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Two trivial overlapping changes conflicts in MPLS and mlx5.
Signed-off-by: David S. Miller <davem@davemloft.net>
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Pull networking fixes from David Miller:
1) GTP fixes from Andreas Schultz (missing genl module alias, clear IP
DF on transmit).
2) Netfilter needs to reflect the fwmark when sending resets, from Pau
Espin Pedrol.
3) nftable dump OOPS fix from Liping Zhang.
4) Fix erroneous setting of VIRTIO_NET_HDR_F_DATA_VALID on transmit,
from Rolf Neugebauer.
5) Fix build error of ipt_CLUSTERIP when procfs is disabled, from Arnd
Bergmann.
6) Fix regression in handling of NETIF_F_SG in harmonize_features(),
from Eric Dumazet.
7) Fix RTNL deadlock wrt. lwtunnel module loading, from David Ahern.
8) tcp_fastopen_create_child() needs to setup tp->max_window, from
Alexey Kodanev.
9) Missing kmemdup() failure check in ipv6 segment routing code, from
Eric Dumazet.
10) Don't execute unix_bind() under the bindlock, otherwise we deadlock
with splice. From WANG Cong.
11) ip6_tnl_parse_tlv_enc_lim() potentially reallocates the skb buffer,
therefore callers must reload cached header pointers into that skb.
Fix from Eric Dumazet.
12) Fix various bugs in legacy IRQ fallback handling in alx driver, from
Tobias Regnery.
13) Do not allow lwtunnel drivers to be unloaded while they are
referenced by active instances, from Robert Shearman.
14) Fix truncated PHY LED trigger names, from Geert Uytterhoeven.
15) Fix a few regressions from virtio_net XDP support, from John
Fastabend and Jakub Kicinski.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (102 commits)
ISDN: eicon: silence misleading array-bounds warning
net: phy: micrel: add support for KSZ8795
gtp: fix cross netns recv on gtp socket
gtp: clear DF bit on GTP packet tx
gtp: add genl family modules alias
tcp: don't annotate mark on control socket from tcp_v6_send_response()
ravb: unmap descriptors when freeing rings
virtio_net: reject XDP programs using header adjustment
virtio_net: use dev_kfree_skb for small buffer XDP receive
r8152: check rx after napi is enabled
r8152: re-schedule napi for tx
r8152: avoid start_xmit to schedule napi when napi is disabled
r8152: avoid start_xmit to call napi_schedule during autosuspend
net: dsa: Bring back device detaching in dsa_slave_suspend()
net: phy: leds: Fix truncated LED trigger names
net: phy: leds: Break dependency of phy.h on phy_led_triggers.h
net: phy: leds: Clear phy_num_led_triggers on failure to avoid crash
net-next: ethernet: mediatek: change the compatible string
Documentation: devicetree: change the mediatek ethernet compatible string
bnxt_en: Fix RTNL lock usage on bnxt_get_port_module_status().
...
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Pull power management fixes from Rafael Wysocki:
"These fix two regressions introduced recently, one by reverting the
problematic commit and one by fixing up the behavior in an overlooked
case.
Specifics:
- Revert the recent change that caused suspend-to-idle to be used as
the default suspend method on systems where it is indicated to be
efficient by the ACPI tables, as that turned out to be premature
and introduced suspend regressions on some systems with missing
power management support in device drivers (Rafael Wysocki).
- Fix up the intel_pstate driver to take changes of the global limits
via sysfs correctly when the performance policy is used which has
been broken by a recent change in it (Srinivas Pandruvada)"
* tag 'pm-4.10-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
cpufreq: intel_pstate: Fix sysfs limits enforcement for performance policy
Revert "PM / sleep / ACPI: Use the ACPI_FADT_LOW_POWER_S0 flag"
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* pm-sleep:
Revert "PM / sleep / ACPI: Use the ACPI_FADT_LOW_POWER_S0 flag"
* pm-cpufreq:
cpufreq: intel_pstate: Fix sysfs limits enforcement for performance policy
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We perform the conversion between kernel jiffies and ms only when
exporting kernel value to user space.
We need to do the opposite operation when value is written by user.
Only matters when HZ != 1000
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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This work adds a number of tracepoints to paths that are either
considered slow-path or exception-like states, where monitoring or
inspecting them would be desirable.
For bpf(2) syscall, tracepoints have been placed for main commands
when they succeed. In XDP case, tracepoint is for exceptions, that
is, f.e. on abnormal BPF program exit such as unknown or XDP_ABORTED
return code, or when error occurs during XDP_TX action and the packet
could not be forwarded.
Both have been split into separate event headers, and can be further
extended. Worst case, if they unexpectedly should get into our way in
future, they can also removed [1]. Of course, these tracepoints (like
any other) can be analyzed by eBPF itself, etc. Example output:
# ./perf record -a -e bpf:* sleep 10
# ./perf script
sock_example 6197 [005] 283.980322: bpf:bpf_map_create: map type=ARRAY ufd=4 key=4 val=8 max=256 flags=0
sock_example 6197 [005] 283.980721: bpf:bpf_prog_load: prog=a5ea8fa30ea6849c type=SOCKET_FILTER ufd=5
sock_example 6197 [005] 283.988423: bpf:bpf_prog_get_type: prog=a5ea8fa30ea6849c type=SOCKET_FILTER
sock_example 6197 [005] 283.988443: bpf:bpf_map_lookup_elem: map type=ARRAY ufd=4 key=[06 00 00 00] val=[00 00 00 00 00 00 00 00]
[...]
sock_example 6197 [005] 288.990868: bpf:bpf_map_lookup_elem: map type=ARRAY ufd=4 key=[01 00 00 00] val=[14 00 00 00 00 00 00 00]
swapper 0 [005] 289.338243: bpf:bpf_prog_put_rcu: prog=a5ea8fa30ea6849c type=SOCKET_FILTER
[1] https://lwn.net/Articles/705270/
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
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For upcoming tracepoint support for BPF, we want to dump the program's
tag. Format should be similar to __print_hex(), but without spacing.
Add a __print_hex_str() variant for exactly that purpose that reuses
trace_print_hex_seq().
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Merge fixes from Andrew Morton:
"26 fixes"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (26 commits)
MAINTAINERS: add Dan Streetman to zbud maintainers
MAINTAINERS: add Dan Streetman to zswap maintainers
mm: do not export ioremap_page_range symbol for external module
mn10300: fix build error of missing fpu_save()
romfs: use different way to generate fsid for BLOCK or MTD
frv: add missing atomic64 operations
mm, page_alloc: fix premature OOM when racing with cpuset mems update
mm, page_alloc: move cpuset seqcount checking to slowpath
mm, page_alloc: fix fast-path race with cpuset update or removal
mm, page_alloc: fix check for NULL preferred_zone
kernel/panic.c: add missing \n
fbdev: color map copying bounds checking
frv: add atomic64_add_unless()
mm/mempolicy.c: do not put mempolicy before using its nodemask
radix-tree: fix private list warnings
Documentation/filesystems/proc.txt: add VmPin
mm, memcg: do not retry precharge charges
proc: add a schedule point in proc_pid_readdir()
mm: alloc_contig: re-allow CMA to compact FS pages
mm/slub.c: trace free objects at KERN_INFO
...
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When a system panics, the "Rebooting in X seconds.." message is never
printed because it lacks a new line. Fix it.
Link: http://lkml.kernel.org/r/20170119114751.2724-1-jslaby@suse.cz
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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On an overloaded system, it is possible that a change in the watchdog
threshold can be delayed long enough to trigger a false positive.
