pathnames are listed unescaped in /proc/[pid]/maps, so using %s as the
conversion specifier cuts pathnames off at space characters. Use %[^\n]
instead, to read everything until the end of the line.
Also, the scanf manpage states: "String input conversions store a
terminating null byte ('\0') to mark the end of the input; the maximum
field width does not include this terminator". So set the maximum field
width to 511 instead of 512, to leave one free byte in the buffer for
the terminating null byte.
Fixes#70
Really what we want to deal with here is tracking an overlay that we may
need to be able to decode after the fact (in case processes exit or we
need to do post-processing symbol resolution).
For the podman case, that is $some_path mapped to root (/), generally
speaking. For flatpak though, that would have two mappings, one for
/app and another for /usr (possibly more).
For processes we find in a podman container, we can sniff the libpod
cgroup scope. Using that we can translate into the podman layer that
contains the files.
With that, future work could find the proper .so when resolving based on
alternate roots for the process.
The kallsyms is huge (like 12Mb) and we want to avoid adding anything we
don't need. Instead, we can rely on the symbols source to decode the
symbols immediately and add them to supplemental.
As we gain in usage, we need to be more careful about using a prefix
that will not collide with other symbols. So version 3 of our ABI will
change to using Sysprof/SYSPROF/sysprof as the various prefixes.
The soname/api version bump will happen later on this branch so that
things are easier to test up until then.
