Re: introduce dynamic shared memory registry

Nathan Bossart <nathandbossart(at)gmail(dot)com> writes:
> Committed. Thanks everyone for reviewing!

Coverity complained about this:

*** CID 1586660: Null pointer dereferences (NULL_RETURNS)
/srv/coverity/git/pgsql-git/postgresql/src/backend/storage/ipc/dsm_registry.c: 185 in GetNamedDSMSegment()
179 }
180 else if (!dsm_find_mapping(entry->handle))
181 {
182 /* Attach to existing segment. */
183 dsm_segment *seg = dsm_attach(entry->handle);
184
>>> CID 1586660: Null pointer dereferences (NULL_RETURNS)
>>> Dereferencing a pointer that might be "NULL" "seg" when calling "dsm_pin_mapping".
185 dsm_pin_mapping(seg);
186 ret = dsm_segment_address(seg);
187 }
188 else
189 {
190 /* Return address of an already-attached segment. */

I think it's right --- the comments for dsm_attach explicitly
point out that a NULL return is possible. You need to handle
that scenario in some way other than SIGSEGV.

regards, tom lane