
> following issue:
>
> b8000586c9 ("perf/x86/intel: Cure bogus unwind from PEBS entries")
>
> This is basically the ORC version of that. setup_pebs_sample_data() is
> assembling a franken-pt_regs which ORC isn't happy about. RIP is
> inconsistent with some of the other registers (like RSP and RBP).
And where the previous unwinder only needed BP,SP ORC also requires
IP. But we cannot spoof IP because then the sample will get displaced,
entirely negating the point of PEBS.
So cure the whole thing differently by doing the unwind early; this
does however require a means to communicate we did the unwind early.
We (ab)use an unused sample_type bit for this, which we set on events
that fill out the data->callchain before the normal
perf_prepare_sample().
Debugged-by: Josh Poimboeuf <jpoimboe@redhat.com>
Reported-by: Vince Weaver <vincent.weaver@maine.edu>
Tested-by: Josh Poimboeuf <jpoimboe@redhat.com>
Tested-by: Prashant Bhole <bhole_prashant_q7@lab.ntt.co.jp>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
NO_RT_RUNTIME_SHARE feature is used to prevent a CPU borrow enough
runtime with a spin-rt-task.
However, if RT_RUNTIME_SHARE feature is enabled and rt_rq has borrowd
enough rt_runtime at the beginning, rt_runtime can't be restored to
its initial bandwidth rt_runtime after we disable RT_RUNTIME_SHARE.
E.g. on my PC with 4 cores, procedure to reproduce:
1) Make sure RT_RUNTIME_SHARE is enabled
cat /sys/kernel/debug/sched_features
GENTLE_FAIR_SLEEPERS START_DEBIT NO_NEXT_BUDDY LAST_BUDDY
CACHE_HOT_BUDDY WAKEUP_PREEMPTION NO_HRTICK NO_DOUBLE_TICK
LB_BIAS NONTASK_CAPACITY TTWU_QUEUE NO_SIS_AVG_CPU SIS_PROP
NO_WARN_DOUBLE_CLOCK RT_PUSH_IPI RT_RUNTIME_SHARE NO_LB_MIN
ATTACH_AGE_LOAD WA_IDLE WA_WEIGHT WA_BIAS
2) Start a spin-rt-task
./loop_rr &
3) set affinity to the last cpu
taskset -p 8 $pid_of_loop_rr
4) Observe that last cpu have borrowed enough runtime.
cat /proc/sched_debug | grep rt_runtime
.rt_runtime : 950.000000
.rt_runtime : 900.000000
.rt_runtime : 950.000000
.rt_runtime : 1000.000000
5) Disable RT_RUNTIME_SHARE
echo NO_RT_RUNTIME_SHARE > /sys/kernel/debug/sched_features
6) Observe that rt_runtime can not been restored
cat /proc/sched_debug | grep rt_runtime
.rt_runtime : 950.000000
.rt_runtime : 900.000000
.rt_runtime : 950.000000
.rt_runtime : 1000.000000
This patch help to restore rt_runtime after we disable
RT_RUNTIME_SHARE.
Signed-off-by: Hailong Liu <liu.hailong6@zte.com.cn>
Signed-off-by: Jiang Biao <jiang.biao2@zte.com.cn>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: zhong.weidong@zte.com.cn
Link: http://lkml.kernel.org/r/1531874815-39357-1-git-send-email-liu.hailong6@zte.com.cn
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit:
9fb8d5dc4b ("stop_machine, Disable preemption when waking two stopper threads")
does not fully address the race condition that can occur
as follows:
On one CPU, call it CPU 3, thread 1 invokes
cpu_stop_queue_two_works(2, 3,...), and the execution is such
that thread 1 queues the works for migration/2 and migration/3,
and is preempted after releasing the locks for migration/2 and
migration/3, but before waking the threads.
Then, On CPU 2, a kworker, call it thread 2, is running,
and it invokes cpu_stop_queue_two_works(1, 2,...), such that
thread 2 queues the works for migration/1 and migration/2.
Meanwhile, on CPU 3, thread 1 resumes execution, and wakes
migration/2 and migration/3. This means that when CPU 2
releases the locks for migration/1 and migration/2, but before
it wakes those threads, it can be preempted by migration/2.
