linux-stable.git/kernel/trace/trace.c, branch v3.16.50

tracing: Fix kmemleak in instance_rmdir

2017-11-11T13:33:03+00:00

commit db9108e054700c96322b0f0028546aa4e643cf0b upstream.

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:
    [] kmemleak_alloc+0x4a/0xa0
    [] __kmalloc_node+0xf1/0x280
    [] alloc_cpumask_var_node+0x23/0x30
    [] alloc_cpumask_var+0xe/0x10
    [] instance_mkdir+0x90/0x240
    [] tracefs_syscall_mkdir+0x40/0x70
    [] vfs_mkdir+0x109/0x1b0
    [] SyS_mkdir+0xd0/0x100
    [] do_syscall_64+0x67/0x150
    [] return_from_SYSCALL_64+0x0/0x6a
    [] 0xffffffffffffffff

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

Fixes: ccfe9e42e451 ("tracing: Make tracing_cpumask available for all instances")
Signed-off-by: Chunyu Hu 
Signed-off-by: Steven Rostedt (VMware) 
Signed-off-by: Ben Hutchings

tracing: Allocate the snapshot buffer before enabling probe

2017-07-18T17:40:37+00:00

commit df62db5be2e5f070ecd1a5ece5945b590ee112e0 upstream.

Currently the snapshot trigger enables the probe and then allocates the
snapshot. If the probe triggers before the allocation, it could cause the
snapshot to fail and turn tracing off. It's best to allocate the snapshot
buffer first, and then enable the trigger. If something goes wrong in the
enabling of the trigger, the snapshot buffer is still allocated, but it can
also be freed by the user by writting zero into the snapshot buffer file.

Also add a check of the return status of alloc_snapshot().

Fixes: 77fd5c15e3 ("tracing: Add snapshot trigger to function probes")
Signed-off-by: Steven Rostedt (VMware) 
Signed-off-by: Ben Hutchings

tracing: Use strlcpy() instead of strcpy() in __trace_find_cmdline()

2017-06-05T20:17:22+00:00

commit e09e28671cda63e6308b31798b997639120e2a21 upstream.

Strcpy is inherently not safe, and strlcpy() should be used instead.
__trace_find_cmdline() uses strcpy() because the comms saved must have a
terminating nul character, but it doesn't hurt to add the extra protection
of using strlcpy() instead of strcpy().

Link: http://lkml.kernel.org/r/1493806274-13936-1-git-send-email-amit.pundir@linaro.org

Signed-off-by: Amey Telawane 
[AmitP: Cherry-picked this commit from CodeAurora kernel/msm-3.10
https://source.codeaurora.org/quic/la/kernel/msm-3.10/commit/?id=2161ae9a70b12cf18ac8e5952a20161ffbccb477]
Signed-off-by: Amit Pundir 
[ Updated change log and removed the "- 1" from len parameter ]
Signed-off-by: Steven Rostedt (VMware) 
Signed-off-by: Ben Hutchings

tracing: Move mutex to protect against resetting of seq data

2016-11-20T01:17:35+00:00

commit 1245800c0f96eb6ebb368593e251d66c01e61022 upstream.

The iter->seq can be reset outside the protection of the mutex. So can
reading of user data. Move the mutex up to the beginning of the function.

Fixes: d7350c3f45694 ("tracing/core: make the read callbacks reentrants")
Reported-by: Al Viro 
Signed-off-by: Steven Rostedt 
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings

tracing: Fix crash from reading trace_pipe with sendfile

2016-04-30T22:06:02+00:00

commit a29054d9478d0435ab01b7544da4f674ab13f533 upstream.

If tracing contains data and the trace_pipe file is read with sendfile(),
then it can trigger a NULL pointer dereference and various BUG_ON within the
VM code.

There's a patch to fix this in the splice_to_pipe() code, but it's also a
good idea to not let that happen from trace_pipe either.

Link: http://lkml.kernel.org/r/1457641146-9068-1-git-send-email-rabin@rab.in

Reported-by: Rabin Vincent 
Signed-off-by: Steven Rostedt 
Signed-off-by: Ben Hutchings

tracing: Fix unmapping loop in tracing_mark_write

2015-03-02T13:17:11+00:00

commit 7215853e985a4bef1a6c14e00e89dfec84f1e457 upstream.

Commit 6edb2a8a385f0cdef51dae37ff23e74d76d8a6ce introduced
an array map_pages that contains the addresses returned by
kmap_atomic. However, when unmapping those pages, map_pages[0]
is unmapped before map_pages[1], breaking the nesting requirement
as specified in the documentation for kmap_atomic/kunmap_atomic.

This was caught by the highmem debug code present in kunmap_atomic.
Fix the loop to do the unmapping properly.

