Pull scheduler updates from Ingo Molnar:
"The main changes in this cycle were:
- fix affine wakeups (Peter Zijlstra)
- improve CPU onlining (and general bootup) scalability on systems
with ridiculous number (thousands) of CPUs (Peter Zijlstra)
- sched/numa updates (Rik van Riel)
- sched/deadline updates (Byungchul Park)
- sched/cpufreq enhancements and related cleanups (Viresh Kumar)
- sched/debug enhancements (Xie XiuQi)
- various fixes"
* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (27 commits)
sched/debug: Optimize sched_domain sysctl generation
sched/topology: Avoid pointless rebuild
sched/topology, cpuset: Avoid spurious/wrong domain rebuilds
sched/topology: Improve comments
sched/topology: Fix memory leak in __sdt_alloc()
sched/completion: Document that reinit_completion() must be called after complete_all()
sched/autogroup: Fix error reporting printk text in autogroup_create()
sched/fair: Fix wake_affine() for !NUMA_BALANCING
sched/debug: Intruduce task_state_to_char() helper function
sched/debug: Show task state in /proc/sched_debug
sched/debug: Use task_pid_nr_ns in /proc/$pid/sched
sched/core: Remove unnecessary initialization init_idle_bootup_task()
sched/deadline: Change return value of cpudl_find()
sched/deadline: Make find_later_rq() choose a closer CPU in topology
sched/numa: Scale scan period with tasks in group and shared/private
sched/numa: Slow down scan rate if shared faults dominate
sched/pelt: Fix false running accounting
sched: Mark pick_next_task_dl() and build_sched_domain() as static
sched/cpupri: Don't re-initialize 'struct cpupri'
sched/deadline: Don't re-initialize 'struct cpudl'
...
Pull perf updates from Ingo Molnar:
"Kernel side changes:
- Add branch type profiling/tracing support. (Jin Yao)
- Add the PERF_SAMPLE_PHYS_ADDR ABI to allow the tracing/profiling of
physical memory addresses, where the PMU supports it. (Kan Liang)
- Export some PMU capability details in the new
/sys/bus/event_source/devices/cpu/caps/ sysfs directory. (Andi
Kleen)
- Aux data fixes and updates (Will Deacon)
- kprobes fixes and updates (Masami Hiramatsu)
- AMD uncore PMU driver fixes and updates (Janakarajan Natarajan)
On the tooling side, here's a (limited!) list of highlights - there
were many other changes that I could not list, see the shortlog and
git history for details:
UI improvements:
- Implement a visual marker for fused x86 instructions in the
annotate TUI browser, available now in 'perf report', more work
needed to have it available as well in 'perf top' (Jin Yao)
Further explanation from one of Jin's patches:
│ ┌──cmpl $0x0,argp_program_version_hook
81.93 │ ├──je 20
│ │ lock cmpxchg %esi,0x38a9a4(%rip)
│ │↓ jne 29
│ │↓ jmp 43
11.47 │20:└─→cmpxch %esi,0x38a999(%rip)
That means the cmpl+je is a fused instruction pair and they should
be considered together.
- Record the branch type and then show statistics and info about in
callchain entries (Jin Yao)
Example from one of Jin's patches:
# perf record -g -j any,save_type
# perf report --branch-history --stdio --no-children
38.50% div.c:45 [.] main div
|
---main div.c:42 (RET CROSS_2M cycles:2)
compute_flag div.c:28 (cycles:2)
compute_flag div.c:27 (RET CROSS_2M cycles:1)
rand rand.c:28 (cycles:1)
rand rand.c:28 (RET CROSS_2M cycles:1)
__random random.c:298 (cycles:1)
__random random.c:297 (COND_BWD CROSS_2M cycles:1)
__random random.c:295 (cycles:1)
__random random.c:295 (COND_BWD CROSS_2M cycles:1)
__random random.c:295 (cycles:1)
__random random.c:295 (RET CROSS_2M cycles:9)
namespaces support:
- Add initial support for namespaces, using setns to access files in
namespaces, grabbing their build-ids, etc. (Krister Johansen)
perf trace enhancements:
- Beautify pkey_{alloc,free,mprotect} arguments in 'perf trace'
(Arnaldo Carvalho de Melo)
- Add initial 'clone' syscall args beautifier in 'perf trace'
(Arnaldo Carvalho de Melo)
- Ignore 'fd' and 'offset' args for MAP_ANONYMOUS in 'perf trace'
(Arnaldo Carvalho de Melo)
- Beautifiers for the 'cmd' arg of several ioctl types, including:
sound, DRM, KVM, vhost virtio and perf_events. (Arnaldo Carvalho de
Melo)
- Add PERF_SAMPLE_CALLCHAIN and PERF_RECORD_MMAP[2] to 'perf data'
CTF conversion, allowing CTF trace visualization tools to show
callchains and to resolve symbols (Geneviève Bastien)
- Beautify the fcntl syscall, which is an interesting one in the
sense that infrastructure had to be put in place to change the
formatters of some arguments according to the value in a previous
one, i.e. cmd dictates how arg and the syscall return will be
formatted. (Arnaldo Carvalho de Melo
perf stat enhancements:
- Use group read for event groups in 'perf stat', reducing overhead
when groups are defined in the event specification, i.e. when using
{} to enclose a list of events, asking them to be read at the same
time, e.g.: "perf stat -e '{cycles,instructions}'" (Jiri Olsa)
pipe mode improvements:
- Process tracing data in 'perf annotate' pipe mode (David
Carrillo-Cisneros)
- Add header record types to pipe-mode, now this command:
$ perf record -o - -e cycles sleep 1 | perf report --stdio --header
Will show the same as in non-pipe mode, i.e. involving a perf.data
file (David Carrillo-Cisneros)
Vendor specific hardware event support updates/enhancements:
- Update POWER9 vendor events tables (Sukadev Bhattiprolu)
- Add POWER9 PMU events Sukadev (Bhattiprolu)
- Support additional POWER8+ PVR in PMU mapfile (Shriya)
- Add Skylake server uncore JSON vendor events (Andi Kleen)
- Support exporting Intel PT data to sqlite3 with python perf
scripts, this is in addition to the postgresql support that was
already there (Adrian Hunter)"
* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (253 commits)
perf symbols: Fix plt entry calculation for ARM and AARCH64
perf probe: Fix kprobe blacklist checking condition
perf/x86: Fix caps/ for !Intel
perf/core, x86: Add PERF_SAMPLE_PHYS_ADDR
perf/core, pt, bts: Get rid of itrace_started
perf trace beauty: Beautify pkey_{alloc,free,mprotect} arguments
tools headers: Sync cpu features kernel ABI headers with tooling headers
perf tools: Pass full path of FEATURES_DUMP
perf tools: Robustify detection of clang binary
tools lib: Allow external definition of CC, AR and LD
perf tools: Allow external definition of flex and bison binary names
tools build tests: Don't hardcode gcc name
perf report: Group stat values on global event id
perf values: Zero value buffers
perf values: Fix allocation check
perf values: Fix thread index bug
perf report: Add dump_read function
perf record: Set read_format for inherit_stat
perf c2c: Fix remote HITM detection for Skylake
perf tools: Fix static build with newer toolchains
...
