Signal handlers used by recoverable tests are unsupported on Fuchsia.
Exclude the set of tests that test recoverable code paths (i.e.
BacktraceGuardedPoolAllocator tests in recoverable.cpp) and always set
the `Recoverable` testing bool to `false` on the Fuchsia platform.
Differential Revision: https://reviews.llvm.org/D149311
AllocMeta could be null when returned from __gwp_asan_get_metadata() for
a bad access into the GuardedPagePool that was never allocated.
Currently, then we dereference the null pointer, oops.
Hoist the check up and print a message (only once in recoverable mode)
about the bad memory access.
Reviewed By: fmayer
Differential Revision: https://reviews.llvm.org/D144973
The GWP-ASan recoverable mode allows a process to continue to function
after a GWP-ASan error is detected. The error will continue to be
dumped, but GWP-ASan now has APIs that a signal handler (like the
example optional crash handler) can call in order to allow the
continuation of a process.
When an error occurs with an allocation, the slot used for that
allocation will be permanently disabled. This means that free() of that
pointer is a no-op, and use-after-frees will succeed (writing and
reading the data present in the page).
For heap-buffer-overflow/underflow, the guard page is marked as accessible
and buffer-overflows will succeed (writing and reading the data present
in the now-accessible guard page). This does impact adjacent
allocations, buffer-underflow and buffer-overflows from adjacent
allocations will no longer touch an inaccessible guard page. This could
be improved in future by having two guard pages between each adjacent
allocation, but that's out of scope of this patch.
Each allocation only ever has a single error report generated. It's
whatever came first between invalid-free, double-free, use-after-free or
heap-buffer-overflow, but only one.
Reviewed By: eugenis, fmayer
Differential Revision: https://reviews.llvm.org/D140173
This modifies the tests so that they can be run on Fuchsia:
- add the necessary includes for `set`/`vector` etc
- do the few modifications required to use zxtest instead og gtest
`backtrace.cpp` requires stacktrace support that Fuchsia doesn't have
yet, and `enable_disable.cpp` currently uses `fork()` which Fuchsia
doesn't support yet. I'll revisit this later.
I chose to use `harness.h` to hold my "platform-specific" include and
namespace, and using this header in tests rather than `gtest.h`,
which I am open to change if someone would rather go another direction.
Differential Revision: https://reviews.llvm.org/D91575
Summary:
* Implement enable() and disable() in GWP-ASan.
* Setup atfork handler.
* Improve test harness sanity and re-enable GWP-ASan in Scudo.
Scudo_standalone disables embedded GWP-ASan as necessary around fork().
Standalone GWP-ASan sets the atfork handler in init() if asked to. This
requires a working malloc(), therefore GWP-ASan initialization in Scudo
is delayed to the post-init callback.
Test harness changes are about setting up a single global instance of
the GWP-ASan allocator so that pthread_atfork() does not create
dangling pointers.
Test case shamelessly stolen from D72470.
Reviewers: cryptoad, hctim, jfb
Subscribers: mgorny, jfb, #sanitizers, llvm-commits
Tags: #sanitizers, #llvm
Differential Revision: https://reviews.llvm.org/D73294
