- fix NULL pointer dereference:
kernel/bpf/arraymap.c:41 array_map_alloc() error: potential null dereference 'array'. (kzalloc returns null)
kernel/bpf/arraymap.c:41 array_map_alloc() error: we previously assumed 'array' could be null (see line 40)
- integer overflow check was missing in arraymap
(hashmap checks for overflow via kmalloc_array())
- arraymap can round_up(value_size, 8) to zero. check was missing.
- hashmap was missing zero size check as well, since roundup_pow_of_two() can
truncate into zero
- found a typo in the arraymap comment and unnecessary empty line
Fix all of these issues and make both overflow checks explicit U32 in size.
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
proper types and function helpers are ready. Use them in verifier testsuite.
Remove temporary stubs
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
expose bpf_map_lookup_elem(), bpf_map_update_elem(), bpf_map_delete_elem()
map accessors to eBPF programs
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
fix errno of BPF_MAP_LOOKUP_ELEM command as bpf manpage
described it in commit b4fc1a460f30("Merge branch 'bpf-next'"):
-----
BPF_MAP_LOOKUP_ELEM
int bpf_lookup_elem(int fd, void *key, void *value)
{
union bpf_attr attr = {
.map_fd = fd,
.key = ptr_to_u64(key),
.value = ptr_to_u64(value),
};
return bpf(BPF_MAP_LOOKUP_ELEM, &attr, sizeof(attr));
}
bpf() syscall looks up an element with given key in a map fd.
If element is found it returns zero and stores element's value
into value. If element is not found it returns -1 and sets
errno to ENOENT.
and further down in manpage:
ENOENT For BPF_MAP_LOOKUP_ELEM or BPF_MAP_DELETE_ELEM, indicates that
element with given key was not found.
-----
In general all BPF commands return ENOENT when map element is not found
(including BPF_MAP_GET_NEXT_KEY and BPF_MAP_UPDATE_ELEM with
flags == BPF_MAP_UPDATE_ONLY)
Subsequent patch adds a testsuite to check return values for all of
these combinations.
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
add new map type BPF_MAP_TYPE_ARRAY and its implementation
- optimized for fastest possible lookup()
. in the future verifier/JIT may recognize lookup() with constant key
and optimize it into constant pointer. Can optimize non-constant
key into direct pointer arithmetic as well, since pointers and
value_size are constant for the life of the eBPF program.
In other words array_map_lookup_elem() may be 'inlined' by verifier/JIT
while preserving concurrent access to this map from user space
- two main use cases for array type:
. 'global' eBPF variables: array of 1 element with key=0 and value is a
collection of 'global' variables which programs can use to keep the state
between events
. aggregation of tracing events into fixed set of buckets
- all array elements pre-allocated and zero initialized at init time
- key as an index in array and can only be 4 byte
- map_delete_elem() returns EINVAL, since elements cannot be deleted
- map_update_elem() replaces elements in an non-atomic way
(for atomic updates hashtable type should be used instead)
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
add new map type BPF_MAP_TYPE_HASH and its implementation
- maps are created/destroyed by userspace. Both userspace and eBPF programs
can lookup/update/delete elements from the map
- eBPF programs can be called in_irq(), so use spin_lock_irqsave() mechanism
for concurrent updates
- key/value are opaque range of bytes (aligned to 8 bytes)
- user space provides 3 configuration attributes via BPF syscall:
key_size, value_size, max_entries
- map takes care of allocating/freeing key/value pairs
- map_update_elem() must fail to insert new element when max_entries
limit is reached to make sure that eBPF programs cannot exhaust memory
- map_update_elem() replaces elements in an atomic way
- optimized for speed of lookup() which can be called multiple times from
eBPF program which itself is triggered by high volume of events
. in the future JIT compiler may recognize lookup() call and optimize it
further, since key_size is constant for life of eBPF program
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
the current meaning of BPF_MAP_UPDATE_ELEM syscall command is:
either update existing map element or create a new one.
Initially the plan was to add a new command to handle the case of
'create new element if it didn't exist', but 'flags' style looks
cleaner and overall diff is much smaller (more code reused), so add 'flags'
attribute to BPF_MAP_UPDATE_ELEM command with the following meaning:
#define BPF_ANY 0 /* create new element or update existing */
#define BPF_NOEXIST 1 /* create new element if it didn't exist */
#define BPF_EXIST 2 /* update existing element */
bpf_update_elem(fd, key, value, BPF_NOEXIST) call can fail with EEXIST
if element already exists.
bpf_update_elem(fd, key, value, BPF_EXIST) can fail with ENOENT
if element doesn't exist.
Userspace will call it as:
int bpf_update_elem(int fd, void *key, void *value, __u64 flags)
{
union bpf_attr attr = {
.map_fd = fd,
.key = ptr_to_u64(key),
.value = ptr_to_u64(value),
.flags = flags;
};
return bpf(BPF_MAP_UPDATE_ELEM, &attr, sizeof(attr));
}
First two bits of 'flags' are used to encode style of bpf_update_elem() command.
Bits 2-63 are reserved for future use.
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Conflicts:
drivers/net/ethernet/chelsio/cxgb4vf/sge.c
drivers/net/ethernet/intel/ixgbe/ixgbe_phy.c
sge.c was overlapping two changes, one to use the new
__dev_alloc_page() in net-next, and one to use s->fl_pg_order in net.
ixgbe_phy.c was a set of overlapping whitespace changes.
Signed-off-by: David S. Miller <davem@davemloft.net>
Commit 69361eef90 ("panic: add TAINT_SOFTLOCKUP") added the 'L' flag,
but failed to update the comments for print_tainted(). So, update the
comments.