If thread 2 is preempted by migration/2, then migration/2 will
execute the first work item successfully, since migration/3
was woken up by CPU 3, but when it goes to execute the second
work item, it disables preemption, calls multi_cpu_stop(),
and thus, CPU 2 will wait forever for migration/1, which should
have been woken up by thread 2. However migration/1 cannot be
woken up by thread 2, since it is a kworker, so it is affine to
CPU 2, but CPU 2 is running migration/2 with preemption
disabled, so thread 2 will never run.
Disable preemption after queueing works for stopper threads
to ensure that the operation of queueing the works and waking
the stopper threads is atomic.
Co-Developed-by: Prasad Sodagudi <psodagud@codeaurora.org>
Co-Developed-by: Pavankumar Kondeti <pkondeti@codeaurora.org>
Signed-off-by: Isaac J. Manjarres <isaacm@codeaurora.org>
Signed-off-by: Prasad Sodagudi <psodagud@codeaurora.org>
Signed-off-by: Pavankumar Kondeti <pkondeti@codeaurora.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: bigeasy@linutronix.de
Cc: gregkh@linuxfoundation.org
Cc: matt@codeblueprint.co.uk
Fixes: 9fb8d5dc4b ("stop_machine, Disable preemption when waking two stopper threads")
Link: http://lkml.kernel.org/r/1531856129-9871-1-git-send-email-isaacm@codeaurora.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The 'group' variable in sched_domain_debug_one() is not checked
when firstly used in cpumask_test_cpu(cpu, sched_group_span(group)),
but it might be NULL (it is checked later in the following while loop)
and may cause NULL pointer dereference.
We need to check it before using to avoid NULL dereference.
Signed-off-by: Yi Wang <wang.yi59@zte.com.cn>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Jiang Biao <jiang.biao2@zte.com.cn>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: zhong.weidong@zte.com.cn
Link: http://lkml.kernel.org/r/1532319547-33335-1-git-send-email-wang.yi59@zte.com.cn
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Pull networking fixes from David Miller:
1) Handle stations tied to AP_VLANs properly during mac80211 hw
reconfig. From Manikanta Pubbisetty.
2) Fix jump stack depth validation in nf_tables, from Taehee Yoo.
3) Fix quota handling in aRFS flow expiration of mlx5 driver, from Eran
Ben Elisha.
4) Exit path handling fix in powerpc64 BPF JIT, from Daniel Borkmann.
5) Use ptr_ring_consume_bh() in page pool code, from Tariq Toukan.
6) Fix cached netdev name leak in nf_tables, from Florian Westphal.
7) Fix memory leaks on chain rename, also from Florian Westphal.
8) Several fixes to DCTCP congestion control ACK handling, from Yuchunk
Cheng.
9) Missing rcu_read_unlock() in CAIF protocol code, from Yue Haibing.
10) Fix link local address handling with VRF, from David Ahern.
11) Don't clobber 'err' on a successful call to __skb_linearize() in
skb_segment(). From Eric Dumazet.
12) Fix vxlan fdb notification races, from Roopa Prabhu.
13) Hash UDP fragments consistently, from Paolo Abeni.
14) If TCP receives lots of out of order tiny packets, we do really
silly stuff. Make the out-of-order queue ending more robust to this
kind of behavior, from Eric Dumazet.
15) Don't leak netlink dump state in nf_tables, from Florian Westphal.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (76 commits)
net: axienet: Fix double deregister of mdio
qmi_wwan: fix interface number for DW5821e production firmware
ip: in cmsg IP(V6)_ORIGDSTADDR call pskb_may_pull
bnx2x: Fix invalid memory access in rss hash config path.
net/mlx4_core: Save the qpn from the input modifier in RST2INIT wrapper
r8169: restore previous behavior to accept BIOS WoL settings
cfg80211: never ignore user regulatory hint
sock: fix sg page frag coalescing in sk_alloc_sg
netfilter: nf_tables: move dumper state allocation into ->start
tcp: add tcp_ooo_try_coalesce() helper
tcp: call tcp_drop() from tcp_data_queue_ofo()
tcp: detect malicious patterns in tcp_collapse_ofo_queue()
tcp: avoid collapses in tcp_prune_queue() if possible
tcp: free batches of packets in tcp_prune_ofo_queue()
ip: hash fragments consistently
ipv6: use fib6_info_hold_safe() when necessary
can: xilinx_can: fix power management handling
can: xilinx_can: fix incorrect clear of non-processed interrupts
can: xilinx_can: fix RX overflow interrupt not being enabled
can: xilinx_can: keep only 1-2 frames in TX FIFO to fix TX accounting
...
