🚀 go-pugleaf

"Nabeel Shaheen" <sonicshaheen@yahoo.com> wrote:
> Hi,
>
> Guys I am stuck with a problem and need some help.
>
> Platform     : Linux(RedHat 7.3)
> Problem Area : Dynamic Shared Object Libraries, POSIX Threads
> glibc        : 2.96
>
> Problem:
> =======
> The Scenario is such that I have made a module which call a .so file
> in a new thread and executes it. The .so file has to be provided by
> the end-user and if that .so gives any runtime-error(SEGFAULTS), the
> whole process terminates i.e. all the threads executing .so files and
> more importantly my .so-calling module, which I dont want to be
> terminated.
>
> so ***IS THERE ANY WAY THAT MY SO-CALLING MODULE DOES NOT TERMINATE
> DUE TO SOME SEGFAULTS IN A .SO FILE WRITTEN BY THE END-USER OF MY
> MODULE?***.
>
> Any relevant comment will be appreciated.

Hi Nabeel,

since the *.so file is provided by the end-user we cannot assume it to be
...
   ... free of errors (can we ever assume this?)
   ... protect itself against crashes
   etc.

I think the only way to handle this problem is to use
   setjmp() /longjmp() along with a signal-handler registered for all
relevant signals.

Before each call to the user-so-file you register the actual settings with
setjump().
   Whenever a signal occurs the signal-routine will be called and can
longjmp() to
   the previously stored position. At least, this way you'll be able to
write a proper Log
   and to do a proper program-cleanup. Generally I wouldn't trust this
construction to
   be stable enough so that the program can continue...the call to the
user-so-file might
   have corrupted stack/heap and anything else (including the
jumpbuf-structure stored with
   setjmp())...so that normal operation is not longer guaranteed.

Regards ... Rainer