Signed-off-by: Xie XiuQi <xiexiuqi@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull audit fixes from Paul Moore:
"After he sent the initial audit pull request for 3.18, Eric asked me
to take over the management of the audit tree, hence this pull request
to fix a couple of problems with audit.
As you can see below, the changes are minimal: adding some whitespace
to a string so userspace parses it correctly, and fixing a problem
with audit's usage of fsnotify that was causing audit watch rules to
be lost. Neither of these patches were very controversial on the
mailing lists and they fix real problems, getting them into 3.18 would
be a good thing"
* 'stable-3.18' of git://git.infradead.org/users/pcmoore/audit:
audit: keep inode pinned
audit: AUDIT_FEATURE_CHANGE message format missing delimiting space
Audit rules disappear when an inode they watch is evicted from the cache.
This is likely not what we want.
The guilty commit is "fsnotify: allow marks to not pin inodes in core",
which didn't take into account that audit_tree adds watches with a zero
mask.
Adding any mask should fix this.
Fixes: 90b1e7a578 ("fsnotify: allow marks to not pin inodes in core")
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Cc: stable@vger.kernel.org # 2.6.36+
Signed-off-by: Paul Moore <pmoore@redhat.com>
If the read loop in trace_buffers_splice_read() keeps failing due to
memory allocation failures without reading even a single page then this
function will keep busy looping.
Remove the risk for that by exiting the function if memory allocation
failures are seen.
Link: http://lkml.kernel.org/r/1415309167-2373-2-git-send-email-rabin@rab.in
Signed-off-by: Rabin Vincent <rabin@rab.in>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
On a !PREEMPT kernel, attempting to use trace-cmd results in a soft
lockup:
# trace-cmd record -e raw_syscalls:* -F false
NMI watchdog: BUG: soft lockup - CPU#0 stuck for 22s! [trace-cmd:61]
...
Call Trace:
[<ffffffff8105b580>] ? __wake_up_common+0x90/0x90
[<ffffffff81092e25>] wait_on_pipe+0x35/0x40
[<ffffffff810936e3>] tracing_buffers_splice_read+0x2e3/0x3c0
[<ffffffff81093300>] ? tracing_stats_read+0x2a0/0x2a0
[<ffffffff812d10ab>] ? _raw_spin_unlock+0x2b/0x40
[<ffffffff810dc87b>] ? do_read_fault+0x21b/0x290
[<ffffffff810de56a>] ? handle_mm_fault+0x2ba/0xbd0
[<ffffffff81095c80>] ? trace_event_buffer_lock_reserve+0x40/0x80
[<ffffffff810951e2>] ? trace_buffer_lock_reserve+0x22/0x60
[<ffffffff81095c80>] ? trace_event_buffer_lock_reserve+0x40/0x80
[<ffffffff8112415d>] do_splice_to+0x6d/0x90
[<ffffffff81126971>] SyS_splice+0x7c1/0x800
[<ffffffff812d1edd>] tracesys_phase2+0xd3/0xd8
The problem is this: tracing_buffers_splice_read() calls
ring_buffer_wait() to wait for data in the ring buffers. The buffers
are not empty so ring_buffer_wait() returns immediately. But
tracing_buffers_splice_read() calls ring_buffer_read_page() with full=1,
meaning it only wants to read a full page. When the full page is not
available, tracing_buffers_splice_read() tries to wait again with
ring_buffer_wait(), which again returns immediately, and so on.
Fix this by adding a "full" argument to ring_buffer_wait() which will
make ring_buffer_wait() wait until the writer has left the reader's
page, i.e. until full-page reads will succeed.
Link: http://lkml.kernel.org/r/1415645194-25379-1-git-send-email-rabin@rab.in
Cc: stable@vger.kernel.org # 3.16+
Fixes: b1169cc69b ("tracing: Remove mock up poll wait function")
Signed-off-by: Rabin Vincent <rabin@rab.in>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
- Fix a crash on r8a7791/koelsch during resume from system suspend
caused by a recent cpufreq-dt commit (Geert Uytterhoeven).
- Fix an MFD enumeration problem introduced by a recent commit
adding ACPI support to the MFD subsystem that exposed a weakness
in the ACPI core causing ACPI enumeration to be applied to all
devices associated with one ACPI companion object, although it
should be used for one of them only (Mika Westerberg).
- Fix an ACPI EC regression introduced during the 3.17 cycle
causing some Samsung laptops to misbehave as a result of a
workaround targeted at some Acer machines. That includes
a revert of a commit that went too far and a quirk for the
Acer machines in question. From Lv Zheng.
- Fix a regression in the system suspend error code path introduced
during the 3.15 cycle that causes it to fail to take errors from
asychronous execution of "late" suspend callbacks into account
(Imre Deak).
- Fix a long-standing bug in the hibernation resume error code path
that fails to roll back everything correcty on "freeze" callback
errors and leaves some devices in a "suspended" state causing more
breakage to happen subsequently (Imre Deak).
- Make the cpufreq-dt driver disable operation performance points
that are not supported by the VR connected to the CPU voltage
plane with acceptable tolerance instead of constantly failing
voltage scaling later on (Lucas Stach).
/
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Merge tag 'pm+acpi-3.18-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull ACPI and power management fixes from Rafael Wysocki:
"These are fixes received after my previous pull request plus one that
has been in the works for quite a while, but its previous version
caused problems to happen, so it's been deferred till now.
Fixed are two recent regressions (MFD enumeration and cpufreq-dt),
ACPI EC regression introduced in 3.17, system suspend error code path
regression introduced in 3.15, an older bug related to recovery from
failing resume from hibernation and a cpufreq-dt driver issue related
to operation performance points.
Specifics:
- Fix a crash on r8a7791/koelsch during resume from system suspend
caused by a recent cpufreq-dt commit (Geert Uytterhoeven).
