"global-init", "global-init-src" and "global-init-type" were originally
used to blacklist entities in ASan init-order checker. However, they
were never documented, and later were replaced by "=init" category.
Old blacklist entries should be converted as follows:
* global-init:foo -> global:foo=init
* global-init-src:bar -> src:bar=init
* global-init-type:baz -> type:baz=init
llvm-svn: 222401
This commit changes the way we blacklist global variables in ASan.
Now the global is excluded from instrumentation (either regular
bounds checking, or initialization-order checking) if:
1) Global is explicitly blacklisted by its mangled name.
This part is left unchanged.
2) SourceLocation of a global is in blacklisted source file.
This changes the old behavior, where instead of looking at the
SourceLocation of a variable we simply considered llvm::Module
identifier. This was wrong, as identifier may not correspond to
the file name, and we incorrectly disabled instrumentation
for globals coming from #include'd files.
3) Global is blacklisted by type.
Now we build the type of a global variable using Clang machinery
(QualType::getAsString()), instead of llvm::StructType::getName().
After this commit, the active users of ASan blacklist files
may have to revisit them (this is a backwards-incompatible change).
llvm-svn: 220097
See https://code.google.com/p/address-sanitizer/issues/detail?id=299 for the
original feature request.
Introduce llvm.asan.globals metadata, which Clang (or any other frontend)
may use to report extra information about global variables to ASan
instrumentation pass in the backend. This metadata replaces
llvm.asan.dynamically_initialized_globals that was used to detect init-order
bugs. llvm.asan.globals contains the following data for each global:
1) source location (file/line/column info);
2) whether it is dynamically initialized;
3) whether it is blacklisted (shouldn't be instrumented).
Source location data is then emitted in the binary and can be picked up
by ASan runtime in case it needs to print error report involving some global.
For example:
0x... is located 4 bytes to the right of global variable 'C::array' defined in '/path/to/file:17:8' (0x...) of size 40
These source locations are printed even if the binary doesn't have any
debug info.
This is an ABI-breaking change. ASan initialization is renamed to
__asan_init_v4(). Pre-built libraries compiled with older Clang will not work
with the fresh runtime.
llvm-svn: 212188
Init-order and use-after-return modes can currently be enabled
by runtime flags. use-after-scope mode is not really working at the
moment.
The only problem I see is that users won't be able to disable extra
instrumentation for init-order and use-after-scope by a top-level Clang flag.
But this instrumentation was implicitly enabled for quite a while and
we didn't hear from users hurt by it.
llvm-svn: 210924
Clang knows about the sanitizer blacklist and it makes no sense to
add global to the list of llvm.asan.dynamically_initialized_globals if it
will be blacklisted in the instrumentation pass anyway. Instead, we should
do as much blacklisting as possible (if not all) in the frontend.
llvm-svn: 209789
Duncan P. N. Exon Smith