This patch ensures the member->offset of a struct
is in the correct order (i.e the later member's offset cannot
go backward).
The current "pahole -J" BTF encoder does not generate something
like this. However, checking this can ensure future encoder
will not violate this.
Fixes: 69b693f0ae ("bpf: btf: Introduce BPF Type Format (BTF)")
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Pull scheduler fixes from Ingo Molnar:
"Two fixes: a stop-machine preemption fix and a SCHED_DEADLINE fix"
* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched/deadline: Fix switched_from_dl() warning
stop_machine: Disable preemption when waking two stopper threads
Like vm_area_dup(), it initializes the anon_vma_chain head, and the
basic mm pointer.
The rest of the fields end up being different for different users,
although the plan is to also initialize the 'vm_ops' field to a dummy
entry.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
.. and re-initialize th eanon_vma_chain head.
This removes some boiler-plate from the users, and also makes it clear
why it didn't need use the 'zalloc()' version.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The vm_area_struct is one of the most fundamental memory management
objects, but the management of it is entirely open-coded evertwhere,
ranging from allocation and freeing (using kmem_cache_[z]alloc and
kmem_cache_free) to initializing all the fields.
We want to unify this in order to end up having some unified
initialization of the vmas, and the first step to this is to at least
have basic allocation functions.
Right now those functions are literally just wrappers around the
kmem_cache_*() calls. This is a purely mechanical conversion:
# new vma:
kmem_cache_zalloc(vm_area_cachep, GFP_KERNEL) -> vm_area_alloc()
# copy old vma
kmem_cache_alloc(vm_area_cachep, GFP_KERNEL) -> vm_area_dup(old)
# free vma
kmem_cache_free(vm_area_cachep, vma) -> vm_area_free(vma)
to the point where the old vma passed in to the vm_area_dup() function
isn't even used yet (because I've left all the old manual initialization
alone).
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch shrinks the BTF_INT_BITS() mask. The current
btf_int_check_meta() ensures the nr_bits of an integer
cannot exceed 64. Hence, it is mostly an uapi cleanup.
The actual btf usage (i.e. seq_show()) is also modified
to use u8 instead of u16. The verification (e.g. btf_int_check_meta())
path stays as is to deal with invalid BTF situation.
Fixes: 69b693f0ae ("bpf: btf: Introduce BPF Type Format (BTF)")
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Pull networking fixes from David Miller:
"Lots of fixes, here goes:
1) NULL deref in qtnfmac, from Gustavo A. R. Silva.
2) Kernel oops when fw download fails in rtlwifi, from Ping-Ke Shih.
3) Lost completion messages in AF_XDP, from Magnus Karlsson.
4) Correct bogus self-assignment in rhashtable, from Rishabh
Bhatnagar.
5) Fix regression in ipv6 route append handling, from David Ahern.
6) Fix masking in __set_phy_supported(), from Heiner Kallweit.
7) Missing module owner set in x_tables icmp, from Florian Westphal.
8) liquidio's timeouts are HZ dependent, fix from Nicholas Mc Guire.
9) Link setting fixes for sh_eth and ravb, from Vladimir Zapolskiy.
10) Fix NULL deref when using chains in act_csum, from Davide Caratti.
11) XDP_REDIRECT needs to check if the interface is up and whether the
MTU is sufficient. From Toshiaki Makita.
12) Net diag can do a double free when killing TCP_NEW_SYN_RECV
connections, from Lorenzo Colitti.
13) nf_defrag in ipv6 can unnecessarily hold onto dst entries for a
full minute, delaying device unregister. From Eric Dumazet.
14) Update MAC entries in the correct order in ixgbe, from Alexander
Duyck.
15) Don't leave partial mangles bpf program in jit_subprogs, from
Daniel Borkmann.
16) Fix pfmemalloc SKB state propagation, from Stefano Brivio.
17) Fix ACK handling in DCTCP congestion control, from Yuchung Cheng.
18) Use after free in tun XDP_TX, from Toshiaki Makita.
19) Stale ipv6 header pointer in ipv6 gre code, from Prashant Bhole.
20) Don't reuse remainder of RX page when XDP is set in mlx4, from
Saeed Mahameed.
21) Fix window probe handling of TCP rapair sockets, from Stefan
Baranoff.