- Fix an MFD enumeration problem introduced by a recent commit adding
ACPI support to the MFD subsystem that exposed a weakness in the
ACPI core causing ACPI enumeration to be applied to all devices
associated with one ACPI companion object, although it should be
used for one of them only (Mika Westerberg).
- Fix an ACPI EC regression introduced during the 3.17 cycle causing
some Samsung laptops to misbehave as a result of a workaround
targeted at some Acer machines. That includes a revert of a commit
that went too far and a quirk for the Acer machines in question.
From Lv Zheng.
- Fix a regression in the system suspend error code path introduced
during the 3.15 cycle that causes it to fail to take errors from
asychronous execution of "late" suspend callbacks into account
(Imre Deak).
- Fix a long-standing bug in the hibernation resume error code path
that fails to roll back everything correcty on "freeze" callback
errors and leaves some devices in a "suspended" state causing more
breakage to happen subsequently (Imre Deak).
- Make the cpufreq-dt driver disable operation performance points
that are not supported by the VR connected to the CPU voltage plane
with acceptable tolerance instead of constantly failing voltage
scaling later on (Lucas Stach)"
* tag 'pm+acpi-3.18-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
ACPI / EC: Fix regression due to conflicting firmware behavior between Samsung and Acer.
Revert "ACPI / EC: Add support to disallow QR_EC to be issued before completing previous QR_EC"
cpufreq: cpufreq-dt: Restore default cpumask_setall(policy->cpus)
PM / Sleep: fix recovery during resuming from hibernation
PM / Sleep: fix async suspend_late/freeze_late error handling
ACPI: Use ACPI companion to match only the first physical device
cpufreq: cpufreq-dt: disable unsupported OPPs
Pull networking fixes from David Miller:
"A bit has accumulated, but it's been a week or so since my last batch
of post-merge-window fixes, so...
1) Missing module license in netfilter reject module, from Pablo.
Lots of people ran into this.
2) Off by one in mac80211 baserate calculation, from Karl Beldan.
3) Fix incorrect return value from ax88179_178a driver's set_mac_addr
op, which broke use of it with bonding. From Ian Morgan.
4) Checking of skb_gso_segment()'s return value was not all
encompassing, it can return an SKB pointer, a pointer error, or
NULL. Fix from Florian Westphal.
This is crummy, and longer term will be fixed to just return error
pointers or a real SKB.
6) Encapsulation offloads not being handled by
skb_gso_transport_seglen(). From Florian Westphal.
7) Fix deadlock in TIPC stack, from Ying Xue.
8) Fix performance regression from using rhashtable for netlink
sockets. The problem was the synchronize_net() invoked for every
socket destroy. From Thomas Graf.
9) Fix bug in eBPF verifier, and remove the strong dependency of BPF
on NET. From Alexei Starovoitov.
10) In qdisc_create(), use the correct interface to allocate
->cpu_bstats, otherwise the u64_stats_sync member isn't
initialized properly. From Sabrina Dubroca.
11) Off by one in ip_set_nfnl_get_byindex(), from Dan Carpenter.
12) nf_tables_newchain() was erroneously expecting error pointers from
netdev_alloc_pcpu_stats(). It only returna a valid pointer or
NULL. From Sabrina Dubroca.
13) Fix use-after-free in _decode_session6(), from Li RongQing.
14) When we set the TX flow hash on a socket, we mistakenly do so
before we've nailed down the final source port. Move the setting
deeper to fix this. From Sathya Perla.
15) NAPI budget accounting in amd-xgbe driver was counting descriptors
instead of full packets, fix from Thomas Lendacky.
16) Fix total_data_buflen calculation in hyperv driver, from Haiyang
Zhang.
17) Fix bcma driver build with OF_ADDRESS disabled, from Hauke
Mehrtens.
18) Fix mis-use of per-cpu memory in TCP md5 code. The problem is
that something that ends up being vmalloc memory can't be passed
to the crypto hash routines via scatter-gather lists. From Eric
Dumazet.
19) Fix regression in promiscuous mode enabling in cdc-ether, from
Olivier Blin.
20) Bucket eviction and frag entry killing can race with eachother,
causing an unlink of the object from the wrong list. Fix from
Nikolay Aleksandrov.
21) Missing initialization of spinlock in cxgb4 driver, from Anish
Bhatt.
22) Do not cache ipv4 routing failures, otherwise if the sysctl for
forwarding is subsequently enabled this won't be seen. From
Nicolas Cavallari"
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (131 commits)
drivers: net: cpsw: Support ALLMULTI and fix IFF_PROMISC in switch mode
drivers: net: cpsw: Fix broken loop condition in switch mode
net: ethtool: Return -EOPNOTSUPP if user space tries to read EEPROM with lengh 0
stmmac: pci: set default of the filter bins
net: smc91x: Fix gpios for device tree based booting
mpls: Allow mpls_gso to be built as module
mpls: Fix mpls_gso handler.
r8152: stop submitting intr for -EPROTO
netfilter: nft_reject_bridge: restrict reject to prerouting and input
netfilter: nft_reject_bridge: don't use IP stack to reject traffic
netfilter: nf_reject_ipv6: split nf_send_reset6() in smaller functions
netfilter: nf_reject_ipv4: split nf_send_reset() in smaller functions
netfilter: nf_tables_bridge: update hook_mask to allow {pre,post}routing
drivers/net: macvtap and tun depend on INET
drivers/net, ipv6: Select IPv6 fragment idents for virtio UFO packets
drivers/net: Disable UFO through virtio
net: skb_fclone_busy() needs to detect orphaned skb
gre: Use inner mac length when computing tunnel length
mlx4: Avoid leaking steering rules on flow creation error flow
net/mlx4_en: Don't attempt to TX offload the outer UDP checksum for VXLAN
...
