On 15 August 2017 at 01:25, Richard Smith <rich...@metafoo.co.uk> wrote: > On 14 August 2017 at 03:27, Diana Picus via cfe-commits > <cfe-commits@lists.llvm.org> wrote: >> >> Hi, >> >> Strangely enough, it turns out that if I run >> Asan-armhf-with-calls-Noinst-Test on the command line it fails, >> although it doesn't fail when run with lit. > > > Looks like the crash is within the "use_colors == true" portion of > ColoredPrintf, so this would make sense if running the test within lit turns > off color support (perhaps because the output is not a terminal). >
That's a good catch, it seems if I run it with --gtest-color=no it still passes, but prints some garbage at the end: [ PASSED ] 97 tests. YOU HAVE -1094542056 DISABLED F]�뀼��_8�pG����D2 >> >> I've attached the stack >> trace from gdb. It looks like some trouble passing down va_arg >> parameters, but I haven't looked into too much details. The segfault >> happens when we try to do a ldrb r3, [r0, r1], with r1 set to 0 by >> the current function and r0 passed down from the caller. I'm not sure >> if this is the exact same problem as the other tests, but feel free to >> have a look at that code. > > > Have you tried running Asan-armhf-with-calls-Noinst-Test on the command line > without this patch applied? (It's possible that this is a pre-existing bug > in ARM varargs call lowering, and is unrelated to the bug we're trying to > track down. This code path performs an unrelated varargs call between a > va_start / va_end pair, which seems like quite a rare situation, and I could > easily believe there's something wrong with our lowering that allows some > portion of the outer va_list state to be clobbered in that scenario.) > It seems to work without the patch. I'm currently trying to reduce Asan-armhf-with-calls-Test and I'll get back to you with the IR or assembly files (whichever makes any difference). >> Meanwhile, I've removed some clutter from Asan-armhf-with-calls-Test >> (which is the original failure that we were seeing) and left only one >> failing test that seemed small enough. I'll try to look at the >> disassembly before/after the patch and maybe even run valgrind on it >> (running it on the original binary naturally takes forever). >> >> Let me know if there's anything else I could try. I can also send you >> disassembly or even LLVM IR for the Asan-armhf-with-calls-Noinst-Test >> if you think it helps. >> >> Cheers, >> Diana _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
