linux-toradex.git/kernel/trace/trace_syscalls.c, branch v4.14-rc3

perf/bpf: fix a clang compilation issue

2017-09-11T21:28:45+00:00

clang does not support variable length array for structure member.
It has the following error during compilation:

kernel/trace/trace_syscalls.c:568:17: error: fields must have a constant size:
'variable length array in structure' extension will never be supported
                unsigned long args[sys_data->nb_args];
                              ^

The fix is to use a fixed array length instead.

Reported-by: Nick Desaulniers 
Signed-off-by: Yonghong Song 
Signed-off-by: David S. Miller

Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next

2017-09-06T21:45:08+00:00

Pull networking updates from David Miller:

 1) Support ipv6 checksum offload in sunvnet driver, from Shannon
    Nelson.

 2) Move to RB-tree instead of custom AVL code in inetpeer, from Eric
    Dumazet.

 3) Allow generic XDP to work on virtual devices, from John Fastabend.

 4) Add bpf device maps and XDP_REDIRECT, which can be used to build
    arbitrary switching frameworks using XDP. From John Fastabend.

 5) Remove UFO offloads from the tree, gave us little other than bugs.

 6) Remove the IPSEC flow cache, from Florian Westphal.

 7) Support ipv6 route offload in mlxsw driver.

 8) Support VF representors in bnxt_en, from Sathya Perla.

 9) Add support for forward error correction modes to ethtool, from
    Vidya Sagar Ravipati.

10) Add time filter for packet scheduler action dumping, from Jamal Hadi
    Salim.

11) Extend the zerocopy sendmsg() used by virtio and tap to regular
    sockets via MSG_ZEROCOPY. From Willem de Bruijn.

12) Significantly rework value tracking in the BPF verifier, from Edward
    Cree.

13) Add new jump instructions to eBPF, from Daniel Borkmann.

14) Rework rtnetlink plumbing so that operations can be run without
    taking the RTNL semaphore. From Florian Westphal.

15) Support XDP in tap driver, from Jason Wang.

16) Add 32-bit eBPF JIT for ARM, from Shubham Bansal.

17) Add Huawei hinic ethernet driver.

18) Allow to report MD5 keys in TCP inet_diag dumps, from Ivan
    Delalande.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1780 commits)
  i40e: point wb_desc at the nvm_wb_desc during i40e_read_nvm_aq
  i40e: avoid NVM acquire deadlock during NVM update
  drivers: net: xgene: Remove return statement from void function
  drivers: net: xgene: Configure tx/rx delay for ACPI
  drivers: net: xgene: Read tx/rx delay for ACPI
  rocker: fix kcalloc parameter order
  rds: Fix non-atomic operation on shared flag variable
  net: sched: don't use GFP_KERNEL under spin lock
  vhost_net: correctly check tx avail during rx busy polling
  net: mdio-mux: add mdio_mux parameter to mdio_mux_init()
  rxrpc: Make service connection lookup always check for retry
  net: stmmac: Delete dead code for MDIO registration
  gianfar: Fix Tx flow control deactivation
  cxgb4: Ignore MPS_TX_INT_CAUSE[Bubble] for T6
  cxgb4: Fix pause frame count in t4_get_port_stats
  cxgb4: fix memory leak
  tun: rename generic_xdp to skb_xdp
  tun: reserve extra headroom only when XDP is set
  net: dsa: bcm_sf2: Configure IMP port TC2QOS mapping
  net: dsa: bcm_sf2: Advertise number of egress queues
  ...

perf/ftrace: Fix double traces of perf on ftrace:function

2017-08-29T11:29:29+00:00

When running perf on the ftrace:function tracepoint, there is a bug
which can be reproduced by:

  perf record -e ftrace:function -a sleep 20 &
  perf record -e ftrace:function ls
  perf script

              ls 10304 [005]   171.853235: ftrace:function:
  perf_output_begin
              ls 10304 [005]   171.853237: ftrace:function:
  perf_output_begin
              ls 10304 [005]   171.853239: ftrace:function:
  task_tgid_nr_ns
              ls 10304 [005]   171.853240: ftrace:function:
  task_tgid_nr_ns
              ls 10304 [005]   171.853242: ftrace:function:
  __task_pid_nr_ns
              ls 10304 [005]   171.853244: ftrace:function:
  __task_pid_nr_ns

We can see that all the function traces are doubled.

