tools/testing/vma: cover hole filling through __mmap_region()

The mmap tests extend existing mappings one neighbor at a time, while
merge tests construct merge state directly.  Neither exercises filling a
hole between compatible mappings through the mmap setup and completion
path.

Fill a gap through __mmap_region() and require both neighbors to merge
into one VMA.  Repeat with only the new mapping's execute permission set
and require three separate VMAs.  Check boundaries, permissions, page
offsets, map_count and cleanup.

Link: https://lore.kernel.org/178886112560.138404.17741948638665342936.vma-v2@tychen.cc
Signed-off-by: Tianyi Chen <hi@tychen.cc>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Lorenzo Stoakes (ARM) <ljs@kernel.org>
Assisted-by: Codex:GPT-6
Cc: Jann Horn <jannh@google.com>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Pedro Falcato <pfalcato@suse.de>
Cc: Vlastimil Babka <vbabka@kernel.org>

0 files changed, 0 insertions, 0 deletions