similar to: [RFC] ASan: patches to support 32-byte shadow granularity

+ 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

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

I ran our test suite with grain of 8 and 32, and more tests were able to avoid running out of memory with grain of 32 than 8. The ones that run out of memory on 8 but not 32 all failed trying to allocate a large region from the heap (350M). I haven't had any tests that run out of memory for other reasons. Given that, I will check in the current selected granularity of 32. I will try grain

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 alignment > requirements, > > especially if an

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

Apple File System Guide is released. https://developer.apple.com/library/prerelease/content/documentation/FileManagement/Conceptual/APFS_Guide/GeneralCharacteristics/GeneralCharacteristics.html >Nanosecond Timestamp Granularity > >APFS supports 1 nanosecond timestamp granularity, which improves >upon the 1 second timestamp granularity of HFS+. >Compatibility > >You can share

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.

On Wed, Jul 8, 2020 at 6:30 PM Kostya Serebryany <kcc at google.com> wrote: > > > On Wed, Jun 24, 2020 at 4:58 PM Teresa Johnson <tejohnson at google.com> > wrote: > >> Hi all, >> >> I've included an RFC for a heap profiler design I've been working on in >> conjunction with David Li. Please send any questions or feedback. For >>

This simple patch makes asan compile for mips (tested on mips32r2el). The following test code: int main() { char *x = (char*)malloc(10 * sizeof(char*)); free(x); return x[5]; } leads to the following output at runtime: ================================================================= ==267== ERROR: AddressSanitizer: heap-use-after-free on address 0x77900fd5 at pc 0x409e1c bp 0x7fb781d8 sp

On Thu, Nov 12, 2015 at 8:42 PM, Kostya Serebryany <kcc at google.com> wrote: > 2 questions: > - Do you see this with the fresh llvm trunk? > - Can you prepare a minimized example? Pretty recent, I updated a couple days ago. I tried to minimize the attached but at the same time I didn't want to lose too many unions and casts in case it didn't trigger any more. $ clang

The one remaining caller of set_limit, the PnP BIOS code, calls into the PnP BIOS, passing kernel parameters in and out. These parameteres may be passed from arbitrary kernel virtual memory, so they deserve strict protection to stop a bad BIOS from smashing beyond the object size. Unfortunately, the use of set_limit was badly botching this by setting the limit in terms of pages, when it really

The one remaining caller of set_limit, the PnP BIOS code, calls into the PnP BIOS, passing kernel parameters in and out. These parameteres may be passed from arbitrary kernel virtual memory, so they deserve strict protection to stop a bad BIOS from smashing beyond the object size. Unfortunately, the use of set_limit was badly botching this by setting the limit in terms of pages, when it really

I'm struggling to explain an ASAN report I'm now getting that I didn't get previously on the same code. In fact the report only happens with -O2 and not when I remove the -O flags which makes it hard to debug and makes me suspect it's dependent on exactly which instructions the code generation decides to access the bytes involved. Afaict the C code shouldn't be accessing the

Hi llvm-dev! I'm writing my master's thesis on sandboxing/isolation of plugins running in a multithreaded environment. These plugins run in a real-time environment where the cost of IPC/context switching and being at the scheduler's mercy is not an option. There can be a lot of plugin instances running and all have to perform some computations and return the result to the main thread

A few folks have asked for specifics, at the spec level, on how sample granularity editing works in Vorbis. So, here's a whitepaper as the beginnings of a real document. This doc is also in CVS on branch_beta3. Note that vorbisfile is not actually tested with the beginning sample-offset spec for editing. I'll be testing/fixing any bugs in vorbisfile on that front now, and keeping

Hello, I have been working on porting ASan to AArch64. I am building compiler-rt in "standalone mode" targeting aarch64. My build is successful, but I get the following runtime error when I run an ASan enabled executable through qemu-aarch64: ==29184==Parsed ASAN_OPTIONS: verbosity=1 ==29184==AddressSanitizer: failed to intercept '__isoc99_printf' ==29184==AddressSanitizer:

Hello, I am building sanitizers for our different platforms and trying to use it in an example program, but while it seems like ASAN is running it's init functions (see stdout below with ASAN_OPTIONS=verbosity=1) it never catches anything in the program. This is LLVM 8.0.1 btw. I was using this small test case: int main(int argc, char** argv) { int *array = new int[100]; delete []

On 31 Jul 2017, at 19:26, Hans Wennborg <hans at chromium.org> wrote: > > On Sat, Jul 29, 2017 at 4:59 AM, Dimitry Andric <dimitry at andric.com> wrote: >> On 27 Jul 2017, at 00:41, Hans Wennborg via cfe-dev <cfe-dev at lists.llvm.org> wrote: >>> >>> 5.0.0-rc1 has just been tagged. >>> >>> Please build, test and upload binaries

Hi, Teresa, This looks really useful. It seems like this general infrastructure could be useful for diagnosing places where we have a lot of false sharing too. This could be between cores, sockets, or devices. Looking forward, especially with HMM and support under Linux for transparent unified memory between CPUs and accelerators, I anticipate we'll end up looking for places where some

Hello Alex, Thanks for the hint. It was actually not the -O flag that created the problem. But it pointed me in the right direction, when I passed -fno-experimental-new-pass-manager it started to show the error. My guess is that the new pass manager is more aggressive in removing UB? Thanks, Tobias On Mon, Feb 3, 2020 at 5:29 PM Alex Brachet-Mialot <alexbrachetmialot at gmail.com> wrote: