[PATCH] [Compiler-rt][Sanitizer][MSan][i386] Adding support for i386

Fri Feb 27 00:45:00 PST 2015

0x555 is where a PIE binary is mapped when ASLR is disabled (1/3rd of
the address space). No idea why that happens with lit.

On Fri, Feb 27, 2015 at 8:53 AM, Mohit Bhakkad <mohit.bhakkad at gmail.com> wrote:
> Update:
>
> - Thanks @eugenis, issue with i386 support is resolved.
>
>
>
> - Right now, while testing msan32 using lit, most of the tests are failing with:
>
>
>
>   FATAL: Code 0x5556aec0 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'.
>   ==23092==Process memory map follows:
>         0x55555000-0x555ed000   /home/mohit/compiler-rt_build/test/msan/Output/strlen_of_shadow.cc.tmp
>         0x555ed000-0x555ee000   /home/mohit/compiler-rt_build/test/msan/Output/strlen_of_shadow.cc.tmp
>         0x555ee000-0x555f1000   /home/mohit/compiler-rt_build/test/msan/Output/strlen_of_shadow.cc.tmp
>         0x555f1000-0x56648000
>         0x56648000-0x56668000   /lib/i386-linux-gnu/ld-2.19.so
>         0x56668000-0x56669000   /lib/i386-linux-gnu/ld-2.19.so
>         0x56669000-0x5666a000   /lib/i386-linux-gnu/ld-2.19.so
>         0x5666a000-0x5666b000   [vdso]
>         0x5666b000-0x56672000
>         0x5668c000-0x56768000   /usr/lib/i386-linux-gnu/libstdc++.so.6.0.19
>         0x56768000-0x56769000   /usr/lib/i386-linux-gnu/libstdc++.so.6.0.19
>         0x56769000-0x5676d000   /usr/lib/i386-linux-gnu/libstdc++.so.6.0.19
>         0x5676d000-0x5676e000   /usr/lib/i386-linux-gnu/libstdc++.so.6.0.19
>         0x5676e000-0x56775000
>         0x56775000-0x567b9000   /lib/i386-linux-gnu/libm-2.19.so
>         0x567b9000-0x567ba000   /lib/i386-linux-gnu/libm-2.19.so
>         0x567ba000-0x567bb000   /lib/i386-linux-gnu/libm-2.19.so
>         0x567bb000-0x567bc000
>         0x567bc000-0x567d4000   /lib/i386-linux-gnu/libpthread-2.19.so
>         0x567d4000-0x567d5000   /lib/i386-linux-gnu/libpthread-2.19.so
>         0x567d5000-0x567d6000   /lib/i386-linux-gnu/libpthread-2.19.so
>         0x567d6000-0x567d8000
>         0x567d8000-0x567df000   /lib/i386-linux-gnu/librt-2.19.so
>         0x567df000-0x567e0000   /lib/i386-linux-gnu/librt-2.19.so
>         0x567e0000-0x567e1000   /lib/i386-linux-gnu/librt-2.19.so
>         0x567e1000-0x567e4000   /lib/i386-linux-gnu/libdl-2.19.so
>         0x567e4000-0x567e5000   /lib/i386-linux-gnu/libdl-2.19.so
>         0x567e5000-0x567e6000   /lib/i386-linux-gnu/libdl-2.19.so
>         0x567e6000-0x56802000   /lib/i386-linux-gnu/libgcc_s.so.1
>         0x56802000-0x56803000   /lib/i386-linux-gnu/libgcc_s.so.1
>         0x56803000-0x569ac000   /lib/i386-linux-gnu/libc-2.19.so
>         0x569ac000-0x569ae000   /lib/i386-linux-gnu/libc-2.19.so
>         0x569ae000-0x569af000   /lib/i386-linux-gnu/libc-2.19.so
>         0x569af000-0x56b5f000
>         0xffac2000-0xffae3000   [stack]
>   ==23092==End of process memory map.
>
> but when I run tests individually, almost all tests are giving expected o/p:
> for eg:(see that I have used exact options that of in lit suite)
>
>   mohit at mohit:~$ /home/mohit/LLVM_x86/install/bin/clang --driver-mode=g++ -fsanitize=memory -mno-omit-leaf-frame-pointer -fno-omit-frame-pointer -fno-optimize-sibling-calls  -gline-tables-only -m32 -fsanitize-memory-track-origins=2  -O3 /home/mohit/compiler-rt/test/msan/chained_origin.cc
>   mohit at mohit:~$ ./a.out
>   ==23140== WARNING: MemorySanitizer: use-of-uninitialized-value
>       #0 0xf77b17dd in main /home/mohit/compiler-rt/test/msan/chained_origin.cc:47:3
>       #1 0xf73e6a82 in __libc_start_main (/lib/i386-linux-gnu/libc.so.6+0x19a82)
>       #2 0xf774be95 in _start (/home/mohit/a.out+0x14e95)
>
>     Uninitialized value was stored to memory at
>       #0 0xf77b1722 in fn_h() /home/mohit/compiler-rt/test/msan/chained_origin.cc:35:5
>       #1 0xf77b17a2 in main /home/mohit/compiler-rt/test/msan/chained_origin.cc:46:3
>       #2 0xf73e6a82 in __libc_start_main (/lib/i386-linux-gnu/libc.so.6+0x19a82)
>
>     Uninitialized value was stored to memory at
>       #0 0xf77b1692 in fn_g(int) /home/mohit/compiler-rt/test/msan/chained_origin.cc:25:5
>       #1 0xf77b16bb in fn_f(int) /home/mohit/compiler-rt/test/msan/chained_origin.cc:30:3
>       #2 0xf77b179d in main /home/mohit/compiler-rt/test/msan/chained_origin.cc:45:3
>       #3 0xf73e6a82 in __libc_start_main (/lib/i386-linux-gnu/libc.so.6+0x19a82)
>
>     Uninitialized value was created by an allocation of 'z' in the stack frame of function 'main'
>       #0 0xf77b1730 in main /home/mohit/compiler-rt/test/msan/chained_origin.cc:38
>
>   SUMMARY: MemorySanitizer: use-of-uninitialized-value /home/mohit/compiler-rt/test/msan/chained_origin.cc:47 main
>   Exiting
>
> I am pretty sure about the correctness of address ranges in this patch. It looks like it is failing some check, investigating it now.
>
> **tl;dr: most of the test cases are passing individually, but with lit test suite, almost all are failing due to conflict in addresses.**
>
>
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>
> http://reviews.llvm.org/D6433
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