Re: trying again to get incremental backup

On Wed, Nov 22, 2023 at 3:14 AM Jakub Wartak
<jakub(dot)wartak(at)enterprisedb(dot)com> wrote:
> CFbot failed on two hosts this time, I haven't looked at the details
> yet (https://cirrus-ci.com/task/6425149646307328 -> end of EOL? ->
> LOG: WAL summarizer process (PID 71511) was terminated by signal 6:
> Aborted?)

Robert pinged me to see if I had any ideas.

The reason it fails on Windows is because there is a special code path
for WIN32 in the patch's src/bin/pg_combinebackup/copy_file.c, but it
is incomplete: it returns early without feeding the data into the
checksum, so all the checksums have the same initial and bogus value.
I commented that part out so it took the normal path like Unix, and it
passed.

The reason it fails on Linux 32 bit with -fsanitize is because this
has uncovered a bug in xlogreader.c, which overflows a 32 bit pointer
when doing a size test that could easily be changed to non-overflowing
formulation. AFAICS it is not a live bug because it comes to the
right conclusion without deferencing the pointer due to other checks,
but the sanitizer is not wrong to complain about it and I will post a
patch to fix that in a new thread. With the draft patch I am testing,
the sanitizer is happy and this passes too.