We currently skip all "Noinst" unit tests on OS X, which was probably caused when we removed the "allow_reexec" flag. The MaybeReexec function fails to re-execute when the runtime is linked statically, because there is no dylib to use. This patch adds an explicit DisableReexec function that is used from asan_noinst_test.cc and the runtime then doesn't try to re-execute.
Reviewed at http://reviews.llvm.org/D7493
llvm-svn: 228740
MaybeReexec() in asan_mac.cc checks for presence of the ASan dylib in DYLD_INSERT_LIBRARIES, and if it is there, it will process this env. var. and remove the dylib from its value, so that spawned children don't have this variable set. However, the current implementation only works when using a canonical absolute path to the dylib, it fails to remove the dylib for example when using @executable_path.
This patch changes the processing of DYLD_INSERT_LIBRARIES to comparing values only based on filenames (ignoring directories).
Reviewed at http://reviews.llvm.org/D7160
llvm-svn: 228392
This patch is a proposed solution for https://code.google.com/p/address-sanitizer/issues/detail?id=375:
When the stacktraces are captured and printed by ASan itself, they are fine, but when the program has already printed the report (or is just printing it), capturing a stacktrace via other means is broken. "Other means" include OS X CrashReporter, debuggers or calling backtrace() within the program. For example calling backtrace() from a sanitizer_set_death_callback function prints a very truncated stacktrace.
Reviewed at http://reviews.llvm.org/D7103
llvm-svn: 226878
As mentioned in
https://code.google.com/p/address-sanitizer/issues/detail?id=365, when the
re-exec that adds the required DYLD_INSERT_LIBRARIES variable fails, ASan
currently continues to run, but things are broken (some memory can be
overwritten, interceptors don't work, ...). This patch aborts if the execv()
fails and prints an error message that DYLD_INSERT_LIBRARIES is required. It
also removes the "alllow_reexec" flag, since using it causes the same issues.
Reviewed at http://reviews.llvm.org/D6752
llvm-svn: 224712
NULL handler
Per
https://developer.apple.com/library/mac/documentation/Performance/Reference/GCD_libdispatch_Ref/index.html,
the dispatch_source_set_cancel_handler() API *can* be called with a NULL
handler. In that case, the libdispatch removes an already existing cancellation
handler, if there was one. ASan's interceptor always creates a new block that
always tries to call the original handler. In case the original block is NULL,
a segmentation fault happens. Let's fix that by not wrapping a NULL-block at
all.
It looks like all the other libdispatch APIs (which we intercept) do *not*
allow NULL. So it's really only the dispatch_source_set_cancel_handler one that
needs this fix.
Reviewed at http://reviews.llvm.org/D6747
llvm-svn: 224711
Reviewed at http://reviews.llvm.org/D6238
ASan on Darwin during launch reads DYLD_INSERT_LIBRARIES env. variable and if it's not set or if the ASan dylib is not present in there, it relaunches the process. The check whether the dylib is present in the variable is now trying to find a full path in there. This fails in the scenarios where we want to copy the dylib to the executable's directory or somewhere else and set the DYLD_INSERT_LIBRARIES manually, see http://reviews.llvm.org/D6018.
Let's change the search in DYLD_INSERT_LIBRARIES to only look for the filename of the dylib and not the full path.
llvm-svn: 222297
that had been used on OS X only.
The INTERCEPTOR() macro on OS X is now responsible for declaring the wrapped function, the wrapper and the
pair of pointers to them in __DATA,__interposition section. Thus adding an interceptor requires editing a single file now.
llvm-svn: 175740
This patch makes asan instrument memory accesses with unusual sizes (e.g. 5 bytes or 10 bytes), e.g. long double or
packed structures.
Instrumentation is done with two 1-byte checks
(first and last bytes) and if the error is found
__asan_report_load_n(addr, real_size) or
__asan_report_store_n(addr, real_size)
is called.
asan-rt part
Also fix lint.
llvm-svn: 175508
MaybeReexec() does now a tricky job to manage DYLD_INSERT_LIBRARIES in a safe way.
Because we're using library interposition, it's critical for an instrumented app
to be executed with the runtime library present in DYLD_INSERT_LIBRARIES list.
Therefore if it's initially missing in that list, we append the runtime library name
to the value of DYLD_INSERT_LIBRARIES and then exec() ourselves.
On the other hand, some of the apps exec()ed by our program may not want to have
ASan runtime library preloaded, so we remove the runtime library from the
DYLD_INSERT_LIBRARIES if it's already there.
Users may want to preload other libraries using DYLD_INSERT_LIBRARIES, so we preserve those.
llvm-svn: 175276
This CL drastically simplifies the way we're hooking the memory allocation routines in ASan on Mac by using dylib interposition to replace the main malloc_zone_* functions. This allows us to avoid replacing the default CFAllocator and drop the CF dependency at all.
Committing this patch will result in the static runtime being broken. A follow-up CL will switch ASan to use the dynamic runtime library.
llvm-svn: 173134
Kuba Brecka