[LTP] [PATCH v7 4/4] Add documentation about syscalls.h generator

Andrea Cervesato
2024-10-31T11:58:39Z

From: Andrea Cervesato <andrea.cervesato@suse.com>

Signed-off-by: Andrea Cervesato <andrea.cervesato@suse.com>
---
doc/developers/test_case_tutorial.rst | 27 ++++++++++++++-------------
1 file changed, 14 insertions(+), 13 deletions(-)

diff --git a/doc/developers/test_case_tutorial.rst b/doc/developers/test_case_tutorial.rst
index be9a0ea8bac1d690b4ed4879d110f87c3f2a381a..b48ea4a7a3594266466fcca364f5d0ff1e42d235 100644
--- a/doc/developers/test_case_tutorial.rst
+++ b/doc/developers/test_case_tutorial.rst
@@ -302,24 +302,25 @@ for a distribution's C library version to be older than its kernel or it may use
cut down C library in comparison to the GNU one. So we must call ``statx()``
using the general ``syscall()`` interface.

-The LTP contains a library for dealing with the ``syscall`` interface, which is
+LTP contains a library for dealing with the ``syscall`` interface, which is
located in :master:`include/lapi`. System call numbers are listed against the relevant
call in the ``*.in`` files (e.g. ``x86_64.in``) which are used to generate
-``syscalls.h``, which is the header you should include. On rare occasions you
-may find the system call number is missing from the ``*.in`` files and will need
-to add it (see :master:`include/lapi/syscalls/strip_syscall.awk`).
+``syscalls.h``, the header you should include.

-System call numbers vary between architectures, hence there are multiple
-``*.in`` files for each architecture. You can find the various values for the
-``statx`` system call across a number of ``unistd.h`` files in the Linux kernel.
+On rare occasions, you may find that system call number is missing from ``*.in``
+files. In these cases, they will need to be updated using
+`include/lapi/syscalls/generate_arch.sh` script as following:

-Note that we don't use the system-call-identifier value available in
-``/usr/include/linux/uinstd.h`` because the kernel might be much newer than the
-user land development packages.
+.. code-block:: bash
+
+ $ include/lapi/syscalls/generate_arch.sh /path/of/linux/sources
+
+The script will generate all the needed ``*.in`` files according to the Linux
+source code which has been used. Make sure that your Linux source code has
+been updated to the latest version.

-For ``statx`` we had to add ``statx 332`` to :master:`include/lapi/syscalls/x86_64.in`,
-``statx 383`` to :master:`include/lapi/syscalls/powerpc.in`, etc. Now lets look at
-the code, which I will explain in more detail further down.
+Once the new syscalls files have been updated, to rebuild our ``syscalls.h``
+file, please use ``./configure`` command.

.. code-block:: c

--
2.43.0