Pull RCU updates from Ingo Molnad:
"The main RCU related changes in this cycle were:
- Removal of spin_unlock_wait()
- SRCU updates
- RCU torture-test updates
- RCU Documentation updates
- Extend the sys_membarrier() ABI with the MEMBARRIER_CMD_PRIVATE_EXPEDITED variant
- Miscellaneous RCU fixes
- CPU-hotplug fixes"
* 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (63 commits)
arch: Remove spin_unlock_wait() arch-specific definitions
locking: Remove spin_unlock_wait() generic definitions
drivers/ata: Replace spin_unlock_wait() with lock/unlock pair
ipc: Replace spin_unlock_wait() with lock/unlock pair
exit: Replace spin_unlock_wait() with lock/unlock pair
completion: Replace spin_unlock_wait() with lock/unlock pair
doc: Set down RCU's scheduling-clock-interrupt needs
doc: No longer allowed to use rcu_dereference on non-pointers
doc: Add RCU files to docbook-generation files
doc: Update memory-barriers.txt for read-to-write dependencies
doc: Update RCU documentation
membarrier: Provide expedited private command
rcu: Remove exports from rcu_idle_exit() and rcu_idle_enter()
rcu: Add warning to rcu_idle_enter() for irqs enabled
rcu: Make rcu_idle_enter() rely on callers disabling irqs
rcu: Add assertions verifying blocked-tasks list
rcu/tracing: Set disable_rcu_irq_enter on rcu_eqs_exit()
rcu: Add TPS() protection for _rcu_barrier_trace strings
rcu: Use idle versions of swait to make idle-hack clear
swait: Add idle variants which don't contribute to load average
...
Pull timer fix from Thomas Gleixner:
"A single fix for a thinko in the raw timekeeper update which causes
clock MONOTONIC_RAW to run with erratically increased frequency"
* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
time: Fix ktime_get_raw() incorrect base accumulation
Pull perf fixes from Thomas Gleixner:
- Prevent a potential inconistency in the perf user space access which
might lead to evading sanity checks.
- Prevent perf recording function trace entries twice
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf/ftrace: Fix double traces of perf on ftrace:function
perf/core: Fix potential double-fetch bug
Pull networking fixes from David Miller:
1) Fix handling of pinned BPF map nodes in hash of maps, from Daniel
Borkmann.
2) IPSEC ESP error paths leak memory, from Steffen Klassert.
3) We need an RCU grace period before freeing fib6_node objects, from
Wei Wang.
4) Must check skb_put_padto() return value in HSR driver, from FLorian
Fainelli.
5) Fix oops on PHY probe failure in ftgmac100 driver, from Andrew
Jeffery.
6) Fix infinite loop in UDP queue when using SO_PEEK_OFF, from Eric
Dumazet.
7) Use after free when tcf_chain_destroy() called multiple times, from
Jiri Pirko.
8) Fix KSZ DSA tag layer multiple free of SKBS, from Florian Fainelli.
9) Fix leak of uninitialized memory in sctp_get_sctp_info(),
inet_diag_msg_sctpladdrs_fill() and inet_diag_msg_sctpaddrs_fill().
From Stefano Brivio.
10) L2TP tunnel refcount fixes from Guillaume Nault.
11) Don't leak UDP secpath in udp_set_dev_scratch(), from Yossi
Kauperman.
12) Revert a PHY layer change wrt. handling of PHY_HALTED state in
phy_stop_machine(), it causes regressions for multiple people. From
Florian Fainelli.
13) When packets are sent out of br0 we have to clear the
offload_fwdq_mark value.
14) Several NULL pointer deref fixes in packet schedulers when their
->init() routine fails. From Nikolay Aleksandrov.
15) Aquantium devices cannot checksum offload correctly when the packet
is <= 60 bytes. From Pavel Belous.
16) Fix vnet header access past end of buffer in AF_PACKET, from
Benjamin Poirier.
17) Double free in probe error paths of nfp driver, from Dan Carpenter.
18) QOS capability not checked properly in DCB init paths of mlx5
driver, from Huy Nguyen.
19) Fix conflicts between firmware load failure and health_care timer in
mlx5, also from Huy Nguyen.
20) Fix dangling page pointer when DMA mapping errors occur in mlx5,
from Eran Ben ELisha.
21) ->ndo_setup_tc() in bnxt_en driver doesn't count rings properly,
from Michael Chan.
22) Missing MSIX vector free in bnxt_en, also from Michael Chan.
23) Refcount leak in xfrm layer when using sk_policy, from Lorenzo
Colitti.
24) Fix copy of uninitialized data in qlge driver, from Arnd Bergmann.
25) bpf_setsockopts() erroneously always returns -EINVAL even on
success. Fix from Yuchung Cheng.
26) tipc_rcv() needs to linearize the SKB before parsing the inner
headers, from Parthasarathy Bhuvaragan.
27) Fix deadlock between link status updates and link removal in netvsc
driver, from Stephen Hemminger.
28) Missed locking of page fragment handling in ESP output, from Steffen
Klassert.
29) Fix refcnt leak in ebpf congestion control code, from Sabrina
Dubroca.
30) sxgbe_probe_config_dt() doesn't check devm_kzalloc()'s return value,
from Christophe Jaillet.
31) Fix missing ipv6 rx_dst_cookie update when rx_dst is updated during
early demux, from Paolo Abeni.
32) Several info leaks in xfrm_user layer, from Mathias Krause.
33) Fix out of bounds read in cxgb4 driver, from Stefano Brivio.
34) Properly propagate obsolete state of route upwards in ipv6 so that
upper holders like xfrm can see it. From Xin Long.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (118 commits)
udp: fix secpath leak
bridge: switchdev: Clear forward mark when transmitting packet
mlxsw: spectrum: Forbid linking to devices that have uppers
wl1251: add a missing spin_lock_init()
Revert "net: phy: Correctly process PHY_HALTED in phy_stop_machine()"
net: dsa: bcm_sf2: Fix number of CFP entries for BCM7278
kcm: do not attach PF_KCM sockets to avoid deadlock
sch_tbf: fix two null pointer dereferences on init failure
sch_sfq: fix null pointer dereference on init failure
sch_netem: avoid null pointer deref on init failure
sch_fq_codel: avoid double free on init failure
sch_cbq: fix null pointer dereferences on init failure
sch_hfsc: fix null pointer deref and double free on init failure
sch_hhf: fix null pointer dereference on init failure
sch_multiq: fix double free on init failure
sch_htb: fix crash on init failure
net/mlx5e: Fix CQ moderation mode not set properly
net/mlx5e: Fix inline header size for small packets
net/mlx5: E-Switch, Unload the representors in the correct order
net/mlx5e: Properly resolve TC offloaded ipv6 vxlan tunnel source address
...
