linux-stable.git/kernel, branch v3.18.76

tracing: Erase irqsoff trace with empty write

2017-10-05T07:35:50+00:00

commit 8dd33bcb7050dd6f8c1432732f930932c9d3a33e upstream.

One convenient way to erase trace is "echo > trace". However, this
is currently broken if the current tracer is irqsoff tracer. This
is because irqsoff tracer use max_buffer as the default trace
buffer.

Set the max_buffer as the one to be cleared when it's the trace
buffer currently in use.

Link: http://lkml.kernel.org/r/1505754215-29411-1-git-send-email-byan@nvidia.com

Cc: 
Fixes: 4acd4d00f ("tracing: give easy way to clear trace buffer")
Signed-off-by: Bo Yan 
Signed-off-by: Steven Rostedt (VMware) 
Signed-off-by: Greg Kroah-Hartman

tracing: Fix trace_pipe behavior for instance traces

2017-10-05T07:35:50+00:00

commit 75df6e688ccd517e339a7c422ef7ad73045b18a2 upstream.

When reading data from trace_pipe, tracing_wait_pipe() performs a
check to see if tracing has been turned off after some data was read.
Currently, this check always looks at global trace state, but it
should be checking the trace instance where trace_pipe is located at.

Because of this bug, cat instances/i1/trace_pipe in the following
script will immediately exit instead of waiting for data:

cd /sys/kernel/debug/tracing
echo 0 > tracing_on
mkdir -p instances/i1
echo 1 > instances/i1/tracing_on
echo 1 > instances/i1/events/sched/sched_process_exec/enable
cat instances/i1/trace_pipe

Link: http://lkml.kernel.org/r/20170917102348.1615-1-tahsin@google.com

Fixes: 10246fa35d4f ("tracing: give easy way to clear trace buffer")
Signed-off-by: Tahsin Erdogan 
Signed-off-by: Steven Rostedt (VMware) 
Signed-off-by: Greg Kroah-Hartman

tracing: Apply trace_clock changes to instance max buffer

2017-09-27T08:57:21+00:00

commit 170b3b1050e28d1ba0700e262f0899ffa4fccc52 upstream.

Currently trace_clock timestamps are applied to both regular and max
buffers only for global trace. For instance trace, trace_clock
timestamps are applied only to regular buffer. But, regular and max
buffers can be swapped, for example, following a snapshot. So, for
instance trace, bad timestamps can be seen following a snapshot.
Let's apply trace_clock timestamps to instance max buffer as well.

Link: http://lkml.kernel.org/r/ebdb168d0be042dcdf51f81e696b17fabe3609c1.1504642143.git.tom.zanussi@linux.intel.com

Fixes: 277ba0446 ("tracing: Add interface to allow multiple trace buffers")
Signed-off-by: Baohong Liu 
Signed-off-by: Steven Rostedt (VMware) 
Signed-off-by: Greg Kroah-Hartman

ftrace: Fix selftest goto location on error

2017-09-27T08:57:21+00:00

commit 46320a6acc4fb58f04bcf78c4c942cc43b20f986 upstream.

In the second iteration of trace_selftest_ops(), the error goto label is
wrong in the case where trace_selftest_test_global_cnt is off. In the
case of error, it leaks the dynamic ops that was allocated.

Fixes: 95950c2e ("ftrace: Add self-tests for multiple function trace users")
Signed-off-by: Steven Rostedt (VMware) 
Signed-off-by: Greg Kroah-Hartman

locktorture: Fix potential memory leak with rw lock test

2017-09-13T21:03:47+00:00

commit f4dbba591945dc301c302672adefba9e2ec08dc5 upstream.

When running locktorture module with the below commands with kmemleak enabled:

$ modprobe locktorture torture_type=rw_lock_irq
$ rmmod locktorture

The below kmemleak got caught:

