The semicolon is usually added when the macro is used. Update both the
macro definition and all uses.
Signed-off-by: Song Liu <songliubraving@fb.com>

Add option to print virtual address to trace.py

Miscellaneous BCC patches

doc: bpf_get_current_task helper

__delitem__ has some code duplication for the common case. The common
case is to call the low-level bpf_delete_elem function.  Refactor the
code a bit for this case. It avoids duplication of code and will also
make the communication with BPFd simpler as well.

Test: Ran test_tools_smoke tests with all tests passing except for
test_shared_table.py which fails for me with or without this patch.
(Filing separate issue for that).
Signed-off-by: Joel Fernandes <joelaf@google.com>

fix map a type parsing issue for export/extern types

Update man page for funccount

cc: missing bpf helpers in export/helpers.h

Fix issue #1562.

Currently, bcc allows a map defined in one module and
used in the same or a different module. At tests/python directory,
test_clang.py and test_shared_table.py have such an example.
  ...
  b1 = BPF(text="""BPF_TABLE_PUBLIC("hash", int, int, table1, 10);""")
  b2 = BPF(text="""BPF_TABLE("extern", int, int, table1, 10);""")
  t = b2["table"]
  ...

With current implementation, the map key/value types are parsed
twice, resulting a type "int int" instead of "int". When type
is retrieved through `t = b2["table"]`, python decoding error
will appear.

The issue is fixed by preventing the second map key/value type
parsing if the map is `extern`. Also add `t = b2["table"]`
so the issue will be triggered if bcc clang frontend fix is not there.
Signed-off-by: Yonghong Song <yhs@fb.com>

cc: error hint for 'invalid func'

Systems such as Android mostly use openat which makes us miss all
attempts to open. Instead use do_sys_open for the kprobe hook where
all the open calls finally end up, so that we don't miss anything.
Signed-off-by: Joel Fernandes <joelaf@google.com>

libclang does use functions from libbcc so it does depend on it.
When defining new symbols in bpf_common.cc, linker errors appear
when the same symbols are used in libclang. This is because of
incorrect linker dependency, this patch fixes the issue by making
sure the dependency is correctly tracked.
Signed-off-by: Joel Fernandes <joelaf@google.com>

Finish man page update for b03d9eb2.

bpf_getsockopt in docs/kernel-versions.md

add a probe alias $task in trace.py

The $task refers to the current task. In my particular case, I need
to trace the number of users for file system associated with the current
task. With the probe alias $task, trace.py can easily trace this event

  ......
  trace.py -I 'linux/fs_struct.h' 'mntns_install "users = %d", $task->fs->users'
  PID     TID     COMM            FUNC             -
  176566  176566  python2.7       mntns_install    users = 2
  176566  176566  python2.7       mntns_install    users = 2
  ......

With $task probe alias, kernel tast_struct fields can be used in trace.py
filter or output easily even if they cannot be accessed through input
parameters.
Signed-off-by: Yonghong Song <yhs@fb.com>

use __builtin_memset instead of memset with frontend rewriter

fix flaky test py_test_usdt3

When kernel CONFIG_KASAN is enabled, the function memset becomes
a global function __memset. The bcc application with probe
rewrite will incur an error like:

  error: <unknown>:0:0: in function tracepoint__task__task_newtask i32
         (%struct.tracepoint__task__task_newtask*): A call to global function
         '__memset' is not supported. Only calls to predefined BPF helpers
         are allowed.

Replace memset function with clang __builtin_memset so that
the compiler is able to eventually optimize it away.
Signed-off-by: Yonghong Song <yhs@localhost.localdomain>

py_test_usdt3 has shown flakiness recently, and I actually reproduced
it on FC27. This patch increases the iteration number for
kprobe_poll and I ran the test for more than 20 times
without any failure.

Also fix a python3 compability issue. Open the file to write with
attribute "wb" instead of "w" since the text string is a byte array.
Signed-off-by: Yonghong Song <yhs@fb.com>

fix a race condition between perf_reader munmap and read

adding filtering example to trace.py help

Fix issue #1533.

Currently, there exist a race condition between perf_reader
buffer munmap and read if they are happening in two different
threads, crash is possible as in issue #1533.

          thread 1                    thread 2
          perf_reader_event_read      ...
                                      detach_probe
                                      munmap
          access ring buffer

detach_probe may happen as part of bpf object exit cleanup process
at which point thread 1 is still alive. In this case, accessing
ring buffer may cause segfault since the original mmap'ed memory
is not available any more.

It is hard to fix such races outside bcc since user
calls kprobe_poll which has valid BPF object when it is called,
but race happens inside the kprobe_poll.

This patch adds a state of the ring buffer and the read will
not happen once the state comes to the munmap.
Signed-off-by: Yonghong Song <yhs@fb.com>

Signed-off-by: Yonghong Song <yhs@fb.com>

Add a few trace.py examples in tutorial.md

Allow for sharing of python tools/ scripts

Use of this argparse constructor keyword is causing regression
test failures, and its use was nice-to-have - this means the -e
shorthand for --ebpf will be available iff its not been used in
another add_argument call.  Neither -e/--ebpf are advertised in
the usage message anyway.

Signed-off-by: Yonghong Song <yhs@fb.com>

Small fixes to some man pages for bcc tools

Fix folding option

Add bpf_override_return() helper definition