Commit Graph

25308 Commits

Author SHA1 Message Date
Linus Torvalds f79ec886f9 Three minor updates
- Use of the new GFP_RETRY_MAYFAIL to be more aggressive in allocating
    memory for the ring buffer without causing OOMs
 
  - Fix a memory leak in adding and removing instances
 
  - Add __rcu annotation to be able to debug RCU usage of function
    tracing a bit better.
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Merge tag 'trace-v4.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fixes from Steven Rostedt:
 "Three minor updates

   - Use the new GFP_RETRY_MAYFAIL to be more aggressive in allocating
     memory for the ring buffer without causing OOMs

   - Fix a memory leak in adding and removing instances

   - Add __rcu annotation to be able to debug RCU usage of function
     tracing a bit better"

* tag 'trace-v4.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  trace: fix the errors caused by incompatible type of RCU variables
  tracing: Fix kmemleak in instance_rmdir
  tracing/ring_buffer: Try harder to allocate
2017-07-21 13:59:51 -07:00
Linus Torvalds 5a77f0254b Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler fixes from Ingo Molnar:
 "A cputime fix and code comments/organization fix to the deadline
  scheduler"

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/deadline: Fix confusing comments about selection of top pi-waiter
  sched/cputime: Don't use smp_processor_id() in preemptible context
2017-07-21 11:16:12 -07:00
Linus Torvalds bbcdea658f Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf fixes from Ingo Molnar:
 "Two hw-enablement patches, two race fixes, three fixes for regressions
  of semantics, plus a number of tooling fixes"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/x86/intel: Add proper condition to run sched_task callbacks
  perf/core: Fix locking for children siblings group read
  perf/core: Fix scheduling regression of pinned groups
  perf/x86/intel: Fix debug_store reset field for freq events
  perf/x86/intel: Add Goldmont Plus CPU PMU support
  perf/x86/intel: Enable C-state residency events for Apollo Lake
  perf symbols: Accept zero as the kernel base address
  Revert "perf/core: Drop kernel samples even though :u is specified"
  perf annotate: Fix broken arrow at row 0 connecting jmp instruction to its target
  perf evsel: State in the default event name if attr.exclude_kernel is set
  perf evsel: Fix attr.exclude_kernel setting for default cycles:p
2017-07-21 11:12:48 -07:00
Linus Torvalds 8b810a3a35 Merge branch 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking fixlet from Ingo Molnar:
 "Remove an unnecessary priority adjustment in the rtmutex code"

* 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  locking/rtmutex: Remove unnecessary priority adjustment
2017-07-21 11:11:23 -07:00
Linus Torvalds 34eddefee4 Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull irq fixes from Ingo Molnar:
 "A resume_irq() fix, plus a number of static declaration fixes"

* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  irqchip/digicolor: Drop unnecessary static
  irqchip/mips-cpu: Drop unnecessary static
  irqchip/gic/realview: Drop unnecessary static
  irqchip/mips-gic: Remove population of irq domain names
  genirq/PM: Properly pretend disabled state when force resuming interrupts
2017-07-21 11:07:41 -07:00
Jiri Olsa 2aeb188354 perf/core: Fix locking for children siblings group read
We're missing ctx lock when iterating children siblings
within the perf_read path for group reading. Following
race and crash can happen:

User space doing read syscall on event group leader:

T1:
  perf_read
    lock event->ctx->mutex
    perf_read_group
      lock leader->child_mutex
      __perf_read_group_add(child)
        list_for_each_entry(sub, &leader->sibling_list, group_entry)

---->   sub might be invalid at this point, because it could
        get removed via perf_event_exit_task_context in T2

Child exiting and cleaning up its events:

T2:
  perf_event_exit_task_context
    lock ctx->mutex
    list_for_each_entry_safe(child_event, next, &child_ctx->event_list,...
      perf_event_exit_event(child)
        lock ctx->lock
        perf_group_detach(child)
        unlock ctx->lock

---->   child is removed from sibling_list without any sync
        with T1 path above

        ...
        free_event(child)

Before the child is removed from the leader's child_list,
(and thus is omitted from perf_read_group processing), we
need to ensure that perf_read_group touches child's
siblings under its ctx->lock.

Peter further notes:

| One additional note; this bug got exposed by commit:
|
|   ba5213ae6b ("perf/core: Correct event creation with PERF_FORMAT_GROUP")
|
| which made it possible to actually trigger this code-path.

Tested-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: ba5213ae6b ("perf/core: Correct event creation with PERF_FORMAT_GROUP")
Link: http://lkml.kernel.org/r/20170720141455.2106-1-jolsa@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-07-21 09:54:23 +02:00
Linus Torvalds 96080f6977 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Pull networking fixes from David Miller:

 1) BPF verifier signed/unsigned value tracking fix, from Daniel
    Borkmann, Edward Cree, and Josef Bacik.

 2) Fix memory allocation length when setting up calls to
    ->ndo_set_mac_address, from Cong Wang.

 3) Add a new cxgb4 device ID, from Ganesh Goudar.

 4) Fix FIB refcount handling, we have to set it's initial value before
    the configure callback (which can bump it). From David Ahern.

 5) Fix double-free in qcom/emac driver, from Timur Tabi.

 6) A bunch of gcc-7 string format overflow warning fixes from Arnd
    Bergmann.

 7) Fix link level headroom tests in ip_do_fragment(), from Vasily
    Averin.

 8) Fix chunk walking in SCTP when iterating over error and parameter
    headers. From Alexander Potapenko.

 9) TCP BBR congestion control fixes from Neal Cardwell.

10) Fix SKB fragment handling in bcmgenet driver, from Doug Berger.

11) BPF_CGROUP_RUN_PROG_SOCK_OPS needs to check for null __sk, from Cong
    Wang.

12) xmit_recursion in ppp driver needs to be per-device not per-cpu,
    from Gao Feng.

13) Cannot release skb->dst in UDP if IP options processing needs it.
    From Paolo Abeni.

14) Some netdev ioctl ifr_name[] NULL termination fixes. From Alexander
    Levin and myself.

15) Revert some rtnetlink notification changes that are causing
    regressions, from David Ahern.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (83 commits)
  net: bonding: Fix transmit load balancing in balance-alb mode
  rds: Make sure updates to cp_send_gen can be observed
  net: ethernet: ti: cpsw: Push the request_irq function to the end of probe
  ipv4: initialize fib_trie prior to register_netdev_notifier call.
  rtnetlink: allocate more memory for dev_set_mac_address()
  net: dsa: b53: Add missing ARL entries for BCM53125
  bpf: more tests for mixed signed and unsigned bounds checks
  bpf: add test for mixed signed and unsigned bounds checks
  bpf: fix up test cases with mixed signed/unsigned bounds
  bpf: allow to specify log level and reduce it for test_verifier
  bpf: fix mixed signed/unsigned derived min/max value bounds
  ipv6: avoid overflow of offset in ip6_find_1stfragopt
  net: tehuti: don't process data if it has not been copied from userspace
  Revert "rtnetlink: Do not generate notifications for CHANGEADDR event"
  net: dsa: mv88e6xxx: Enable CMODE config support for 6390X
  dt-binding: ptp: Add SoC compatibility strings for dte ptp clock
  NET: dwmac: Make dwmac reset unconditional
  net: Zero terminate ifr_name in dev_ifname().
  wireless: wext: terminate ifr name coming from userspace
  netfilter: fix netfilter_net_init() return
  ...
2017-07-20 16:33:39 -07:00
Daniel Borkmann 4cabc5b186 bpf: fix mixed signed/unsigned derived min/max value bounds
Edward reported that there's an issue in min/max value bounds
tracking when signed and unsigned compares both provide hints
on limits when having unknown variables. E.g. a program such
as the following should have been rejected:

   0: (7a) *(u64 *)(r10 -8) = 0
   1: (bf) r2 = r10
   2: (07) r2 += -8
   3: (18) r1 = 0xffff8a94cda93400
   5: (85) call bpf_map_lookup_elem#1
   6: (15) if r0 == 0x0 goto pc+7
  R0=map_value(ks=8,vs=8,id=0),min_value=0,max_value=0 R10=fp
   7: (7a) *(u64 *)(r10 -16) = -8
   8: (79) r1 = *(u64 *)(r10 -16)
   9: (b7) r2 = -1
  10: (2d) if r1 > r2 goto pc+3
  R0=map_value(ks=8,vs=8,id=0),min_value=0,max_value=0 R1=inv,min_value=0
  R2=imm-1,max_value=18446744073709551615,min_align=1 R10=fp
  11: (65) if r1 s> 0x1 goto pc+2
  R0=map_value(ks=8,vs=8,id=0),min_value=0,max_value=0 R1=inv,min_value=0,max_value=1
  R2=imm-1,max_value=18446744073709551615,min_align=1 R10=fp
  12: (0f) r0 += r1
  13: (72) *(u8 *)(r0 +0) = 0
  R0=map_value_adj(ks=8,vs=8,id=0),min_value=0,max_value=1 R1=inv,min_value=0,max_value=1
  R2=imm-1,max_value=18446744073709551615,min_align=1 R10=fp
  14: (b7) r0 = 0
  15: (95) exit

What happens is that in the first part ...