root@10:~# echo scan > /sys/kernel/debug/kmemleak
[  323.197029] kmemleak: 2 new suspected memory leaks (see /sys/kernel/debug/kmemleak)
root@10:~# cat /sys/kernel/debug/kmemleak
unreferenced object 0xffffffc07592d500 (size 128):
  comm "modprobe", pid 368, jiffies 4294924118 (age 205.824s)
  hex dump (first 32 bytes):
    00 00 00 00 00 00 00 00 c3 7b 02 00 00 00 00 00  .........{......
    00 00 00 00 00 00 00 00 d7 9b 02 00 00 00 00 00  ................
  backtrace:
    [] create_object+0x110/0x288
    [] kmemleak_alloc+0x58/0xa0
    [] __kmalloc+0x234/0x318
    [] 0xffffff80006fa130
    [] do_one_initcall+0x44/0x138
    [] do_init_module+0x68/0x1cc
    [] load_module+0x1a68/0x22e0
    [] SyS_finit_module+0xe0/0xf0
    [] el0_svc_naked+0x24/0x28
    [] 0xffffffffffffffff
unreferenced object 0xffffffc07592d480 (size 128):
  comm "modprobe", pid 368, jiffies 4294924118 (age 205.824s)
  hex dump (first 32 bytes):
    00 00 00 00 00 00 00 00 3b 6f 01 00 00 00 00 00  ........;o......
    00 00 00 00 00 00 00 00 23 6a 01 00 00 00 00 00  ........#j......
  backtrace:
    [] create_object+0x110/0x288
    [] kmemleak_alloc+0x58/0xa0
    [] __kmalloc+0x234/0x318
    [] 0xffffff80006fa22c
    [] do_one_initcall+0x44/0x138
    [] do_init_module+0x68/0x1cc
    [] load_module+0x1a68/0x22e0
    [] SyS_finit_module+0xe0/0xf0
    [] el0_svc_naked+0x24/0x28
    [] 0xffffffffffffffff

It is because cxt.lwsa and cxt.lrsa don't get freed in module_exit, so free
them in lock_torture_cleanup() and free writer_tasks if reader_tasks is
failed at memory allocation.

Signed-off-by: Yang Shi 
Signed-off-by: Paul E. McKenney 
Reviewed-by: Josh Triplett 
Cc: 石洋 
Signed-off-by: Greg Kroah-Hartman

gcov: support GCC 7.1

2017-09-02T05:05:45+00:00

commit 05384213436ab690c46d9dfec706b80ef8d671ab upstream.

Starting from GCC 7.1, __gcov_exit is a new symbol expected to be
implemented in a profiling runtime.

[akpm@linux-foundation.org: coding-style fixes]
[mliska@suse.cz: v2]
  Link: http://lkml.kernel.org/r/e63a3c59-0149-c97e-4084-20ca8f146b26@suse.cz
Link: http://lkml.kernel.org/r/8c4084fa-3885-29fe-5fc4-0d4ca199c785@suse.cz
Signed-off-by: Martin Liska 
Acked-by: Peter Oberparleiter 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

gcov: add support for gcc version >= 6

2017-09-02T05:05:45+00:00

commit d02038f972538b93011d78c068f44514fbde0a8c upstream.

Link: http://lkml.kernel.org/r/20160701130914.GA23225@styxhp
Signed-off-by: Florian Meier 
Reviewed-by: Peter Oberparleiter 
Tested-by: Peter Oberparleiter 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

gcov: add support for GCC 5.1

2017-09-02T05:05:45+00:00

commit 3e44c471a2dab210f7e9b1e5f7d4d54d52df59eb upstream.

Fix kernel gcov support for GCC 5.1.  Similar to commit a992bf836f9
("gcov: add support for GCC 4.9"), this patch takes into account the
existence of a new gcov counter (see gcc's gcc/gcov-counter.def.)

Firstly, it increments GCOV_COUNTERS (to 10), which makes the data
structure struct gcov_info compatible with GCC 5.1.

Secondly, a corresponding counter function __gcov_merge_icall_topn (Top N
value tracking for indirect calls) is included in base.c with the other
gcov counters unused for kernel profiling.

Signed-off-by: Lorenzo Stoakes 
Cc: Andrey Ryabinin 
Cc: Yuan Pengfei 
Tested-by: Peter Oberparleiter 
Reviewed-by: Peter Oberparleiter 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

perf/core: Fix group {cpu,task} validation

2017-08-30T08:16:56+00:00

commit 64aee2a965cf2954a038b5522f11d2cd2f0f8f3e upstream.

Regardless of which events form a group, it does not make sense for the
events to target different tasks and/or CPUs, as this leaves the group
inconsistent and impossible to schedule. The core perf code assumes that
these are consistent across (successfully intialised) groups.

Core perf code only verifies this when moving SW events into a HW
context. Thus, we can violate this requirement for pure SW groups and
pure HW groups, unless the relevant PMU driver happens to perform this
verification itself. These mismatched groups subsequently wreak havoc
elsewhere.

For example, we handle watchpoints as SW events, and reserve watchpoint
HW on a per-CPU basis at pmu::event_init() time to ensure that any event
that is initialised is guaranteed to have a slot at pmu::add() time.
However, the core code only checks the group leader's cpu filter (via
event_filter_match()), and can thus install follower events onto CPUs
violating thier (mismatched) CPU filters, potentially installing them
into a CPU without sufficient reserved slots.

This can be triggered with the below test case, resulting in warnings
from arch backends.

