Doubt: core not dumped when binary give up root privileges.

[Alexandre Pereira Nunes]

Hi,

I wrote a program which runs with uid 0, but later give up root privs by 
calling setreuid(x, x) where x is an unprivileged user.
Before doing that, it chdirs to a directory owned by that unprivileged 
user, with mode 700.

The program explicitly sets RLIMIT_CORE to RLIM_INFINITY when still 
running with uid 0.

If instead of calling the program as root, I call it from the non-priv 
uid in question, if it crashes, it dumps core on the mentioned dir. 
That's the desired behaviour, since I can then take the core and debug. 
But if I run it as root (in fact, I would have to), and it crashes (or 
is forced to ,by means of kill -SEGV), after it gives up root 
credentials, it won't leave a core dump file, which in turn means I 
cannot debug it later.

Any ideas?


Please CC-me since I'm not subscribed.

Thanks,

Alexandre

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