We use a lot of TLS variables yet GDB is not of much help when working
with these. So in this patch I document where they are located in
memory, how to calculate the address of a known TLS variable and how to
find (identify) one given an address.
Signed-off-by: Botond Dénes <bdenes@scylladb.com>
Message-Id: <20200903131802.1068288-1-bdenes@scylladb.com>
Instead, label the mapped volume by passing `:z` options to `-v`
argument, like we do for other mapped volumes in the `dbuild` script.
Passing the `--privileged` flag doesn't work after the most recent
Fedora update and anyway, using `:z` is the proper way to make sure the
mounted volume is accessible. Historically it was needed to be able to
open cores as well, but since 5b08e91bd this is not necessary as the
container is created with SYS_PTRACE capability.
Signed-off-by: Botond Dénes <bdenes@scylladb.com>
Message-Id: <20200703072703.10355-1-bdenes@scylladb.com>
Currently the section on "Debugging coredumps" only briefly mentions
relocatable binaries, then starts with an extensive subsection on how to
open cores generated by non-relocatable binaries. There is a subsection
about relocatable binaries, but it just contains some out-of-date
workaround without any context.
In this patch we completely replace this outdated and not very useful
subsection on relocatable binaries, with a much more extensive one,
documenting step-by-step a procedure that is known to work. Also, this
subsection is moved above the non-relocatable one. All our current
releases except for 2019.1 use relocatable binaries, so the subsection
about these should be the more prominent one.
Signed-off-by: Botond Dénes <bdenes@scylladb.com>
Message-Id: <20200630145655.159926-1-bdenes@scylladb.com>
To the 'Debuggin Scylla with GDB` chapter. The '### Debugging
relocatable binaries built with the toolchain' subchapter is demoted to
be just a section in this new subchapter. It is also renamed to
'Relocatable binaries'.
This subchapter intends to be a complete guide on how to debug coredumps
from how to obtain the correct version of all the binaries all the way
to how to correctly open the core with GDB.
A documentation file that is intended to be a place for anything
debugging related: getting started tutorial, tips and tricks and
advanced guides.
For now it contains a short introductions, some selected links to
more in-depth documentation and some trips and tricks that I could think
off the top of my head.
One of those tricks describes how to load cores obtained from
relocatable packages inside the `dbuild` container. I originally
intended to add that to `tools/toolchain/README.md` but was convinced
that `docs/debugging.md` would be a better place for this.
Signed-off-by: Botond Dénes <bdenes@scylladb.com>
Message-Id: <20190924133110.15069-1-bdenes@scylladb.com>
