linux-toradex.git/tools/testing/selftests/filesystems/configfs, branch master

selftests/configfs: fix the build on 32-bit architectures

2026-11-04T11:09:57+00:00

The fixture setup checks the result of mkdtemp() with ASSERT_NE(), which
hands the pointer to the harness. The harness casts both operands to
intmax_t to print them, and on 32-bit architectures gcc warns about the
cast from a pointer to an integer of a different size. The configfs
test builds with -Werror, so it fails to build there:

  kselftest_harness.h:797:49: error: cast from pointer to integer of different size [-Werror=pointer-to-int-cast]

Compare the result against NULL inside ASSERT_TRUE(), so that the
harness only sees an int.

Fixes: a7fdcb2edd0f ("selftests/configfs: add tests for the userspace interface")
Signed-off-by: Sasha Levin 
Reviewed-by: Breno Leitao 
Link: https://patch.msgid.link/20261103141627.30838-1-sashal@kernel.org
Signed-off-by: Breno Leitao

selftests/configfs: race symlink against rmdir of the target

2026-10-16T16:17:20+00:00

configfs_rmdir() drops the last reference to an item while its dentry is
still hashed, so a symlink(2) resolving that target takes a reference on
freed memory.  syzbot reported it [1].

Race mkdir/rmdir of a target against symlink/unlink of a link to it,
watching /sys/kernel/warn_count.

Fails until the fix [2] lands.

Link: https://syzkaller.appspot.com/bug?extid=6b16e3d085833cbf3e25 [1]
Link: https://lore.kernel.org/all/20260730093435.195441-1-vasilisalmpanis@gmail.com/ [2]
Link: https://patch.msgid.link/20260826-config_selftest-v1-4-e364b07e91ac@debian.org
Signed-off-by: Breno Leitao

selftests/configfs: cover symlink and unlink

2026-10-16T16:17:19+00:00

samples/configfs had nothing to link from, so symlink(2) went untested
beyond the EPERM a subsystem without ->allow_link() returns.

Cover creating and removing a link, the relative body configfs stores, the
count ->allow_link() and ->drop_link() keep, the busy errors both ends
return, and what get_target() rejects.

Link: https://patch.msgid.link/20260826-config_selftest-v1-3-e364b07e91ac@debian.org
Signed-off-by: Breno Leitao

selftests/configfs: add tests for the userspace interface

2026-10-16T16:17:19+00:00

configfs has no selftest coverage.  Its userspace ABI is entirely
mkdir/rmdir/read/write on attribute files, and the error each of those
returns is part of the contract.

Add tests driving the subsystems samples/configfs registers, each in its
own mount namespace on a private configfs mount.

Link: https://patch.msgid.link/20260826-config_selftest-v1-1-e364b07e91ac@debian.org
Signed-off-by: Breno Leitao