Re: [PATCH] Expose SHM_HUGETLB in shmctl(id, IPC_STAT, ...)

Andrew Morton wrote:

+	shp->shm_flags = (shmflg & (S_IRWXUGO | SHM_HUGETLB));

[...]
I dunno.  The manpage says:

       The highlighted fields in the member shm_perm can be set:

           struct ipc_perm {
       ...
               ushort mode;  /* lower 9 bits of access modes */
       ...
           };

So if an application used to do:

	if (perm.mode == 0666)

it will now break, because we've gone and set bit 9 on hugetlb segments.

The man page on my system says:

              unsigned short mode;  /* Permissions + SHM_DEST and
                                        SHM_LOCKED flags */

I looked for a precendent before sending the patch and thought that SHM_LOCKED was a good one.

	-Arun
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