   8: (79) r1 = *(u64 *)(r10 -16)
   9: (b7) r2 = -1
  10: (2d) if r1 > r2 goto pc+3

... r1 carries an unsigned value, and is compared as unsigned
against a register carrying an immediate. Verifier deduces in
reg_set_min_max() that since the compare is unsigned and operation
is greater than (>), that in the fall-through/false case, r1's
minimum bound must be 0 and maximum bound must be r2. Latter is
larger than the bound and thus max value is reset back to being
'invalid' aka BPF_REGISTER_MAX_RANGE. Thus, r1 state is now
'R1=inv,min_value=0'. The subsequent test ...

  11: (65) if r1 s> 0x1 goto pc+2

... is a signed compare of r1 with immediate value 1. Here,
verifier deduces in reg_set_min_max() that since the compare
is signed this time and operation is greater than (>), that
in the fall-through/false case, we can deduce that r1's maximum
bound must be 1, meaning with prior test, we result in r1 having
the following state: R1=inv,min_value=0,max_value=1. Given that
the actual value this holds is -8, the bounds are wrongly deduced.
When this is being added to r0 which holds the map_value(_adj)
type, then subsequent store access in above case will go through
check_mem_access() which invokes check_map_access_adj(), that
will then probe whether the map memory is in bounds based
on the min_value and max_value as well as access size since
the actual unknown value is min_value <= x <= max_value; commit
fce366a9dd ("bpf, verifier: fix alu ops against map_value{,
_adj} register types") provides some more explanation on the
semantics.

It's worth to note in this context that in the current code,
min_value and max_value tracking are used for two things, i)
dynamic map value access via check_map_access_adj() and since
commit 06c1c04972 ("bpf: allow helpers access to variable memory")
ii) also enforced at check_helper_mem_access() when passing a
memory address (pointer to packet, map value, stack) and length
pair to a helper and the length in this case is an unknown value
defining an access range through min_value/max_value in that
case. The min_value/max_value tracking is /not/ used in the
direct packet access case to track ranges. However, the issue
also affects case ii), for example, the following crafted program
based on the same principle must be rejected as well:

   0: (b7) r2 = 0
   1: (bf) r3 = r10
   2: (07) r3 += -512
   3: (7a) *(u64 *)(r10 -16) = -8
   4: (79) r4 = *(u64 *)(r10 -16)
   5: (b7) r6 = -1
   6: (2d) if r4 > r6 goto pc+5
  R1=ctx R2=imm0,min_value=0,max_value=0,min_align=2147483648 R3=fp-512
  R4=inv,min_value=0 R6=imm-1,max_value=18446744073709551615,min_align=1 R10=fp
   7: (65) if r4 s> 0x1 goto pc+4
  R1=ctx R2=imm0,min_value=0,max_value=0,min_align=2147483648 R3=fp-512
  R4=inv,min_value=0,max_value=1 R6=imm-1,max_value=18446744073709551615,min_align=1
  R10=fp
   8: (07) r4 += 1
   9: (b7) r5 = 0
  10: (6a) *(u16 *)(r10 -512) = 0
  11: (85) call bpf_skb_load_bytes#26
  12: (b7) r0 = 0
  13: (95) exit

Meaning, while we initialize the max_value stack slot that the
verifier thinks we access in the [1,2] range, in reality we
pass -7 as length which is interpreted as u32 in the helper.
Thus, this issue is relevant also for the case of helper ranges.
Resetting both bounds in check_reg_overflow() in case only one
of them exceeds limits is also not enough as similar test can be
created that uses values which are within range, thus also here
learned min value in r1 is incorrect when mixed with later signed
test to create a range:

   0: (7a) *(u64 *)(r10 -8) = 0
   1: (bf) r2 = r10
   2: (07) r2 += -8
   3: (18) r1 = 0xffff880ad081fa00
   5: (85) call bpf_map_lookup_elem#1
   6: (15) if r0 == 0x0 goto pc+7
  R0=map_value(ks=8,vs=8,id=0),min_value=0,max_value=0 R10=fp
   7: (7a) *(u64 *)(r10 -16) = -8
   8: (79) r1 = *(u64 *)(r10 -16)
   9: (b7) r2 = 2
  10: (3d) if r2 >= r1 goto pc+3
  R0=map_value(ks=8,vs=8,id=0),min_value=0,max_value=0 R1=inv,min_value=3
  R2=imm2,min_value=2,max_value=2,min_align=2 R10=fp
  11: (65) if r1 s> 0x4 goto pc+2
  R0=map_value(ks=8,vs=8,id=0),min_value=0,max_value=0
  R1=inv,min_value=3,max_value=4 R2=imm2,min_value=2,max_value=2,min_align=2 R10=fp
  12: (0f) r0 += r1
  13: (72) *(u8 *)(r0 +0) = 0
  R0=map_value_adj(ks=8,vs=8,id=0),min_value=3,max_value=4
  R1=inv,min_value=3,max_value=4 R2=imm2,min_value=2,max_value=2,min_align=2 R10=fp
  14: (b7) r0 = 0
  15: (95) exit

This leaves us with two options for fixing this: i) to invalidate
all prior learned information once we switch signed context, ii)
to track min/max signed and unsigned boundaries separately as
done in [0]. (Given latter introduces major changes throughout
the whole verifier, it's rather net-next material, thus this
patch follows option i), meaning we can derive bounds either
from only signed tests or only unsigned tests.) There is still the
case of adjust_reg_min_max_vals(), where we adjust bounds on ALU
operations, meaning programs like the following where boundaries
on the reg get mixed in context later on when bounds are merged
on the dst reg must get rejected, too:

   0: (7a) *(u64 *)(r10 -8) = 0
   1: (bf) r2 = r10
   2: (07) r2 += -8
   3: (18) r1 = 0xffff89b2bf87ce00
   5: (85) call bpf_map_lookup_elem#1
   6: (15) if r0 == 0x0 goto pc+6
  R0=map_value(ks=8,vs=8,id=0),min_value=0,max_value=0 R10=fp
   7: (7a) *(u64 *)(r10 -16) = -8
   8: (79) r1 = *(u64 *)(r10 -16)
   9: (b7) r2 = 2
  10: (3d) if r2 >= r1 goto pc+2
  R0=map_value(ks=8,vs=8,id=0),min_value=0,max_value=0 R1=inv,min_value=3
  R2=imm2,min_value=2,max_value=2,min_align=2 R10=fp
  11: (b7) r7 = 1
  12: (65) if r7 s> 0x0 goto pc+2
  R0=map_value(ks=8,vs=8,id=0),min_value=0,max_value=0 R1=inv,min_value=3
  R2=imm2,min_value=2,max_value=2,min_align=2 R7=imm1,max_value=0 R10=fp
  13: (b7) r0 = 0
  14: (95) exit

  from 12 to 15: R0=map_value(ks=8,vs=8,id=0),min_value=0,max_value=0
  R1=inv,min_value=3 R2=imm2,min_value=2,max_value=2,min_align=2 R7=imm1,min_value=1 R10=fp
  15: (0f) r7 += r1
  16: (65) if r7 s> 0x4 goto pc+2
  R0=map_value(ks=8,vs=8,id=0),min_value=0,max_value=0 R1=inv,min_value=3
  R2=imm2,min_value=2,max_value=2,min_align=2 R7=inv,min_value=4,max_value=4 R10=fp
  17: (0f) r0 += r7
  18: (72) *(u8 *)(r0 +0) = 0
  R0=map_value_adj(ks=8,vs=8,id=0),min_value=4,max_value=4 R1=inv,min_value=3
  R2=imm2,min_value=2,max_value=2,min_align=2 R7=inv,min_value=4,max_value=4 R10=fp
  19: (b7) r0 = 0
  20: (95) exit

