> On Oct 23, 2020, at 11:51 AM, Tom Lane <t...@sss.pgh.pa.us> wrote: > > Hmm, we're not out of the woods yet: thorntail is even less happy > than before. > > https://buildfarm.postgresql.org/cgi-bin/show_log.pl?nm=thorntail&dt=2020-10-23%2018%3A08%3A11 > > I do not have 64-bit big-endian hardware to play with unfortunately. > But what I suspect is happening here is less about endianness and > more about alignment pickiness; or maybe we were unlucky enough to > index off the end of the shmem segment. I see that verify_heapam > does this for non-redirect tuples: > > /* Set up context information about this next tuple */ > ctx.lp_len = ItemIdGetLength(ctx.itemid); > ctx.tuphdr = (HeapTupleHeader) PageGetItem(ctx.page, ctx.itemid); > ctx.natts = HeapTupleHeaderGetNatts(ctx.tuphdr); > > with absolutely no thought for the possibility that lp_off is out of > range or not maxaligned. The checks for a sane lp_len seem to have > gone missing as well.
You certainly appear to be right about that. I've added the extra checks, and extended the regression test to include them. Patch attached.
v23-0001-Sanity-checking-line-pointers.patch
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— Mark Dilger EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company
