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On Fri, May 4, 2018 at 7:09 PM Walter Lee <waltl at google.com> wrote: > On Fri, May 4, 2018 at 6:21 PM Kostya Serebryany <kcc at google.com> wrote: > > > On RAM... > > > You chose the 32-byte shadow granularity to reduce the RAM overhead, > > but I am afraid this will actually increase it due to extra alignme...

...Given that, I will check in the current selected granularity of 32. I will try grain 16 and to collect finer grained data when I have a chance. Thanks, Walter On Mon, May 7, 2018 at 2:07 PM Kostya Serebryany <kcc at google.com> wrote: > On Fri, May 4, 2018 at 7:09 PM Walter Lee <waltl at google.com> wrote: >> On Fri, May 4, 2018 at 6:21 PM Kostya Serebryany <kcc at google.com> wrote: >> > On RAM... >> > You chose the 32-byte shadow granularity to reduce the RAM overhead, >> > but I am afraid this will actually increase it due to extra...

I've finished my initial set of patches to make 32-byte shadow granularity work on x86. Here is a summary of the changes from last week: - As discussed, I added a full redzone after every stack variable. - We discussed adding a -fsanitize-address-granularity=N flag, but I found the following existing flag has been sufficient for my purposes: -asan-mapping-scale N. If anyone thinks I

...ms PP-COP department,IS Division Volkswagen Group South Africa PO Box 80 Uitenhage 6230 Tel: +27-(0)41-994-5581 Fax: +27-(0)41-994-5451 Mobile: 084-510-9735 Mailto: metcalf at vwsa.co.za<mailto:metcalf at vwsa.co.za> Volkswagen of South Africa (Pty) Ltd. (Reg No. 1946/023458/07) Chairman: H Waltl* Managing Director: D Powels Directors: P Hoffmann* (Sales & Marketing), C Stapel* (Finance), S Macozoma, PJ Smith (Human Resources), N Maliza (Corporate and Government Affairs), T du Plessis (Production), C Klingler** German*, Austrian** Volkswagen Group South Africa is a Level 4 Contri...

...s PP-COP department,IS Division Volkswagen Group South Africa PO Box 80 Uitenhage 6230 Tel: +27-(0)41-994-5581 Fax: +27-(0)41-994-5451 Mobile: 084-510-9735 Mailto: metcalf at vwsa.co.za<mailto:metcalf at vwsa.co.za> Volkswagen of South Africa (Pty) Ltd. (Reg No. 1946/023458/07) Chairman: H Waltl* Managing Director: D Powels Directors: P Hoffmann* (Sales & Marketing), C Stapel* (Finance), S Macozoma, PJ Smith (Human Resources), N Maliza (Corporate and Government Affairs), T du Plessis (Production), C Klingler** German*, Austrian** Volkswagen Group South Africa is a Level 4 Contri...

On Fri, May 4, 2018 at 6:21 PM Kostya Serebryany <kcc at google.com> wrote: > On RAM... > You chose the 32-byte shadow granularity to reduce the RAM overhead, > but I am afraid this will actually increase it due to extra alignment requirements, > especially if an average allocation on your typical application is small. Good point. I will run our test suite with 8-byte shadow

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...

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

On Fri, May 4, 2018 at 6:29 PM Walter Lee <waltl at google.com> wrote: > Hi Kostya. Thanks for the quick feedback. I will work on addressing your > comments. > > In regard to initialization checks, I can eliminate most of them by > initializing the shadow memory very early, This will be a very good way to handle this. &gt...

On RAM... You chose the 32-byte shadow granularity to reduce the RAM overhead, but I am afraid this will actually increase it due to extra alignment requirements, especially if an average allocation on your typical application is small. The pointers are 32-bit, right? Given how RAM-constrained your environment is, maybe you should consider something more like HWASAN instead of ASAN.

Hi Jake. Thanks for the info. Where can I keep up to date on the symbolizer status? Our symbolizer is provided by the Myriad vendor and integrated into its host test environment. It doesn't do much: just look for PC string patterns and symbolize them using addr2line. Thanks, Walter On Fri, May 4, 2018 at 5:36 PM Jake Ehrlich <jakehehrlich at google.com> wrote: > Hey, > I

Hi Kostya. Thanks for the quick feedback. I will work on addressing your comments. In regard to initialization checks, I can eliminate most of them by initializing the shadow memory very early, but I still need to do something in two places, __asan_handle_no_return and GetFakeStackFast. Would it be ok to have guards for those two places only? Walter On Fri, May 4, 2018 at 6:10 PM Kostya

I've prepared a preliminary set of patches that makes ASan work with 32-byte shadow granularity, and I would like to get some feedback on those patches as well as my general plan. Some background: I am porting ASan to the Myriad platform. I'm looking to break up that port into components that may be useful/relevant to other platforms -- the first of those pieces is the ability to use a

+ more asan folks, please CC them to the code reviews. Also please make sure llvm-commits is CC-ed (cfe-commits for clang changes) On Tue, Oct 31, 2017 at 2:29 PM, Walter Lee <waltl at google.com> wrote: > I've prepared a preliminary set of patches that makes ASan work with > 32-byte shadow granularity, and I would like to get some feedback on > those patches as well as my general plan. > > Some background: I am porting ASan to the Myriad platform. I...