22) Missing socket locking in smc_ioctl(), from Ursula Braun.
23) IPV6_ILA needs DST_CACHE, from Arnd Bergmann.
24) Spectre v1 fix in cxgb3, from Gustavo A. R. Silva.
25) Two spots in ipv6 do a rol32() on a hash value but ignore the
result. Fixes from Colin Ian King"
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (176 commits)
tcp: identify cryptic messages as TCP seq # bugs
ptp: fix missing break in switch
hv_netvsc: Fix napi reschedule while receive completion is busy
MAINTAINERS: Drop inactive Vitaly Bordug's email
net: cavium: Add fine-granular dependencies on PCI
net: qca_spi: Fix log level if probe fails
net: qca_spi: Make sure the QCA7000 reset is triggered
net: qca_spi: Avoid packet drop during initial sync
ipv6: fix useless rol32 call on hash
ipv6: sr: fix useless rol32 call on hash
net: sched: Using NULL instead of plain integer
net: usb: asix: replace mii_nway_restart in resume path
net: cxgb3_main: fix potential Spectre v1
lib/rhashtable: consider param->min_size when setting initial table size
net/smc: reset recv timeout after clc handshake
net/smc: add error handling for get_user()
net/smc: optimize consumer cursor updates
net/nfc: Avoid stalls when nfc_alloc_send_skb() returned NULL.
ipv6: ila: select CONFIG_DST_CACHE
net: usb: rtl8150: demote allmulti message to dev_dbg()
...
Way back in 4.9, we committed 4cd13c21b2 ("softirq: Let ksoftirqd do
its job"), and ever since we've had small nagging issues with it. For
example, we've had:
1ff688209e ("watchdog: core: make sure the watchdog_worker is not deferred")
8d5755b3f7 ("watchdog: softdog: fire watchdog even if softirqs do not get to run")
217f697436 ("net: busy-poll: allow preemption in sk_busy_loop()")
all of which worked around some of the effects of that commit.
The DVB people have also complained that the commit causes excessive USB
URB latencies, which seems to be due to the USB code using tasklets to
schedule USB traffic. This seems to be an issue mainly when already
living on the edge, but waiting for ksoftirqd to handle it really does
seem to cause excessive latencies.
Now Hanna Hawa reports that this issue isn't just limited to USB URB and
DVB, but also causes timeout problems for the Marvell SoC team:
"I'm facing kernel panic issue while running raid 5 on sata disks
connected to Macchiatobin (Marvell community board with Armada-8040
SoC with 4 ARMv8 cores of CA72) Raid 5 built with Marvell DMA engine
and async_tx mechanism (ASYNC_TX_DMA [=y]); the DMA driver (mv_xor_v2)
uses a tasklet to clean the done descriptors from the queue"
The latency problem causes a panic:
mv_xor_v2 f0400000.xor: dma_sync_wait: timeout!
Kernel panic - not syncing: async_tx_quiesce: DMA error waiting for transaction
We've discussed simply just reverting the original commit entirely, and
also much more involved solutions (with per-softirq threads etc). This
patch is intentionally stupid and fairly limited, because the issue
still remains, and the other solutions either got sidetracked or had
other issues.
We should probably also consider the timer softirqs to be synchronous
and not be delayed to ksoftirqd (since they were the issue with the
earlier watchdog problems), but that should be done as a separate patch.
This does only the tasklet cases.
Reported-and-tested-by: Hanna Hawa <hannah@marvell.com>
Reported-and-tested-by: Josef Griebichler <griebichler.josef@gmx.at>
Reported-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Mark noticed that syzkaller is able to reliably trigger the following warning:
dl_rq->running_bw > dl_rq->this_bw
WARNING: CPU: 1 PID: 153 at kernel/sched/deadline.c:124 switched_from_dl+0x454/0x608
Kernel panic - not syncing: panic_on_warn set ...
CPU: 1 PID: 153 Comm: syz-executor253 Not tainted 4.18.0-rc3+ #29
Hardware name: linux,dummy-virt (DT)
Call trace:
dump_backtrace+0x0/0x458
show_stack+0x20/0x30
dump_stack+0x180/0x250
panic+0x2dc/0x4ec
__warn_printk+0x0/0x150
report_bug+0x228/0x2d8
bug_handler+0xa0/0x1a0
brk_handler+0x2f0/0x568
do_debug_exception+0x1bc/0x5d0
el1_dbg+0x18/0x78
switched_from_dl+0x454/0x608
__sched_setscheduler+0x8cc/0x2018
sys_sched_setattr+0x340/0x758
el0_svc_naked+0x30/0x34
syzkaller reproducer runs a bunch of threads that constantly switch
between DEADLINE and NORMAL classes while interacting through futexes.