Meaning, in adjust_reg_min_max_vals() we must also reset range
values on the dst when src/dst registers have mixed signed/
unsigned derived min/max value bounds with one unbounded value
as otherwise they can be added together deducing false boundaries.
Once both boundaries are established from either ALU ops or
compare operations w/o mixing signed/unsigned insns, then they
can safely be added to other regs also having both boundaries
established. Adding regs with one unbounded side to a map value
where the bounded side has been learned w/o mixing ops is
possible, but the resulting map value won't recover from that,
meaning such op is considered invalid on the time of actual
access. Invalid bounds are set on the dst reg in case i) src reg,
or ii) in case dst reg already had them. The only way to recover
would be to perform i) ALU ops but only 'add' is allowed on map
value types or ii) comparisons, but these are disallowed on
pointers in case they span a range. This is fine as only BPF_JEQ
and BPF_JNE may be performed on PTR_TO_MAP_VALUE_OR_NULL registers
which potentially turn them into PTR_TO_MAP_VALUE type depending
on the branch, so only here min/max value cannot be invalidated
for them.

In terms of state pruning, value_from_signed is considered
as well in states_equal() when dealing with adjusted map values.
With regards to breaking existing programs, there is a small
risk, but use-cases are rather quite narrow where this could
occur and mixing compares probably unlikely.

Joint work with Josef and Edward.

  [0] https://lists.iovisor.org/pipermail/iovisor-dev/2017-June/000822.html

Fixes: 484611357c ("bpf: allow access into map value arrays")
Reported-by: Edward Cree <ecree@solarflare.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Edward Cree <ecree@solarflare.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-07-20 15:20:27 -07:00
Linus Torvalds f58781c983 Merge branch 'stable-4.13' of git://git.infradead.org/users/pcmoore/audit
Pull audit fix from Paul Moore:
 "A small audit fix, just a single line, to plug a memory leak in some
  audit error handling code"

* 'stable-4.13' of git://git.infradead.org/users/pcmoore/audit:
  audit: fix memleak in auditd_send_unicast_skb.
2017-07-20 10:22:26 -07:00
Chunyan Zhang f86f418059 trace: fix the errors caused by incompatible type of RCU variables
The variables which are processed by RCU functions should be annotated
as RCU, otherwise sparse will report the errors like below:

"error: incompatible types in comparison expression (different
address spaces)"

Link: http://lkml.kernel.org/r/1496823171-7758-1-git-send-email-zhang.chunyan@linaro.org

Signed-off-by: Chunyan Zhang <zhang.chunyan@linaro.org>
[ Updated to not be 100% 80 column strict ]
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-07-20 09:27:29 -04:00
Chunyu Hu db9108e054 tracing: Fix kmemleak in instance_rmdir
Hit the kmemleak when executing instance_rmdir, it forgot releasing
mem of tracing_cpumask. With this fix, the warn does not appear any
more.

unreferenced object 0xffff93a8dfaa7c18 (size 8):
  comm "mkdir", pid 1436, jiffies 4294763622 (age 9134.308s)
  hex dump (first 8 bytes):
    ff ff ff ff ff ff ff ff                          ........
  backtrace:
    [<ffffffff88b6567a>] kmemleak_alloc+0x4a/0xa0
    [<ffffffff8861ea41>] __kmalloc_node+0xf1/0x280
    [<ffffffff88b505d3>] alloc_cpumask_var_node+0x23/0x30
    [<ffffffff88b5060e>] alloc_cpumask_var+0xe/0x10
    [<ffffffff88571ab0>] instance_mkdir+0x90/0x240
    [<ffffffff886e5100>] tracefs_syscall_mkdir+0x40/0x70
    [<ffffffff886565c9>] vfs_mkdir+0x109/0x1b0
    [<ffffffff8865b1d0>] SyS_mkdir+0xd0/0x100
    [<ffffffff88403857>] do_syscall_64+0x67/0x150
    [<ffffffff88b710e7>] return_from_SYSCALL_64+0x0/0x6a
    [<ffffffffffffffff>] 0xffffffffffffffff

Link: http://lkml.kernel.org/r/1500546969-12594-1-git-send-email-chuhu@redhat.com

Cc: stable@vger.kernel.org
Fixes: ccfe9e42e4 ("tracing: Make tracing_cpumask available for all instances")
Signed-off-by: Chunyu Hu <chuhu@redhat.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-07-20 09:24:25 -04:00
Alexander Shishkin 3bda69c1c3 perf/core: Fix scheduling regression of pinned groups
Vince Weaver reported:

> I was tracking down some regressions in my perf_event_test testsuite.
> Some of the tests broke in the 4.11-rc1 timeframe.
>
> I've bisected one of them, this report is about
>	tests/overflow/simul_oneshot_group_overflow
> This test creates an event group containing two sampling events, set
> to overflow to a signal handler (which disables and then refreshes the
> event).
>
> On a good kernel you get the following:
> 	Event perf::instructions with period 1000000
> 	Event perf::instructions with period 2000000
> 		fd 3 overflows: 946 (perf::instructions/1000000)
> 		fd 4 overflows: 473 (perf::instructions/2000000)
> 	Ending counts:
> 		Count 0: 946379875
> 		Count 1: 946365218
>
> With the broken kernels you get:
> 	Event perf::instructions with period 1000000
> 	Event perf::instructions with period 2000000
> 		fd 3 overflows: 938 (perf::instructions/1000000)
> 		fd 4 overflows: 318 (perf::instructions/2000000)
> 	Ending counts:
> 		Count 0: 946373080
> 		Count 1: 653373058

The root cause of the bug is that the following commit:

  487f05e18a ("perf/core: Optimize event rescheduling on active contexts")

erronously assumed that event's 'pinned' setting determines whether the
event belongs to a pinned group or not, but in fact, it's the group
leader's pinned state that matters.

This was discovered by Vince in the test case described above, where two instruction
counters are grouped, the group leader is pinned, but the other event is not;
in the regressed case the counters were off by 33% (the difference between events'
periods), but should be the same within the error margin.

Fix the problem by looking at the group leader's pinning.

Reported-by: Vince Weaver <vincent.weaver@maine.edu>
Tested-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Fixes: 487f05e18a ("perf/core: Optimize event rescheduling on active contexts")
Link: http://lkml.kernel.org/r/87lgnmvw7h.fsf@ashishki-desk.ger.corp.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-07-20 09:43:02 +02:00
Linus Torvalds e06fdaf40a Now that IPC and other changes have landed, enable manual markings for
randstruct plugin, including the task_struct.
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Merge tag 'gcc-plugins-v4.13-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull structure randomization updates from Kees Cook:
 "Now that IPC and other changes have landed, enable manual markings for
  randstruct plugin, including the task_struct.

  This is the rest of what was staged in -next for the gcc-plugins, and
  comes in three patches, largest first:

   - mark "easy" structs with __randomize_layout

   - mark task_struct with an optional anonymous struct to isolate the
     __randomize_layout section

   - mark structs to opt _out_ of automated marking (which will come
     later)

  And, FWIW, this continues to pass allmodconfig (normal and patched to
  enable gcc-plugins) builds of x86_64, i386, arm64, arm, powerpc, and
  s390 for me"

* tag 'gcc-plugins-v4.13-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  randstruct: opt-out externally exposed function pointer structs
  task_struct: Allow randomized layout
  randstruct: Mark various structs for randomization
2017-07-19 08:55:18 -07:00
Shu Wang b0659ae5e3 audit: fix memleak in auditd_send_unicast_skb.
Found this issue by kmemleak report, auditd_send_unicast_skb
did not free skb if rcu_dereference(auditd_conn) returns null.

