If the shm file is removed and a subsequent close, only release shm
object, but inode is leaked. Should decrease refcount to release inode
when unmapped, that matched with refcount increase when mapped.
Another fix that remove the shm file failed.
nsh> rm /var/shm/pts_mmap_1_2_5
nsh: rm: unlink failed: 6
Signed-off-by: fangxinyong <fangxinyong@xiaomi.com>
No memory map count limit that will exhaust memory and cause
the system hang. Also that fix pass LTP posix case mmap/24-1.c
Signed-off-by: fangxinyong <fangxinyong@xiaomi.com>
This way the mappings can be modified for any vm area, not only the
process that is running.
Why? This allows mapping pages to kernel dynamically, this functionality
will be presented later.
This implements the file system logic for posix shared memory:
shm_open, shm_unlink, mmap, munmap and close
For flat and protected builds the memory simply allocated from (user) heap
For kernel build the memory is allocated from page pool and mapped with MMU
This doesn't yet support protection flags or re-sizing already truncated shared
memory area.
Co-authored-by: Ville Juven <ville.juven@unikie.com>
Signed-off-by: Jukka Laitinen <jukkax@ssrc.tii.ae>
