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Possible bug in __sfp() libc routine
- From: "Kapania, Ashish" <akapania at ti dot com>
- To: "newlib at sourceware dot org" <newlib at sourceware dot org>
- Date: Fri, 7 Apr 2017 21:57:43 +0000
- Subject: Possible bug in __sfp() libc routine
- Authentication-results: sourceware.org; auth=none
Hi All,
In the __sfp() function in "libc/findfp.c" file, I see that if no free FILE object is found, one is allocated and put on a list in the global re-entrancy structure (_GLOBAL_REENT). This seems like a bug to me. I believe the FILE object should be put on a list in the thread specific reentrancy structure. If I create a thread, do a fopen, do a fwrite (invokes __sfp which in turn allocates the FILE object), do a fclose and then delete the thread, the FILE object allocated by __sfp() is not freed. If a do this sequence repeatedly, I see memory keeps leaking until my app runs out of heap. I have a separate re-entrancy structure for each thread but because the FILE object is not in a list on the local re-entrancy structure, it does not get freed when I delete the thread and run _reclaim_reent() on the local reentrancy structure.
Any thoughts ?
Best,
Ashish