The splat above is caused by the fact that if a DEADLINE task is setattr
back to NORMAL while in non_contending state (blocked on a futex -
inactive timer armed), its contribution to running_bw is not removed
before sub_rq_bw() gets called (!task_on_rq_queued() branch) and the
latter sees running_bw > this_bw.
Fix it by removing a task contribution from running_bw if the task is
not queued and in non_contending state while switched to a different
class.
Reported-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Juri Lelli <juri.lelli@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Daniel Bristot de Oliveira <bristot@redhat.com>
Reviewed-by: Luca Abeni <luca.abeni@santannapisa.it>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: claudio@evidence.eu.com
Cc: rostedt@goodmis.org
Link: http://lkml.kernel.org/r/20180711072948.27061-1-juri.lelli@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
When cpu_stop_queue_two_works() begins to wake the stopper threads, it does
so without preemption disabled, which leads to the following race
condition:
The source CPU calls cpu_stop_queue_two_works(), with cpu1 as the source
CPU, and cpu2 as the destination CPU. When adding the stopper threads to
the wake queue used in this function, the source CPU stopper thread is
added first, and the destination CPU stopper thread is added last.
When wake_up_q() is invoked to wake the stopper threads, the threads are
woken up in the order that they are queued in, so the source CPU's stopper
thread is woken up first, and it preempts the thread running on the source
CPU.
The stopper thread will then execute on the source CPU, disable preemption,
and begin executing multi_cpu_stop(), and wait for an ack from the
destination CPU's stopper thread, with preemption still disabled. Since the
worker thread that woke up the stopper thread on the source CPU is affine
to the source CPU, and preemption is disabled on the source CPU, that
thread will never run to dequeue the destination CPU's stopper thread from
the wake queue, and thus, the destination CPU's stopper thread will never
run, causing the source CPU's stopper thread to wait forever, and stall.
Disable preemption when waking the stopper threads in
cpu_stop_queue_two_works().
Fixes: 0b26351b91 ("stop_machine, sched: Fix migrate_swap() vs. active_balance() deadlock")
Co-Developed-by: Prasad Sodagudi <psodagud@codeaurora.org>
Signed-off-by: Prasad Sodagudi <psodagud@codeaurora.org>
Co-Developed-by: Pavankumar Kondeti <pkondeti@codeaurora.org>
Signed-off-by: Pavankumar Kondeti <pkondeti@codeaurora.org>
Signed-off-by: Isaac J. Manjarres <isaacm@codeaurora.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: peterz@infradead.org
Cc: matt@codeblueprint.co.uk
Cc: bigeasy@linutronix.de
Cc: gregkh@linuxfoundation.org
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/1530655334-4601-1-git-send-email-isaacm@codeaurora.org
Pull timer fixes from Ingo Molnar:
"A clocksource driver fix and a revert"
* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
clocksource: arm_arch_timer: Set arch_mem_timer cpumask to cpu_possible_mask
Revert "tick: Prefer a lower rating device only if it's CPU local device"
Pull rseq fixes from Ingo Molnar:
"Various rseq ABI fixes and cleanups: use get_user()/put_user(),
validate parameters and use proper uapi types, etc"
* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
rseq/selftests: cleanup: Update comment above rseq_prepare_unload
rseq: Remove unused types_32_64.h uapi header
rseq: uapi: Declare rseq_cs field as union, update includes
rseq: uapi: Update uapi comments
rseq: Use get_user/put_user rather than __get_user/__put_user
rseq: Use __u64 for rseq_cs fields, validate user inputs
own patch internally for. I took it back in 4.13. Now he realizes that
he had a mistake, and swapped the values from what Android had. This
means that the old Android tools will break when using a new kernel
that has the new feature on it.
The options are:
1. To swap it back to what Android wants.
2. Add a command line option or something to do the swap
3. Just let Android carry a patch that swaps it back
Since it requires setting a tracing option to enable this anyway,
I doubt there are other users of this than Android. Thus, I've
decided to take option 1. If someone else is actually depending on the
order that is in the kernel, then we will have to revert this change
and go to option 2 or 3.