Link: http://lkml.kernel.org/r/1418871056-6614-1-git-send-email-markivx@codeaurora.org

Reviewed-by: Stephen Boyd 
Reported-by: Lime Yang 
Signed-off-by: Vikram Mulukutla 
Signed-off-by: Steven Rostedt 
Signed-off-by: Luis Henriques

move d_rcu from overlapping d_child to overlapping d_alias

2015-01-15T10:44:58+00:00

commit 946e51f2bf37f1656916eb75bd0742ba33983c28 upstream.

Signed-off-by: Al Viro 
[bwh: Backported to 3.16:
 - Apply name changes in all the different places we use d_alias and d_child
 - Adjust context]
Signed-off-by: Ben Hutchings 
Cc: Moritz Muehlenhoff 
Signed-off-by: Luis Henriques

tracing: Do not busy wait in buffer splice

2014-11-27T11:21:41+00:00

commit e30f53aad2202b5526c40c36d8eeac8bf290bde5 upstream.

On a !PREEMPT kernel, attempting to use trace-cmd results in a soft
lockup:

 # trace-cmd record -e raw_syscalls:* -F false
 NMI watchdog: BUG: soft lockup - CPU#0 stuck for 22s! [trace-cmd:61]
 ...
 Call Trace:
  [] ? __wake_up_common+0x90/0x90
  [] wait_on_pipe+0x35/0x40
  [] tracing_buffers_splice_read+0x2e3/0x3c0
  [] ? tracing_stats_read+0x2a0/0x2a0
  [] ? _raw_spin_unlock+0x2b/0x40
  [] ? do_read_fault+0x21b/0x290
  [] ? handle_mm_fault+0x2ba/0xbd0
  [] ? trace_event_buffer_lock_reserve+0x40/0x80
  [] ? trace_buffer_lock_reserve+0x22/0x60
  [] ? trace_event_buffer_lock_reserve+0x40/0x80
  [] do_splice_to+0x6d/0x90
  [] SyS_splice+0x7c1/0x800
  [] tracesys_phase2+0xd3/0xd8

The problem is this: tracing_buffers_splice_read() calls
ring_buffer_wait() to wait for data in the ring buffers.  The buffers
are not empty so ring_buffer_wait() returns immediately.  But
tracing_buffers_splice_read() calls ring_buffer_read_page() with full=1,
meaning it only wants to read a full page.  When the full page is not
available, tracing_buffers_splice_read() tries to wait again with
ring_buffer_wait(), which again returns immediately, and so on.

Fix this by adding a "full" argument to ring_buffer_wait() which will
make ring_buffer_wait() wait until the writer has left the reader's
page, i.e.  until full-page reads will succeed.

Link: http://lkml.kernel.org/r/1415645194-25379-1-git-send-email-rabin@rab.in

Fixes: b1169cc69ba9 ("tracing: Remove mock up poll wait function")
Signed-off-by: Rabin Vincent 
Signed-off-by: Steven Rostedt 
Signed-off-by: Luis Henriques

tracing: Fix wraparound problems in "uptime" trace clock

2014-07-21T13:56:12+00:00

The "uptime" trace clock added in:

    commit 8aacf017b065a805d27467843490c976835eb4a5
    tracing: Add "uptime" trace clock that uses jiffies

has wraparound problems when the system has been up more
than 1 hour 11 minutes and 34 seconds. It converts jiffies
to nanoseconds using:
        (u64)jiffies_to_usecs(jiffy) * 1000ULL
but since jiffies_to_usecs() only returns a 32-bit value, it
truncates at 2^32 microseconds.  An additional problem on 32-bit
systems is that the argument is "unsigned long", so fixing the
return value only helps until 2^32 jiffies (49.7 days on a HZ=1000
system).

Avoid these problems by using jiffies_64 as our basis, and
not converting to nanoseconds (we do convert to clock_t because
user facing API must not be dependent on internal kernel
HZ values).

Link: http://lkml.kernel.org/p/99d63c5bfe9b320a3b428d773825a37095bf6a51.1405708254.git.tony.luck@intel.com

Cc: stable@vger.kernel.org # 3.10+
Fixes: 8aacf017b065 "tracing: Add "uptime" trace clock that uses jiffies"
Signed-off-by: Tony Luck 
Signed-off-by: Steven Rostedt

tracing: Add TRACE_ITER_PRINTK flag check in __trace_puts/__trace_bputs

2014-07-15T15:58:40+00:00

The TRACE_ITER_PRINTK check in __trace_puts/__trace_bputs is missing,
so add it, to be consistent with __trace_printk/__trace_bprintk.
Those functions are all called by the same function: trace_printk().

Link: http://lkml.kernel.org/p/51E7A7D6.8090900@huawei.com

Cc: stable@vger.kernel.org # 3.11+
Signed-off-by: zhangwei(Jovi) 
Signed-off-by: Steven Rostedt