unreferenced object 0xffff88082568ce00 (size 256):
comm "auditd", pid 1119, jiffies 4294708499
backtrace:
[<ffffffff8176166a>] kmemleak_alloc+0x4a/0xa0
[<ffffffff8121820c>] kmem_cache_alloc_node+0xcc/0x210
[<ffffffff8161b99d>] __alloc_skb+0x5d/0x290
[<ffffffff8113c614>] audit_make_reply+0x54/0xd0
[<ffffffff8113dfa7>] audit_receive_msg+0x967/0xd70
----------------
(gdb) list *audit_receive_msg+0x967
0xffffffff8113dff7 is in audit_receive_msg (kernel/audit.c:1133).
1132    skb = audit_make_reply(0, AUDIT_REPLACE, 0,
                                0, &pvnr, sizeof(pvnr));
---------------
[<ffffffff8113e402>] audit_receive+0x52/0xa0
[<ffffffff8166c561>] netlink_unicast+0x181/0x240
[<ffffffff8166c8e2>] netlink_sendmsg+0x2c2/0x3b0
[<ffffffff816112e8>] sock_sendmsg+0x38/0x50
[<ffffffff816117a2>] SYSC_sendto+0x102/0x190
[<ffffffff81612f4e>] SyS_sendto+0xe/0x10
[<ffffffff8176d337>] entry_SYSCALL_64_fastpath+0x1a/0xa5
[<ffffffffffffffff>] 0xffffffffffffffff

Signed-off-by: Shu Wang <shuwang@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
2017-07-19 10:28:54 -04:00
Joel Fernandes 848618857d tracing/ring_buffer: Try harder to allocate
ftrace can fail to allocate per-CPU ring buffer on systems with a large
number of CPUs coupled while large amounts of cache happening in the
page cache. Currently the ring buffer allocation doesn't retry in the VM
implementation even if direct-reclaim made some progress but still
wasn't able to find a free page. On retrying I see that the allocations
almost always succeed. The retry doesn't happen because __GFP_NORETRY is
used in the tracer to prevent the case where we might OOM, however if we
drop __GFP_NORETRY, we risk destabilizing the system if OOM killer is
triggered. To prevent this situation, use the __GFP_RETRY_MAYFAIL flag
introduced recently [1].

Tested the following still succeeds without destabilizing a system with
1GB memory.
echo 300000 > /sys/kernel/debug/tracing/buffer_size_kb

[1] https://marc.info/?l=linux-mm&m=149820805124906&w=2

Link: http://lkml.kernel.org/r/20170713021416.8897-1-joelaf@google.com

Cc: Tim Murray <timmurray@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Joel Fernandes <joelaf@google.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-07-19 08:22:12 -04:00
Juergen Gross a696712c3d genirq/PM: Properly pretend disabled state when force resuming interrupts
Interrupts with the IRQF_FORCE_RESUME flag set have also the
IRQF_NO_SUSPEND flag set. They are not disabled in the suspend path, but
must be forcefully resumed. That's used by XEN to keep IPIs enabled beyond
the suspension of device irqs. Force resume works by pretending that the
interrupt was disabled and then calling __irq_enable().

Incrementing the disabled depth counter was enough to do that, but with the
recent changes which use state flags to avoid unnecessary hardware access,
this is not longer sufficient. If the state flags are not set, then the
hardware callbacks are not invoked and the interrupt line stays disabled in
"hardware".

Set the disabled and masked state when pretending that an interrupt got
disabled by suspend.

Fixes: bf22ff45be ("genirq: Avoid unnecessary low level irq function calls")
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: xen-devel@lists.xenproject.org
Cc: boris.ostrovsky@oracle.com
Link: http://lkml.kernel.org/r/20170717174703.4603-2-jgross@suse.com
2017-07-17 22:32:20 +02:00
Linus Torvalds 935acd3f5e Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull irq fix from Thomas Gleixner:
 "Fix the fallout from reworking the locking and resource management in
  request/free_irq()"

* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  genirq: Keep chip buslock across irq_request/release_resources()
2017-07-17 13:00:36 -07:00
Linus Torvalds 31ba04d99a Merge branch 'smp-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull SMP fix from Thomas Gleixner:
 "Replace the bogus BUG_ON in the cpu hotplug code"

* 'smp-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  smp/hotplug: Replace BUG_ON and react useful
2017-07-17 12:54:51 -07:00
Linus Torvalds 78dcf73421 Merge branch 'work.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull ->s_options removal from Al Viro:
 "Preparations for fsmount/fsopen stuff (coming next cycle). Everything
  gets moved to explicit ->show_options(), killing ->s_options off +
  some cosmetic bits around fs/namespace.c and friends. Basically, the
  stuff needed to work with fsmount series with minimum of conflicts
  with other work.

  It's not strictly required for this merge window, but it would reduce
  the PITA during the coming cycle, so it would be nice to have those
  bits and pieces out of the way"

* 'work.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  isofs: Fix isofs_show_options()
  VFS: Kill off s_options and helpers
  orangefs: Implement show_options
  9p: Implement show_options
  isofs: Implement show_options
  afs: Implement show_options
  affs: Implement show_options
  befs: Implement show_options
  spufs: Implement show_options
  bpf: Implement show_options
  ramfs: Implement show_options
  pstore: Implement show_options
  omfs: Implement show_options
  hugetlbfs: Implement show_options
  VFS: Don't use save/replace_mount_options if not using generic_show_options
  VFS: Provide empty name qstr
  VFS: Make get_filesystem() return the affected filesystem
  VFS: Clean up whitespace in fs/namespace.c and fs/super.c
  Provide a function to create a NUL-terminated string from unterminated data
2017-07-15 12:00:42 -07:00
Linus Torvalds e37720e25d Power management fixes for v4.13-rc1
- Avoid clearing the PCI PME Enable bit for devices as a result of
    config space restoration which confuses AML executed afterward and
    causes wakeup events to be lost on some systems (Rafael Wysocki).
 
  - Fix the native PCIe PME interrupts handling in the cases when the
    PME IRQ is set up as a system wakeup one so that runtime PM remote
    wakeup works as expected after system resume on systems where that
    happens (Rafael Wysocki).
 
  - Fix the device PM QoS sysfs interface to handle invalid user input
    correctly instead of using an unititialized variable value as the
    latency tolerance for the device at hand (Dan Carpenter).
 
  - Get rid of one more rounding error from intel_pstate computations
    (Srinivas Pandruvada).
 
  - Fix the schedutil cpufreq governor to prevent it from possibly
    accessing unititialized data structures from governor callbacks in
    some cases on systems when multiple CPUs share a single cpufreq
    policy object (Vikram Mulukutla).
 
  - Fix the return values of probe routines in two devfreq drivers
    (Gustavo Silva).
 
  - Constify an attribute_group structure in devfreq (Arvind Yadav).
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Merge tag 'pm-fixes-4.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull power management fixes from Rafael Wysocki:
 "These fix a recently exposed issue in the PCI device wakeup code and
  one older problem related to PCI device wakeup that has been reported
  recently, modify one more piece of computations in intel_pstate to get
  rid of a rounding error, fix a possible race in the schedutil cpufreq
  governor, fix the device PM QoS sysfs interface to correctly handle
  invalid user input, fix return values of two probe routines in devfreq
  drivers and constify an attribute_group structure in devfreq.

  Specifics:

   - Avoid clearing the PCI PME Enable bit for devices as a result of
     config space restoration which confuses AML executed afterward and
     causes wakeup events to be lost on some systems (Rafael Wysocki).

   - Fix the native PCIe PME interrupts handling in the cases when the
     PME IRQ is set up as a system wakeup one so that runtime PM remote
     wakeup works as expected after system resume on systems where that
     happens (Rafael Wysocki).

   - Fix the device PM QoS sysfs interface to handle invalid user input
     correctly instead of using an unititialized variable value as the
     latency tolerance for the device at hand (Dan Carpenter).

   - Get rid of one more rounding error from intel_pstate computations
     (Srinivas Pandruvada).

   - Fix the schedutil cpufreq governor to prevent it from possibly
     accessing unititialized data structures from governor callbacks in
     some cases on systems when multiple CPUs share a single cpufreq
     policy object (Vikram Mulukutla).

   - Fix the return values of probe routines in two devfreq drivers
     (Gustavo Silva).

