FROMGIT: selftests/ftrace: refactor eprobes test to fix argument checks

[ Upstream commit 6e3abef2a27e7402a94111c9eff85d887e64a309 ]

The add/remove eprobe test installs an eprobe for the openat syscall and
runs ls. It checks the filenames that were opened by ls against a
whitelist and a blacklist.

Commit 206b25c09080 ("tracing: eprobe: read the complete FILTER_PTR_STRING
pointer") fixed access to some string fields in eprobes. This triggers
test failures as the blacklist does not allow relative paths for the
openat parameters.

What makes this test unstable is the fact that the openat calls vary a
lot between different systems.

Refactor the test to make it more robust. "cd <directory>" will issue a
chdir syscall with the target directory as parameter. Set an eprobe on
the sys_enter_chdir event and filter for the exact directory name. Allow
(fault) as fallback.

Link: https://lore.kernel.org/all/20260804194705.760893-1-martin@kaiser.cx/

Fixes: 206b25c09080 ("tracing: eprobe: read the complete FILTER_PTR_STRING pointer")
Reported-by: kernel test robot <oliver.sang@intel.com>
Closes: https://lore.kernel.org/oe-lkp/202607151010.b68428e1-lkp@intel.com
Signed-off-by: Martin Kaiser <martin@kaiser.cx>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
(cherry picked from commit 169a7c6e5eea2292781fd36bb650bdfc27049944
 https://kernel.googlesource.com/pub/scm/linux/kernel/git/stable/linux.git linux-6.1.y)

BUG=b:542900253
TEST=cq

Change-Id: Ia0edff949ed9a28af91994782e378f55ace0df40
Disallow-Recycled-Builds: test-failures
Signed-off-by: Tzung-Bi Shih <tzungbi@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/kernel/+/8276237
Reviewed-by: Sean Paul <sean@poorly.run>
Reviewed-by: Jędrzej Ciupis <jciupis@google.com>