The problem is caused by the inconsistency of the register
function perf_ftrace_event_register() with the probe function
perf_ftrace_function_call(). The former registers one probe
for every perf_event. And the latter handles all perf_events
on the current cpu. So when two perf_events on the current cpu,
the traces of them will be doubled.

So this patch adds an extra parameter "event" for perf_tp_event,
only send sample data to this event when it's not NULL.

Signed-off-by: Zhou Chengming 
Reviewed-by: Jiri Olsa 
Acked-by: Steven Rostedt (VMware) 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: acme@kernel.org
Cc: alexander.shishkin@linux.intel.com
Cc: huawei.libin@huawei.com
Link: http://lkml.kernel.org/r/1503668977-12526-1-git-send-email-zhouchengming1@huawei.com
Signed-off-by: Ingo Molnar

bpf: add support for sys_enter_* and sys_exit_* tracepoints

2017-08-07T21:09:48+00:00

Currently, bpf programs cannot be attached to sys_enter_* and sys_exit_*
style tracepoints. The iovisor/bcc issue #748
(https://github.com/iovisor/bcc/issues/748) documents this issue.
For example, if you try to attach a bpf program to tracepoints
syscalls/sys_enter_newfstat, you will get the following error:
   # ./tools/trace.py t:syscalls:sys_enter_newfstat
   Ioctl(PERF_EVENT_IOC_SET_BPF): Invalid argument
   Failed to attach BPF to tracepoint

The main reason is that syscalls/sys_enter_* and syscalls/sys_exit_*
tracepoints are treated differently from other tracepoints and there
is no bpf hook to it.

This patch adds bpf support for these syscalls tracepoints by
  . permitting bpf attachment in ioctl PERF_EVENT_IOC_SET_BPF
  . calling bpf programs in perf_syscall_enter and perf_syscall_exit

The legality of bpf program ctx access is also checked.
Function trace_event_get_offsets returns correct max offset for each
specific syscall tracepoint, which is compared against the maximum offset
access in bpf program.

Signed-off-by: Yonghong Song 
Acked-by: Alexei Starovoitov 
Signed-off-by: David S. Miller

tracing/syscalls: fix multiline in error message text

2016-09-29T08:25:23+00:00

pr_info message spans two lines and the literal string is missing
a white space between words. Add the white space.

Signed-off-by: Colin Ian King 
Acked-by: Ingo Molnar 
Acked-by: Steven Rostedt 
Signed-off-by: Jiri Kosina

perf: split perf_trace_buf_prepare into alloc and update parts

2016-04-08T01:04:26+00:00

split allows to move expensive update of 'struct trace_entry' to later phase.
Repurpose unused 1st argument of perf_tp_event() to indicate event type.

While splitting use temp variable 'rctx' instead of '*rctx' to avoid
unnecessary loads done by the compiler due to -fno-strict-aliasing

Signed-off-by: Alexei Starovoitov 
Acked-by: Peter Zijlstra (Intel) 
Signed-off-by: David S. Miller

Merge tag 'trace-v4.6' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

2016-03-24T17:52:25+00:00

Pull tracing updates from Steven Rostedt:
 "Nothing major this round.  Mostly small clean ups and fixes.

  Some visible changes:

   - A new flag was added to distinguish traces done in NMI context.

   - Preempt tracer now shows functions where preemption is disabled but
     interrupts are still enabled.

  Other notes:

   - Updates were done to function tracing to allow better performance
     with perf.

   - Infrastructure code has been added to allow for a new histogram
     feature for recording live trace event histograms that can be
     configured by simple user commands.  The feature itself was just
     finished, but needs a round in linux-next before being pulled.

