tools/syscalls/README

   1 LTTng system call tracing
   2
   3 1) lttng-syscall-extractor
   4
   5 You need to build a kernel with CONFIG_FTRACE_SYSCALLS=y and
   6 CONFIG_KALLSYMS_ALL=y for extraction. Apply the linker patch to get your
   7 kernel to keep the system call metadata after boot.  Then build and load
   8 the LTTng syscall extractor module. The module will fail to load (this
   9 is expected). See the dmesg output for system call metadata.
  10
  11 2) Generate system call TRACE_EVENT().
  12
  13 Take the dmesg data and feed it to lttng-syscalls-generate-headers.sh from the
  14 tools/syscalls directory. See the script header for usage example. It should be
  15 run for both the integers and pointers types.
  16
  17 After these are created, you just need to follow the new system call additions,
  18 no need to regenerate the whole thing, since system calls are only appended to.
  19
  20 3) Override headers
  21
  22 You need to provide override headers (even if they don't contain
  23 overrides) for each architecture. Those are meant to contain manual
  24 overrides for specific system calls for cases where the script do not
  25 generate the correct typing for specific system calls.
  26
  27 4) Integrating the new architecture, updating architecture header
  28
  29 Edit instrumentation/syscalls/syscalls_integers.h and
  30 instrumentation/syscalls/syscalls_pointers.h. Add the new architecture (e.g.
  31 CONFIG_X86_64) to the newly-generated headers (e.g. changing the current
  32 x86-64-syscalls_<CLASS>.h into x86-64-syscalls_<CLASS>.h), then rebuild
  33 lttng-modules.