Commit 7c051267931a ("mm, fork: make dup_mmap wait for mmap_sem for
write killable") made it possible to kill a forking task while it is
waiting to acquire its ->mmap_sem for write, in dup_mmap().
However, it was overlooked that this introduced an new error path before
the new mm_struct's ->uprobes_state.xol_area has been set to NULL after
being copied from the old mm_struct by the memcpy in dup_mm(). For a
task that has previously hit a uprobe tracepoint, this resulted in the
'struct xol_area' being freed multiple times if the task was killed at
just the right time while forking.
Fix it by setting ->uprobes_state.xol_area to NULL in mm_init() rather
than in uprobe_dup_mmap().
With CONFIG_UPROBE_EVENTS=y, the bug can be reproduced by the same C
program given by commit 2b7e8665b4ff ("fork: fix incorrect fput of
->exe_file causing use-after-free"), provided that a uprobe tracepoint
has been set on the fork_thread() function. For example:
$ gcc reproducer.c -o reproducer -lpthread
$ nm reproducer | grep fork_thread
0000000000400719 t fork_thread
$ echo "p $PWD/reproducer:0x719" > /sys/kernel/debug/tracing/uprobe_events
$ echo 1 > /sys/kernel/debug/tracing/events/uprobes/enable
$ ./reproducer
Here is the use-after-free reported by KASAN:
BUG: KASAN: use-after-free in uprobe_clear_state+0x1c4/0x200
Read of size 8 at addr ffff8800320a8b88 by task reproducer/198
CPU: 1 PID: 198 Comm: reproducer Not tainted 4.13.0-rc7-00015-g36fde05f3fb5 #255
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-20170228_101828-anatol 04/01/2014
Call Trace:
dump_stack+0xdb/0x185
print_address_description+0x7e/0x290
kasan_report+0x23b/0x350
__asan_report_load8_noabort+0x19/0x20
uprobe_clear_state+0x1c4/0x200
mmput+0xd6/0x360
do_exit+0x740/0x1670
do_group_exit+0x13f/0x380
get_signal+0x597/0x17d0
do_signal+0x99/0x1df0
exit_to_usermode_loop+0x166/0x1e0
syscall_return_slowpath+0x258/0x2c0
entry_SYSCALL_64_fastpath+0xbc/0xbe
...
Allocated by task 199:
save_stack_trace+0x1b/0x20
kasan_kmalloc+0xfc/0x180
kmem_cache_alloc_trace+0xf3/0x330
__create_xol_area+0x10f/0x780
uprobe_notify_resume+0x1674/0x2210
exit_to_usermode_loop+0x150/0x1e0
prepare_exit_to_usermode+0x14b/0x180
retint_user+0x8/0x20
Freed by task 199:
save_stack_trace+0x1b/0x20
kasan_slab_free+0xa8/0x1a0
kfree+0xba/0x210
uprobe_clear_state+0x151/0x200
mmput+0xd6/0x360
copy_process.part.8+0x605f/0x65d0
_do_fork+0x1a5/0xbd0
SyS_clone+0x19/0x20
do_syscall_64+0x22f/0x660
return_from_SYSCALL_64+0x0/0x7a
Note: without KASAN, you may instead see a "Bad page state" message, or
simply a general protection fault.
Link: http://lkml.kernel.org/r/20170830033303.17927-1-ebiggers3@gmail.com
Fixes: 7c051267931a ("mm, fork: make dup_mmap wait for mmap_sem for write killable")
Signed-off-by: Eric Biggers <ebiggers@google.com>
Reported-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: <stable@vger.kernel.org> [4.7+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If the worker thread continues getting work, it will hog the cpu and rcu
stall complains. Make it a good citizen. This is triggered in a loop
block device test.
Link: http://lkml.kernel.org/r/5de0a179b3184e1a2183fc503448b0269f24d75b.1503697127.git.shli@fb.com
Signed-off-by: Shaohua Li <shli@fb.com>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tejun Heo <tj@kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull cgroup fix from Tejun Heo:
"A late but obvious fix for cgroup.
I broke the 'cpuset.memory_pressure' file a long time ago (v4.4) by
accidentally deleting its file index, which made it a duplicate of the
'cpuset.memory_migrate' file. Spotted and fixed by Waiman"
* 'for-4.13-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
cpuset: Fix incorrect memory_pressure control file mapping
For understanding how the workload maps to memory channels and hardware
behavior, it's very important to collect address maps with physical
addresses. For example, 3D XPoint access can only be found by filtering
the physical address.
Add a new sample type for physical address.
perf already has a facility to collect data virtual address. This patch
introduces a function to convert the virtual address to physical address.
The function is quite generic and can be extended to any architecture as
long as a virtual address is provided.
- For kernel direct mapping addresses, virt_to_phys is used to convert
the virtual addresses to physical address.
- For user virtual addresses, __get_user_pages_fast is used to walk the
pages tables for user physical address.
- This does not work for vmalloc addresses right now. These are not
resolved, but code to do that could be added.
The new sample type requires collecting the virtual address. The
virtual address will not be output unless SAMPLE_ADDR is applied.
For security, the physical address can only be exposed to root or
privileged user.
Tested-by: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Signed-off-by: Kan Liang <kan.liang@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: 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: mpe@ellerman.id.au
Link: http://lkml.kernel.org/r/1503967969-48278-1-git-send-email-kan.liang@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
I just noticed that hw.itrace_started and hw.config are aliased to the
same location. Now, the PT driver happens to use both, which works out
fine by sheer luck:
- STORE(hw.itrace_start) is ordered before STORE(hw.config), in the
program order, although there are no compiler barriers to ensure that,
- to the perf_log_itrace_start() hw.itrace_start looks set at the same
time as when it is intended to be set because both stores happen in the
same path,
- hw.config is never reset to zero in the PT driver.
Now, the use of hw.config by the PT driver makes more sense (it being a
HW PMU) than messing around with itrace_started, which is an awkward API
to begin with.
This patch replaces hw.itrace_started with an attach_state bit and an
API call for the PMU drivers to use to communicate the condition.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@infradead.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>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: vince@deater.net
Link: http://lkml.kernel.org/r/20170330153956.25994-1-alexander.shishkin@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
When running perf on the ftrace:function tracepoint, there is a bug
which can be reproduced by:
perf record -e ftrace:function -a sleep 20 &
perf record -e ftrace:function ls
perf script
ls 10304 [005] 171.853235: ftrace:function:
perf_output_begin
ls 10304 [005] 171.853237: ftrace:function:
perf_output_begin
ls 10304 [005] 171.853239: ftrace:function:
task_tgid_nr_ns
ls 10304 [005] 171.853240: ftrace:function:
task_tgid_nr_ns
ls 10304 [005] 171.853242: ftrace:function:
__task_pid_nr_ns
ls 10304 [005] 171.853244: ftrace:function:
__task_pid_nr_ns
We can see that all the function traces are doubled.
The problem is caused by the inconsistency of the register
function perf_ftrace_event_register() with the probe function
perf_ftrace_function_call(). The former registers one probe
for every perf_event. And the latter handles all perf_events
on the current cpu. So when two perf_events on the current cpu,
the traces of them will be doubled.
So this patch adds an extra parameter "event" for perf_tp_event,
only send sample data to this event when it's not NULL.
Signed-off-by: Zhou Chengming <zhouchengming1@huawei.com>
Reviewed-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: acme@kernel.org
Cc: alexander.shishkin@linux.intel.com
Cc: huawei.libin@huawei.com
Link: http://lkml.kernel.org/r/1503668977-12526-1-git-send-email-zhouchengming1@huawei.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
While examining the kernel source code, I found a dangerous operation that
could turn into a double-fetch situation (a race condition bug) where the same
userspace memory region are fetched twice into kernel with sanity checks after
the first fetch while missing checks after the second fetch.
1. The first fetch happens in line 9573 get_user(size, &uattr->size).
2. Subsequently the 'size' variable undergoes a few sanity checks and
transformations (line 9577 to 9584).
3. The second fetch happens in line 9610 copy_from_user(attr, uattr, size)
4. Given that 'uattr' can be fully controlled in userspace, an attacker can
race condition to override 'uattr->size' to arbitrary value (say, 0xFFFFFFFF)
after the first fetch but before the second fetch. The changed value will be
copied to 'attr->size'.
5. There is no further checks on 'attr->size' until the end of this function,
and once the function returns, we lose the context to verify that 'attr->size'
conforms to the sanity checks performed in step 2 (line 9577 to 9584).
6. My manual analysis shows that 'attr->size' is not used elsewhere later,
so, there is no working exploit against it right now. However, this could
easily turns to an exploitable one if careless developers start to use
'attr->size' later.
To fix this, override 'attr->size' from the second fetch to the one from the
first fetch, regardless of what is actually copied in.
In this way, it is assured that 'attr->size' is consistent with the checks
performed after the first fetch.
Signed-off-by: Meng Xu <mengxu.gatech@gmail.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: acme@kernel.org
Cc: alexander.shishkin@linux.intel.com
Cc: meng.xu@gatech.edu
Cc: sanidhya@gatech.edu
Cc: taesoo@gatech.edu
Link: http://lkml.kernel.org/r/1503522470-35531-1-git-send-email-meng.xu@gatech.edu
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tim Chen and Kan Liang have been battling a customer load that shows
extremely long page wakeup lists. The cause seems to be constant NUMA
migration of a hot page that is shared across a lot of threads, but the
actual root cause for the exact behavior has not been found.
Tim has a patch that batches the wait list traversal at wakeup time, so
that we at least don't get long uninterruptible cases where we traverse
and wake up thousands of processes and get nasty latency spikes. That
is likely 4.14 material, but we're still discussing the page waitqueue
specific parts of it.
In the meantime, I've tried to look at making the page wait queues less
expensive, and failing miserably. If you have thousands of threads
waiting for the same page, it will be painful. We'll need to try to
figure out the NUMA balancing issue some day, in addition to avoiding
the excessive spinlock hold times.
That said, having tried to rewrite the page wait queues, I can at least
fix up some of the braindamage in the current situation. In particular:
(a) we don't want to continue walking the page wait list if the bit
we're waiting for already got set again (which seems to be one of
the patterns of the bad load). That makes no progress and just
causes pointless cache pollution chasing the pointers.
(b) we don't want to put the non-locking waiters always on the front of
the queue, and the locking waiters always on the back. Not only is
that unfair, it means that we wake up thousands of reading threads
that will just end up being blocked by the writer later anyway.
Also add a comment about the layout of 'struct wait_page_key' - there is
an external user of it in the cachefiles code that means that it has to
match the layout of 'struct wait_bit_key' in the two first members. It
so happens to match, because 'struct page *' and 'unsigned long *' end
up having the same values simply because the page flags are the first
member in struct page.
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Kan Liang <kan.liang@intel.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Christopher Lameter <cl@linux.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull timer fix from Ingo Molnar:
"Fix a timer granularity handling race+bug, which would manifest itself
by spuriously increasing timeouts of some timers (from 1 jiffy to ~500
jiffies in the worst case measured) in certain nohz states"
* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
timers: Fix excessive granularity of new timers after a nohz idle
Pull perf fix from Ingo Molnar:
"A single fix to not allow nonsensical event groups that result in
kernel warnings"
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf/core: Fix group {cpu,task} validation
In comqit fc6eead7c1e2 ("time: Clean up CLOCK_MONOTONIC_RAW time
handling"), the following code got mistakenly added to the update of the
raw timekeeper:
/* Update the monotonic raw base */
seconds = tk->raw_sec;
nsec = (u32)(tk->tkr_raw.xtime_nsec >> tk->tkr_raw.shift);
tk->tkr_raw.base = ns_to_ktime(seconds * NSEC_PER_SEC + nsec);
Which adds the raw_sec value and the shifted down raw xtime_nsec to the
base value.
But the read function adds the shifted down tk->tkr_raw.xtime_nsec value
another time, The result of this is that ktime_get_raw() users (which are
all internal users) see the raw time move faster then it should (the rate
at which can vary with the current size of tkr_raw.xtime_nsec), which has
resulted in at least problems with graphics rendering performance.
The change tried to match the monotonic base update logic:
seconds = (u64)(tk->xtime_sec + tk->wall_to_monotonic.tv_sec);
nsec = (u32) tk->wall_to_monotonic.tv_nsec;
tk->tkr_mono.base = ns_to_ktime(seconds * NSEC_PER_SEC + nsec);
Which adds the wall_to_monotonic.tv_nsec value, but not the
tk->tkr_mono.xtime_nsec value to the base.
To fix this, simplify the tkr_raw.base accumulation to only accumulate the
raw_sec portion, and do not include the tkr_raw.xtime_nsec portion, which
will be added at read time.
Fixes: fc6eead7c1e2 ("time: Clean up CLOCK_MONOTONIC_RAW time handling")
Reported-and-tested-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: John Stultz <john.stultz@linaro.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Kevin Brodsky <kevin.brodsky@arm.com>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Stephen Boyd <stephen.boyd@linaro.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Miroslav Lichvar <mlichvar@redhat.com>
Cc: Daniel Mentz <danielmentz@google.com>
Link: http://lkml.kernel.org/r/1503701824-1645-1-git-send-email-john.stultz@linaro.org
Commit 7c051267931a ("mm, fork: make dup_mmap wait for mmap_sem for
write killable") made it possible to kill a forking task while it is
waiting to acquire its ->mmap_sem for write, in dup_mmap().
However, it was overlooked that this introduced an new error path before
a reference is taken on the mm_struct's ->exe_file. Since the
->exe_file of the new mm_struct was already set to the old ->exe_file by
the memcpy() in dup_mm(), it was possible for the mmput() in the error
path of dup_mm() to drop a reference to ->exe_file which was never
taken.
This caused the struct file to later be freed prematurely.
Fix it by updating mm_init() to NULL out the ->exe_file, in the same
place it clears other things like the list of mmaps.
This bug was found by syzkaller. It can be reproduced using the
following C program:
#define _GNU_SOURCE
#include <pthread.h>
#include <stdlib.h>
#include <sys/mman.h>
#include <sys/syscall.h>
#include <sys/wait.h>
#include <unistd.h>
static void *mmap_thread(void *_arg)
{
for (;;) {
mmap(NULL, 0x1000000, PROT_READ,
MAP_POPULATE|MAP_ANONYMOUS|MAP_PRIVATE, -1, 0);
}
}
static void *fork_thread(void *_arg)
{
usleep(rand() % 10000);
fork();
}
int main(void)
{
fork();
fork();
fork();
for (;;) {
if (fork() == 0) {
pthread_t t;
pthread_create(&t, NULL, mmap_thread, NULL);
pthread_create(&t, NULL, fork_thread, NULL);
usleep(rand() % 10000);
syscall(__NR_exit_group, 0);
}
wait(NULL);
}
}
No special kernel config options are needed. It usually causes a NULL
pointer dereference in __remove_shared_vm_struct() during exit, or in
dup_mmap() (which is usually inlined into copy_process()) during fork.
Both are due to a vm_area_struct's ->vm_file being used after it's
already been freed.
Google Bug Id: 64772007
Link: http://lkml.kernel.org/r/20170823211408.31198-1-ebiggers3@gmail.com
Fixes: 7c051267931a ("mm, fork: make dup_mmap wait for mmap_sem for write killable")
Signed-off-by: Eric Biggers <ebiggers@google.com>
Tested-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: <stable@vger.kernel.org> [v4.7+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently we unconditionally destroy all sysctl bits and regenerate
them after we've rebuild the domains (even if that rebuild is a
no-op).
And since we unconditionally (re)build the sysctl for all possible
CPUs, onlining all CPUs gets us O(n^2) time. Instead change this to
only rebuild the bits for CPUs we've actually installed new domains
on.
Reported-by: Ofer Levi(SW) <oferle@mellanox.com>
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>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Fix partition_sched_domains() to try and preserve the existing machine
wide domain instead of unconditionally destroying it. We do this by
attempting to allocate the new single domain, only when that fails to
we reuse the fallback_doms.
When using fallback_doms we need to first destroy and then recreate
because both the old and new could be backed by it.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Ofer Levi(SW) <oferle@mellanox.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vineet.Gupta1@synopsys.com <Vineet.Gupta1@synopsys.com>
Cc: rusty@rustcorp.com.au <rusty@rustcorp.com.au>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
When disabling cpuset.sched_load_balance we expect to be able to online
CPUs without generating sched_domains. However this is currently
completely broken.
What happens is that we generate the sched_domains and then destroy
them. This is because of the spurious 'default' domain build in
cpuset_update_active_cpus(). That builds a single machine wide domain
and then schedules a work to build the 'real' domains. The work then
finds there are _no_ domains and destroys the lot again.
Furthermore, if there actually were cpusets, building the machine wide
domain is actively wrong, because it would allow tasks to 'escape' their
cpuset. Also I don't think its needed, the scheduler really should
respect the active mask.
Reported-by: Ofer Levi(SW) <oferle@mellanox.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vineet.Gupta1@synopsys.com <Vineet.Gupta1@synopsys.com>
Cc: rusty@rustcorp.com.au <rusty@rustcorp.com.au>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Mike provided a better comment for destroy_sched_domain() ...
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
In an XDP redirect applications using tracepoint xdp:xdp_redirect to
diagnose TX overrun, I noticed perf_swevent_get_recursion_context()
was consuming 2% CPU. This was reduced to 1.85% with this simple
change.
Looking at the annotated asm code, it was clear that the unlikely case
in_nmi() test was chosen (by the compiler) as the most likely
event/branch. This small adjustment makes the compiler (GCC version
7.1.1 20170622 (Red Hat 7.1.1-3)) put in_nmi() as an unlikely branch.
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/150342256382.16595.986861478681783732.stgit@firesoul
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The exiting/dead task has no PIDs and in this case perf_event_pid/tid()
return zero, change them to return -1 to distinguish this case from
idle threads.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho <acme@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20170822155928.GA6892@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The aux_watermark member of struct ring_buffer represents the period (in
terms of bytes) at which wakeup events should be generated when data is
written to the aux buffer in non-snapshot mode. On hardware that cannot
generate an interrupt when the aux_head reaches an arbitrary wakeup index
(such as ARM SPE), the aux_head sampled from handle->head in
perf_aux_output_{skip,end} may in fact be past the wakeup index. This
can lead to wakeup slowly falling behind the head. For example, consider
the case where hardware can only generate an interrupt on a page-boundary
and the aux buffer is initialised as follows:
// Buffer size is 2 * PAGE_SIZE
rb->aux_head = rb->aux_wakeup = 0
rb->aux_watermark = PAGE_SIZE / 2
following the first perf_aux_output_begin call, the handle is
initialised with:
handle->head = 0
handle->size = 2 * PAGE_SIZE
handle->wakeup = PAGE_SIZE / 2
and the hardware will be programmed to generate an interrupt at
PAGE_SIZE.
When the interrupt is raised, the hardware head will be at PAGE_SIZE,
so calling perf_aux_output_end(handle, PAGE_SIZE) puts the ring buffer
into the following state:
rb->aux_head = PAGE_SIZE
rb->aux_wakeup = PAGE_SIZE / 2
rb->aux_watermark = PAGE_SIZE / 2
and then the next call to perf_aux_output_begin will result in:
handle->head = handle->wakeup = PAGE_SIZE
for which the semantics are unclear and, for a smaller aux_watermark
(e.g. PAGE_SIZE / 4), then the wakeup would in fact be behind head at
this point.
This patch fixes the problem by rounding down the aux_head (as sampled
from the handle) to the nearest aux_watermark boundary when updating
rb->aux_wakeup, therefore taking into account any overruns by the
hardware.
Reported-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/1502900297-21839-2-git-send-email-will.deacon@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The aux_head and aux_wakeup members of struct ring_buffer are defined
using the local_t type, despite the fact that they are only accessed via
the perf_aux_output_*() functions, which cannot race with each other for a
given ring buffer.
This patch changes the type of the members to long, so we can avoid
using the local_*() API where it isn't needed.
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/1502900297-21839-1-git-send-email-will.deacon@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Regardless of which events form a group, it does not make sense for the
events to target different tasks and/or CPUs, as this leaves the group
inconsistent and impossible to schedule. The core perf code assumes that
these are consistent across (successfully intialised) groups.
Core perf code only verifies this when moving SW events into a HW
context. Thus, we can violate this requirement for pure SW groups and
pure HW groups, unless the relevant PMU driver happens to perform this
verification itself. These mismatched groups subsequently wreak havoc
elsewhere.
For example, we handle watchpoints as SW events, and reserve watchpoint
HW on a per-CPU basis at pmu::event_init() time to ensure that any event
that is initialised is guaranteed to have a slot at pmu::add() time.
However, the core code only checks the group leader's cpu filter (via
event_filter_match()), and can thus install follower events onto CPUs
violating thier (mismatched) CPU filters, potentially installing them
into a CPU without sufficient reserved slots.
This can be triggered with the below test case, resulting in warnings
from arch backends.
#define _GNU_SOURCE
#include <linux/hw_breakpoint.h>
#include <linux/perf_event.h>
#include <sched.h>
#include <stdio.h>
#include <sys/prctl.h>
#include <sys/syscall.h>
#include <unistd.h>
static int perf_event_open(struct perf_event_attr *attr, pid_t pid, int cpu,
int group_fd, unsigned long flags)
{
return syscall(__NR_perf_event_open, attr, pid, cpu, group_fd, flags);
}
char watched_char;
struct perf_event_attr wp_attr = {
.type = PERF_TYPE_BREAKPOINT,
.bp_type = HW_BREAKPOINT_RW,
.bp_addr = (unsigned long)&watched_char,
.bp_len = 1,
.size = sizeof(wp_attr),
};
int main(int argc, char *argv[])
{
int leader, ret;
cpu_set_t cpus;
/*
* Force use of CPU0 to ensure our CPU0-bound events get scheduled.
*/
CPU_ZERO(&cpus);
CPU_SET(0, &cpus);
ret = sched_setaffinity(0, sizeof(cpus), &cpus);
if (ret) {
printf("Unable to set cpu affinity\n");
return 1;
}
/* open leader event, bound to this task, CPU0 only */
leader = perf_event_open(&wp_attr, 0, 0, -1, 0);
if (leader < 0) {
printf("Couldn't open leader: %d\n", leader);
return 1;
}
/*
* Open a follower event that is bound to the same task, but a
* different CPU. This means that the group should never be possible to
* schedule.
*/
ret = perf_event_open(&wp_attr, 0, 1, leader, 0);
if (ret < 0) {
printf("Couldn't open mismatched follower: %d\n", ret);
return 1;
} else {
printf("Opened leader/follower with mismastched CPUs\n");
}
/*
* Open as many independent events as we can, all bound to the same
* task, CPU0 only.
*/
do {
ret = perf_event_open(&wp_attr, 0, 0, -1, 0);
} while (ret >= 0);
/*
* Force enable/disble all events to trigger the erronoeous
* installation of the follower event.
*/
printf("Opened all events. Toggling..\n");
for (;;) {
prctl(PR_TASK_PERF_EVENTS_DISABLE, 0, 0, 0, 0);
prctl(PR_TASK_PERF_EVENTS_ENABLE, 0, 0, 0, 0);
}
return 0;
}
Fix this by validating this requirement regardless of whether we're
moving events.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Zhou Chengming <zhouchengming1@huawei.com>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/1498142498-15758-1-git-send-email-mark.rutland@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
- Two small memory leaks in error paths.
- A missed return error code on an error path.
- A fix to check the tracing ring buffer CPU when it doesn't
exist (caused by setting maxcpus on the command line that is less
than the actual number of CPUs, and then onlining them manually).
- A fix to have the reset of boot tracers called by lateinit_sync()
instead of just lateinit(). As some of the tracers register via
lateinit(), and if the clear happens before the tracer is registered,
it will never start even though it was told to via the kernel command
line.
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Merge tag 'trace-v4.13-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing fixes from Steven Rostedt:
"Various bug fixes:
- Two small memory leaks in error paths.
- A missed return error code on an error path.
- A fix to check the tracing ring buffer CPU when it doesn't exist
(caused by setting maxcpus on the command line that is less than
the actual number of CPUs, and then onlining them manually).
- A fix to have the reset of boot tracers called by lateinit_sync()
instead of just lateinit(). As some of the tracers register via
lateinit(), and if the clear happens before the tracer is
registered, it will never start even though it was told to via the
kernel command line"
* tag 'trace-v4.13-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
tracing: Fix freeing of filter in create_filter() when set_str is false
tracing: Fix kmemleak in tracing_map_array_free()
ftrace: Check for null ret_stack on profile function graph entry function
ring-buffer: Have ring_buffer_alloc_read_page() return error on offline CPU
tracing: Missing error code in tracer_alloc_buffers()
tracing: Call clear_boot_tracer() at lateinit_sync
The memory_pressure control file was incorrectly set up without
a private value (0, by default). As a result, this control
file was treated like memory_migrate on read. By adding back the
FILE_MEMORY_PRESSURE private value, the correct memory pressure value
will be returned.
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Fixes: 7dbdb199d3bf ("cgroup: replace cftype->mode with CFTYPE_WORLD_WRITABLE")
Cc: stable@vger.kernel.org # v4.4+
Performing the following task with kmemleak enabled:
# cd /sys/kernel/tracing/events/irq/irq_handler_entry/
# echo 'enable_event:kmem:kmalloc:3 if irq >' > trigger
# echo 'enable_event:kmem:kmalloc:3 if irq > 31' > trigger
# echo scan > /sys/kernel/debug/kmemleak
# cat /sys/kernel/debug/kmemleak
unreferenced object 0xffff8800b9290308 (size 32):
comm "bash", pid 1114, jiffies 4294848451 (age 141.139s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<ffffffff81cef5aa>] kmemleak_alloc+0x4a/0xa0
[<ffffffff81357938>] kmem_cache_alloc_trace+0x158/0x290
[<ffffffff81261c09>] create_filter_start.constprop.28+0x99/0x940
[<ffffffff812639c9>] create_filter+0xa9/0x160
[<ffffffff81263bdc>] create_event_filter+0xc/0x10
[<ffffffff812655e5>] set_trigger_filter+0xe5/0x210
[<ffffffff812660c4>] event_enable_trigger_func+0x324/0x490
[<ffffffff812652e2>] event_trigger_write+0x1a2/0x260
[<ffffffff8138cf87>] __vfs_write+0xd7/0x380
[<ffffffff8138f421>] vfs_write+0x101/0x260
[<ffffffff8139187b>] SyS_write+0xab/0x130
[<ffffffff81cfd501>] entry_SYSCALL_64_fastpath+0x1f/0xbe
[<ffffffffffffffff>] 0xffffffffffffffff
The function create_filter() is passed a 'filterp' pointer that gets
allocated, and if "set_str" is true, it is up to the caller to free it, even
on error. The problem is that the pointer is not freed by create_filter()
when set_str is false. This is a bug, and it is not up to the caller to free
the filter on error if it doesn't care about the string.
