[llvm-dev] Some feedback on Libfuzzer

Greg Stark via llvm-dev llvm-dev at lists.llvm.org
Wed Oct 21 01:22:36 PDT 2015

On Tue, Oct 20, 2015 at 10:53 PM, Kostya Serebryany <kcc at google.com> wrote:
> Can you open a separate bug with exact repro instructions?

Well the bug tracker seems to require an account.

But in any case I don't see anything specific to reproduce. I did an
svn update of llvm and clang and built and installed (I even tried
make clean and removed the old install but it didn't change anything).
Then any program I compile with -fsanitize=memory behaves just like it
did before the patch:

$ uname -a
Linux pixel 4.2.0-trunk-amd64 #1 SMP Debian 4.2-1~exp1 (2015-08-31)
x86_64 GNU/Linux

$ cat foo.c
int main(int argc, char *argv[], char *env[]) {
return 0;

$ clang -fPIE -pie -fsanitize=memory foo.c

$ ./a.out
FATAL: Code 0x562988448390 is out of application range. Non-PIE build?
FATAL: MemorySanitizer can not mmap the shadow memory.
FATAL: Make sure to compile with -fPIE and to link with -pie.
FATAL: Disabling ASLR is known to cause this error.
FATAL: If running under GDB, try 'set disable-randomization off'.
==3120==Process memory map follows:
0x56298842b000-0x5629884ca000 /tmp/a.out
0x5629886ca000-0x5629886ce000 /tmp/a.out


More information about the llvm-dev mailing list