lkml.org 
[lkml]   [2018]   [Jan]   [23]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH] kasan: add __asan_report_loadN/storeN_noabort callbacks
From
Date
On 01/19/2018 08:44 PM, Andrey Konovalov wrote:
> Instead of __asan_report_load_n_noabort and __asan_report_store_n_noabort
> callbacks Clang emits differently named __asan_report_loadN_noabort and
> __asan_report_storeN_noabort (similar to __asan_loadN/storeN_noabort, whose
> names both GCC and Clang agree on).
>
> Add callback implementation for __asan_report_loadN/storeN_noabort.
>

This made me wonder why this wasn't observed before. So I noticed that
inline instrumentation with -fsanitize=kernel-addresss is broken in clang,
and clang never calls __asan_report*() functions. I see that you guys fixed this
just yesterday https://reviews.llvm.org/D42384 .

But it seems that you didn't fix the rest of "if (CompileKernel)" crap.
Clang generates "__asan_report_[load,store]N*" instead of "__asan_report_[load,store]_n*"
only because of this idiocy:

const std::string SuffixStr = CompileKernel ? "N" : "_n";

See https://github.com/llvm-mirror/llvm/blob/ca19eaabd75f55865efd321b7a6f1d4ba3db8bc8/lib/Transforms/Instrumentation/AddressSanitizer.cpp#L2250

Note that SuffixStr is used *only* for __asan_report_* callbacks, which makes no sense because
we never ever had __asan_report* callbacks with "N" suffix.

So I think that you should just fix the llvm here.

And there is probably one more "if (CompileKernel)" crap in runOnModule()
which breaks globals instrumentation.



\
 
 \ /
  Last update: 2018-01-23 11:45    [W:0.056 / U:0.124 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site