Link: http://lkml.kernel.org/r/1502705898-27571-2-git-send-email-chuhu@redhat.com
Cc: stable@vger.kernel.org
Fixes: 38b78eb85 ("tracing: Factorize filter creation")
Reported-by: Chunyu Hu <chuhu@redhat.com>
Tested-by: Chunyu Hu <chuhu@redhat.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
There's a small race when function graph shutsdown and the calling of the
registered function graph entry callback. The callback must not reference
the task's ret_stack without first checking that it is not NULL. Note, when
a ret_stack is allocated for a task, it stays allocated until the task exits.
The problem here, is that function_graph is shutdown, and a new task was
created, which doesn't have its ret_stack allocated. But since some of the
functions are still being traced, the callbacks can still be called.
The normal function_graph code handles this, but starting with commit
8861dd303c ("ftrace: Access ret_stack->subtime only in the function
profiler") the profiler code references the ret_stack on function entry, but
doesn't check if it is NULL first.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=196611
Cc: stable@vger.kernel.org
Fixes: 8861dd303c ("ftrace: Access ret_stack->subtime only in the function profiler")
Reported-by: lilydjwg@gmail.com
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
When a timer base is idle, it is forwarded when a new timer is added
to ensure that granularity does not become excessive. When not idle,
the timer tick is expected to increment the base.
However there are several problems:
- If an existing timer is modified, the base is forwarded only after
the index is calculated.
- The base is not forwarded by add_timer_on.
- There is a window after a timer is restarted from a nohz idle, after
it is marked not-idle and before the timer tick on this CPU, where a
timer may be added but the ancient base does not get forwarded.
These result in excessive granularity (a 1 jiffy timeout can blow out
to 100s of jiffies), which cause the rcu lockup detector to trigger,
among other things.
Fix this by keeping track of whether the timer base has been idle
since it was last run or forwarded, and if so then forward it before
adding a new timer.
There is still a case where mod_timer optimises the case of a pending
timer mod with the same expiry time, where the timer can see excessive
granularity relative to the new, shorter interval. A comment is added,
but it's not changed because it is an important fastpath for
networking.
This has been tested and found to fix the RCU softlockup messages.
Testing was also done with tracing to measure requested versus
achieved wakeup latencies for all non-deferrable timers in an idle
system (with no lockup watchdogs running). Wakeup latency relative to
absolute latency is calculated (note this suffers from round-up skew
at low absolute times) and analysed:
max avg std
upstream 506.0 1.20 4.68
patched 2.0 1.08 0.15
The bug was noticed due to the lockup detector Kconfig changes
dropping it out of people's .configs and resulting in larger base
clk skew When the lockup detectors are enabled, no CPU can go idle for
longer than 4 seconds, which limits the granularity errors.
Sub-optimal timer behaviour is observable on a smaller scale in that
case:
max avg std
upstream 9.0 1.05 0.19
patched 2.0 1.04 0.11
Fixes: Fixes: a683f390b93f ("timers: Forward the wheel clock whenever possible")
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Tested-by: David Miller <davem@davemloft.net>
Cc: dzickus@redhat.com
Cc: sfr@canb.auug.org.au
Cc: mpe@ellerman.id.au
Cc: Stephen Boyd <sboyd@codeaurora.org>
Cc: linuxarm@huawei.com
Cc: abdhalee@linux.vnet.ibm.com
Cc: John Stultz <john.stultz@linaro.org>
Cc: akpm@linux-foundation.org
Cc: paulmck@linux.vnet.ibm.com
Cc: torvalds@linux-foundation.org
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/20170822084348.21436-1-npiggin@gmail.com
Currently, iproute2's BPF ELF loader works fine with array of maps
when retrieving the fd from a pinned node and doing a selfcheck
against the provided map attributes from the object file, but we
fail to do the same for hash of maps and thus refuse to get the
map from pinned node.
Reason is that when allocating hash of maps, fd_htab_map_alloc() will
set the value size to sizeof(void *), and any user space map creation
requests are forced to set 4 bytes as value size. Thus, selfcheck
will complain about exposed 8 bytes on 64 bit archs vs. 4 bytes from
object file as value size. Contract is that fdinfo or BPF_MAP_GET_FD_BY_ID
returns the value size used to create the map.
Fix it by handling it the same way as we do for array of maps, which
means that we leave value size at 4 bytes and in the allocation phase
round up value size to 8 bytes. alloc_htab_elem() needs an adjustment
in order to copy rounded up 8 bytes due to bpf_fd_htab_map_update_elem()
calling into htab_map_update_elem() with the pointer of the map
pointer as value. Unlike array of maps where we just xchg(), we're
using the generic htab_map_update_elem() callback also used from helper
calls, which published the key/value already on return, so we need
to ensure to memcpy() the right size.
Fixes: bcc6b1b7ebf8 ("bpf: Add hash of maps support")
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This was reported many times, and this was even mentioned in commit
52ee2dfdd4f5 ("pids: refactor vnr/nr_ns helpers to make them safe") but
somehow nobody bothered to fix the obvious problem: task_tgid_nr_ns() is
not safe because task->group_leader points to nowhere after the exiting
task passes exit_notify(), rcu_read_lock() can not help.
We really need to change __unhash_process() to nullify group_leader,
parent, and real_parent, but this needs some cleanups. Until then we
can turn task_tgid_nr_ns() into another user of __task_pid_nr_ns() and
fix the problem.
Reported-by: Troy Kensinger <tkensinger@google.com>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull perf fixes from Thomas Gleixner:
"Two fixes for the perf subsystem:
- Fix an inconsistency of RDPMC mm struct tagging across exec() which
causes RDPMC to fault.
- Correct the timestamp mechanics across IOC_DISABLE/ENABLE which
causes incorrect timestamps and total time calculations"
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf/core: Fix time on IOC_ENABLE
perf/x86: Fix RDPMC vs. mm_struct tracking
Pull irq fixes from Thomas Gleixner:
"A pile of smallish changes all over the place:
- Add a missing ISB in the GIC V1 driver
- Remove an ACPI version check in the GIC V3 ITS driver
- Add the missing irq_pm_shutdown function for BRCMSTB-L2 to avoid
spurious wakeups
- Remove the artifical limitation of ITS instances to the number of
NUMA nodes which prevents utilizing the ITS hardware correctly
- Prevent a infinite parsing loop in the GIC-V3 ITS/MSI code
- Honour the force affinity argument in the GIC-V3 driver which is
required to make perf work correctly
- Correctly report allocation failures in GIC-V2/V3 to avoid using
half allocated and initialized interrupts.
