From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 25887 invoked by alias); 12 Dec 2014 18:58:31 -0000 Mailing-List: contact gcc-bugs-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Archive: List-Post: List-Help: Sender: gcc-bugs-owner@gcc.gnu.org Received: (qmail 25805 invoked by uid 48); 12 Dec 2014 18:58:23 -0000 From: "bernd.edlinger at hotmail dot de" To: gcc-bugs@gcc.gnu.org Subject: [Bug sanitizer/64265] [5 Regression] r217669 broke tsan Date: Fri, 12 Dec 2014 18:58:00 -0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: sanitizer X-Bugzilla-Version: 5.0 X-Bugzilla-Keywords: X-Bugzilla-Severity: normal X-Bugzilla-Who: bernd.edlinger at hotmail dot de X-Bugzilla-Status: NEW X-Bugzilla-Priority: P3 X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org X-Bugzilla-Target-Milestone: 5.0 X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: Message-ID: In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/ Auto-Submitted: auto-generated MIME-Version: 1.0 X-SW-Source: 2014-12/txt/msg01474.txt.bz2 https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64265 --- Comment #14 from Bernd Edlinger --- (In reply to Jakub Jelinek from comment #7) > Note, I don't see any kind of memory leak on any of the testcases. > Sure, calling __tsan_func_entry many times is of course wrong. > As for #c5, clang doesn't call __tsan_func_exit in that case either. Dmitry? > If we were to call it even for exceptions, I'm afraid expanding this in tsan > pass is too late, we'd need to add the __tsan_func_exit call say during > gimplification as a cleanup of the whole body and then EH code would take > care of adding the needed landing pads etc. > But libtsan e.g. wraps longjmp and pops frames in there, not sure if it > doesn't do something similar for exceptions already. Hi Jakub, __tsan_func_entry pushes a few bytes on a call stack heap, and __tsan_func_exit pops these again. Therefore it is absolotely necessary to call these functions in pairs. If I run the a.out from the test cases, and I have the system monitor in the background, I can see my 8GB of memory quickly used up, and then my linux starts to page a lot so that it is hardly possible to press CTRL-C. There may of course also be a SIGSEGV in __tsan_func_entry when the heap finally overflows. Bernd.