kernel/git/next/linux-next.git/init/initramfs_test.c, branch master

kunit: use scoped_with_init_fs() in tests that resolve paths

2026-07-02T06:53:32+00:00

KUnit runs each test in a kthread (kunit_generic_run_threadfn_adapter()). Since commit 32750c77e811 ("fs: start all kthreads in nullfs") every kthread starts out with its fs_struct root and pwd pointing at an empty, immutable nullfs and can no longer resolve paths. Two test suites resolve paths from test context and now fail. The misc minor tests create a device node and open it: # miscdev_test_static_basic: EXPECTATION FAILED at drivers/char/misc_minor_kunit.c:166 failed to create node # miscdev_test_static_basic: EXPECTATION FAILED at drivers/char/misc_minor_kunit.c:170 failed to open misc device: -2 init_mknod("/dev/...") resolves relative to current->fs, which is now nullfs with no /dev, so node creation returns -ENOENT and the following filp_open() fails with -ENOENT (-2). The initramfs tests hit the same wall: they call unpack_to_rootfs() (init_mkdir()/init_mknod() under the hood) and then verify with relative-name init_stat()/init_unlink()/ filp_open(), all of which resolve against the nullfs root and pwd. Wrap the path-resolving regions of both suites in scoped_with_init_fs(), which borrows the userspace init fs_struct (set up by init_userspace_fs() before kunit_run_all_tests()) for the duration. This is the same opt-in the rest of the tree uses for kthread path resolution. Doing it per test rather than blanket-wrapping the KUnit runner keeps the nullfs isolation in place for the many tests that should never touch the filesystem. Link: https://patch.msgid.link/20260701-work-kunit-nullfs-v1-1-dfa60270434f@kernel.org Fixes: 32750c77e811 ("fs: start all kthreads in nullfs") Reported-by: Mark Brown Closes: https://lore.kernel.org/r/akOrbOsKUqgZarGw@sirena.org.uk Signed-off-by: Christian Brauner (Amutable)

init/initramfs_test: wait_for_initramfs() before running

2026-05-27T13:11:02+00:00

initramfs_test_extract() and friends call unpack_to_rootfs() from a kunit kthread while do_populate_rootfs() may still be running asynchronously from rootfs_initcall. unpack_to_rootfs() keeps its parser state in module-static variables (victim, byte_count, state, this_header, header_buf, name_buf, ...), so the two writers corrupt each other. On arm64 v7.0-rc5+ this oopses early in boot: Unable to handle kernel paging request at virtual address ffff80018f9f0ffc pc : do_reset+0x3c/0x98 Call trace: do_reset initramfs_test_extract kunit_try_run_case Initramfs unpacking failed: junk within compressed archive do_reset() faults because 'victim' was overwritten by the boot-time unpacker; the boot unpacker meanwhile logs the bogus "junk within compressed archive" on the real initrd because the test wrecked its state machine. Add a .suite_init callback that calls wait_for_initramfs() so the async unpack is quiescent before the first case runs. suite_init runs once per suite rather than before every individual test case. Fixes: 83c0b27266ec ("initramfs_test: kunit tests for initramfs unpacking") Signed-off-by: Jia He Link: https://patch.msgid.link/20260519093937.1064628-1-justin.he@arm.com Reviewed-by: David Disseldorp Signed-off-by: Christian Brauner (Amutable)

initramfs: Refactor to use hex2bin() instead of custom approach

2026-05-21T07:32:46+00:00

There is a simple_strntoul() function used solely as a shortcut for hex2bin() with proper endianess conversions. Replace that and drop the unneeded function in the next changes. This implementation will abort if we fail to parse the cpio header, instead of using potentially bogus header values. Co-developed-by: David Disseldorp Signed-off-by: David Disseldorp Signed-off-by: Andy Shevchenko Link: https://patch.msgid.link/20260331070519.5974-5-ddiss@suse.de Reviewed-by: Petr Mladek Signed-off-by: Christian Brauner