- Fixup checks against nr_cpu_ids in the generic IPI code"
* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
genirq/ipi: Fixup checks against nr_cpu_ids
genirq: Restore trigger settings in irq_modify_status()
MAINTAINERS: Remove Jason Cooper's irqchip git tree
irqchip/gic-v3-its-platform-msi: Fix msi-parent parsing loop
irqchip/gic-v3-its: Allow GIC ITS number more than MAX_NUMNODES
irqchip: brcmstb-l2: Define an irq_pm_shutdown function
irqchip/gic: Ensure we have an ISB between ack and ->handle_irq
irqchip/gic-v3-its: Remove ACPICA version check for ACPI NUMA
irqchip/gic-v3: Honor forced affinity setting
irqchip/gic-v3: Report failures in gic_irq_domain_alloc
irqchip/gic-v2: Report failures in gic_irq_domain_alloc
irqchip/atmel-aic: Remove root argument from ->fixup() prototype
irqchip/atmel-aic: Fix unbalanced refcount in aic_common_rtc_irq_fixup()
irqchip/atmel-aic: Fix unbalanced of_node_put() in aic_common_irq_fixup()
Pull watchdog fix from Thomas Gleixner:
"A fix for the hardlockup watchdog to prevent false positives with
extreme Turbo-Modes which make the perf/NMI watchdog fire faster than
the hrtimer which is used to verify.
Slightly larger than the minimal fix, which just would increase the
hrtimer frequency, but comes with extra overhead of more watchdog
timer interrupts and thread wakeups for all users.
With this change we restrict the overhead to the extreme Turbo-Mode
systems"
* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
kernel/watchdog: Prevent false positives with turbo modes
Valid CPU ids are [0, nr_cpu_ids-1] inclusive.
Fixes: 3b8e29a82dd1 ("genirq: Implement ipi_send_mask/single()")
Fixes: f9bce791ae2a ("genirq: Add a new function to get IPI reverse mapping")
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/20170819095751.GB27864@avx2
When forcing a signal, SIGNAL_UNKILLABLE is removed to prevent recursive
faults, but this is undesirable when tracing. For example, debugging an
init process (whether global or namespace), hitting a breakpoint and
SIGTRAP will force SIGTRAP and then remove SIGNAL_UNKILLABLE.
Everything continues fine, but then once debugging has finished, the
init process is left killable which is unlikely what the user expects,
resulting in either an accidentally killed init or an init that stops
reaping zombies.
Link: http://lkml.kernel.org/r/20170815112806.10728-1-jamie.iles@oracle.com
Signed-off-by: Jamie Iles <jamie.iles@oracle.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Recursive loops with module loading were previously handled in kmod by
restricting the number of modprobe calls to 50 and if that limit was
breached request_module() would return an error and a user would see the
following on their kernel dmesg:
request_module: runaway loop modprobe binfmt-464c
Starting init:/sbin/init exists but couldn't execute it (error -8)
This issue could happen for instance when a 64-bit kernel boots a 32-bit
userspace on some architectures and has no 32-bit binary format
hanlders. This is visible, for instance, when a CONFIG_MODULES enabled
64-bit MIPS kernel boots a into o32 root filesystem and the binfmt
handler for o32 binaries is not built-in.
After commit 6d7964a722af ("kmod: throttle kmod thread limit") we now
don't have any visible signs of an error and the kernel just waits for
the loop to end somehow.
Although this *particular* recursive loop could also be addressed by
doing a sanity check on search_binary_handler() and disallowing a
modular binfmt to be required for modprobe, a generic solution for any
recursive kernel kmod issues is still needed.
This should catch these loops. We can investigate each loop and address
each one separately as they come in, this however puts a stop gap for
them as before.
Link: http://lkml.kernel.org/r/20170809234635.13443-3-mcgrof@kernel.org
Fixes: 6d7964a722af ("kmod: throttle kmod thread limit")
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Reported-by: Matt Redfearn <matt.redfearn@imgtec.com>
Tested-by: Matt Redfearn <matt.redfearn@imgetc.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Colin Ian King <colin.king@canonical.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Daniel Mentz <danielmentz@google.com>
Cc: David Binderman <dcb314@hotmail.com>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jessica Yu <jeyu@redhat.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Michal Marek <mmarek@suse.com>
Cc: Miroslav Benes <mbenes@suse.cz>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The hardlockup detector on x86 uses a performance counter based on unhalted
CPU cycles and a periodic hrtimer. The hrtimer period is about 2/5 of the
performance counter period, so the hrtimer should fire 2-3 times before the
performance counter NMI fires. The NMI code checks whether the hrtimer
fired since the last invocation. If not, it assumess a hard lockup.
The calculation of those periods is based on the nominal CPU
frequency. Turbo modes increase the CPU clock frequency and therefore
shorten the period of the perf/NMI watchdog. With extreme Turbo-modes (3x
nominal frequency) the perf/NMI period is shorter than the hrtimer period
which leads to false positives.
A simple fix would be to shorten the hrtimer period, but that comes with
the side effect of more frequent hrtimer and softlockup thread wakeups,
which is not desired.
Implement a low pass filter, which checks the perf/NMI period against
kernel time. If the perf/NMI fires before 4/5 of the watchdog period has
elapsed then the event is ignored and postponed to the next perf/NMI.
That solves the problem and avoids the overhead of shorter hrtimer periods
and more frequent softlockup thread wakeups.
Fixes: 58687acba592 ("lockup_detector: Combine nmi_watchdog and softlockup detector")
Reported-and-tested-by: Kan Liang <Kan.liang@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: dzickus@redhat.com
Cc: prarit@redhat.com
Cc: ak@linux.intel.com
Cc: babu.moger@oracle.com
Cc: peterz@infradead.org
Cc: eranian@google.com
Cc: acme@redhat.com
Cc: stable@vger.kernel.org
Cc: atomlin@redhat.com
Cc: akpm@linux-foundation.org
Cc: torvalds@linux-foundation.org
Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1708150931310.1886@nanos
irq_modify_status starts by clearing the trigger settings from
irq_data before applying the new settings, but doesn't restore them,
leaving them to IRQ_TYPE_NONE.
That's pretty confusing to the potential request_irq() that could
follow. Instead, snapshot the settings before clearing them, and restore
them if the irq_modify_status() invocation was not changing the trigger.
Fixes: 1e2a7d78499e ("irqdomain: Don't set type when mapping an IRQ")
Reported-and-tested-by: jeffy <jeffy.chen@rock-chips.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Jon Hunter <jonathanh@nvidia.com>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/20170818095345.12378-1-marc.zyngier@arm.com