   - Constify an attribute_group structure in devfreq (Arvind Yadav)"

* tag 'pm-fixes-4.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  PCI / PM: Fix native PME handling during system suspend/resume
  PCI / PM: Restore PME Enable after config space restoration
  cpufreq: schedutil: Fix sugov_start() versus sugov_update_shared() race
  PM / QoS: return -EINVAL for bogus strings
  cpufreq: intel_pstate: Fix ratio setting for min_perf_pct
  PM / devfreq: constify attribute_group structures.
  PM / devfreq: tegra: fix error return code in tegra_devfreq_probe()
  PM / devfreq: rk3399_dmc: fix error return code in rk3399_dmcfreq_probe()
2017-07-14 22:24:25 -07:00
Luis R. Rodriguez 6d7964a722 kmod: throttle kmod thread limit
If we reach the limit of modprobe_limit threads running the next
request_module() call will fail.  The original reason for adding a kill
was to do away with possible issues with in old circumstances which would
create a recursive series of request_module() calls.

We can do better than just be super aggressive and reject calls once we've
reached the limit by simply making pending callers wait until the
threshold has been reduced, and then throttling them in, one by one.

This throttling enables requests over the kmod concurrent limit to be
processed once a pending request completes.  Only the first item queued up
to wait is woken up.  The assumption here is once a task is woken it will
have no other option to also kick the queue to check if there are more
pending tasks -- regardless of whether or not it was successful.

By throttling and processing only max kmod concurrent tasks we ensure we
avoid unexpected fatal request_module() calls, and we keep memory
consumption on module loading to a minimum.

With x86_64 qemu, with 4 cores, 4 GiB of RAM it takes the following run
time to run both tests:

time ./kmod.sh -t 0008
real    0m16.366s
user    0m0.883s
sys     0m8.916s

time ./kmod.sh -t 0009
real    0m50.803s
user    0m0.791s
sys     0m9.852s

Link: http://lkml.kernel.org/r/20170628223155.26472-4-mcgrof@kernel.org
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Cc: Jessica Yu <jeyu@redhat.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Michal Marek <mmarek@suse.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-14 15:05:13 -07:00
Kefeng Wang 5f92a7b0fc kernel/watchdog.c: use better pr_fmt prefix
After commit 73ce0511c4 ("kernel/watchdog.c: move hardlockup
detector to separate file"), 'NMI watchdog' is inappropriate in
kernel/watchdog.c, using 'watchdog' only.

Link: http://lkml.kernel.org/r/1499928642-48983-1-git-send-email-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Babu Moger <babu.moger@oracle.com>
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-14 15:05:13 -07:00
Rafael J. Wysocki a252c258dd Merge branches 'pm-cpufreq-sched' and 'intel_pstate'
* pm-cpufreq-sched:
  cpufreq: schedutil: Fix sugov_start() versus sugov_update_shared() race

* intel_pstate:
  cpufreq: intel_pstate: Fix ratio setting for min_perf_pct
2017-07-14 13:16:16 +02:00
Joel Fernandes 193be41e33 sched/deadline: Fix confusing comments about selection of top pi-waiter
This comment in the code is incomplete, and I believe it begs a definition of
dl_boosted to make sense of the condition that follows. Rewrite the comment and
also rearrange the condition that follows to reflect the first condition "we
have a top pi-waiter which is a SCHED_DEADLINE task" in that order. Also fix a
typo that follows.

Signed-off-by: Joel Fernandes <joelaf@google.com>
Reviewed-by: Daniel Bristot de Oliveira <bristot@redhat.com>
Acked-by: Juri Lelli <juri.lelli@arm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20170713022429.10307-1-joelaf@google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-07-14 10:35:16 +02:00
Wanpeng Li 0e4097c335 sched/cputime: Don't use smp_processor_id() in preemptible context
Recent kernels trigger this warning:

 BUG: using smp_processor_id() in preemptible [00000000] code: 99-trinity/181
 caller is debug_smp_processor_id+0x17/0x19
 CPU: 0 PID: 181 Comm: 99-trinity Not tainted 4.12.0-01059-g2a42eb9 #1
 Call Trace:
  dump_stack+0x82/0xb8
  check_preemption_disabled()
  debug_smp_processor_id()
  vtime_delta()
  task_cputime()
  thread_group_cputime()
  thread_group_cputime_adjusted()
  wait_consider_task()
  do_wait()
  SYSC_wait4()
  do_syscall_64()
  entry_SYSCALL64_slow_path()

As Frederic pointed out:

| Although those sched_clock_cpu() things seem to only matter when the
| sched_clock() is unstable. And that stability is a condition for nohz_full
| to work anyway. So probably sched_clock() alone would be enough.

This patch fixes it by replacing sched_clock_cpu() with sched_clock() to
avoid calling smp_processor_id() in a preemptible context.

Reported-by: Xiaolong Ye <xiaolong.ye@intel.com>
Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Luiz Capitulino <lcapitulino@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1499586028-7402-1-git-send-email-wanpeng.li@hotmail.com
[ Prettified the changelog. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-07-14 10:27:15 +02:00
Linus Torvalds bc0f51d359 A few more minor updates:
- Show the tgid mappings for user space trace tools to use
 
  - Fix and optimize the comm and tgid cache recording
 
  - Sanitize derived kprobe names
 
  - Ftrace selftest updates
 
  - trace file header fix
 
  - Update of Documentation/trace/ftrace.txt
 
  - Compiler warning fixes
 
  - Fix possible uninitialized variable
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Merge tag 'trace-v4.13-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull more tracing updates from Steven Rostedt:
 "A few more minor updates:

   - Show the tgid mappings for user space trace tools to use

   - Fix and optimize the comm and tgid cache recording

   - Sanitize derived kprobe names

   - Ftrace selftest updates

   - trace file header fix

   - Update of Documentation/trace/ftrace.txt

   - Compiler warning fixes

   - Fix possible uninitialized variable"

* tag 'trace-v4.13-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  ftrace: Fix uninitialized variable in match_records()
  ftrace: Remove an unneeded NULL check
  ftrace: Hide cached module code for !CONFIG_MODULES
  tracing: Do note expose stack_trace_filter without DYNAMIC_FTRACE
  tracing: Update Documentation/trace/ftrace.txt
  tracing: Fixup trace file header alignment
  selftests/ftrace: Add a testcase for kprobe event naming
  selftests/ftrace: Add a test to probe module functions
  selftests/ftrace: Update multiple kprobes test for powerpc
  trace/kprobes: Sanitize derived event names
  tracing: Attempt to record other information even if some fail
  tracing: Treat recording tgid for idle task as a success
  tracing: Treat recording comm for idle task as a success
  tracing: Add saved_tgids file to show cached pid to tgid mappings
2017-07-13 13:17:19 -07:00
Linus Torvalds ad51271afc Merge branch 'akpm' (patches from Andrew)
Merge yet more updates from Andrew Morton:

- various misc things

- kexec updates

- sysctl core updates

- scripts/gdb udpates

- checkpoint-restart updates

- ipc updates

- kernel/watchdog updates

- Kees's "rough equivalent to the glibc _FORTIFY_SOURCE=1 feature"

- "stackprotector: ascii armor the stack canary"

- more MM bits

- checkpatch updates

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (96 commits)
  writeback: rework wb_[dec|inc]_stat family of functions
  ARM: samsung: usb-ohci: move inline before return type
  video: fbdev: omap: move inline before return type
  video: fbdev: intelfb: move inline before return type
  USB: serial: safe_serial: move __inline__ before return type
  drivers: tty: serial: move inline before return type
  drivers: s390: move static and inline before return type
  x86/efi: move asmlinkage before return type
  sh: move inline before return type
  MIPS: SMP: move asmlinkage before return type
  m68k: coldfire: move inline before return type
  ia64: sn: pci: move inline before type
  ia64: move inline before return type
  FRV: tlbflush: move asmlinkage before return type
  CRIS: gpio: move inline before return type
  ARM: HP Jornada 7XX: move inline before return type
  ARM: KVM: move asmlinkage before type
  checkpatch: improve the STORAGE_CLASS test
  mm, migration: do not trigger OOM killer when migrating memory
  drm/i915: use __GFP_RETRY_MAYFAIL
  ...
2017-07-13 12:38:49 -07:00
Alex Shi 69f0d429c4 locking/rtmutex: Remove unnecessary priority adjustment
We don't need to adjust priority before adding a new pi_waiter, the
priority only needs to be updated after pi_waiter change or task
priority change.

Steven Rostedt pointed out:

  "Interesting, I did some git mining and this was added with the original
   entry of the rtmutex.c (23f78d4a03). Looking at even that version, I
   don't see the purpose of adjusting the task prio here. It is done
   before anything changes in the task."

