kengiter/lrsan

LRSan: Detecting Lacking-Recheck Bugs in OS Kernels

lrsan's Issues

complie Linux kernel with LLVM

Hi,
I encountered some problems when compiling the Linux kernel with LLVM. Could you describe the detailed steps of compiling the Linux kernel?

Thanks

Definition of findLackingChecks?

When I was reading lrsan code, I could not find the definition of findLackingChecks() in /lrsan/analyzer/src/lib/CriticalVar.h.
line 171: bool findLackingChecks(Value *V, Instruction *CI);

CriticalVar.cc line 1119: CV->users() or cvAddr->users()?

@kengiter
Something is confusing me.
in CriticalVar.cc line 1119, it should be CV->users() or cvAddr->users()?

Please checkout this test.c https://github.com/zhanggenex/mylr/blob/master/test.c and test.ll https://github.com/zhanggenex/mylr/blob/master/test.ll.

Since CV is %3 = load i32, i32* @x, align 4, so CV->users() will only return %4 = icmp sgt i32 %3, 2. In this situation, def-use chain in test.c cannot be built and bugs is not found.

However, cvAddr is @x = dso_local global i32 1, align 4, cvAddr->users() has%12 = load i32, i32* @x, align 4, store i32 %11, i32* @x, align 4, %6 = load i32, i32* @x, align 4 and %3 = load i32, i32* @x, align 4. And the program can execute correctly.
So where could be the problem?

Having no result running Lrsan

Hi, I am trying to reproduce your work in the paper and encounter some issues.

Operating system: Ubuntu 16.04
LLVM version: 7.0.0

I successfully build llvm and lrsan analyzer. For preparing llvm bitcode files I am using your tool to successfully generate 16802 bitcode files(for linux kernel 4.17).

However, after I run the lrsan, it shows nothing about the lacking recheck bugs. The output I am getting is like:

[CallGraph] Initializing 16802 modules.....
[CallGraph /1][1/16082][$bcfile's path]
...
[CallGraph /1][16082/16082][$bcfile's path]
[CallGraph] Updated in 0 modules.
[CallGraph] Postprocessing ...
[CallGraph] Done!

[PointerAnalysis] Initializing 16802 modules.....
[PointerAnalysis /1][1/16082][$bcfile's path]
...
[PointerAnalysis /1][16082/16082][$bcfile's path]
[PointerAnalysis] Updated in 0 modules.
[PointerAnalysis] Postprocessing ...
[PointerAnalysis] Done!

[CriticalVar] Initializing 16802 modules.....
[CriticalVar /1][1/16082][$bcfile's path]
...
[CriticalVar /1][16082/16082][$bcfile's path]
[CriticalVar] Updated in 0 modules.
[CriticalVar] Postprocessing ...
[CriticalVar] Done!