Pull scheduler fixes from Ingo Molnar:
"Various scheduler fixes all over the place: three SCHED_DL fixes,
three sched/numa fixes, two generic race fixes and a comment fix"
* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched/dl: Fix preemption checks
sched: Update comments for CLONE_NEWNS
sched: stop the unbound recursion in preempt_schedule_context()
sched/fair: Fix division by zero sysctl_numa_balancing_scan_size
sched/fair: Care divide error in update_task_scan_period()
sched/numa: Fix unsafe get_task_struct() in task_numa_assign()
sched/deadline: Fix races between rt_mutex_setprio() and dl_task_timer()
sched/deadline: Don't replenish from a !SCHED_DEADLINE entity
sched: Fix race between task_group and sched_task_group
Pull perf fixes from Ingo Molnar:
"Mostly tooling fixes, plus on the kernel side:
- a revert for a newly introduced PMU driver which isn't complete yet
and where we ran out of time with fixes (to be tried again in
v3.19) - this makes up for a large chunk of the diffstat.
- compilation warning fixes
- a printk message fix
- event_idx usage fixes/cleanups"
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf probe: Trivial typo fix for --demangle
perf tools: Fix report -F dso_from for data without branch info
perf tools: Fix report -F dso_to for data without branch info
perf tools: Fix report -F symbol_from for data without branch info
perf tools: Fix report -F symbol_to for data without branch info
perf tools: Fix report -F mispredict for data without branch info
perf tools: Fix report -F in_tx for data without branch info
perf tools: Fix report -F abort for data without branch info
perf tools: Make CPUINFO_PROC an array to support different kernel versions
perf callchain: Use global caching provided by libunwind
perf/x86/intel: Revert incomplete and undocumented Broadwell client support
perf/x86: Fix compile warnings for intel_uncore
perf: Fix typos in sample code in the perf_event.h header
perf: Fix and clean up initialization of pmu::event_idx
perf: Fix bogus kernel printk
perf diff: Add missing hists__init() call at tool start
Pull futex fixes from Ingo Molnar:
"This contains two futex fixes: one fixes a race condition, the other
clarifies shared/private futex comments"
* 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
futex: Fix a race condition between REQUEUE_PI and task death
futex: Mention key referencing differences between shared and private futexes
Pull core fixes from Ingo Molnar:
"The tree contains two RCU fixes and a compiler quirk comment fix"
* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
rcu: Make rcu_barrier() understand about missing rcuo kthreads
compiler/gcc4+: Remove inaccurate comment about 'asm goto' miscompiles
rcu: More on deadlock between CPU hotplug and expedited grace periods
Pull timer fixes from Thomas Gleixner:
"As you requested in the rc2 release mail the timer department serves
you a few real bug fixes:
- Fix the probe logic of the architected arm/arm64 timer
- Plug a stack info leak in posix-timers
- Prevent a shift out of bounds issue in the clockevents core"
* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
ARM/ARM64: arch-timer: fix arch_timer_probed logic
clockevents: Prevent shift out of bounds
posix-timers: Fix stack info leak in timer_create()
tracing system does not support that and without checks, it can cause
an oops to be reported.
Rabin Vincent added checks in the return code on syscall events to make
sure that the system call number is within the range that tracing
knows about, and if not, simply ignores the system call.
The system call tracing infrastructure needs to be rewritten to handle these
cases better, but for now, to keep from oopsing, this patch will do.
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Merge tag 'trace-fixes-v3.18-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing fix from Steven Rostedt:
"ARM has system calls outside the NR_syscalls range, and the generic
tracing system does not support that and without checks, it can cause
an oops to be reported.
Rabin Vincent added checks in the return code on syscall events to
make sure that the system call number is within the range that tracing
knows about, and if not, simply ignores the system call.
The system call tracing infrastructure needs to be rewritten to handle
these cases better, but for now, to keep from oopsing, this patch will
do"
* tag 'trace-fixes-v3.18-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
tracing/syscalls: Ignore numbers outside NR_syscalls' range
ARM has some private syscalls (for example, set_tls(2)) which lie
outside the range of NR_syscalls. If any of these are called while
syscall tracing is being performed, out-of-bounds array access will
occur in the ftrace and perf sys_{enter,exit} handlers.
# trace-cmd record -e raw_syscalls:* true && trace-cmd report
...
true-653 [000] 384.675777: sys_enter: NR 192 (0, 1000, 3, 4000022, ffffffff, 0)
true-653 [000] 384.675812: sys_exit: NR 192 = 1995915264
true-653 [000] 384.675971: sys_enter: NR 983045 (76f74480, 76f74000, 76f74b28, 76f74480, 76f76f74, 1)
true-653 [000] 384.675988: sys_exit: NR 983045 = 0
...
# trace-cmd record -e syscalls:* true
[ 17.289329] Unable to handle kernel paging request at virtual address aaaaaace
[ 17.289590] pgd = 9e71c000
[ 17.289696] [aaaaaace] *pgd=00000000
[ 17.289985] Internal error: Oops: 5 [#1] PREEMPT SMP ARM
[ 17.290169] Modules linked in:
[ 17.290391] CPU: 0 PID: 704 Comm: true Not tainted 3.18.0-rc2+ #21
[ 17.290585] task: 9f4dab00 ti: 9e710000 task.ti: 9e710000
[ 17.290747] PC is at ftrace_syscall_enter+0x48/0x1f8
[ 17.290866] LR is at syscall_trace_enter+0x124/0x184
Fix this by ignoring out-of-NR_syscalls-bounds syscall numbers.