     This only includes some infrastructure changes that will be needed"

* tag 'trace-v4.6' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: (22 commits)
  tracing: Record and show NMI state
  tracing: Fix trace_printk() to print when not using bprintk()
  tracing: Remove redundant reset per-CPU buff in irqsoff tracer
  x86: ftrace: Fix the misleading comment for arch/x86/kernel/ftrace.c
  tracing: Fix crash from reading trace_pipe with sendfile
  tracing: Have preempt(irqs)off trace preempt disabled functions
  tracing: Fix return while holding a lock in register_tracer()
  ftrace: Use kasprintf() in ftrace_profile_tracefs()
  ftrace: Update dynamic ftrace calls only if necessary
  ftrace: Make ftrace_hash_rec_enable return update bool
  tracing: Fix typoes in code comment and printk in trace_nop.c
  tracing, writeback: Replace cgroup path to cgroup ino
  tracing: Use flags instead of bool in trigger structure
  tracing: Add an unreg_all() callback to trigger commands
  tracing: Add needs_rec flag to event triggers
  tracing: Add a per-event-trigger 'paused' field
  tracing: Add get_syscall_name()
  tracing: Add event record param to trigger_ops.func()
  tracing: Make event trigger functions available
  tracing: Make ftrace_event_field checking functions available
  ...

tracing: Add get_syscall_name()

2016-03-08T16:19:32+00:00

Add a utility function to grab the syscall name from the syscall
metadata, given a syscall id.

Link: http://lkml.kernel.org/r/be26a8dfe3f15e16a837799f1c1e2b4d62742843.1449767187.git.tom.zanussi@linux.intel.com

Signed-off-by: Tom Zanussi 
Tested-by: Masami Hiramatsu 
Reviewed-by: Namhyung Kim 
Signed-off-by: Steven Rostedt

tracing/syscalls: Rename "/format" tracepoint field name "nr" to "__syscall_nr:

2016-02-29T14:34:53+00:00

Some tracepoint have multiple fields with the same name, "nr", the first
one is a unique syscall ID, the other is a syscall argument:

  # cat /sys/kernel/debug/tracing/events/syscalls/sys_enter_io_getevents/format
  name: sys_enter_io_getevents
  ID: 747
  format:
 	field:unsigned short common_type;	offset:0;	size:2;	signed:0;
 	field:unsigned char common_flags;	offset:2;	size:1;	signed:0;
 	field:unsigned char common_preempt_count;	offset:3;	size:1;	signed:0;
 	field:int common_pid;	offset:4;	size:4;	signed:1;

 	field:int nr;	offset:8;	size:4;	signed:1;
 	field:aio_context_t ctx_id;	offset:16;	size:8;	signed:0;
 	field:long min_nr;	offset:24;	size:8;	signed:0;
 	field:long nr;	offset:32;	size:8;	signed:0;
 	field:struct io_event * events;	offset:40;	size:8;	signed:0;
 	field:struct timespec * timeout;	offset:48;	size:8;	signed:0;

  print fmt: "ctx_id: 0x%08lx, min_nr: 0x%08lx, nr: 0x%08lx, events: 0x%08lx, timeout: 0x%08lx", ((unsigned long)(REC->ctx_id)), ((unsigned long)(REC->min_nr)), ((unsigned long)(REC->nr)), ((unsigned long)(REC->events)), ((unsigned long)(REC->timeout))
  #

Fix it by renaming the "/format" common tracepoint field "nr" to "__syscall_nr".

Signed-off-by: Taeung Song 
[ Do not rename the struct member, just the '/format' field name ]
Signed-off-by: Steven Rostedt 
Acked-by: Peter Zijlstra 
Cc: Jiri Olsa 
Cc: Lai Jiangshan 
Cc: Namhyung Kim 
Cc: Thomas Gleixner 
Link: http://lkml.kernel.org/r/20160226132301.3ae065a4@gandalf.local.home
Signed-off-by: Arnaldo Carvalho de Melo

tracing: Move trace_flags from global to a trace_array field

2015-09-30T19:22:55+00:00

In preparation to make trace options per instance, the global trace_flags
needs to be moved from being a global variable to a field within the trace
instance trace_array structure.

There's still more work to do, as there's some functions that use
trace_flags without passing in a way to get to the current_trace array. For
those, the global_trace is used directly (from trace.c). This includes
setting and clearing the trace_flags. This means that when a new instance is
created, it just gets the trace_flags of the global_trace and will not be
able to modify them. Depending on the functions that have access to the
trace_array, the flags of an instance may not affect parts of its trace,
where the global_trace is used. These will be fixed in future changes.

Signed-off-by: Steven Rostedt