It looks like the root of this is that we're treating calls to `allocsize` functions as AllocLike (e.g. any allocation function type except realloc) functions, which caused us to perform invalid optimizations. For example, in ReallocFreedPointerTest, EarlyCSE DCE'd the realloc because llvm::isInstructionTriviallyDead calls llvm::isAllocLikeFn, and isAllocLikeFn would return true if it saw the allocsize attribute. It really shouldn't do that.
r290397 should fix this behavior by making allocsize alone insufficient to consider a function an allocation function. Thanks for your help! On Thu, Dec 22, 2016 at 1:10 PM, George Burgess IV < george.burgess...@gmail.com> wrote: > Okay, I'm seeing this failure now if I tag my system's `realloc` > declaration with `alloc_size`. (Which FreeBSD seems to do in their > headers). Because all that clang does with `alloc_size` is use it to answer > `__builtin_object_size` queries and lower it to LLVM's `allocsize` > attribute, this is presumably a latent bug in LLVM's `allocsize` attribute. > > Let me mess around for a bit and see what I can dig up. :) > > On Thu, Dec 22, 2016 at 11:59 AM, Dimitry Andric <dimi...@andric.com> > wrote: > >> This is when running "ninja check-all", in a tree with llvm, clang and >> compiler-rt checked out. The first program that shows a failure is >> projects/compiler-rt/lib/asan/tests/default/Asan-i386-inline-Test: >> >> [==========] Running 92 tests from 3 test cases. >> [----------] Global test environment set-up. >> [----------] 14 tests from AddressSanitizerInterface >> ... >> [ RUN ] AddressSanitizer.ReallocFreedPointerTest >> /share/dim/src/llvm/trunk/projects/compiler-rt/lib/asan/tests/asan_test.cc:377: >> Failure >> Death test: ptr = realloc(ptr, 77) >> Result: failed to die. >> Error msg: >> [ DEATH ] >> [ FAILED ] AddressSanitizer.ReallocFreedPointerTest (48 ms) >> >> A similar failure shows when running projects/compiler-rt/lib/asan/ >> tests/default/Asan-i386-with-calls-Test: >> >> [==========] Running 92 tests from 3 test cases. >> [----------] Global test environment set-up. >> [----------] 14 tests from AddressSanitizerInterface >> ... >> [ RUN ] AddressSanitizer.ReallocFreedPointerTest >> /share/dim/src/llvm/trunk/projects/compiler-rt/lib/asan/tests/asan_test.cc:377: >> Failure >> Death test: ptr = realloc(ptr, 77) >> Result: failed to die. >> Error msg: >> [ DEATH ] >> [ FAILED ] AddressSanitizer.ReallocFreedPointerTest (55 ms) >> >> Interestingly, the Asan-i386-inline-Noinst-Test and >> Asan-i386-with-calls-Noinst-Test do not show this particular failure. >> >> The other test that fails is projects/compiler-rt/test/asan >> /I386FreeBSDConfig/TestCases/Posix/Output/free_hook_realloc.cc.tmp, >> which simply returns 1 without printing any output. Debugging the program >> shows that it seems to be skipping completely over the realloc() call, and >> jumping directly to the _exit(1), but this may be due to optimization. >> >> -Dimitry >> >> > On 22 Dec 2016, at 20:27, George Burgess IV < >> george.burgess...@gmail.com> wrote: >> > >> > Yes, this was reapplied in r290297 with fixes for the msan issue we >> caught; these asan unit test failures are news to me. Can you give me the >> command that you're using to run these tests, please? >> > >> > On Thu, Dec 22, 2016 at 11:10 AM, Dimitry Andric <dimi...@andric.com> >> wrote: >> > On 20 Dec 2016, at 09:28, Chandler Carruth via cfe-commits < >> cfe-commits@lists.llvm.org> wrote: >> > > Author: chandlerc >> > > Date: Tue Dec 20 02:28:19 2016 >> > > New Revision: 290169 >> > > >> > > URL: http://llvm.org/viewvc/llvm-project?rev=290169&view=rev >> > > Log: >> > > Revert r290149: Add the alloc_size attribute to clang. >> > > >> > > This commit fails MSan when running test/CodeGen/object-size.c in >> > > a confusing way. After some discussion with George, it isn't really >> > > clear what is going on here. We can make the MSan failure go away by >> > > testing for the invalid bit, but *why* things are invalid isn't clear. >> > > And yet, other code in the surrounding area is doing precisely this >> and >> > > testing for invalid. >> > > >> > > George is going to take a closer look at this to better understand the >> > > nature of the failure and recommit it, for now backing it out to clean >> > > up MSan builds. >> > >> > Hmm, was this reapplied later on? I'm still getting the following >> AddressSanitizer failures on FreeBSD, and bisecting has pointed to r290149 >> as the cause: >> > >> > FAIL: AddressSanitizer-Unit :: Asan-i386-inline-Test/AddressS >> anitizer.ReallocFreedPointerTest (2124 of 30204) >> > ******************** TEST 'AddressSanitizer-Unit :: >> Asan-i386-inline-Test/AddressSanitizer.ReallocFreedPointerTest' FAILED >> ******************** >> > Note: Google Test filter = AddressSanitizer.ReallocFreedPointerTest >> > [==========] Running 1 test from 1 test case. >> > [----------] Global test environment set-up. >> > [----------] 1 test from AddressSanitizer >> > [ RUN ] AddressSanitizer.ReallocFreedPointerTest >> > /share/dim/src/llvm/trunk/projects/compiler-rt/lib/asan/tests/asan_test.cc:377: >> Failure >> > Death test: ptr = realloc(ptr, 77) >> > Result: failed to die. >> > Error msg: >> > [ DEATH ] >> > [ FAILED ] AddressSanitizer.ReallocFreedPointerTest (30 ms) >> > [----------] 1 test from AddressSanitizer (30 ms total) >> > >> > [----------] Global test environment tear-down >> > [==========] 1 test from 1 test case ran. (31 ms total) >> > [ PASSED ] 0 tests. >> > [ FAILED ] 1 test, listed below: >> > [ FAILED ] AddressSanitizer.ReallocFreedPointerTest >> > >> > 1 FAILED TEST >> > YOU HAVE 24 DISABLED TESTS >> > >> > >> > ******************** >> > Testing: 0 . >> > FAIL: AddressSanitizer-Unit :: Asan-i386-with-calls-Test/Addr >> essSanitizer.ReallocFreedPointerTest (2233 of 30204) >> > ******************** TEST 'AddressSanitizer-Unit :: >> Asan-i386-with-calls-Test/AddressSanitizer.ReallocFreedPointerTest' >> FAILED ******************** >> > Note: Google Test filter = AddressSanitizer.ReallocFreedPointerTest >> > [==========] Running 1 test from 1 test case. >> > [----------] Global test environment set-up. >> > [----------] 1 test from AddressSanitizer >> > [ RUN ] AddressSanitizer.ReallocFreedPointerTest >> > /share/dim/src/llvm/trunk/projects/compiler-rt/lib/asan/tests/asan_test.cc:377: >> Failure >> > Death test: ptr = realloc(ptr, 77) >> > Result: failed to die. >> > Error msg: >> > [ DEATH ] >> > [ FAILED ] AddressSanitizer.ReallocFreedPointerTest (24 ms) >> > [----------] 1 test from AddressSanitizer (24 ms total) >> > >> > [----------] Global test environment tear-down >> > [==========] 1 test from 1 test case ran. (25 ms total) >> > [ PASSED ] 0 tests. >> > [ FAILED ] 1 test, listed below: >> > [ FAILED ] AddressSanitizer.ReallocFreedPointerTest >> > >> > 1 FAILED TEST >> > YOU HAVE 24 DISABLED TESTS >> > >> > >> > ******************** >> > Testing: 0 . >> > FAIL: AddressSanitizer-i386-freebsd :: TestCases/Posix/free_hook_realloc.cc >> (2399 of 30204) >> > ******************** TEST 'AddressSanitizer-i386-freebsd :: >> TestCases/Posix/free_hook_realloc.cc' FAILED ******************** >> > Script: >> > -- >> > /home/dim/obj/llvm-290338-trunk-freebsd12-i386-ninja-rel-1/./bin/clang >> --driver-mode=g++ -fsanitize=address -mno-omit-leaf-frame-pointer >> -fno-omit-frame-pointer -fno-optimize-sibling-calls -gline-tables-only -m32 >> -O2 /share/dim/src/llvm/trunk/projects/compiler-rt/test/asan/Tes >> tCases/Posix/free_hook_realloc.cc -o /home/dim/obj/llvm-290338-trun >> k-freebsd12-i386-ninja-rel-1/projects/compiler-rt/test/asan/ >> I386FreeBSDConfig/TestCases/Posix/Output/free_hook_realloc.cc.tmp >> > /home/dim/obj/llvm-290338-trunk-freebsd12-i386-ninja-rel-1/p >> rojects/compiler-rt/test/asan/I386FreeBSDConfig/TestCases/Po >> six/Output/free_hook_realloc.cc.tmp 2>&1 | FileCheck >> /share/dim/src/llvm/trunk/projects/compiler-rt/test/asan/Tes >> tCases/Posix/free_hook_realloc.cc >> > -- >> > Exit Code: 2 >> > >> > Command Output (stderr): >> > -- >> > FileCheck error: '-' is empty. >> > FileCheck command line: FileCheck /share/dim/src/llvm/trunk/proj >> ects/compiler-rt/test/asan/TestCases/Posix/free_hook_realloc.cc >> > >> > -- >> > >> > ******************** >> > Testing: 0 .. 10.. 20.. 30.. 40.. 50.. 60.. 70.. 80.. 90.. >> > Testing Time: 880.55s >> > ******************** >> > Failing Tests (3): >> > AddressSanitizer-Unit :: Asan-i386-inline-Test/AddressS >> anitizer.ReallocFreedPointerTest >> > AddressSanitizer-Unit :: Asan-i386-with-calls-Test/Addr >> essSanitizer.ReallocFreedPointerTest >> > AddressSanitizer-i386-freebsd :: TestCases/Posix/free_hook_real >> loc.cc >> > >> > Expected Passes : 26881 >> > Expected Failures : 144 >> > Unsupported Tests : 3176 >> > Unexpected Failures: 3 >> > >> > 1 warning(s) in tests. >> > >> > -Dimitry >> > >> > >> >> >
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