Signed-off-by: Alex Shi <alex.shi@linaro.org>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Juri Lelli <juri.lelli@arm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Sebastian Siewior <bigeasy@linutronix.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1499926704-28841-1-git-send-email-alex.shi@linaro.org
[ Enhance the changelog. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-07-13 11:44:06 +02:00
Linus Torvalds 3a75ad1457 Modules updates for v4.13
Summary of modules changes for the 4.13 merge window:
 
 - Minor code cleanups
 
 - Avoid accessing mod struct prior to checking module struct version, from Kees
 
 - Fix racy atomic inc/dec logic of kmod_concurrent_max in kmod, from Luis
 
 Signed-off-by: Jessica Yu <jeyu@kernel.org>
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Merge tag 'modules-for-v4.13' of git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux

Pull modules updates from Jessica Yu:
 "Summary of modules changes for the 4.13 merge window:

   - Minor code cleanups

   - Avoid accessing mod struct prior to checking module struct version,
     from Kees

   - Fix racy atomic inc/dec logic of kmod_concurrent_max in kmod, from
     Luis"

* tag 'modules-for-v4.13' of git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux:
  module: make the modinfo name const
  kmod: reduce atomic operations on kmod_concurrent and simplify
  module: use list_for_each_entry_rcu() on find_module_all()
  kernel/module.c: suppress warning about unused nowarn variable
  module: Add module name to modinfo
  module: Pass struct load_info into symbol checks
2017-07-12 17:22:01 -07:00
Rik van Riel 7cd815bce8 fork,random: use get_random_canary() to set tsk->stack_canary
Use the ascii-armor canary to prevent unterminated C string overflows
from being able to successfully overwrite the canary, even if they
somehow obtain the canary value.

Inspired by execshield ascii-armor and Daniel Micay's linux-hardened
tree.

Link: http://lkml.kernel.org/r/20170524155751.424-3-riel@redhat.com
Signed-off-by: Rik van Riel <riel@redhat.com>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Daniel Micay <danielmicay@gmail.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-12 16:26:03 -07:00
Kees Cook e2ae8ab4b5 kexec_file: adjust declaration of kexec_purgatory
Defining kexec_purgatory as a zero-length char array upsets compile time
size checking.  Since this is built on a per-arch basis, define it as an
unsized char array (like is done for other similar things, e.g.  linker
sections).  This silences the warning generated by the future
CONFIG_FORTIFY_SOURCE, which did not like the memcmp() of a "0 byte"
array.  This drops the __weak and uses an extern instead, since both
users define kexec_purgatory.

Link: http://lkml.kernel.org/r/1497903987-21002-4-git-send-email-keescook@chromium.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Daniel Micay <danielmicay@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-12 16:26:02 -07:00
Nicholas Piggin a10a842ff8 kernel/watchdog: provide watchdog_nmi_reconfigure() for arch watchdogs
After reconfiguring watchdog sysctls etc., architecture specific
watchdogs may not get all their parameters updated.

watchdog_nmi_reconfigure() can be implemented to pull the new values in
and set the arch NMI watchdog.

[npiggin@gmail.com: add code comments]
  Link: http://lkml.kernel.org/r/20170617125933.774d3858@roar.ozlabs.ibm.com
[arnd@arndb.de: hide unused function]
  Link: http://lkml.kernel.org/r/20170620204854.966601-1-arnd@arndb.de
Link: http://lkml.kernel.org/r/20170616065715.18390-5-npiggin@gmail.com
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Don Zickus <dzickus@redhat.com>
Tested-by: Babu Moger <babu.moger@oracle.com>	[sparc]
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-12 16:26:02 -07:00
Nicholas Piggin 05a4a95279 kernel/watchdog: split up config options
Split SOFTLOCKUP_DETECTOR from LOCKUP_DETECTOR, and split
HARDLOCKUP_DETECTOR_PERF from HARDLOCKUP_DETECTOR.

LOCKUP_DETECTOR implies the general boot, sysctl, and programming
interfaces for the lockup detectors.

An architecture that wants to use a hard lockup detector must define
HAVE_HARDLOCKUP_DETECTOR_PERF or HAVE_HARDLOCKUP_DETECTOR_ARCH.

Alternatively an arch can define HAVE_NMI_WATCHDOG, which provides the
minimum arch_touch_nmi_watchdog, and it otherwise does its own thing and
does not implement the LOCKUP_DETECTOR interfaces.

sparc is unusual in that it has started to implement some of the
interfaces, but not fully yet.  It should probably be converted to a full
HAVE_HARDLOCKUP_DETECTOR_ARCH.

[npiggin@gmail.com: fix]
  Link: http://lkml.kernel.org/r/20170617223522.66c0ad88@roar.ozlabs.ibm.com
Link: http://lkml.kernel.org/r/20170616065715.18390-4-npiggin@gmail.com
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Don Zickus <dzickus@redhat.com>
Reviewed-by: Babu Moger <babu.moger@oracle.com>
Tested-by: Babu Moger <babu.moger@oracle.com>	[sparc]
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-12 16:26:02 -07:00
Nicholas Piggin f2e0cff85e kernel/watchdog: introduce arch_touch_nmi_watchdog()
For architectures that define HAVE_NMI_WATCHDOG, instead of having them
provide the complete touch_nmi_watchdog() function, just have them
provide arch_touch_nmi_watchdog().

This gives the generic code more flexibility in implementing this
function, and arch implementations don't miss out on touching the
softlockup watchdog or other generic details.

Link: http://lkml.kernel.org/r/20170616065715.18390-3-npiggin@gmail.com
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Don Zickus <dzickus@redhat.com>
Reviewed-by: Babu Moger <babu.moger@oracle.com>
Tested-by: Babu Moger <babu.moger@oracle.com>	[sparc]
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-12 16:26:02 -07:00
Dmitry Vyukov e41d58185f fault-inject: support systematic fault injection
Add /proc/self/task/<current-tid>/fail-nth file that allows failing
0-th, 1-st, 2-nd and so on calls systematically.
Excerpt from the added documentation:

 "Write to this file of integer N makes N-th call in the current task
  fail (N is 0-based). Read from this file returns a single char 'Y' or
  'N' that says if the fault setup with a previous write to this file
  was injected or not, and disables the fault if it wasn't yet injected.
  Note that this file enables all types of faults (slab, futex, etc).
  This setting takes precedence over all other generic settings like
  probability, interval, times, etc. But per-capability settings (e.g.
  fail_futex/ignore-private) take precedence over it. This feature is
  intended for systematic testing of faults in a single system call. See
  an example below"

Why add a new setting:
1. Existing settings are global rather than per-task.
   So parallel testing is not possible.
2. attr->interval is close but it depends on attr->count
   which is non reset to 0, so interval does not work as expected.
3. Trying to model this with existing settings requires manipulations
   of all of probability, interval, times, space, task-filter and
   unexposed count and per-task make-it-fail files.
4. Existing settings are per-failure-type, and the set of failure
   types is potentially expanding.
5. make-it-fail can't be changed by unprivileged user and aggressive
   stress testing better be done from an unprivileged user.
   Similarly, this would require opening the debugfs files to the
   unprivileged user, as he would need to reopen at least times file
   (not possible to pre-open before dropping privs).

The proposed interface solves all of the above (see the example).

We want to integrate this into syzkaller fuzzer.  A prototype has found
10 bugs in kernel in first day of usage:

  https://groups.google.com/forum/#!searchin/syzkaller/%22FAULT_INJECTION%22%7Csort:relevance

I've made the current interface work with all types of our sandboxes.
For setuid the secret sauce was prctl(PR_SET_DUMPABLE, 1, 0, 0, 0) to
make /proc entries non-root owned.  So I am fine with the current
version of the code.

[akpm@linux-foundation.org: fix build]
Link: http://lkml.kernel.org/r/20170328130128.101773-1-dvyukov@google.com
Signed-off-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-12 16:26:01 -07:00
Cyrill Gorcunov 0791e3644e kcmp: add KCMP_EPOLL_TFD mode to compare epoll target files
With current epoll architecture target files are addressed with
file_struct and file descriptor number, where the last is not unique.
Moreover files can be transferred from another process via unix socket,
added into queue and closed then so we won't find this descriptor in the
task fdinfo list.