This can easily be achieved by having a cpu spinning indefinitely on a
task, while another cpu updates watchdog threshold.
What happens is while trying to park the watchdog threads, the hrtimers
on the other cpus trigger and reprogram themselves with the new slower
watchdog threshold. Meanwhile, the nmi watchdog is still programmed
with the old faster threshold.
Because the one cpu is blocked, it prevents the thread parking on the
other cpus from completing, which is needed to shutdown the nmi watchdog
and reprogram it correctly. As a result, a false positive from the nmi
watchdog is reported.
Fix this by setting a park_in_progress flag to block all lockups until
the parking is complete.
Fix provided by Ulrich Obergfell.
[akpm@linux-foundation.org: s/park_in_progress/watchdog_park_in_progress/]
Link: http://lkml.kernel.org/r/1481041033-192236-1-git-send-email-dzickus@redhat.com
Signed-off-by: Don Zickus <dzickus@redhat.com>
Reviewed-by: Aaron Tomlin <atomlin@redhat.com>
Cc: Ulrich Obergfell <uobergfe@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Pull namespace fix from Eric Biederman:
"This has a single brown bag fix.
The possible deadlock with dec_pid_namespaces that I had thought was
fixed earlier turned out only to have been moved. So instead of being
cleaver this change takes ucounts_lock with irqs disabled. So
dec_ucount can be used from any context without fear of deadlock.
The items accounted for dec_ucount and inc_ucount are all
comparatively heavy weight objects so I don't exepct this will have
any measurable performance impact"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
userns: Make ucounts lock irq-safe
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William reported couple of issues in relation to direct packet
access. Typical scheme is to check for data + [off] <= data_end,
where [off] can be either immediate or coming from a tracked
register that contains an immediate, depending on the branch, we
can then access the data. However, in case of calculating [off]
for either the mentioned test itself or for access after the test
in a more "complex" way, then the verifier will stop tracking the
CONST_IMM marked register and will mark it as UNKNOWN_VALUE one.
Adding that UNKNOWN_VALUE typed register to a pkt() marked
register, the verifier then bails out in check_packet_ptr_add()
as it finds the registers imm value below 48. In the first below
example, that is due to evaluate_reg_imm_alu() not handling right
shifts and thus marking the register as UNKNOWN_VALUE via helper
__mark_reg_unknown_value() that resets imm to 0.
In the second case the same happens at the time when r4 is set
to r4 &= r5, where it transitions to UNKNOWN_VALUE from
evaluate_reg_imm_alu(). Later on r4 we shift right by 3 inside
evaluate_reg_alu(), where the register's imm turns into 3. That
is, for registers with type UNKNOWN_VALUE, imm of 0 means that
we don't know what value the register has, and for imm > 0 it
means that the value has [imm] upper zero bits. F.e. when shifting
an UNKNOWN_VALUE register by 3 to the right, no matter what value
it had, we know that the 3 upper most bits must be zero now.
This is to make sure that ALU operations with unknown registers
don't overflow. Meaning, once we know that we have more than 48
upper zero bits, or, in other words cannot go beyond 0xffff offset
with ALU ops, such an addition will track the target register
as a new pkt() register with a new id, but 0 offset and 0 range,
so for that a new data/data_end test will be required. Is the source
register a CONST_IMM one that is to be added to the pkt() register,
or the source instruction is an add instruction with immediate
value, then it will get added if it stays within max 0xffff bounds.
>From there, pkt() type, can be accessed should reg->off + imm be
within the access range of pkt().
[...]
from 28 to 30: R0=imm1,min_value=1,max_value=1
R1=pkt(id=0,off=0,r=22) R2=pkt_end
R3=imm144,min_value=144,max_value=144
R4=imm0,min_value=0,max_value=0
R5=inv48,min_value=2054,max_value=2054 R10=fp
30: (bf) r5 = r3
31: (07) r5 += 23
32: (77) r5 >>= 3
33: (bf) r6 = r1
34: (0f) r6 += r5
cannot add integer value with 0 upper zero bits to ptr_to_packet
[...]
from 52 to 80: R0=imm1,min_value=1,max_value=1
R1=pkt(id=0,off=0,r=34) R2=pkt_end R3=inv
R4=imm272 R5=inv56,min_value=17,max_value=17
R6=pkt(id=0,off=26,r=34) R10=fp
80: (07) r4 += 71
81: (18) r5 = 0xfffffff8
83: (5f) r4 &= r5
84: (77) r4 >>= 3
85: (0f) r1 += r4
cannot add integer value with 3 upper zero bits to ptr_to_packet
Thus to get above use-cases working, evaluate_reg_imm_alu() has
been extended for further ALU ops. This is fine, because we only
operate strictly within realm of CONST_IMM types, so here we don't
care about overflows as they will happen in the simulated but also
real execution and interaction with pkt() in check_packet_ptr_add()
will check actual imm value once added to pkt(), but it's irrelevant
before.
With regards to 06c1c049721a ("bpf: allow helpers access to variable
memory") that works on UNKNOWN_VALUE registers, the verifier becomes
now a bit smarter as it can better resolve ALU ops, so we need to
adapt two test cases there, as min/max bound tracking only becomes
necessary when registers were spilled to stack. So while mask was
set before to track upper bound for UNKNOWN_VALUE case, it's now
resolved directly as CONST_IMM, and such contructs are only necessary
when f.e. registers are spilled.
For commit 6b17387307ba ("bpf: recognize 64bit immediate loads as
consts") that initially enabled dw load tracking only for nfp jit/
analyzer, I did couple of tests on large, complex programs and we
don't increase complexity badly (my tests were in ~3% range on avg).
I've added a couple of tests similar to affected code above, and
it works fine with verifier now.
Reported-by: William Tu <u9012063@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Cc: Gianluca Borello <g.borello@gmail.com>
Cc: William Tu <u9012063@gmail.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
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We need to initialize im_node to NULL, otherwise in case of error path
it gets passed to kfree() as uninitialized pointer.
Fixes: b95a5c4db09b ("bpf: add a longest prefix match trie map implementation")
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
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This trie implements a longest prefix match algorithm that can be used
to match IP addresses to a stored set of ranges.
Internally, data is stored in an unbalanced trie of nodes that has a
maximum height of n, where n is the prefixlen the trie was created
with.
Tries may be created with prefix lengths that are multiples of 8, in
the range from 8 to 2048. The key used for lookup and update operations
is a struct bpf_lpm_trie_key, and the value is a uint64_t.
The code carries more information about the internal implementation.
Signed-off-by: Daniel Mack <daniel@zonque.org>
Reviewed-by: David Herrmann <dh.herrmann@gmail.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
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The ucounts_lock is being used to protect various ucounts lifecycle
management functionalities. However, those services can also be invoked
when a pidns is being freed in an RCU callback (e.g. softirq context).
This can lead to deadlocks. There were already efforts trying to
prevent similar deadlocks in add7c65ca426 ("pid: fix lockdep deadlock
warning due to ucount_lock"), however they just moved the context
from hardirq to softrq. Fix this issue once and for all by explictly
making the lock disable irqs altogether.
Dmitry Vyukov <dvyukov@google.com> reported:
> I've got the following deadlock report while running syzkaller fuzzer
> on eec0d3d065bfcdf9cd5f56dd2a36b94d12d32297 of linux-next (on odroid
> device if it matters):
>
> =================================
> [ INFO: inconsistent lock state ]
> 4.10.0-rc3-next-20170112-xc2-dirty #6 Not tainted
> ---------------------------------
> inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage.
