[PATCH i-g-t 0/2] tests/intel/xe_compute: check root-only write permission for ccs_mode

[Peter Senna Tschudin <peter.senna@linux.intel.com>]

I've recently sent a patch that created a dedicated security check to
verify that 13 files are only accessible by the root user. The problem
with the first submission was that it was not very maintainable because
it duplicated code that is required to find the files in sysfs.

This series takes a different and more maintainable approach: instead of
adding new tests, it extends existing ones. Specifically, this series:
- Adds the helper function
  `bool igt_fs_check_root_perm(int dirfd, const char *pathname)` to
   lib/igt_fs.c.

- Uses `igt_fs_check_root_perm()` in the `test_ccs_mode()` function
  in tests/intel/xe_compute.c to verify that the "ccs_mode" sysfs
  attribute is writable only by root.

Intentionally ignoring checkpatch warnings:
 - WARNING:SYMBOLIC_PERMS: Symbolic permissions 'S_IWGRP' are not preferred.
   Consider using octal permissions '0020'.
   #53: FILE: lib/igt_fs.c:164:
   +       if (st.st_mode & S_IWGRP)

 - WARNING:SYMBOLIC_PERMS: Symbolic permissions 'S_IWOTH' are not preferred.
   Consider using octal permissions '0002'.
   #56: FILE: lib/igt_fs.c:167:
   +       if (st.st_mode & S_IWOTH)

Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Cc: Michal Winiarski <michal.winiarski@intel.com>
Cc: Kamil Konieczny  <kamil.konieczny@linux.intel.com>

Peter Senna Tschudin (2):
  lib/igt_fs: add igt_fs_check_root_perm() helper
  tests/intel/xe_compute: check root-only write permission for ccs_mode

 lib/igt_fs.c             | 28 ++++++++++++++++++++++++++++
 lib/igt_fs.h             |  1 +
 tests/intel/xe_compute.c |  7 +++++++
 3 files changed, 36 insertions(+)

-- 
2.43.0