Thus to checkpoint and restore such processes CRIU needs to find out
where exactly the target file is present to add it into epoll queue.
For this sake one can use kcmp call where some particular target file
from the queue is compared with arbitrary file passed as an argument.

Because epoll target files can have same file descriptor number but
different file_struct a caller should explicitly specify the offset
within.

To test if some particular file is matching entry inside epoll one have
to

 - fill kcmp_epoll_slot structure with epoll file descriptor,
   target file number and target file offset (in case if only
   one target is present then it should be 0)

 - call kcmp as kcmp(pid1, pid2, KCMP_EPOLL_TFD, fd, &kcmp_epoll_slot)
    - the kernel fetch file pointer matching file descriptor @fd of pid1
    - lookups for file struct in epoll queue of pid2 and returns traditional
      0,1,2 result for sorting purpose

Link: http://lkml.kernel.org/r/20170424154423.511592110@gmail.com
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Acked-by: Andrey Vagin <avagin@openvz.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Pavel Emelyanov <xemul@virtuozzo.com>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Jason Baron <jbaron@akamai.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-12 16:26:01 -07:00
Mateusz Jurczyk 9380fa60b1 kernel/sysctl_binary.c: check name array length in deprecated_sysctl_warning()
Prevent use of uninitialized memory (originating from the stack frame of
do_sysctl()) by verifying that the name array is filled with sufficient
input data before comparing its specific entries with integer constants.

Through timing measurement or analyzing the kernel debug logs, a
user-mode program could potentially infer the results of comparisons
against the uninitialized memory, and acquire some (very limited)
information about the state of the kernel stack.  The change also
eliminates possible future warnings by tools such as KMSAN and other
code checkers / instrumentations.

Link: http://lkml.kernel.org/r/20170524122139.21333-1-mjurczyk@google.com
Signed-off-by: Mateusz Jurczyk <mjurczyk@google.com>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Matthew Whitehead <tedheadster@gmail.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Alexander Potapenko <glider@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-12 16:26:00 -07:00
Luis R. Rodriguez 61d9b56a89 sysctl: add unsigned int range support
To keep parity with regular int interfaces provide the an unsigned int
proc_douintvec_minmax() which allows you to specify a range of allowed
valid numbers.

Adding proc_douintvec_minmax_sysadmin() is easy but we can wait for an
actual user for that.

Link: http://lkml.kernel.org/r/20170519033554.18592-6-mcgrof@kernel.org
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Cc: Heinrich Schuchardt <xypron.glpk@gmx.de>
Cc: Kees Cook <keescook@chromium.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-12 16:26:00 -07:00
Luis R. Rodriguez 4f2fec00af sysctl: simplify unsigned int support
Commit e7d316a02f ("sysctl: handle error writing UINT_MAX to u32
fields") added proc_douintvec() to start help adding support for
unsigned int, this however was only half the work needed.  Two fixes
have come in since then for the following issues:

  o Printing the values shows a negative value, this happens since
    do_proc_dointvec() and this uses proc_put_long()

This was fixed by commit 5380e5644a ("sysctl: don't print negative
flag for proc_douintvec").

  o We can easily wrap around the int values: UINT_MAX is 4294967295, if
    we echo in 4294967295 + 1 we end up with 0, using 4294967295 + 2 we
    end up with 1.
  o We echo negative values in and they are accepted

This was fixed by commit 425fffd886 ("sysctl: report EINVAL if value
is larger than UINT_MAX for proc_douintvec").

It still also failed to be added to sysctl_check_table()...  instead of
adding it with the current implementation just provide a proper and
simplified unsigned int support without any array unsigned int support
with no negative support at all.

Historically sysctl proc helpers have supported arrays, due to the
complexity this adds though we've taken a step back to evaluate array
users to determine if its worth upkeeping for unsigned int.  An
evaluation using Coccinelle has been done to perform a grammatical
search to ask ourselves:

  o How many sysctl proc_dointvec() (int) users exist which likely
    should be moved over to proc_douintvec() (unsigned int) ?
	Answer: about 8
	- Of these how many are array users ?
		Answer: Probably only 1
  o How many sysctl array users exist ?
	Answer: about 12

This last question gives us an idea just how popular arrays: they are not.
Array support should probably just be kept for strings.

The identified uint ports are:

  drivers/infiniband/core/ucma.c - max_backlog
  drivers/infiniband/core/iwcm.c - default_backlog
  net/core/sysctl_net_core.c - rps_sock_flow_sysctl()
  net/netfilter/nf_conntrack_timestamp.c - nf_conntrack_timestamp -- bool
  net/netfilter/nf_conntrack_acct.c nf_conntrack_acct -- bool
  net/netfilter/nf_conntrack_ecache.c - nf_conntrack_events -- bool
  net/netfilter/nf_conntrack_helper.c - nf_conntrack_helper -- bool
  net/phonet/sysctl.c proc_local_port_range()

The only possible array users is proc_local_port_range() but it does not
seem worth it to add array support just for this given the range support
works just as well.  Unsigned int support should be desirable more for
when you *need* more than INT_MAX or using int min/max support then does
not suffice for your ranges.

If you forget and by mistake happen to register an unsigned int proc
entry with an array, the driver will fail and you will get something as
follows:

sysctl table check failed: debug/test_sysctl//uint_0002 array now allowed
CPU: 2 PID: 1342 Comm: modprobe Tainted: G        W   E <etc>
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS <etc>
Call Trace:
 dump_stack+0x63/0x81
 __register_sysctl_table+0x350/0x650
 ? kmem_cache_alloc_trace+0x107/0x240
 __register_sysctl_paths+0x1b3/0x1e0
 ? 0xffffffffc005f000
 register_sysctl_table+0x1f/0x30
 test_sysctl_init+0x10/0x1000 [test_sysctl]
 do_one_initcall+0x52/0x1a0
 ? kmem_cache_alloc_trace+0x107/0x240
 do_init_module+0x5f/0x200
 load_module+0x1867/0x1bd0
 ? __symbol_put+0x60/0x60
 SYSC_finit_module+0xdf/0x110
 SyS_finit_module+0xe/0x10
 entry_SYSCALL_64_fastpath+0x1e/0xad
RIP: 0033:0x7f042b22d119
<etc>

Fixes: e7d316a02f ("sysctl: handle error writing UINT_MAX to u32 fields")
Link: http://lkml.kernel.org/r/20170519033554.18592-5-mcgrof@kernel.org
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Suggested-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Subash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Cc: Liping Zhang <zlpnobody@gmail.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Heinrich Schuchardt <xypron.glpk@gmx.de>
Cc: Kees Cook <keescook@chromium.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-12 16:26:00 -07:00
Luis R. Rodriguez d383d48470 sysctl: fold sysctl_writes_strict checks into helper
The mode sysctl_writes_strict positional checks keep being copy and pasted
as we add new proc handlers.  Just add a helper to avoid code duplication.

Link: http://lkml.kernel.org/r/20170519033554.18592-4-mcgrof@kernel.org
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Suggested-by: Kees Cook <keescook@chromium.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-12 16:26:00 -07:00
Luis R. Rodriguez a19ac33749 sysctl: kdoc'ify sysctl_writes_strict
Document the different sysctl_writes_strict modes in code.

Link: http://lkml.kernel.org/r/20170519033554.18592-3-mcgrof@kernel.org
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-12 16:26:00 -07:00
Xunlei Pang 1229384f5b kdump: protect vmcoreinfo data under the crash memory
Currently vmcoreinfo data is updated at boot time subsys_initcall(), it
has the risk of being modified by some wrong code during system is
running.

As a result, vmcore dumped may contain the wrong vmcoreinfo.  Later on,
when using "crash", "makedumpfile", etc utility to parse this vmcore, we
probably will get "Segmentation fault" or other unexpected errors.

E.g.  1) wrong code overwrites vmcoreinfo_data; 2) further crashes the
system; 3) trigger kdump, then we obviously will fail to recognize the
crash context correctly due to the corrupted vmcoreinfo.

Now except for vmcoreinfo, all the crash data is well
protected(including the cpu note which is fully updated in the crash
path, thus its correctness is guaranteed).  Given that vmcoreinfo data
is a large chunk prepared for kdump, we better protect it as well.