> swapper/2/0 [HC0[0]:SC1[1]:HE1:SE0] takes:
> (ucounts_lock){+.?...}, at: [< inline >] spin_lock
> ./include/linux/spinlock.h:302
> (ucounts_lock){+.?...}, at: [<ffff2000081678c8>]
> put_ucounts+0x60/0x138 kernel/ucount.c:162
> {SOFTIRQ-ON-W} state was registered at:
> [<ffff2000081c82d8>] mark_lock+0x220/0xb60 kernel/locking/lockdep.c:3054
> [< inline >] mark_irqflags kernel/locking/lockdep.c:2941
> [<ffff2000081c97a8>] __lock_acquire+0x388/0x3260 kernel/locking/lockdep.c:3295
> [<ffff2000081cce24>] lock_acquire+0xa4/0x138 kernel/locking/lockdep.c:3753
> [< inline >] __raw_spin_lock ./include/linux/spinlock_api_smp.h:144
> [<ffff200009798128>] _raw_spin_lock+0x90/0xd0 kernel/locking/spinlock.c:151
> [< inline >] spin_lock ./include/linux/spinlock.h:302
> [< inline >] get_ucounts kernel/ucount.c:131
> [<ffff200008167c28>] inc_ucount+0x80/0x6c8 kernel/ucount.c:189
> [< inline >] inc_mnt_namespaces fs/namespace.c:2818
> [<ffff200008481850>] alloc_mnt_ns+0x78/0x3a8 fs/namespace.c:2849
> [<ffff200008487298>] create_mnt_ns+0x28/0x200 fs/namespace.c:2959
> [< inline >] init_mount_tree fs/namespace.c:3199
> [<ffff200009bd6674>] mnt_init+0x258/0x384 fs/namespace.c:3251
> [<ffff200009bd60bc>] vfs_caches_init+0x6c/0x80 fs/dcache.c:3626
> [<ffff200009bb1114>] start_kernel+0x414/0x460 init/main.c:648
> [<ffff200009bb01e8>] __primary_switched+0x6c/0x70 arch/arm64/kernel/head.S:456
> irq event stamp: 2316924
> hardirqs last enabled at (2316924): [< inline >] rcu_do_batch
> kernel/rcu/tree.c:2911
> hardirqs last enabled at (2316924): [< inline >]
> invoke_rcu_callbacks kernel/rcu/tree.c:3182
> hardirqs last enabled at (2316924): [< inline >]
> __rcu_process_callbacks kernel/rcu/tree.c:3149
> hardirqs last enabled at (2316924): [<ffff200008210414>]
> rcu_process_callbacks+0x7a4/0xc28 kernel/rcu/tree.c:3166
> hardirqs last disabled at (2316923): [< inline >] rcu_do_batch
> kernel/rcu/tree.c:2900
> hardirqs last disabled at (2316923): [< inline >]
> invoke_rcu_callbacks kernel/rcu/tree.c:3182
> hardirqs last disabled at (2316923): [< inline >]
> __rcu_process_callbacks kernel/rcu/tree.c:3149
> hardirqs last disabled at (2316923): [<ffff20000820fe80>]
> rcu_process_callbacks+0x210/0xc28 kernel/rcu/tree.c:3166
> softirqs last enabled at (2316912): [<ffff20000811b4c4>]
> _local_bh_enable+0x4c/0x80 kernel/softirq.c:155
> softirqs last disabled at (2316913): [< inline >]
> do_softirq_own_stack ./include/linux/interrupt.h:488
> softirqs last disabled at (2316913): [< inline >]
> invoke_softirq kernel/softirq.c:371
> softirqs last disabled at (2316913): [<ffff20000811c994>]
> irq_exit+0x264/0x308 kernel/softirq.c:405
>
> other info that might help us debug this:
> Possible unsafe locking scenario:
>
> CPU0
> ----
> lock(ucounts_lock);
> <Interrupt>
> lock(ucounts_lock);
>
> *** DEADLOCK ***
>
> 1 lock held by swapper/2/0:
> #0: (rcu_callback){......}, at: [< inline >] __rcu_reclaim
> kernel/rcu/rcu.h:108
> #0: (rcu_callback){......}, at: [< inline >] rcu_do_batch
> kernel/rcu/tree.c:2919
> #0: (rcu_callback){......}, at: [< inline >]
> invoke_rcu_callbacks kernel/rcu/tree.c:3182
> #0: (rcu_callback){......}, at: [< inline >]
> __rcu_process_callbacks kernel/rcu/tree.c:3149
> #0: (rcu_callback){......}, at: [<ffff200008210390>]
> rcu_process_callbacks+0x720/0xc28 kernel/rcu/tree.c:3166
>
> stack backtrace:
> CPU: 2 PID: 0 Comm: swapper/2 Not tainted 4.10.0-rc3-next-20170112-xc2-dirty #6
> Hardware name: Hardkernel ODROID-C2 (DT)
> Call trace:
> [<ffff20000808fa60>] dump_backtrace+0x0/0x440 arch/arm64/kernel/traps.c:500
> [<ffff20000808fec0>] show_stack+0x20/0x30 arch/arm64/kernel/traps.c:225
> [<ffff2000088a99e0>] dump_stack+0x110/0x168
> [<ffff2000082fa2b4>] print_usage_bug.part.27+0x49c/0x4bc
> kernel/locking/lockdep.c:2387
> [< inline >] print_usage_bug kernel/locking/lockdep.c:2357
> [< inline >] valid_state kernel/locking/lockdep.c:2400
> [< inline >] mark_lock_irq kernel/locking/lockdep.c:2617
> [<ffff2000081c89ec>] mark_lock+0x934/0xb60 kernel/locking/lockdep.c:3065
> [< inline >] mark_irqflags kernel/locking/lockdep.c:2923
> [<ffff2000081c9a60>] __lock_acquire+0x640/0x3260 kernel/locking/lockdep.c:3295
> [<ffff2000081cce24>] lock_acquire+0xa4/0x138 kernel/locking/lockdep.c:3753
> [< inline >] __raw_spin_lock ./include/linux/spinlock_api_smp.h:144
> [<ffff200009798128>] _raw_spin_lock+0x90/0xd0 kernel/locking/spinlock.c:151
> [< inline >] spin_lock ./include/linux/spinlock.h:302
> [<ffff2000081678c8>] put_ucounts+0x60/0x138 kernel/ucount.c:162
> [<ffff200008168364>] dec_ucount+0xf4/0x158 kernel/ucount.c:214
> [< inline >] dec_pid_namespaces kernel/pid_namespace.c:89
> [<ffff200008293dc8>] delayed_free_pidns+0x40/0xe0 kernel/pid_namespace.c:156
> [< inline >] __rcu_reclaim kernel/rcu/rcu.h:118
> [< inline >] rcu_do_batch kernel/rcu/tree.c:2919
> [< inline >] invoke_rcu_callbacks kernel/rcu/tree.c:3182
> [< inline >] __rcu_process_callbacks kernel/rcu/tree.c:3149
> [<ffff2000082103d8>] rcu_process_callbacks+0x768/0xc28 kernel/rcu/tree.c:3166
> [<ffff2000080821dc>] __do_softirq+0x324/0x6e0 kernel/softirq.c:284
> [< inline >] do_softirq_own_stack ./include/linux/interrupt.h:488
> [< inline >] invoke_softirq kernel/softirq.c:371
> [<ffff20000811c994>] irq_exit+0x264/0x308 kernel/softirq.c:405
> [<ffff2000081ecc28>] __handle_domain_irq+0xc0/0x150 kernel/irq/irqdesc.c:636
> [<ffff200008081c80>] gic_handle_irq+0x68/0xd8
> Exception stack(0xffff8000648e7dd0 to 0xffff8000648e7f00)
> 7dc0: ffff8000648d4b3c 0000000000000007
> 7de0: 0000000000000000 1ffff0000c91a967 1ffff0000c91a967 1ffff0000c91a967
> 7e00: ffff20000a4b6b68 0000000000000001 0000000000000007 0000000000000001
> 7e20: 1fffe4000149ae90 ffff200009d35000 0000000000000000 0000000000000002
> 7e40: 0000000000000000 0000000000000000 0000000002624a1a 0000000000000000
> 7e60: 0000000000000000 ffff200009cbcd88 000060006d2ed000 0000000000000140
> 7e80: ffff200009cff000 ffff200009cb6000 ffff200009cc2020 ffff200009d2159d
> 7ea0: 0000000000000000 ffff8000648d4380 0000000000000000 ffff8000648e7f00
> 7ec0: ffff20000820a478 ffff8000648e7f00 ffff20000820a47c 0000000010000145
> 7ee0: 0000000000000140 dfff200000000000 ffffffffffffffff ffff20000820a478