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Merge tag 'trace-v4.18-rc3-3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing fixlet from Steven Rostedt:
"Joel Fernandes asked to add a feature in tracing that Android had its
own patch internally for. I took it back in 4.13. Now he realizes that
he had a mistake, and swapped the values from what Android had. This
means that the old Android tools will break when using a new kernel
that has the new feature on it.
The options are:
1. To swap it back to what Android wants.
2. Add a command line option or something to do the swap
3. Just let Android carry a patch that swaps it back
Since it requires setting a tracing option to enable this anyway, I
doubt there are other users of this than Android. Thus, I've decided
to take option 1. If someone else is actually depending on the order
that is in the kernel, then we will have to revert this change and go
to option 2 or 3"
* tag 'trace-v4.18-rc3-3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
tracing: Reorder display of TGID to be after PID
Currently ftrace displays data in trace output like so:
_-----=> irqs-off
/ _----=> need-resched
| / _---=> hardirq/softirq
|| / _--=> preempt-depth
||| / delay
TASK-PID CPU TGID |||| TIMESTAMP FUNCTION
| | | | |||| | |
bash-1091 [000] ( 1091) d..2 28.313544: sched_switch:
However Android's trace visualization tools expect a slightly different
format due to an out-of-tree patch patch that was been carried for a
decade, notice that the TGID and CPU fields are reversed:
_-----=> irqs-off
/ _----=> need-resched
| / _---=> hardirq/softirq
|| / _--=> preempt-depth
||| / delay
TASK-PID TGID CPU |||| TIMESTAMP FUNCTION
| | | | |||| | |
bash-1091 ( 1091) [002] d..2 64.965177: sched_switch:
From kernel v4.13 onwards, during which TGID was introduced, tracing
with systrace on all Android kernels will break (most Android kernels
have been on 4.9 with Android patches, so this issues hasn't been seen
yet). From v4.13 onwards things will break.
The chrome browser's tracing tools also embed the systrace viewer which
uses the legacy TGID format and updates to that are known to be
difficult to make.
Considering this, I suggest we make this change to the upstream kernel
and backport it to all Android kernels. I believe this feature is merged
recently enough into the upstream kernel that it shouldn't be a problem.
Also logically, IMO it makes more sense to group the TGID with the
TASK-PID and the CPU after these.
Link: http://lkml.kernel.org/r/20180626000822.113931-1-joel@joelfernandes.org
Cc: jreck@google.com
Cc: tkjos@google.com
Cc: stable@vger.kernel.org
Fixes: 441dae8f2f ("tracing: Add support for display of tgid in trace output")
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
syzkaller managed to trigger the following bug through fault injection:
[...]
[ 141.043668] verifier bug. No program starts at insn 3
[ 141.044648] WARNING: CPU: 3 PID: 4072 at kernel/bpf/verifier.c:1613
get_callee_stack_depth kernel/bpf/verifier.c:1612 [inline]
[ 141.044648] WARNING: CPU: 3 PID: 4072 at kernel/bpf/verifier.c:1613
fixup_call_args kernel/bpf/verifier.c:5587 [inline]
[ 141.044648] WARNING: CPU: 3 PID: 4072 at kernel/bpf/verifier.c:1613
bpf_check+0x525e/0x5e60 kernel/bpf/verifier.c:5952
[ 141.047355] CPU: 3 PID: 4072 Comm: a.out Not tainted 4.18.0-rc4+ #51
[ 141.048446] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996),BIOS 1.10.2-1 04/01/2014
[ 141.049877] Call Trace:
[ 141.050324] __dump_stack lib/dump_stack.c:77 [inline]
[ 141.050324] dump_stack+0x1c9/0x2b4 lib/dump_stack.c:113
[ 141.050950] ? dump_stack_print_info.cold.2+0x52/0x52 lib/dump_stack.c:60
[ 141.051837] panic+0x238/0x4e7 kernel/panic.c:184
[ 141.052386] ? add_taint.cold.5+0x16/0x16 kernel/panic.c:385
[ 141.053101] ? __warn.cold.8+0x148/0x1ba kernel/panic.c:537
[ 141.053814] ? __warn.cold.8+0x117/0x1ba kernel/panic.c:530
[ 141.054506] ? get_callee_stack_depth kernel/bpf/verifier.c:1612 [inline]
[ 141.054506] ? fixup_call_args kernel/bpf/verifier.c:5587 [inline]
[ 141.054506] ? bpf_check+0x525e/0x5e60 kernel/bpf/verifier.c:5952
[ 141.055163] __warn.cold.8+0x163/0x1ba kernel/panic.c:538
[ 141.055820] ? get_callee_stack_depth kernel/bpf/verifier.c:1612 [inline]
[ 141.055820] ? fixup_call_args kernel/bpf/verifier.c:5587 [inline]
[ 141.055820] ? bpf_check+0x525e/0x5e60 kernel/bpf/verifier.c:5952
[...]