To solve this, we relocate and copy vmcoreinfo_data to the crash memory
when kdump is loading via kexec syscalls.  Because the whole crash
memory will be protected by existing arch_kexec_protect_crashkres()
mechanism, we naturally protect vmcoreinfo_data from write(even read)
access under kernel direct mapping after kdump is loaded.

Since kdump is usually loaded at the very early stage after boot, we can
trust the correctness of the vmcoreinfo data copied.

On the other hand, we still need to operate the vmcoreinfo safe copy
when crash happens to generate vmcoreinfo_note again, we rely on vmap()
to map out a new kernel virtual address and update to use this new one
instead in the following crash_save_vmcoreinfo().

BTW, we do not touch vmcoreinfo_note, because it will be fully updated
using the protected vmcoreinfo_data after crash which is surely correct
just like the cpu crash note.

Link: http://lkml.kernel.org/r/1493281021-20737-3-git-send-email-xlpang@redhat.com
Signed-off-by: Xunlei Pang <xlpang@redhat.com>
Tested-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Dave Young <dyoung@redhat.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Hari Bathini <hbathini@linux.vnet.ibm.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-12 16:26:00 -07:00
Xunlei Pang 5203f4995d powerpc/fadump: use the correct VMCOREINFO_NOTE_SIZE for phdr
vmcoreinfo_max_size stands for the vmcoreinfo_data, the correct one we
should use is vmcoreinfo_note whose total size is VMCOREINFO_NOTE_SIZE.

Like explained in commit 77019967f0 ("kdump: fix exported size of
vmcoreinfo note"), it should not affect the actual function, but we
better fix it, also this change should be safe and backward compatible.

After this, we can get rid of variable vmcoreinfo_max_size, let's use
the corresponding macros directly, fewer variables means more safety for
vmcoreinfo operation.

[xlpang@redhat.com: fix build warning]
  Link: http://lkml.kernel.org/r/1494830606-27736-1-git-send-email-xlpang@redhat.com
Link: http://lkml.kernel.org/r/1493281021-20737-2-git-send-email-xlpang@redhat.com
Signed-off-by: Xunlei Pang <xlpang@redhat.com>
Reviewed-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Reviewed-by: Dave Young <dyoung@redhat.com>
Cc: Hari Bathini <hbathini@linux.vnet.ibm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-12 16:25:59 -07:00
Xunlei Pang 203e9e4121 kexec: move vmcoreinfo out of the kernel's .bss section
As Eric said,
 "what we need to do is move the variable vmcoreinfo_note out of the
  kernel's .bss section. And modify the code to regenerate and keep this
  information in something like the control page.

  Definitely something like this needs a page all to itself, and ideally
  far away from any other kernel data structures. I clearly was not
  watching closely the data someone decided to keep this silly thing in
  the kernel's .bss section."

This patch allocates extra pages for these vmcoreinfo_XXX variables, one
advantage is that it enhances some safety of vmcoreinfo, because
vmcoreinfo now is kept far away from other kernel data structures.

Link: http://lkml.kernel.org/r/1493281021-20737-1-git-send-email-xlpang@redhat.com
Signed-off-by: Xunlei Pang <xlpang@redhat.com>
Tested-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Suggested-by: Eric Biederman <ebiederm@xmission.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Dave Young <dyoung@redhat.com>
Cc: Hari Bathini <hbathini@linux.vnet.ibm.com>
Cc: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-12 16:25:59 -07:00
Christoph Lameter 112166f88c kernel/fork.c: virtually mapped stacks: do not disable interrupts
The reason to disable interrupts seems to be to avoid switching to a
different processor while handling per cpu data using individual loads and
stores.  If we use per cpu RMV primitives we will not have to disable
interrupts.

Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1705171055130.5898@east.gentwo.org
Signed-off-by: Christoph Lameter <cl@linux.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-12 16:25:59 -07:00
Al Viro 58c7ffc074 fix a braino in compat_sys_getrlimit()
Reported-and-tested-by: Meelis Roos <mroos@linux.ee>
Fixes: commit d9e968cb9f "getrlimit()/setrlimit(): move compat to native"
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-12 09:15:00 -07:00
Dan Carpenter 2e028c4fe1 ftrace: Fix uninitialized variable in match_records()
My static checker complains that if "func" is NULL then "clear_filter"
is uninitialized.  This seems like it could be true, although it's
possible something subtle is happening that I haven't seen.

    kernel/trace/ftrace.c:3844 match_records()
    error: uninitialized symbol 'clear_filter'.

Link: http://lkml.kernel.org/r/20170712073556.h6tkpjcdzjaozozs@mwanda

Cc: stable@vger.kernel.org
Fixes: f0a3b154bd ("ftrace: Clarify code for mod command")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-07-12 09:48:31 -04:00
Dan Carpenter 44925dfff0 ftrace: Remove an unneeded NULL check
"func" can't be NULL and it doesn't make sense to check because we've
already derefenced it.

Link: http://lkml.kernel.org/r/20170712073340.4enzeojeoupuds5a@mwanda

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2017-07-12 09:45:42 -04:00
Vikram Mulukutla ab2f7cf141 cpufreq: schedutil: Fix sugov_start() versus sugov_update_shared() race
With a shared policy in place, when one of the CPUs in the policy is
hotplugged out and then brought back online, sugov_stop() and
sugov_start() are called in order.

sugov_stop() removes utilization hooks for each CPU in the policy and
does nothing else in the for_each_cpu() loop. sugov_start() on the
other hand iterates through the CPUs in the policy and re-initializes
the per-cpu structure _and_ adds the utilization hook.  This implies
that the scheduler is allowed to invoke a CPU's utilization update
hook when the rest of the per-cpu structures have yet to be
re-inited.

Apart from some strange values in tracepoints this doesn't cause a
problem, but if we do end up accessing a pointer from the per-cpu
sugov_cpu structure somewhere in the sugov_update_shared() path,
we will likely see crashes since the memset for another CPU in the
policy is free to race with sugov_update_shared from the CPU that is
ready to go.  So let's fix this now to first init all per-cpu
structures, and then add the per-cpu utilization update hooks all at
once.

Signed-off-by: Vikram Mulukutla <markivx@codeaurora.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2017-07-12 14:47:48 +02:00
Thomas Gleixner 19d39a3810 genirq: Keep chip buslock across irq_request/release_resources()
Moving the irq_request/release_resources() callbacks out of the spinlocked,
irq disabled and bus locked region, unearthed an interesting abuse of the
irq_bus_lock/irq_bus_sync_unlock() callbacks.

The OMAP GPIO driver does merily power management inside of them. The
irq_request_resources() callback of this GPIO irqchip calls a function
which reads a GPIO register. That read aborts now because the clock of the
GPIO block is not magically enabled via the irq_bus_lock() callback.

Move the callbacks under the bus lock again to prevent this. In the
free_irq() path this requires to drop the bus_lock before calling
synchronize_irq() and reaquiring it before calling the
irq_release_resources() callback.

The bus lock can't be held because:

   1) The data which has been changed between bus_lock/un_lock is cached in
      the irq chip driver private data and needs to go out to the irq chip
      via the slow bus (usually SPI or I2C) before calling
      synchronize_irq().

      That's the reason why this bus_lock/unlock magic exists in the first
      place, as you cannot do SPI/I2C transactions while holding desc->lock
      with interrupts disabled.

   2) synchronize_irq() will actually deadlock, if there is a handler on
      flight. These chips use threaded handlers for obvious reasons, as
      they allow to do SPI/I2C communication. When the threaded handler
      returns then bus_lock needs to be taken in irq_finalize_oneshot() as
      we need to talk to the actual irq chip once more. After that the
      threaded handler is marked done, which makes synchronize_irq() return.

      So if we hold bus_lock accross the synchronize_irq() call, the
      handler cannot mark itself done because it blocks on the bus
      lock. That in turn makes synchronize_irq() wait forever on the
      threaded handler to complete....

Add the missing unlock of desc->request_mutex in the error path of
__free_irq() and add a bunch of comments to explain the locking and
protection rules.

Fixes: 46e48e2573 ("genirq: Move irq resource handling out of spinlocked region")
Reported-and-tested-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk>
Reported-and-tested-by: Tony Lindgren <tony@atomide.com>
Reported-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Not-longer-ranted-at-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Grygorii Strashko <grygorii.strashko@ti.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
2017-07-12 10:14:42 +02:00