> [<ffff2000080837f8>] el1_irq+0xb8/0x130 arch/arm64/kernel/entry.S:486
> [< inline >] arch_local_irq_restore
> ./arch/arm64/include/asm/irqflags.h:81
> [<ffff20000820a47c>] rcu_idle_exit+0x64/0xa8 kernel/rcu/tree.c:1030
> [< inline >] cpuidle_idle_call kernel/sched/idle.c:200
> [<ffff2000081bcbfc>] do_idle+0x1dc/0x2d0 kernel/sched/idle.c:243
> [<ffff2000081bd1cc>] cpu_startup_entry+0x24/0x28 kernel/sched/idle.c:345
> [<ffff200008099f8c>] secondary_start_kernel+0x2cc/0x358
> arch/arm64/kernel/smp.c:276
> [<000000000279f1a4>] 0x279f1a4
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Tested-by: Dmitry Vyukov <dvyukov@google.com>
Fixes: add7c65ca426 ("pid: fix lockdep deadlock warning due to ucount_lock")
Fixes: f333c700c610 ("pidns: Add a limit on the number of pid namespaces")
Cc: stable@vger.kernel.org
Link: https://www.spinics.net/lists/kernel/msg2426637.html
Signed-off-by: Nikolay Borisov <n.borisov.lkml@gmail.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
|
|
Pull smp/hotplug fix from Thomas Gleixner:
"Remove an unused variable which is a leftover from the notifier
removal"
* 'smp-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
cpu/hotplug: Remove unused but set variable in _cpu_down()
|
|
Provide a simple helper with the same semantics of strncpy_from_unsafe():
int bpf_probe_read_str(void *dst, int size, const void *unsafe_addr)
This gives more flexibility to a bpf program. A typical use case is
intercepting a file name during sys_open(). The current approach is:
SEC("kprobe/sys_open")
void bpf_sys_open(struct pt_regs *ctx)
{
char buf[PATHLEN]; // PATHLEN is defined to 256
bpf_probe_read(buf, sizeof(buf), ctx->di);
/* consume buf */
}
This is suboptimal because the size of the string needs to be estimated
at compile time, causing more memory to be copied than often necessary,
and can become more problematic if further processing on buf is done,
for example by pushing it to userspace via bpf_perf_event_output(),
since the real length of the string is unknown and the entire buffer
must be copied (and defining an unrolled strnlen() inside the bpf
program is a very inefficient and unfeasible approach).
With the new helper, the code can easily operate on the actual string
length rather than the buffer size:
SEC("kprobe/sys_open")
void bpf_sys_open(struct pt_regs *ctx)
{
char buf[PATHLEN]; // PATHLEN is defined to 256
int res = bpf_probe_read_str(buf, sizeof(buf), ctx->di);
/* consume buf, for example push it to userspace via
* bpf_perf_event_output(), but this time we can use
* res (the string length) as event size, after checking
* its boundaries.
*/
}
Another useful use case is when parsing individual process arguments or
individual environment variables navigating current->mm->arg_start and
current->mm->env_start: using this helper and the return value, one can
quickly iterate at the right offset of the memory area.
The code changes simply leverage the already existent
strncpy_from_unsafe() kernel function, which is safe to be called from a
bpf program as it is used in bpf_trace_printk().
Signed-off-by: Gianluca Borello <g.borello@gmail.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
Revert commit 08b98d329165 (PM / sleep / ACPI: Use the ACPI_FADT_LOW_POWER_S0
flag) as it caused system suspend (in the default configuration) to fail
on Dell XPS13 (9360) with the Kaby Lake processor.
Fixes: 08b98d329165 (PM / sleep / ACPI: Use the ACPI_FADT_LOW_POWER_S0 flag)
Reported-by: Paul Menzel <pmenzel@molgen.mpg.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
|
|
This patch adds two helpers, bpf_map_area_alloc() and bpf_map_area_free(),
that are to be used for map allocations. Using kmalloc() for very large
allocations can cause excessive work within the page allocator, so i) fall
back earlier to vmalloc() when the attempt is considered costly anyway,
and even more importantly ii) don't trigger OOM killer with any of the
allocators.
Since this is based on a user space request, for example, when creating
maps with element pre-allocation, we really want such requests to fail
instead of killing other user space processes.
Also, don't spam the kernel log with warnings should any of the allocations
fail under pressure. Given that, we can make backend selection in
bpf_map_area_alloc() generic, and convert all maps over to use this API
for spots with potentially large allocation requests.
Note, replacing the one kmalloc_array() is fine as overflow checks happen
earlier in htab_map_alloc(), since it must also protect the multiplication
for vmalloc() should kmalloc_array() fail.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
Pull SMP hotplug update from Thomas Gleixner:
"This contains a trivial typo fix and an extension to the core code for
dynamically allocating states in the prepare stage.
The extension is necessary right now because we need a proper way to
unbreak LTTNG, which iscurrently non functional due to the removal of
the notifiers. Surely it's out of tree, but it's widely used by
distros.
The simple solution would have been to reserve a state for LTTNG, but
I'm not fond about unused crap in the kernel and the dynamic range,
which we admittedly should have done right away, allows us to remove
quite some of the hardcoded states, i.e. those which have no ordering
requirements. So doing the right thing now is better than having an
smaller intermediate solution which needs to be reworked anyway"
* 'smp-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
cpu/hotplug: Provide dynamic range for prepare stage
perf/x86/amd/ibs: Fix typo after cleanup state names in cpu/hotplug
|
|
Pull RCU fixes from Ingo Molnar:
"This fixes sporadic ACPI related hangs in synchronize_rcu() that were
caused by the ACPI code mistakenly relying on an aspect of RCU that
was neither promised to work nor reliable but which happened to work -
until in v4.9 we changed the RCU implementation, which made the hangs
more prominent.
Since the mis-use of the RCU facility wasn't properly detected and
prevented either, these fixes make the RCU side work reliably instead
of working around the problem in the ACPI code.