What happens in jit_subprogs() is that kcalloc() for the subprog func
buffer is failing with NULL where we then bail out. Latter is a plain
return -ENOMEM, and this is definitely not okay since earlier in the
loop we are walking all subprogs and temporarily rewrite insn->off to
remember the subprog id as well as insn->imm to temporarily point the
call to __bpf_call_base + 1 for the initial JIT pass. Thus, bailing
out in such state and handing this over to the interpreter is troublesome
since later/subsequent e.g. find_subprog() lookups are based on wrong
insn->imm.
Therefore, once we hit this point, we need to jump to out_free path
where we undo all changes from earlier loop, so that interpreter can
work on unmodified insn->{off,imm}.
Another point is that should find_subprog() fail in jit_subprogs() due
to a verifier bug, then we also should not simply defer the program to
the interpreter since also here we did partial modifications. Instead
we should just bail out entirely and return an error to the user who is
trying to load the program.
Fixes: 1c2a088a66 ("bpf: x64: add JIT support for multi-function programs")
Reported-by: syzbot+7d427828b2ea6e592804@syzkaller.appspotmail.com
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
When extracting bitfield from a number, btf_int_bits_seq_show() builds
a mask and accesses least significant byte of the number in a way
specific to little-endian. This patch fixes that by checking endianness
of the machine and then shifting left and right the unneeded bits.
Thanks to Martin Lau for the help in navigating potential pitfalls when
dealing with endianess and for the final solution.
Fixes: b00b8daec8 ("bpf: btf: Add pretty print capability for data with BTF type info")
Signed-off-by: Okash Khawaja <osk@fb.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
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Merge tag 'trace-v4.18-rc3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull kprobe fix from Steven Rostedt:
"This fixes a memory leak in the kprobe code"
* tag 'trace-v4.18-rc3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
tracing/kprobe: Release kprobe print_fmt properly
We don't release tk->tp.call.print_fmt when destroying
local uprobe. Also there's missing print_fmt kfree in
create_local_trace_kprobe error path.
Link: http://lkml.kernel.org/r/20180709141906.2390-1-jolsa@kernel.org
Cc: stable@vger.kernel.org
Fixes: e12f03d703 ("perf/core: Implement the 'perf_kprobe' PMU")
Acked-by: Song Liu <songliubraving@fb.com>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Declaring the rseq_cs field as a union between __u64 and two __u32
allows both 32-bit and 64-bit kernels to read the full __u64, and
therefore validate that a 32-bit user-space cleared the upper 32
bits, thus ensuring a consistent behavior between native 32-bit
kernels and 32-bit compat tasks on 64-bit kernels.
Check that the rseq_cs value read is < TASK_SIZE.
The asm/byteorder.h header needs to be included by rseq.h, now
that it is not using linux/types_32_64.h anymore.
Considering that only __32 and __u64 types are declared in linux/rseq.h,
the linux/types.h header should always be included for both kernel and
user-space code: including stdint.h is just for u64 and u32, which are
not used in this header at all.
Use copy_from_user()/clear_user() to interact with a 64-bit field,
because arm32 does not implement 64-bit __get_user, and ppc32 does not
64-bit get_user. Considering that the rseq_cs pointer does not need to
be loaded/stored with single-copy atomicity from the kernel anymore, we
can simply use copy_from_user()/clear_user().
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-api@vger.kernel.org
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: "Paul E . McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Dave Watson <davejwatson@fb.com>
Cc: Paul Turner <pjt@google.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: "H . Peter Anvin" <hpa@zytor.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Chris Lameter <cl@linux.com>
Cc: Ben Maurer <bmaurer@fb.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Joel Fernandes <joelaf@google.com>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Link: https://lkml.kernel.org/r/20180709195155.7654-5-mathieu.desnoyers@efficios.com
Linus Torvalds