On Mon, May 7, 2018 at 2:05 PM Kostya Serebryany <kcc at google.com> wrote:> > >> and GetFakeStackFast. > > > Not sure. Why don't just disable stack-use-after-return? >Yeah originally I was going to do that, but: 1. We had a stack use-after-return last month that people had to debug by hand. that would have been caught by ASan with stack-use-after-return. So it seems like a worthwhile feature to support. 2. Initially I was concerned about code size and one thing I was planning to do was to disable stack-use-after-return instrumentation. But in practice, we find that this was a non-issue: we are able to run the same number of tests with and without such instrumentation. 3. It seems like a good idea to keep the same default behavior and feature parity with x86 ASan when possible. Thanks, Walter -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20180507/df58132f/attachment.html>
Kostya Serebryany via llvm-dev
2018-May-07 19:42 UTC
[llvm-dev] ASan port for Myriad RTEMS
On Mon, May 7, 2018 at 12:35 PM Walter Lee <waltl at google.com> wrote:> On Mon, May 7, 2018 at 2:05 PM Kostya Serebryany <kcc at google.com> wrote: > >> >> >>> and GetFakeStackFast. >> >> >> Not sure. Why don't just disable stack-use-after-return? >> > > Yeah originally I was going to do that, but: >I probably misunderstood. You are not disabling UAR completely, just disabling the fast-path getter? Hmm. Maybe let's leave this one out for now and once everything else is resolved will look at it again?> 1. We had a stack use-after-return last month that people had to debug by > hand. that would have been caught by ASan with stack-use-after-return. So > it seems like a worthwhile feature to support. > > 2. Initially I was concerned about code size and one thing I was planning > to do was to disable stack-use-after-return instrumentation. But in > practice, we find that this was a non-issue: we are able to run the same > number of tests with and without such instrumentation. > > 3. It seems like a good idea to keep the same default behavior and feature > parity with x86 ASan when possible. > > Thanks, > > Walter > >-------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.llvm.org/pipermail/llvm-dev/attachments/20180507/60a4c679/attachment.html>
On Mon, May 7, 2018 at 3:42 PM Kostya Serebryany <kcc at google.com> wrote:> I probably misunderstood. You are not disabling UAR completely, justdisabling the fast-path getter? I may not be putting the guard in the right place, but the problem is when !asan_inited, AsanThreads has not been set up => GetCurrentThread won't work. So in that scenario, I want GetFakeStack and GetFakeStackFast to just return nullptr, and OnMalloc to return 0.> Hmm. > Maybe let's leave this one out for now and once everything else isresolved will look at it again? Sounds good.