Re: v15b1: FailedAssertion("segment_map->header->magic == (DSA_SEGMENT_HEADER_MAGIC ^ area->control->handle ^ index)", File: "dsa.c", ..)

On Wed, Apr 12, 2023 at 11:49:51AM +1200, Thomas Munro wrote:
> On Wed, Apr 12, 2023 at 11:37 AM Justin Pryzby <pryzby(at)telsasoft(dot)com> wrote:
> > $ ls /dev/shm/ |grep 3696856876 || echo not found
> > not found
>
> Oh, of course it would have restarted after it crashed and unlinked
> that... So the remaining traces of that memory *might* be in the core
> file, depending (IIRC) on the core filter settings (you definitely get
> shared anonymous memory like our main shm region by default, but IIRC
> there's something extra needed if you want the shm_open'd DSM segments
> to be dumped too...)

I scrounged around and found:
/var/spool/abrt/ccpp-2023-03-11-13:07:02-24257/maps

Which has (including the size):

$ sudo cat /var/spool/abrt/ccpp-2023-03-11-13:07:02-24257/maps |awk --non-decimal-data -F'[- ]' '/shm|zero|SYSV/{a="0x"$1; b="0x"$2; print $0,0+b-a}'
7fd39c981000-7fd39ca81000 rw-s 00000000 00:0f 1698691690 /dev/shm/PostgreSQL.3696856876 1048576
7fd39ca81000-7fd39cc81000 rw-s 00000000 00:0f 1699005881 /dev/shm/PostgreSQL.433426374 2097152
7fd39cc81000-7fd39d081000 rw-s 00000000 00:0f 2443340900 /dev/shm/PostgreSQL.2754923922 4194304
7fd39d081000-7fd3b6a09000 rw-s 00000000 00:04 1698308066 /dev/zero (deleted) 429424640
7fd3bcf58000-7fd3bcf63000 rw-s 00000000 00:0f 1698308074 /dev/shm/PostgreSQL.2386569568 45056
7fd3bcf63000-7fd3bcf64000 rw-s 00000000 00:04 9732096 /SYSV0001581b (deleted) 4096

But except for the last one, none of these are available in the corefile.

--
Justin