Commit cd0980fc8a "tracing: Check invalid syscall nr while tracing syscalls"
added the check for less than zero, but it should have also checked
for greater than NR_syscalls.
Link: http://lkml.kernel.org/p/1414620418-29472-1-git-send-email-rabin@rab.in
Fixes: cd0980fc8a "tracing: Check invalid syscall nr while tracing syscalls"
Cc: stable@vger.kernel.org # 2.6.33+
Signed-off-by: Rabin Vincent <rabin@rab.in>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Add a space between subj= and feature= fields to make them parsable.
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Paul Moore <pmoore@redhat.com>
verifier keeps track of register state spilled to stack.
registers are 8-byte wide and always aligned, so instead of tracking them
in every byte-sized stack slot, use MAX_BPF_STACK / 8 array to track
spilled register state.
Though verifier runs in user context and its state freed immediately
after verification, it makes sense to reduce its memory usage.
This optimization reduces sizeof(struct verifier_state)
from 12464 to 1712 on 64-bit and from 6232 to 1112 on 32-bit.
Note, this patch doesn't change existing limits, which are there to bound
time and memory during verification: 4k total number of insns in a program,
1k number of jumps (states to visit) and 32k number of processed insn
(since an insn may be visited multiple times). Theoretical worst case memory
during verification is 1712 * 1k = 17Mbyte. Out-of-memory situation triggers
cleanup and rejects the program.
Suggested-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Pull two RCU fixes from Paul E. McKenney:
" - Complete the work of commit dd56af42bd (rcu: Eliminate deadlock
between CPU hotplug and expedited grace periods), which was
intended to allow synchronize_sched_expedited() to be safely
used when holding locks acquired by CPU-hotplug notifiers.
This commit makes the put_online_cpus() avoid the deadlock
instead of just handling the get_online_cpus().
- Complete the work of commit 35ce7f29a4 (rcu: Create rcuo
kthreads only for onlined CPUs), which was intended to allow
RCU to avoid allocating unneeded kthreads on systems where the
firmware says that there are more CPUs than are really present.
This commit makes rcu_barrier() aware of the mismatch, so that
it doesn't hang waiting for non-existent CPUs. "
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Found this in the message log on a s390 system:
BUG kmalloc-192 (Not tainted): Poison overwritten
Disabling lock debugging due to kernel taint
INFO: 0x00000000684761f4-0x00000000684761f7. First byte 0xff instead of 0x6b
INFO: Allocated in call_usermodehelper_setup+0x70/0x128 age=71 cpu=2 pid=648
__slab_alloc.isra.47.constprop.56+0x5f6/0x658
kmem_cache_alloc_trace+0x106/0x408
call_usermodehelper_setup+0x70/0x128
call_usermodehelper+0x62/0x90
cgroup_release_agent+0x178/0x1c0
process_one_work+0x36e/0x680
worker_thread+0x2f0/0x4f8
kthread+0x10a/0x120
kernel_thread_starter+0x6/0xc
kernel_thread_starter+0x0/0xc
INFO: Freed in call_usermodehelper_exec+0x110/0x1b8 age=71 cpu=2 pid=648
__slab_free+0x94/0x560
kfree+0x364/0x3e0
call_usermodehelper_exec+0x110/0x1b8
cgroup_release_agent+0x178/0x1c0
process_one_work+0x36e/0x680
worker_thread+0x2f0/0x4f8
kthread+0x10a/0x120
kernel_thread_starter+0x6/0xc
kernel_thread_starter+0x0/0xc
There is a use-after-free bug on the subprocess_info structure allocated
by the user mode helper. In case do_execve() returns with an error
____call_usermodehelper() stores the error code to sub_info->retval, but
sub_info can already have been freed.
Regarding UMH_NO_WAIT, the sub_info structure can be freed by
__call_usermodehelper() before the worker thread returns from
do_execve(), allowing memory corruption when do_execve() failed after
exec_mmap() is called.
Regarding UMH_WAIT_EXEC, the call to umh_complete() allows
call_usermodehelper_exec() to continue which then frees sub_info.
To fix this race the code needs to make sure that the call to
call_usermodehelper_freeinfo() is always done after the last store to
sub_info->retval.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Following up the arm testing of gcov, turns out gcov on ARM64 works fine
as well. Only change needed is adding ARM64 to Kconfig depends.
Tested with qemu and mach-virt
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
Acked-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
the accounting of the ftrace_ops trampoline logic. One was that the
old hash was not updated before calling the modify code for an ftrace_ops.
The second bug was what let the first bug go unnoticed, as the update would
check the current hash for all ftrace_ops (where it should only check the
old hash for modified ones). This let things work when only one ftrace_ops
was registered to a function, but could break if more than one was
registered depending on the order of the look ups.
The worse thing that can happen if this bug triggers is that the ftrace
self checks would find an anomaly and shut itself down.
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Merge tag 'trace-fixes-v3.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull ftrace trampoline accounting fixes from Steven Rostedt:
"Adding the new code for 3.19, I discovered a couple of minor bugs with
the accounting of the ftrace_ops trampoline logic.
One was that the old hash was not updated before calling the modify
code for an ftrace_ops. The second bug was what let the first bug go
unnoticed, as the update would check the current hash for all
ftrace_ops (where it should only check the old hash for modified
ones). This let things work when only one ftrace_ops was registered
to a function, but could break if more than one was registered
depending on the order of the look ups.
The worse thing that can happen if this bug triggers is that the
ftrace self checks would find an anomaly and shut itself down"
* tag 'trace-fixes-v3.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
ftrace: Fix checking of trampoline ftrace_ops in finding trampoline
ftrace: Set ops->old_hash on modifying what an ops hooks to
Commit 35ce7f29a4 (rcu: Create rcuo kthreads only for onlined CPUs)
avoids creating rcuo kthreads for CPUs that never come online. This
fixes a bug in many instances of firmware: Instead of lying about their
age, these systems instead lie about the number of CPUs that they have.