Hence the slightly larger diffstat that goes beyond the normal scope
of RCU fixes in -rc kernels"
* 'rcu-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
rcu: Narrow early boot window of illegal synchronous grace periods
rcu: Remove cond_resched() from Tiny synchronize_sched()
|
|
After the recent removal of the hotplug notifiers the variable 'hasdied' in
_cpu_down() is set but no longer read, leading to the following GCC warning
when building with 'make W=1':
kernel/cpu.c:767:7: warning: variable ‘hasdied’ set but not used [-Wunused-but-set-variable]
Fix it by removing the variable.
Fixes: 530e9b76ae8f ("cpu/hotplug: Remove obsolete cpu hotplug register/unregister functions")
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: rt@linutronix.de
Link: http://lkml.kernel.org/r/20170117143501.20893-1-tklauser@distanz.ch
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
|
|
Pull modules fix from Jessica Yu:
- fix out-of-tree module breakage when it supplies its own definitions
of true and false
* tag 'modules-for-v4.10-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux:
taint/module: Fix problems when out-of-kernel driver defines true or false
|
|
|
|
Commit 7fd8329ba502 ("taint/module: Clean up global and module taint
flags handling") used the key words true and false as character members
of a new struct. These names cause problems when out-of-kernel modules
such as VirtualBox include their own definitions of true and false.
Fixes: 7fd8329ba502 ("taint/module: Clean up global and module taint flags handling")
Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Jessica Yu <jeyu@redhat.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Reported-by: Valdis Kletnieks <Valdis.Kletnieks@vt.edu>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Jessica Yu <jeyu@redhat.com>
|
|
Pull networking fixes from David Miller:
1) Handle multicast packets properly in fast-RX path of mac80211, from
Johannes Berg.
2) Because of a logic bug, the user can't actually force SW
checksumming on r8152 devices. This makes diagnosis of hw
checksumming bugs really annoying. Fix from Hayes Wang.
3) VXLAN route lookup does not take the source and destination ports
into account, which means IPSEC policies cannot be matched properly.
Fix from Martynas Pumputis.
4) Do proper RCU locking in netvsc callbacks, from Stephen Hemminger.
5) Fix SKB leaks in mlxsw driver, from Arkadi Sharshevsky.
6) If lwtunnel_fill_encap() fails, we do not abort the netlink message
construction properly in fib_dump_info(), from David Ahern.
7) Do not use kernel stack for DMA buffers in atusb driver, from Stefan
Schmidt.
8) Openvswitch conntack actions need to maintain a correct checksum,
fix from Lance Richardson.
9) ax25_disconnect() is missing a check for ax25->sk being NULL, in
fact it already checks this, but not in all of the necessary spots.
Fix from Basil Gunn.
10) Action GET operations in the packet scheduler can erroneously bump
the reference count of the entry, making it unreleasable. Fix from
Jamal Hadi Salim. Jamal gives a great set of example command lines
that trigger this in the commit message.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (46 commits)
net sched actions: fix refcnt when GETing of action after bind
net/mlx4_core: Eliminate warning messages for SRQ_LIMIT under SRIOV
net/mlx4_core: Fix when to save some qp context flags for dynamic VST to VGT transitions
net/mlx4_core: Fix racy CQ (Completion Queue) free
net: stmmac: don't use netdev_[dbg, info, ..] before net_device is registered
net/mlx5e: Fix a -Wmaybe-uninitialized warning
ax25: Fix segfault after sock connection timeout
bpf: rework prog_digest into prog_tag
tipc: allocate user memory with GFP_KERNEL flag
net: phy: dp83867: allow RGMII_TXID/RGMII_RXID interface types
ip6_tunnel: Account for tunnel header in tunnel MTU
mld: do not remove mld souce list info when set link down
be2net: fix MAC addr setting on privileged BE3 VFs
be2net: don't delete MAC on close on unprivileged BE3 VFs
be2net: fix status check in be_cmd_pmac_add()
cpmac: remove hopeless #warning
ravb: do not use zero-length alignment DMA descriptor
mlx4: do not call napi_schedule() without care
openvswitch: maintain correct checksum state in conntrack actions
tcp: fix tcp_fastopen unaligned access complaints on sparc
...
|
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Make sure that ctx cannot potentially be accessed oob by asserting
explicitly that ctx access size into pt_regs for BPF_PROG_TYPE_KPROBE
programs must be within limits. In case some 32bit archs have pt_regs
not being a multiple of 8, then BPF_DW access could cause such access.
BPF_PROG_TYPE_KPROBE progs don't have a ctx conversion function since
there's no extra mapping needed. kprobe_prog_is_valid_access() didn't
enforce sizeof(long) as the only allowed access size, since LLVM can
generate non BPF_W/BPF_DW access to regs from time to time.
For BPF_PROG_TYPE_TRACEPOINT we don't have a ctx conversion either, so
add a BUILD_BUG_ON() check to make sure that BPF_DW access will not be
a similar issue in future (ctx works on event buffer as opposed to
pt_regs there).
Fixes: 2541517c32be ("tracing, perf: Implement BPF programs attached to kprobes")
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
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Commit 7bd509e311f4 ("bpf: add prog_digest and expose it via
fdinfo/netlink") was recently discussed, partially due to
admittedly suboptimal name of "prog_digest" in combination
with sha1 hash usage, thus inevitably and rightfully concerns
about its security in terms of collision resistance were
raised with regards to use-cases.
The intended use cases are for debugging resp. introspection
only for providing a stable "tag" over the instruction sequence
that both kernel and user space can calculate independently.
It's not usable at all for making a security relevant decision.
So collisions where two different instruction sequences generate
the same tag can happen, but ideally at a rather low rate. The
"tag" will be dumped in hex and is short enough to introspect
in tracepoints or kallsyms output along with other data such
as stack trace, etc. Thus, this patch performs a rename into
prog_tag and truncates the tag to a short output (64 bits) to
make it obvious it's not collision-free.
Should in future a hash or facility be needed with a security
relevant focus, then we can think about requirements, constraints,
etc that would fit to that situation. For now, rework the exposed
parts for the current use cases as long as nothing has been
released yet. Tested on x86_64 and s390x.
Fixes: 7bd509e311f4 ("bpf: add prog_digest and expose it via fdinfo/netlink")
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Cc: Andy Lutomirski <luto@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
Mathieu reported that the LTTNG modules are broken as of 4.10-rc1 due to
the removal of the cpu hotplug notifiers.
Usually I don't care much about out of tree modules, but LTTNG is widely
used in distros. There are two ways to solve that:
1) Reserve a hotplug state for LTTNG
2) Add a dynamic range for the prepare states.
While #1 is the simplest solution, #2 is the proper one as we can convert
in tree users, which do not care about ordering, to the dynamic range as
well.
Add a dynamic range which allows LTTNG to request states in the prepare
stage.
Reported-and-tested-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sebastian Sewior <bigeasy@linutronix.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1701101353010.3401@nanos
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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|
Pull an urgent RCU fix from Paul E. McKenney:
"This series contains a pair of commits that permit RCU synchronous grace
periods (synchronize_rcu() and friends) to work correctly throughout boot.
This eliminates the current "dead time" starting when the scheduler spawns
its first taks and ending when the last of RCU's kthreads is spawned
(this last happens during early_initcall() time). Although RCU's
synchronous grace periods have long been documented as not working
during this time, prior to 4.9, the expedited grace periods worked by
accident, and some ACPI code came to rely on this unintentional behavior.
(Note that this unintentional behavior was -not- reliable. For example,
failures from ACPI could occur on !SMP systems and on systems booting
with the rcu_normal kernel boot parameter.)
