lkdtm: Update tests for memcpy() run-time warnings

Clarify the LKDTM FORTIFY tests, and add tests for the mem*() family of
functions, now that run-time checking is distinct.

Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: linux-kselftest@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>

lkdtm: Move crashtype definitions into each category

It's long been annoying that to add a new LKDTM test one had to update
lkdtm.h and core.c to get it "registered". Switch to a per-category
list and update the crashtype walking code in core.c to handle it.

This also means that all the lkdtm_* tests themselves can be static now.

Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kees Cook <keescook@chromium.org>

lkdtm/fortify: Swap memcpy() for strncpy()

The memcpy() runtime defenses are still not landed, so test with
strncpy() for now.

Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reported-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
Reviewed-by: Muhammad Usama Anjum <usama.anjum@collabora.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20220216202548.2093883-1-keescook@chromium.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

lkdtm/fortify: Consolidate FORTIFY_SOURCE tests

The FORTIFY_SOURCE tests were split between bugs.c and fortify.c. Move
tests into fortify.c, standardize their naming, add CONFIG hints, and
add them to the lkdtm selftests.

Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20210818174855.2307828-3-keescook@chromium.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

lkdtm: Add CONFIG hints in errors where possible

For various failure conditions, try to include some details about where
to look for reasons about the failure.

Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20210623203936.3151093-8-keescook@chromium.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/misc/lkdtm: add new file in LKDTM to test fortified strscpy

This new test ensures that fortified strscpy has the same behavior than
vanilla strscpy (e.g. returning -E2BIG when src content is truncated).
Finally, it generates a crash at runtime because there is a write overflow
in destination string.

Link: https://lkml.kernel.org/r/20201122162451.27551-5-laniel_francis@privacyrequired.com
Signed-off-by: Francis Laniel <laniel_francis@privacyrequired.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: Daniel Axtens <dja@axtens.net>
Cc: Daniel Micay <danielmicay@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>