Before commit 35ce7f29a4, this could result in huge numbers of useless
rcuo kthreads being created.
It appears that experience indicates that I should have told the
people suffering from this problem to fix their broken firmware, but
I instead produced what turned out to be a partial fix. The missing
piece supplied by this commit makes sure that rcu_barrier() knows not to
post callbacks for no-CBs CPUs that have not yet come online, because
otherwise rcu_barrier() will hang on systems having firmware that lies
about the number of CPUs.
It is tempting to simply have rcu_barrier() refuse to post a callback on
any no-CBs CPU that does not have an rcuo kthread. This unfortunately
does not work because rcu_barrier() is required to wait for all pending
callbacks. It is therefore required to wait even for those callbacks
that cannot possibly be invoked. Even if doing so hangs the system.
Given that posting a callback to a no-CBs CPU that does not yet have an
rcuo kthread can hang rcu_barrier(), It is tempting to report an error
in this case. Unfortunately, this will result in false positives at
boot time, when it is perfectly legal to post callbacks to the boot CPU
before the scheduler has started, in other words, before it is legal
to invoke rcu_barrier().
So this commit instead has rcu_barrier() avoid posting callbacks to
CPUs having neither rcuo kthread nor pending callbacks, and has it
complain bitterly if it finds CPUs having no rcuo kthread but some
pending callbacks. And when rcu_barrier() does find CPUs having no rcuo
kthread but pending callbacks, as noted earlier, it has no choice but
to hang indefinitely.
Reported-by: Yanko Kaneti <yaneti@declera.com>
Reported-by: Jay Vosburgh <jay.vosburgh@canonical.com>
Reported-by: Meelis Roos <mroos@linux.ee>
Reported-by: Eric B Munson <emunson@akamai.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Tested-by: Eric B Munson <emunson@akamai.com>
Tested-by: Jay Vosburgh <jay.vosburgh@canonical.com>
Tested-by: Yanko Kaneti <yaneti@declera.com>
Tested-by: Kevin Fenzi <kevin@scrye.com>
Tested-by: Meelis Roos <mroos@linux.ee>
Andy reported that the current state of event_idx is rather confused.
So remove all but the x86_pmu implementation and change the default to
return 0 (the safe option).
Reported-by: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: Cody P Schafer <cody@linux.vnet.ibm.com>
Cc: Cody P Schafer <dev@codyps.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Cc: Himangi Saraogi <himangi774@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Gortmaker <paul.gortmaker@windriver.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: sukadev@linux.vnet.ibm.com <sukadev@linux.vnet.ibm.com>
Cc: Thomas Huth <thuth@linux.vnet.ibm.com>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: linux390@de.ibm.com
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-s390@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
1) switched_to_dl() check is wrong. We reschedule only
if rq->curr is deadline task, and we do not reschedule
if it's a lower priority task. But we must always
preempt a task of other classes.
2) dl_task_timer():
Policy does not change in case of priority inheritance.
rt_mutex_setprio() changes prio, while policy remains old.
So we lose some balancing logic in dl_task_timer() and
switched_to_dl() when we check policy instead of priority. Boosted
task may be rq->curr.
(I didn't change switched_from_dl() because no check is necessary
there at all).
I've looked at this place(switched_to_dl) several times and even fixed
this function, but found just now... I suppose some performance tests
may work better after this.
Signed-off-by: Kirill Tkhai <ktkhai@parallels.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Juri Lelli <juri.lelli@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/1413909356.19914.128.camel@tkhai
Signed-off-by: Ingo Molnar <mingo@kernel.org>
preempt_schedule_context() does preempt_enable_notrace() at the end
and this can call the same function again; exception_exit() is heavy
and it is quite possible that need-resched is true again.
1. Change this code to dec preempt_count() and check need_resched()
by hand.
2. As Linus suggested, we can use the PREEMPT_ACTIVE bit and avoid
the enable/disable dance around __schedule(). But in this case
we need to move into sched/core.c.
3. Cosmetic, but x86 forgets to declare this function. This doesn't
really matter because it is only called by asm helpers, still it
make sense to add the declaration into asm/preempt.h to match
preempt_schedule().
Reported-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Graf <agraf@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Peter Anvin <hpa@zytor.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Chuck Ebbert <cebbert.lkml@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Link: http://lkml.kernel.org/r/20141005202322.GB27962@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
While offling node by hot removing memory, the following divide error
occurs:
divide error: 0000 [#1] SMP
[...]
Call Trace:
[...] handle_mm_fault
[...] ? try_to_wake_up
[...] ? wake_up_state
[...] __do_page_fault
[...] ? do_futex
[...] ? put_prev_entity
[...] ? __switch_to
[...] do_page_fault
[...] page_fault
[...]
RIP [<ffffffff810a7081>] task_numa_fault
RSP <ffff88084eb2bcb0>
The issue occurs as follows:
1. When page fault occurs and page is allocated from node 1,
task_struct->numa_faults_buffer_memory[] of node 1 is
incremented and p->numa_faults_locality[] is also incremented
as follows:
o numa_faults_buffer_memory[] o numa_faults_locality[]
NR_NUMA_HINT_FAULT_TYPES
| 0 | 1 |
---------------------------------- ----------------------
node 0 | 0 | 0 | remote | 0 |
node 1 | 0 | 1 | locale | 1 |
---------------------------------- ----------------------
2. node 1 is offlined by hot removing memory.