  #define _GNU_SOURCE
  #include 
  #include 
  #include 
  #include 
  #include 
  #include 
  #include 

  static int perf_event_open(struct perf_event_attr *attr, pid_t pid, int cpu,
			   int group_fd, unsigned long flags)
  {
	return syscall(__NR_perf_event_open, attr, pid, cpu, group_fd, flags);
  }

  char watched_char;

  struct perf_event_attr wp_attr = {
	.type = PERF_TYPE_BREAKPOINT,
	.bp_type = HW_BREAKPOINT_RW,
	.bp_addr = (unsigned long)&watched_char,
	.bp_len = 1,
	.size = sizeof(wp_attr),
  };

  int main(int argc, char *argv[])
  {
	int leader, ret;
	cpu_set_t cpus;

	/*
	 * Force use of CPU0 to ensure our CPU0-bound events get scheduled.
	 */
	CPU_ZERO(&cpus);
	CPU_SET(0, &cpus);
	ret = sched_setaffinity(0, sizeof(cpus), &cpus);
	if (ret) {
		printf("Unable to set cpu affinity\n");
		return 1;
	}

	/* open leader event, bound to this task, CPU0 only */
	leader = perf_event_open(&wp_attr, 0, 0, -1, 0);
	if (leader < 0) {
		printf("Couldn't open leader: %d\n", leader);
		return 1;
	}

	/*
	 * Open a follower event that is bound to the same task, but a
	 * different CPU. This means that the group should never be possible to
	 * schedule.
	 */
	ret = perf_event_open(&wp_attr, 0, 1, leader, 0);
	if (ret < 0) {
		printf("Couldn't open mismatched follower: %d\n", ret);
		return 1;
	} else {
		printf("Opened leader/follower with mismastched CPUs\n");
	}

	/*
	 * Open as many independent events as we can, all bound to the same
	 * task, CPU0 only.
	 */
	do {
		ret = perf_event_open(&wp_attr, 0, 0, -1, 0);
	} while (ret >= 0);

	/*
	 * Force enable/disble all events to trigger the erronoeous
	 * installation of the follower event.
	 */
	printf("Opened all events. Toggling..\n");
	for (;;) {
		prctl(PR_TASK_PERF_EVENTS_DISABLE, 0, 0, 0, 0);
		prctl(PR_TASK_PERF_EVENTS_ENABLE, 0, 0, 0, 0);
	}

	return 0;
  }

Fix this by validating this requirement regardless of whether we're
moving events.

Signed-off-by: Mark Rutland 
Signed-off-by: Peter Zijlstra (Intel) 
Cc: Alexander Shishkin 
Cc: Arnaldo Carvalho de Melo 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: Zhou Chengming 
Link: http://lkml.kernel.org/r/1498142498-15758-1-git-send-email-mark.rutland@arm.com
Signed-off-by: Ingo Molnar 
Signed-off-by: Greg Kroah-Hartman

tracing: Fix freeing of filter in create_filter() when set_str is false

2017-08-30T08:16:55+00:00

commit 8b0db1a5bdfcee0dbfa89607672598ae203c9045 upstream.

Performing the following task with kmemleak enabled:

 # cd /sys/kernel/tracing/events/irq/irq_handler_entry/
 # echo 'enable_event:kmem:kmalloc:3 if irq >' > trigger
 # echo 'enable_event:kmem:kmalloc:3 if irq > 31' > trigger
 # echo scan > /sys/kernel/debug/kmemleak
 # cat /sys/kernel/debug/kmemleak
unreferenced object 0xffff8800b9290308 (size 32):
  comm "bash", pid 1114, jiffies 4294848451 (age 141.139s)
  hex dump (first 32 bytes):
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace:
    [] kmemleak_alloc+0x4a/0xa0
    [] kmem_cache_alloc_trace+0x158/0x290
    [] create_filter_start.constprop.28+0x99/0x940
    [] create_filter+0xa9/0x160
    [] create_event_filter+0xc/0x10
    [] set_trigger_filter+0xe5/0x210
    [] event_enable_trigger_func+0x324/0x490
    [] event_trigger_write+0x1a2/0x260
    [] __vfs_write+0xd7/0x380
    [] vfs_write+0x101/0x260
    [] SyS_write+0xab/0x130
    [] entry_SYSCALL_64_fastpath+0x1f/0xbe
    [] 0xffffffffffffffff

The function create_filter() is passed a 'filterp' pointer that gets
allocated, and if "set_str" is true, it is up to the caller to free it, even
on error. The problem is that the pointer is not freed by create_filter()
when set_str is false. This is a bug, and it is not up to the caller to free
the filter on error if it doesn't care about the string.

Link: http://lkml.kernel.org/r/1502705898-27571-2-git-send-email-chuhu@redhat.com

Fixes: 38b78eb85 ("tracing: Factorize filter creation")
Reported-by: Chunyu Hu 
Tested-by: Chunyu Hu 
Signed-off-by: Steven Rostedt (VMware) 
Signed-off-by: Greg Kroah-Hartman