[v6,0/3] Add new trace-cmd record options: "--proc-map"

Message

Tzvetomir Stoyanov (VMware) Aug. 28, 2019, 11:24 a.m. UTC

New options to trace-cmd record are added:
  - "--proc-map" - Saves traced process(es) address map in trace.dat
    file.
  - "--user" - Executes the traced process as given user.

As "--proc-map" option uses trace-cmd ptrace logic, part of this code is
rewritten. There were some leftovers related to this logic, the code is
upadted.

[
   v6 changes:
        - Added warning message when allocation of pids array fails.
	- Put extra brackets around complex blocks in record_trace(),
          as Steven Rostedt suggested.
   v5 changes:
        - Added new patch: 
            "Extend ptrace logic to work with multiple filtered pids"
          It resolves "filter_pid" leftover in ptrace related logic.
        - "--proc-map" does not depend on option -F, it works with any command,
          specified as trace-cmd argument or option -P.
        - Renamed "mmap" to "proc-map" - the option name and the names of
          the functions, variables and defines related to this feature.
   v4 changes:
        - Added check for strdup() failure.
        - Made input user string argument of change_user() and run_cmd()
         constant.
        - Added description of the new "--mmap" trace-cmd option in the 
          program's help and the man page. (Suggested by Slavomir Kaslev)

      Problems, reported by Yordan Karadzhov:
        - Improved the parsing of /proc/<pid>/maps. Made it not so strict, as it
          failed on some machines due to different size of fields. 
        - Implemented trace_pid_mmap_free() cleanup function to free mmap
          related resources at trace-cmd exit.
        - Fixed potential problem with non-terminated string, returned by
          readlink().
        - Coding style fixes.
   v3 changes:
      - "--user" does not depend on option -F, it works with any command,
        specified as trace-cmd argument.
      - Changed tracecmd_search_task_mmap() API to return not only the library
     name, but also the start and end memory addresses.
      - Renamed *tracee* to *task*
      - Improved resources cleanup, in case of an error.
      - Removed (this) changelog from the commit message.
   v2 changes:
     - Check for errors in change_user(). If an error occurs while
       changing the user, the message is printed and the traced 
       process is not executed.
     - Replaced usage of tracecmd_add_option_v() with tracecmd_add_option() API.
     - Added checks to prevent buffer overflow when sscanf (... "%s", buf) is used.
     - Return error in case memory allocation fails.
     - Return error if option string is not in the expected format.
     - Sort memory maps and use binary search to find matching library in the map.


Tzvetomir Stoyanov (VMware) (3):
  trace-cmd: Extend ptrace logic to work with multiple filtered pids
  trace-cmd: Save the tracee address map into the trace.dat file.
  trace-cmd: Add option to execute traced process as given user

 Documentation/trace-cmd-record.1.txt |   6 +
 include/trace-cmd/trace-cmd.h        |  10 +
 lib/trace-cmd/trace-input.c          | 172 +++++++++++++++-
 tracecmd/include/trace-local.h       |  10 +
 tracecmd/trace-record.c              | 286 +++++++++++++++++++++++++--
 tracecmd/trace-usage.c               |   2 +
 6 files changed, 468 insertions(+), 18 deletions(-)