3. When page fault occurs, fault_types[] is calculated by using
p->numa_faults_buffer_memory[] of all online nodes in
task_numa_placement(). But node 1 was offline by step 2. So
the fault_types[] is calculated by using only
p->numa_faults_buffer_memory[] of node 0. So both of fault_types[]
are set to 0.
4. The values(0) of fault_types[] pass to update_task_scan_period().
5. numa_faults_locality[1] is set to 1. So the following division is
calculated.
static void update_task_scan_period(struct task_struct *p,
unsigned long shared, unsigned long private){
...
ratio = DIV_ROUND_UP(private * NUMA_PERIOD_SLOTS, (private + shared));
}
6. But both of private and shared are set to 0. So divide error
occurs here.
The divide error is rare case because the trigger is node offline.
This patch always increments denominator for avoiding divide error.
Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/54475703.8000505@jp.fujitsu.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Unlocked access to dst_rq->curr in task_numa_compare() is racy.
If curr task is exiting this may be a reason of use-after-free:
task_numa_compare() do_exit()
... current->flags |= PF_EXITING;
... release_task()
... ~~delayed_put_task_struct()~~
... schedule()
rcu_read_lock() ...
cur = ACCESS_ONCE(dst_rq->curr) ...
... rq->curr = next;
... context_switch()
... finish_task_switch()
... put_task_struct()
... __put_task_struct()
... free_task_struct()
task_numa_assign() ...
get_task_struct() ...
As noted by Oleg:
<<The lockless get_task_struct(tsk) is only safe if tsk == current
and didn't pass exit_notify(), or if this tsk was found on a rcu
protected list (say, for_each_process() or find_task_by_vpid()).
IOW, it is only safe if release_task() was not called before we
take rcu_read_lock(), in this case we can rely on the fact that
delayed_put_pid() can not drop the (potentially) last reference
until rcu_read_unlock().
And as Kirill pointed out task_numa_compare()->task_numa_assign()
path does get_task_struct(dst_rq->curr) and this is not safe. The
task_struct itself can't go away, but rcu_read_lock() can't save
us from the final put_task_struct() in finish_task_switch(); this
reference goes away without rcu gp>>
The patch provides simple check of PF_EXITING flag. If it's not set,
this guarantees that call_rcu() of delayed_put_task_struct() callback
hasn't happened yet, so we can safely do get_task_struct() in
task_numa_assign().
Locked dst_rq->lock protects from concurrency with the last schedule().
Reusing or unmapping of cur's memory may happen without it.
Suggested-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Kirill Tkhai <ktkhai@parallels.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/1413962231.19914.130.camel@tkhai
Signed-off-by: Ingo Molnar <mingo@kernel.org>
dl_task_timer() is racy against several paths. Daniel noticed that
the replenishment timer may experience a race condition against an
enqueue_dl_entity() called from rt_mutex_setprio(). With his own
words:
rt_mutex_setprio() resets p->dl.dl_throttled. So the pattern is:
start_dl_timer() throttled = 1, rt_mutex_setprio() throlled = 0,
sched_switch() -> enqueue_task(), dl_task_timer-> enqueue_task()
throttled is 0
=> BUG_ON(on_dl_rq(dl_se)) fires as the scheduling entity is already
enqueued on the -deadline runqueue.
As we do for the other races, we just bail out in the replenishment
timer code.
Reported-by: Daniel Wagner <daniel.wagner@bmw-carit.de>
Tested-by: Daniel Wagner <daniel.wagner@bmw-carit.de>
Signed-off-by: Juri Lelli <juri.lelli@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: vincent@legout.info
Cc: Dario Faggioli <raistlin@linux.it>
Cc: Michael Trimarchi <michael@amarulasolutions.com>
Cc: Fabio Checconi <fchecconi@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/1414142198-18552-5-git-send-email-juri.lelli@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
In the deboost path, right after the dl_boosted flag has been
reset, we can currently end up replenishing using -deadline
parameters of a !SCHED_DEADLINE entity. This of course causes
a bug, as those parameters are empty.
In the case depicted above it is safe to simply bail out, as
the deboosted task is going to be back to its original scheduling
class anyway.
Reported-by: Daniel Wagner <daniel.wagner@bmw-carit.de>
Tested-by: Daniel Wagner <daniel.wagner@bmw-carit.de>
Signed-off-by: Juri Lelli <juri.lelli@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: vincent@legout.info
Cc: Dario Faggioli <raistlin@linux.it>
Cc: Michael Trimarchi <michael@amarulasolutions.com>
Cc: Fabio Checconi <fchecconi@gmail.com>
Link: http://lkml.kernel.org/r/1414142198-18552-4-git-send-email-juri.lelli@arm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
The race may happen when somebody is changing task_group of a forking task.
Child's cgroup is the same as parent's after dup_task_struct() (there just
memory copying). Also, cfs_rq and rt_rq are the same as parent's.
But if parent changes its task_group before it's called cgroup_post_fork(),
we do not reflect this situation on child. Child's cfs_rq and rt_rq remain
the same, while child's task_group changes in cgroup_post_fork().
To fix this we introduce fork() method, which calls sched_move_task() directly.
This function changes sched_task_group on appropriate (also its logic has
no problem with freshly created tasks, so we shouldn't introduce something
special; we are able just to use it).
Possibly, this decides the Burke Libbey's problem: https://lkml.org/lkml/2014/10/24/456
Signed-off-by: Kirill Tkhai <ktkhai@parallels.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/1414405105.19914.169.camel@tkhai
Signed-off-by: Ingo Molnar <mingo@kernel.org>
introduce two configs:
- hidden CONFIG_BPF to select eBPF interpreter that classic socket filters
depend on
- visible CONFIG_BPF_SYSCALL (default off) that tracing and sockets can use
that solves several problems:
- tracing and others that wish to use eBPF don't need to depend on NET.