Either way, there is a bug that needs fixing, and the 4.9 switch of RCU's
expedited grace periods to workqueues could be considered to have caused
a regression. This series therefore makes RCU's expedited grace periods
operate correctly throughout the boot process. This has been demonstrated
to fix the problems ACPI was encountering, and has the added longer-term
benefit of simplifying RCU's behavior."
Signed-off-by: Ingo Molnar <mingo@kernel.org>
|
|
Pull namespace fixes from Eric Biederman:
"This tree contains 4 fixes.
The first is a fix for a race that can causes oopses under the right
circumstances, and that someone just recently encountered.
Past that are several small trivial correct fixes. A real issue that
was blocking development of an out of tree driver, but does not appear
to have caused any actual problems for in-tree code. A potential
deadlock that was reported by lockdep. And a deadlock people have
experienced and took the time to track down caused by a cleanup that
removed the code to drop a reference count"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
sysctl: Drop reference added by grab_header in proc_sys_readdir
pid: fix lockdep deadlock warning due to ucount_lock
libfs: Modify mount_pseudo_xattr to be clear it is not a userspace mount
mnt: Protect the mountpoint hashtable with mount_lock
|
|
Pull NOHZ fix from Ingo Molnar:
"This fixes an old NOHZ race where we incorrectly calculate the next
timer interrupt in certain circumstances where hrtimers are pending,
that can cause hard to reproduce stalled-values artifacts in
/proc/stat"
* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
nohz: Fix collision between tick and other hrtimers
|
|
Pull perf fixes from Ingo Molnar:
"Misc race fixes uncovered by fuzzing efforts, a Sparse fix, two PMU
driver fixes, plus miscellanous tooling fixes"
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf/x86: Reject non sampling events with precise_ip
perf/x86/intel: Account interrupts for PEBS errors
perf/core: Fix concurrent sys_perf_event_open() vs. 'move_group' race
perf/core: Fix sys_perf_event_open() vs. hotplug
perf/x86/intel: Use ULL constant to prevent undefined shift behaviour
perf/x86/intel/uncore: Fix hardcoded socket 0 assumption in the Haswell init code
perf/x86: Set pmu->module in Intel PMU modules
perf probe: Fix to probe on gcc generated symbols for offline kernel
perf probe: Fix --funcs to show correct symbols for offline module
perf symbols: Robustify reading of build-id from sysfs
perf tools: Install tools/lib/traceevent plugins with install-bin
tools lib traceevent: Fix prev/next_prio for deadline tasks
perf record: Fix --switch-output documentation and comment
perf record: Make __record_options static
tools lib subcmd: Add OPT_STRING_OPTARG_SET option
perf probe: Fix to get correct modname from elf header
samples/bpf trace_output_user: Remove duplicate sys/ioctl.h include
samples/bpf sock_example: Avoid getting ethhdr from two includes
perf sched timehist: Show total scheduling time
|
|
The current preemptible RCU implementation goes through three phases
during bootup. In the first phase, there is only one CPU that is running
with preemption disabled, so that a no-op is a synchronous grace period.
In the second mid-boot phase, the scheduler is running, but RCU has
not yet gotten its kthreads spawned (and, for expedited grace periods,
workqueues are not yet running. During this time, any attempt to do
a synchronous grace period will hang the system (or complain bitterly,
depending). In the third and final phase, RCU is fully operational and
everything works normally.
This has been OK for some time, but there has recently been some
synchronous grace periods showing up during the second mid-boot phase.
This code worked "by accident" for awhile, but started failing as soon
as expedited RCU grace periods switched over to workqueues in commit
8b355e3bc140 ("rcu: Drive expedited grace periods from workqueue").
Note that the code was buggy even before this commit, as it was subject
to failure on real-time systems that forced all expedited grace periods
to run as normal grace periods (for example, using the rcu_normal ksysfs
parameter). The callchain from the failure case is as follows:
early_amd_iommu_init()
|-> acpi_put_table(ivrs_base);
|-> acpi_tb_put_table(table_desc);
|-> acpi_tb_invalidate_table(table_desc);
|-> acpi_tb_release_table(...)
|-> acpi_os_unmap_memory
|-> acpi_os_unmap_iomem
|-> acpi_os_map_cleanup
|-> synchronize_rcu_expedited
The kernel showing this callchain was built with CONFIG_PREEMPT_RCU=y,
which caused the code to try using workqueues before they were
initialized, which did not go well.
This commit therefore reworks RCU to permit synchronous grace periods
to proceed during this mid-boot phase. This commit is therefore a
fix to a regression introduced in v4.9, and is therefore being put
forward post-merge-window in v4.10.
This commit sets a flag from the existing rcu_scheduler_starting()
function which causes all synchronous grace periods to take the expedited
path. The expedited path now checks this flag, using the requesting task
to drive the expedited grace period forward during the mid-boot phase.
Finally, this flag is updated by a core_initcall() function named
rcu_exp_runtime_mode(), which causes the runtime codepaths to be used.
Note that this arrangement assumes that tasks are not sent POSIX signals
(or anything similar) from the time that the first task is spawned
through core_initcall() time.
Fixes: 8b355e3bc140 ("rcu: Drive expedited grace periods from workqueue")
Reported-by: "Zheng, Lv" <lv.zheng@intel.com>
Reported-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Tested-by: Stan Kain <stan.kain@gmail.com>
Tested-by: Ivan <waffolz@hotmail.com>
Tested-by: Emanuel Castelo <emanuel.castelo@gmail.com>
Tested-by: Bruno Pesavento <bpesavento@infinito.it>
Tested-by: Borislav Petkov <bp@suse.de>
Tested-by: Frederic Bezies <fredbezies@gmail.com>
Cc: <stable@vger.kernel.org> # 4.9.0-
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|
It is now legal to invoke synchronize_sched() at early boot, which causes
Tiny RCU's synchronize_sched() to emit spurious splats. This commit
therefore removes the cond_resched() from Tiny RCU's synchronize_sched().
Fixes: 8b355e3bc140 ("rcu: Drive expedited grace periods from workqueue")
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: <stable@vger.kernel.org> # 4.9.0-
|
|
It's possible to set up PEBS events to get only errors and not
any data, like on SNB-X (model 45) and IVB-EP (model 62)
via 2 perf commands running simultaneously:
taskset -c 1 ./perf record -c 4 -e branches:pp -j any -C 10
This leads to a soft lock up, because the error path of the
intel_pmu_drain_pebs_nhm() does not account event->hw.interrupt
for error PEBS interrupts, so in case you're getting ONLY
errors you don't have a way to stop the event when it's over
the max_samples_per_tick limit:
NMI watchdog: BUG: soft lockup - CPU#22 stuck for 22s! [perf_fuzzer:5816]
...
RIP: 0010:[<ffffffff81159232>] [<ffffffff81159232>] smp_call_function_single+0xe2/0x140
...
Call Trace:
? trace_hardirqs_on_caller+0xf5/0x1b0
? perf_cgroup_attach+0x70/0x70
perf_install_in_context+0x199/0x1b0
? ctx_resched+0x90/0x90
SYSC_perf_event_open+0x641/0xf90
SyS_perf_event_open+0x9/0x10
do_syscall_64+0x6c/0x1f0
entry_SYSCALL64_slow_path+0x25/0x25
Add perf_event_account_interrupt() which does the interrupt
and frequency checks and call it from intel_pmu_drain_pebs_nhm()'s
error path.
