Hi Jakub, On Tue, 2016-11-29 at 13:37 +0100, h wrote: > I have a question regarding analyzing processes running in a change root > environment or in an own mount namespace with re-mounted /. > I want to debug a process running in a non-system root using elfutils or gdb > from system root, and vice versa. > More precisely, I want to create a container shipping ABRT + GDB + elfutils > and the container should allow users to analyze core dump files on Fedora > Atomic. I need to run eu-stack on a core dump file generated by a program > from system root and I need to run it from a container (non-system root). > > For example, if I run the following command on Fedora Atomic 25, it crashes > in the system namespace and ABRT saves its core file to /var/spool/abrt/ > ccpp* in ABRT's namespace. If I enter the ABRT container and run eu-stack on > the core dump file, I get an error because the container misses some > libraries: > [...] > You may ask what is the binary argument. It's a copy of the crashed program. > It can be replaced with the `/host/bin/ostree` path (I bind mount the hots' > / to the container's /host). > > GDB allows me to configure 'sysroot', so it knows where to look for > libraries. Thus if I run GDB on the same core dump file, I get the > following ouptut: > $ gdb --batch --ex 'set sysroot /host' --ex 'file binary' --ex 'core > coredump' --ex 'bt' > [...] > Do elfutils support such an option too?
We already talked briefly on irc. And the short answer is: No, at the moment not. Thanks for filing https://bugzilla.redhat.com/show_bug.cgi?id=1399637 The slightly longer versions is: No, not "globally" and only for some files/types. You can set how to find debuginfo files by providing a path or alternative callback when setting up a Dwfl. See Dwfl_Callbacks debuginfo_path and find_debuginfo. Usually you would use dwfl_standard_find_debuginfo for this. You can also provide a find_elf callback that finds the Elf image for a module. Usually you would use either dwfl_build_id_find_elf, dwfl_linux_proc_find_elf or dwfl_linux_kernel_find_elf for that. We probably should provide alternatives to those that take some sysroot. But there are some parts inside the link_map scanning code that cannot easily use those callbacks at the moment and use direct open calls that also would need sysroot "hooks" (there are already some XXX hook for sysroot comments). But maybe the above is too flexible. Which (types of) files would you expect a "sysroot" setting to affect? Just direct file paths, lookups through build-ids, separate debuginfo files, kernel module lookups, etc.? Thanks, Mark _______________________________________________ elfutils-devel mailing list -- elfutils-devel@lists.fedorahosted.org To unsubscribe send an email to elfutils-devel-le...@lists.fedorahosted.org