initramfs_test: test header fields with 0x hex prefix

2026-05-21T07:32:46+00:00

cpio header fields are 8-byte hex strings, but one "interesting" side-effect of our historic simple_str[n]toul() use means that a "0x" (or "0X") prefixed header field will be successfully processed when coupled alongside a 6-byte hex remainder string. "0x" prefix support is contrary to the initramfs specification at Documentation/driver-api/early-userspace/buffer-format.rst which states: The structure of the cpio_header is as follows (all fields contain hexadecimal ASCII numbers fully padded with '0' on the left to the full width of the field, for example, the integer 4780 is represented by the ASCII string "000012ac"): Test for this corner case by injecting "0x" prefixes into the uid, gid and namesize cpio header fields. Confirm that init_stat() returns matching uid and gid values. This test can be modified in future to expect unpack_to_rootfs() failure when header validation is changed to properly follow the specification. Add some missing struct kstat initializations to account for possible init_stat() failures. Signed-off-by: David Disseldorp Link: https://patch.msgid.link/20260331070519.5974-3-ddiss@suse.de Reviewed-by: Petr Mladek Reviewed-by: Andy Shevchenko Signed-off-by: Christian Brauner

initramfs_test: add fill_cpio() inject_ox parameter

2026-05-21T07:32:46+00:00

fill_cpio() uses sprintf() to write out the in-memory cpio archive from an array of struct initramfs_test_cpio. This change allows callers to modify the cpio sprintf() format string so that future tests can intentionally corrupt the header with "0x" and "0X" prefixed fields. Signed-off-by: David Disseldorp Link: https://patch.msgid.link/20260331070519.5974-2-ddiss@suse.de Reviewed-by: Andy Shevchenko Reviewed-by: Petr Mladek Signed-off-by: Christian Brauner

Convert 'alloc_obj' family to use the new default GFP_KERNEL argument

2026-02-22T01:09:51+00:00

This was done entirely with mindless brute force, using git grep -l '\

treewide: Replace kmalloc with kmalloc_obj for non-scalar types

2026-02-21T09:02:28+00:00

This is the result of running the Coccinelle script from scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to avoid scalar types (which need careful case-by-case checking), and instead replace kmalloc-family calls that allocate struct or union object instances: Single allocations: kmalloc(sizeof(TYPE), ...) are replaced with: kmalloc_obj(TYPE, ...) Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...) are replaced with: kmalloc_objs(TYPE, COUNT, ...) Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...) are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...) (where TYPE may also be *VAR) The resulting allocations no longer return "void *", instead returning "TYPE *". Signed-off-by: Kees Cook

initramfs_test: kunit test for cpio.filesize > PATH_MAX

2026-01-14T16:05:35+00:00

initramfs unpack skips over cpio entries where namesize > PATH_MAX, instead of returning an error. Add coverage for this behaviour. Signed-off-by: David Disseldorp Link: https://patch.msgid.link/20260114135051.4943-2-ddiss@suse.de Signed-off-by: Christian Brauner

initramfs_test: add filename padding test case

2025-08-21T19:00:10+00:00

Confirm that cpio filenames with multiple trailing zeros (accounted for in namesize) extract successfully. Signed-off-by: David Disseldorp Acked-by: Nicolas Schier Link: https://lore.kernel.org/r/20250819032607.28727-9-ddiss@suse.de [nathan: Fix duplicate filesize initialization, reported at https://lore.kernel.org/202508200304.wF1u78il-lkp@intel.com/] Signed-off-by: Nathan Chancellor

initramfs_test: kunit tests for initramfs unpacking

2025-03-08T11:13:04+00:00

Provide some basic initramfs unpack sanity tests covering: - simple file / dir extraction - filename field overrun, as reported and fixed separately via https://lore.kernel.org/r/20241030035509.20194-2-ddiss@suse.de - "070702" cpio data checksums - hardlinks Signed-off-by: David Disseldorp Link: https://lore.kernel.org/r/20250304061020.9815-3-ddiss@suse.de Signed-off-by: Christian Brauner