We keep the pending_kill and pending_wakeup logic only in the
__perf_event_overflow() path, because they make sense only if
there's any data to deliver.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
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: 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 <vince@deater.net>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Link: http://lkml.kernel.org/r/1482931866-6018-2-git-send-email-jolsa@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
|
|
Di Shen reported a race between two concurrent sys_perf_event_open()
calls where both try and move the same pre-existing software group
into a hardware context.
The problem is exactly that described in commit:
f63a8daa5812 ("perf: Fix event->ctx locking")
... where, while we wait for a ctx->mutex acquisition, the event->ctx
relation can have changed under us.
That very same commit failed to recognise sys_perf_event_context() as an
external access vector to the events and thereby didn't apply the
established locking rules correctly.
So while one sys_perf_event_open() call is stuck waiting on
mutex_lock_double(), the other (which owns said locks) moves the group
about. So by the time the former sys_perf_event_open() acquires the
locks, the context we've acquired is stale (and possibly dead).
Apply the established locking rules as per perf_event_ctx_lock_nested()
to the mutex_lock_double() for the 'move_group' case. This obviously means
we need to validate state after we acquire the locks.
Reported-by: Di Shen (Keen Lab)
Tested-by: John Dias <joaodias@google.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: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Min Chong <mchong@google.com>
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>
Fixes: f63a8daa5812 ("perf: Fix event->ctx locking")
Link: http://lkml.kernel.org/r/20170106131444.GZ3174@twins.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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There is problem with installing an event in a task that is 'stuck' on
an offline CPU.
Blocked tasks are not dis-assosciated from offlined CPUs, after all, a
blocked task doesn't run and doesn't require a CPU etc.. Only on
wakeup do we ammend the situation and place the task on a available
CPU.
If we hit such a task with perf_install_in_context() we'll loop until
either that task wakes up or the CPU comes back online, if the task
waking depends on the event being installed, we're stuck.
While looking into this issue, I also spotted another problem, if we
hit a task with perf_install_in_context() that is in the middle of
being migrated, that is we observe the old CPU before sending the IPI,
but run the IPI (on the old CPU) while the task is already running on
the new CPU, things also go sideways.
Rework things to rely on task_curr() -- outside of rq->lock -- which
is rather tricky. Imagine the following scenario where we're trying to
install the first event into our task 't':
CPU0 CPU1 CPU2
(current == t)
t->perf_event_ctxp[] = ctx;
smp_mb();
cpu = task_cpu(t);
switch(t, n);
migrate(t, 2);
switch(p, t);
ctx = t->perf_event_ctxp[]; // must not be NULL
smp_function_call(cpu, ..);
generic_exec_single()
func();
spin_lock(ctx->lock);
if (task_curr(t)) // false
add_event_to_ctx();
spin_unlock(ctx->lock);
perf_event_context_sched_in();
spin_lock(ctx->lock);
// sees event
So its CPU0's store of t->perf_event_ctxp[] that must not go 'missing'.
Because if CPU2's load of that variable were to observe NULL, it would
not try to schedule the ctx and we'd have a task running without its
counter, which would be 'bad'.
As long as we observe !NULL, we'll acquire ctx->lock. If we acquire it
first and not see the event yet, then CPU0 must observe task_curr()
and retry. If the install happens first, then we must see the event on
sched-in and all is well.
I think we can translate the first part (until the 'must not be NULL')
of the scenario to a litmus test like:
C C-peterz
{
}
P0(int *x, int *y)
{
int r1;
WRITE_ONCE(*x, 1);
smp_mb();
r1 = READ_ONCE(*y);
}
P1(int *y, int *z)
{
WRITE_ONCE(*y, 1);
smp_store_release(z, 1);
}
P2(int *x, int *z)
{
int r1;
int r2;
r1 = smp_load_acquire(z);
smp_mb();
r2 = READ_ONCE(*x);
}
exists
(0:r1=0 /\ 2:r1=1 /\ 2:r2=0)
Where:
x is perf_event_ctxp[],
y is our tasks's CPU, and
z is our task being placed on the rq of CPU2.
The P0 smp_mb() is the one added by this patch, ordering the store to
perf_event_ctxp[] from find_get_context() and the load of task_cpu()
in task_function_call().
The smp_store_release/smp_load_acquire model the RCpc locking of the
rq->lock and the smp_mb() of P2 is the context switch switching from
whatever CPU2 was running to our task 't'.
This litmus test evaluates into:
Test C-peterz Allowed
States 7
0:r1=0; 2:r1=0; 2:r2=0;
0:r1=0; 2:r1=0; 2:r2=1;
0:r1=0; 2:r1=1; 2:r2=1;
0:r1=1; 2:r1=0; 2:r2=0;
0:r1=1; 2:r1=0; 2:r2=1;
0:r1=1; 2:r1=1; 2:r2=0;
0:r1=1; 2:r1=1; 2:r2=1;
No
Witnesses
Positive: 0 Negative: 7
Condition exists (0:r1=0 /\ 2:r1=1 /\ 2:r2=0)
Observation C-peterz Never 0 7
Hash=e427f41d9146b2a5445101d3e2fcaa34
And the strong and weak model agree.
Reported-by: Mark Rutland <mark.rutland@arm.com>
Tested-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: 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: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: Will Deacon <will.deacon@arm.com>
Cc: jeremy.linton@arm.com
Link: http://lkml.kernel.org/r/20161209135900.GU3174@twins.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Pull VFIO fixes from Alex Williamson:
- Cleanups and bug fixes for the mtty sample driver (Dan Carpenter)
- Export and make use of has_capability() to fix incorrect use of
ns_capable() for testing task capabilities (Jike Song)
* tag 'vfio-v4.10-rc4' of git://github.com/awilliam/linux-vfio:
vfio/type1: Remove pid_namespace.h include
vfio iommu type1: fix the testing of capability for remote task
capability: export has_capability
vfio-mdev: remove some dead code
vfio-mdev: buffer overflow in ioctl()
vfio-mdev: return -EFAULT if copy_to_user() fails
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Pull KVM fixes from Paolo Bonzini:
- fix for module unload vs deferred jump labels (note: there might be
other buggy modules!)
- two NULL pointer dereferences from syzkaller
- also syzkaller: fix emulation of fxsave/fxrstor/sgdt/sidt, problem
made worse during this merge window, "just" kernel memory leak on
releases
- fix emulation of "mov ss" - somewhat serious on AMD, less so on Intel
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
KVM: x86: fix emulation of "MOV SS, null selector"
KVM: x86: fix NULL deref in vcpu_scan_ioapic
KVM: eventfd: fix NULL deref irqbypass consumer
KVM: x86: Introduce segmented_write_std
KVM: x86: flush pending lapic jump label updates on module unload
jump_labels: API for flushing deferred jump label updates
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When structs are used to store temporary state in cb[] buffer that is
used with programs and among tail calls, then the generated code will
not always access the buffer in bpf_w chunks. We can ease programming
of it and let this act more natural by allowing for aligned b/h/w/dw
sized access for cb[] ctx member. Various test cases are attached as
well for the selftest suite. Potentially, this can also be reused for
other program types to pass data around.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Currently, when calling convert_ctx_access() callback for the various
program types, we pass in insn->dst_reg, insn->src_reg, insn->off from
the original instruction. This information is needed to rewrite the
instruction that is based on the user ctx structure into a kernel
representation for the ctx. As we'd like to allow access size beyond
just BPF_W, we'd need also insn->code for that in order to decode the
original access size. Given that, lets just pass insn directly to the
convert_ctx_access() callback and work on that to not clutter the
callback with even more arguments we need to pass when everything is
already contained in insn. So lets go through that once, no functional
change.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
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has_capability() is sometimes needed by modules to test capability
for specified task other than current, so export it.
