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| author | Markus Trippelsdorf <markus@trippelsdorf.de> | 2015-09-09 16:34:59 +0000 |
|---|---|---|
| committer | Markus Trippelsdorf <trippels@gcc.gnu.org> | 2015-09-09 16:34:59 +0000 |
| commit | 1842a04ce06a470b731bc9a29bfec17e6e147c3f (patch) | |
| tree | d7242b5c767c60e428b06eec2e0a7d94bbbb6465 | |
| parent | 34bc1d225c5041a789f3fc9386a43148f24c0446 (diff) | |
| download | gcc-1842a04ce06a470b731bc9a29bfec17e6e147c3f.zip gcc-1842a04ce06a470b731bc9a29bfec17e6e147c3f.tar.gz gcc-1842a04ce06a470b731bc9a29bfec17e6e147c3f.tar.bz2 | |
Fix sanitizer/67258 by cherry picking upstream patch
PR sanitizer/67258
* ubsan/ubsan_type_hash.cc: Cherry pick upstream r244101.
Upstraem patch:
commit 1d2477faafda9ad2cc19927b3c31efd22747f013
Author: Alexey Samsonov <vonosmas@gmail.com>
Date: Wed Aug 5 19:35:46 2015 +0000
[UBSan] Fix UBSan-vptr false positive.
Offset from vptr to the start of most-derived object can actually
be positive in some virtual base class vtables.
Patch by Stephan Bergmann!
git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@244101 91177308-0d34-0410-b5e6-96231b3b80d8
From-SVN: r227591
| -rw-r--r-- | gcc/testsuite/g++.dg/ubsan/vptr-10.C | 15 | ||||
| -rw-r--r-- | libsanitizer/ChangeLog | 5 | ||||
| -rw-r--r-- | libsanitizer/ubsan/ubsan_type_hash.cc | 6 |
3 files changed, 23 insertions, 3 deletions
diff --git a/gcc/testsuite/g++.dg/ubsan/vptr-10.C b/gcc/testsuite/g++.dg/ubsan/vptr-10.C new file mode 100644 index 0000000..e05c33b --- /dev/null +++ b/gcc/testsuite/g++.dg/ubsan/vptr-10.C @@ -0,0 +1,15 @@ +// { dg-do run } +// { dg-options "-fsanitize=vptr -fno-sanitize-recover=vptr" } + +struct A +{ + virtual ~A() {} +}; +struct B : virtual A {}; +struct C : virtual A {}; +struct D : B, virtual C {}; + +int main() +{ + D d; +} diff --git a/libsanitizer/ChangeLog b/libsanitizer/ChangeLog index 4995299..ba4c423 100644 --- a/libsanitizer/ChangeLog +++ b/libsanitizer/ChangeLog @@ -1,3 +1,8 @@ +2015-09-09 Markus Trippelsdorf <markus@trippelsdorf.de> + + PR sanitizer/67258 + * ubsan/ubsan_type_hash.cc: Cherry pick upstream r244101. + 2015-07-29 Markus Trippelsdorf <markus@trippelsdorf.de> PR sanitizer/63927 diff --git a/libsanitizer/ubsan/ubsan_type_hash.cc b/libsanitizer/ubsan/ubsan_type_hash.cc index d010094..5eab1f5 100644 --- a/libsanitizer/ubsan/ubsan_type_hash.cc +++ b/libsanitizer/ubsan/ubsan_type_hash.cc @@ -186,8 +186,8 @@ namespace { struct VtablePrefix { /// The offset from the vptr to the start of the most-derived object. - /// This should never be greater than zero, and will usually be exactly - /// zero. + /// This will only be greater than zero in some virtual base class vtables + /// used during object con-/destruction, and will usually be exactly zero. sptr Offset; /// The type_info object describing the most-derived class type. std::type_info *TypeInfo; @@ -197,7 +197,7 @@ VtablePrefix *getVtablePrefix(void *Object) { if (!*VptrPtr) return 0; VtablePrefix *Prefix = *VptrPtr - 1; - if (Prefix->Offset > 0 || !Prefix->TypeInfo) + if (!Prefix->TypeInfo) // This can't possibly be a valid vtable. return 0; return Prefix; |