They can use BPF_SYSCALL to allow loading from userspace or select BPF
to use it directly from kernel in NET-less configs.
- in 3.18 programs cannot be attached to events yet, so don't force it on
- when the rest of eBPF infra is there in 3.19+, it's still useful to
switch it off to minimize kernel size
bloat-o-meter on x64 shows:
add/remove: 0/60 grow/shrink: 0/2 up/down: 0/-15601 (-15601)
tested with many different config combinations. Hopefully didn't miss anything.
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Acked-by: Daniel Borkmann <dborkman@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
If a device's dev_pm_ops::freeze callback fails during the QUIESCE
phase, we don't rollback things correctly calling the thaw and complete
callbacks. This could leave some devices in a suspended state in case of
an error during resuming from hibernation.
Signed-off-by: Imre Deak <imre.deak@intel.com>
Cc: All applicable <stable@vger.kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
free_pi_state and exit_pi_state_list both clean up futex_pi_state's.
exit_pi_state_list takes the hb lock first, and most callers of
free_pi_state do too. requeue_pi doesn't, which means free_pi_state
can free the pi_state out from under exit_pi_state_list. For example:
task A | task B
exit_pi_state_list |
pi_state = |
curr->pi_state_list->next |
| futex_requeue(requeue_pi=1)
| // pi_state is the same as
| // the one in task A
| free_pi_state(pi_state)
| list_del_init(&pi_state->list)
| kfree(pi_state)
list_del_init(&pi_state->list) |
Move the free_pi_state calls in requeue_pi to before it drops the hb
locks which it's already holding.
[ tglx: Removed a pointless free_pi_state() call and the hb->lock held
debugging. The latter comes via a seperate patch ]
Signed-off-by: Brian Silverman <bsilver16384@gmail.com>
Cc: austin.linux@gmail.com
Cc: darren@dvhart.com
Cc: peterz@infradead.org
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/1414282837-23092-1-git-send-email-bsilver16384@gmail.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Update our documentation as of fix 76835b0ebf (futex: Ensure
get_futex_key_refs() always implies a barrier). Explicitly
state that we don't do key referencing for private futexes.
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Cc: Matteo Franchin <Matteo.Franchin@arm.com>
Cc: Davidlohr Bueso <davidlohr@hp.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Darren Hart <dvhart@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Link: http://lkml.kernel.org/r/1414121220.817.0.camel@linux-t7sj.site
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Andrey reported that on a kernel with UBSan enabled he found:
UBSan: Undefined behaviour in ../kernel/time/clockevents.c:75:34
I guess it should be 1ULL here instead of 1U:
(!ismax || evt->mult <= (1U << evt->shift)))
That's indeed the correct solution because shift might be 32.
Reported-by: Andrey Ryabinin <a.ryabinin@samsung.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
If userland creates a timer without specifying a sigevent info, we'll
create one ourself, using a stack local variable. Particularly will we
use the timer ID as sival_int. But as sigev_value is a union containing
a pointer and an int, that assignment will only partially initialize
sigev_value on systems where the size of a pointer is bigger than the
size of an int. On such systems we'll copy the uninitialized stack bytes
from the timer_create() call to userland when the timer actually fires
and we're going to deliver the signal.
Initialize sigev_value with 0 to plug the stack info leak.
Found in the PaX patch, written by the PaX Team.
Fixes: 5a9fa73072 ("posix-timers: kill ->it_sigev_signo and...")
Signed-off-by: Mathias Krause <minipli@googlemail.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Brad Spengler <spender@grsecurity.net>
Cc: PaX Team <pageexec@freemail.hu>
Cc: <stable@vger.kernel.org> # v2.6.28+
Link: http://lkml.kernel.org/r/1412456799-32339-1-git-send-email-minipli@googlemail.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
When modifying code, ftrace has several checks to make sure things
are being done correctly. One of them is to make sure any code it
modifies is exactly what it expects it to be before it modifies it.
In order to do so with the new trampoline logic, it must be able
to find out what trampoline a function is hooked to in order to
see if the code that hooks to it is what's expected.
The logic to find the trampoline from a record (accounting descriptor
for a function that is hooked) needs to only look at the "old_hash"
of an ops that is being modified. The old_hash is the list of function
an ops is hooked to before its update. Since a record would only be
pointing to an ops that is being modified if it was already hooked
before.
Currently, it can pick a modified ops based on its new functions it
will be hooked to, and this picks the wrong trampoline and causes
the check to fail, disabling ftrace.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
ftrace: squash into ordering of ops for modification
The code that checks for trampolines when modifying function hooks
tests against a modified ops "old_hash". But the ops old_hash pointer
is not being updated before the changes are made, making it possible
to not find the right hash to the callback and possibly causing
ftrace to break in accounting and disable itself.
Have the ops set its old_hash before the modifying takes place.
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Commit dd56af42bd (rcu: Eliminate deadlock between CPU hotplug and
expedited grace periods) was incomplete. Although it did eliminate
deadlocks involving synchronize_sched_expedited()'s acquisition of
cpu_hotplug.lock via get_online_cpus(), it did nothing about the similar
deadlock involving acquisition of this same lock via put_online_cpus().
This deadlock became apparent with testing involving hibernation.
This commit therefore changes put_online_cpus() acquisition of this lock
to be conditional, and increments a new cpu_hotplug.puts_pending field
in case of acquisition failure. Then cpu_hotplug_begin() checks for this
new field being non-zero, and applies any changes to cpu_hotplug.refcount.
Reported-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Tested-by: Jiri Kosina <jkosina@suse.cz>
Tested-by: Borislav Petkov <bp@suse.de>