Cc: Kirti Wankhede <kwankhede@nvidia.com>
Signed-off-by: Jike Song <jike.song@intel.com>
Acked-by: Serge Hallyn <serge@hallyn.com>
Acked-by: James Morris <james.l.morris@oracle.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
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Modules that use static_key_deferred need a way to synchronize with
any delayed work that is still pending when the module is unloaded.
Introduce static_key_deferred_flush() which flushes any pending
jump label updates.
Signed-off-by: David Matlack <dmatlack@google.com>
Cc: stable@vger.kernel.org
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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Two AF_* families adding entries to the lockdep tables
at the same time.
Signed-off-by: David S. Miller <davem@davemloft.net>
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When the tick is stopped and an interrupt occurs afterward, we check on
that interrupt exit if the next tick needs to be rescheduled. If it
doesn't need any update, we don't want to do anything.
In order to check if the tick needs an update, we compare it against the
clockevent device deadline. Now that's a problem because the clockevent
device is at a lower level than the tick itself if it is implemented
on top of hrtimer.
Every hrtimer share this clockevent device. So comparing the next tick
deadline against the clockevent device deadline is wrong because the
device may be programmed for another hrtimer whose deadline collides
with the tick. As a result we may end up not reprogramming the tick
accidentally.
In a worst case scenario under full dynticks mode, the tick stops firing
as it is supposed to every 1hz, leaving /proc/stat stalled:
Task in a full dynticks CPU
----------------------------
* hrtimer A is queued 2 seconds ahead
* the tick is stopped, scheduled 1 second ahead
* tick fires 1 second later
* on tick exit, nohz schedules the tick 1 second ahead but sees
the clockevent device is already programmed to that deadline,
fooled by hrtimer A, the tick isn't rescheduled.
* hrtimer A is cancelled before its deadline
* tick never fires again until an interrupt happens...
In order to fix this, store the next tick deadline to the tick_sched
local structure and reuse that value later to check whether we need to
reprogram the clock after an interrupt.
On the other hand, ts->sleep_length still wants to know about the next
clock event and not just the tick, so we want to improve the related
comment to avoid confusion.
Reported-by: James Hartsock <hartsjc@redhat.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Reviewed-by: Wanpeng Li <wanpeng.li@hotmail.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Rik van Riel <riel@redhat.com>
Link: http://lkml.kernel.org/r/1483539124-5693-1-git-send-email-fweisbec@gmail.com
Cc: stable@vger.kernel.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
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Since commit 00cd5c37afd5 ("ptrace: permit ptracing of /sbin/init") we
can now trace init processes. init is initially protected with
SIGNAL_UNKILLABLE which will prevent fatal signals such as SIGSTOP, but
there are a number of paths during tracing where SIGNAL_UNKILLABLE can
be implicitly cleared.
This can result in init becoming stoppable/killable after tracing. For
example, running:
while true; do kill -STOP 1; done &
strace -p 1
and then stopping strace and the kill loop will result in init being
left in state TASK_STOPPED. Sending SIGCONT to init will resume it, but
init will now respond to future SIGSTOP signals rather than ignoring
them.
Make sure that when setting SIGNAL_STOP_CONTINUED/SIGNAL_STOP_STOPPED
that we don't clear SIGNAL_UNKILLABLE.
Link: http://lkml.kernel.org/r/20170104122017.25047-1-jamie.iles@oracle.com
Signed-off-by: Jamie Iles <jamie.iles@oracle.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Both arch_add_memory() and arch_remove_memory() expect a single threaded
context.
For example, arch/x86/mm/init_64.c::kernel_physical_mapping_init() does
not hold any locks over this check and branch:
if (pgd_val(*pgd)) {
pud = (pud_t *)pgd_page_vaddr(*pgd);
paddr_last = phys_pud_init(pud, __pa(vaddr),
__pa(vaddr_end),
page_size_mask);
continue;
}
pud = alloc_low_page();
paddr_last = phys_pud_init(pud, __pa(vaddr), __pa(vaddr_end),
page_size_mask);
The result is that two threads calling devm_memremap_pages()
simultaneously can end up colliding on pgd initialization. This leads
to crash signatures like the following where the loser of the race
initializes the wrong pgd entry:
BUG: unable to handle kernel paging request at ffff888ebfff0000
IP: memcpy_erms+0x6/0x10
PGD 2f8e8fc067 PUD 0 /* <---- Invalid PUD */
Oops: 0000 [#1] SMP DEBUG_PAGEALLOC
CPU: 54 PID: 3818 Comm: systemd-udevd Not tainted 4.6.7+ #13
task: ffff882fac290040 ti: ffff882f887a4000 task.ti: ffff882f887a4000
RIP: memcpy_erms+0x6/0x10
[..]
Call Trace:
? pmem_do_bvec+0x205/0x370 [nd_pmem]
? blk_queue_enter+0x3a/0x280
pmem_rw_page+0x38/0x80 [nd_pmem]
bdev_read_page+0x84/0xb0
Hold the standard memory hotplug mutex over calls to
arch_{add,remove}_memory().
Fixes: 41e94a851304 ("add devm_memremap_pages")
Link: http://lkml.kernel.org/r/148357647831.9498.12606007370121652979.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Commit 01b3f52157ff ("bpf: fix allocation warnings in bpf maps and
integer overflow") has added checks for the maximum allocateable size.
It (ab)used KMALLOC_SHIFT_MAX for that purpose.
While this is not incorrect it is not very clean because we already have
KMALLOC_MAX_SIZE for this very reason so let's change both checks to use
KMALLOC_MAX_SIZE instead.
The original motivation for using KMALLOC_SHIFT_MAX was to work around
an incorrect KMALLOC_MAX_SIZE which could lead to allocation warnings
but it is no longer needed since "slab: make sure that KMALLOC_MAX_SIZE
will fit into MAX_ORDER".
Link: http://lkml.kernel.org/r/20161220130659.16461-3-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Acked-by: Christoph Lameter <cl@linux.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Make the functions __local_list_pop_free(), __local_list_pop_pending(),
bpf_common_lru_populate() and bpf_percpu_lru_populate() static as they
are not used outide of bpf_lru_list.c
This fixes the following GCC warnings when building with 'W=1':
kernel/bpf/bpf_lru_list.c:363:22: warning: no previous prototype for ‘__local_list_pop_free’ [-Wmissing-prototypes]
kernel/bpf/bpf_lru_list.c:376:22: warning: no previous prototype for ‘__local_list_pop_pending’ [-Wmissing-prototypes]
kernel/bpf/bpf_lru_list.c:560:6: warning: no previous prototype for ‘bpf_common_lru_populate’ [-Wmissing-prototypes]
kernel/bpf/bpf_lru_list.c:577:6: warning: no previous prototype for ‘bpf_percpu_lru_populate’ [-Wmissing-prototypes]
Cc: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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David S. Miller
Linus Torvalds
Rafael J. Wysocki
Eric Dumazet
Daniel Borkmann
Jiri Slaby
Don Zickus
Daniel Mack
Nikolay Borisov
Gianluca Borello
Tobias Klauser
Larry Finger
Thomas Gleixner
Ingo Molnar
Paul E. McKenney
Jiri Olsa
Peter Zijlstra
Jike Song
David Matlack
Frederic Weisbecker
Jamie Iles
Dan Williams
Michal Hocko