Summary:
The hwasan interceptor ABI doesn't have interceptors for longjmp and setjmp.
This patch introduces them.
We require the size of the jmp_buf on the platform to be at least as large as
the jmp_buf in our implementation. To enforce this we compile
hwasan_type_test.cpp that ensures a compile time failure if this is not true.
Tested on both GCC and clang using an AArch64 virtual machine.
Reviewers: eugenis, kcc, pcc, Sanatizers
Reviewed By: eugenis, Sanatizers
Tags: #sanatizers, #llvm
Differential Revision: https://reviews.llvm.org/D69045
Patch By: Matthew Malcomson <matthew.malcomson@arm.com>
Summary:
Until now AArch64 development has been on patched kernels that have an always
on relaxed syscall ABI where tagged pointers are accepted.
The patches that have gone into the mainline kernel rely on each process opting
in to this relaxed ABI.
This commit adds code to choose that ABI into __hwasan_init.
The idea has already been agreed with one of the hwasan developers
(http://lists.llvm.org/pipermail/llvm-dev/2019-September/135328.html).
The patch ignores failures of `EINVAL` for Android, since there are older versions of the Android kernel that don't require this `prctl` or even have the relevant values. Avoiding EINVAL will let the library run on them.
I've tested this on an AArch64 VM running a kernel that requires this
prctl, having compiled both with clang and gcc.
Patch by Matthew Malcomson.
Reviewers: eugenis, kcc, pcc
Reviewed By: eugenis
Subscribers: srhines, kristof.beyls, #sanitizers, llvm-commits
Tags: #sanitizers, #llvm
Differential Revision: https://reviews.llvm.org/D68794
llvm-svn: 375166
Globals are instrumented by adding a pointer tag to their symbol values
and emitting metadata into a special section that allows the runtime to tag
their memory when the library is loaded.
Due to order of initialization issues explained in more detail in the comments,
shadow initialization cannot happen during regular global initialization.
Instead, the location of the global section is marked using an ELF note,
and we require libc support for calling a function provided by the HWASAN
runtime when libraries are loaded and unloaded.
Based on ideas discussed with @evgeny777 in D56672.
Differential Revision: https://reviews.llvm.org/D65770
llvm-svn: 368102
Each function's PC is recorded in the ring buffer. From there we can access
the function's local variables and reconstruct the tag of each one with the
help of the information printed by llvm-symbolizer's new FRAME command. We
can then find the variable that was likely being accessed by matching the
pointer's tag against the reconstructed tag.
Differential Revision: https://reviews.llvm.org/D63469
llvm-svn: 364607
Retrying without replacing call sites in sanitizer_common (which might
not have a symbol definition).
Add new Unwind API. This is the final envisioned API with the correct
abstraction level. It hides/slow fast unwinder selection from the caller
and doesn't take any arguments that would leak that abstraction (i.e.,
arguments like stack_top/stack_bottom).
GetStackTrace will become an implementation detail (private method) of
the BufferedStackTrace class.
Reviewers: vitalybuka
Differential Revision: https://reviews.llvm.org/D58741
> llvm-svn: 355168
llvm-svn: 355172
Add new Unwind API. This is the final envisioned API with the correct
abstraction level. It hides/slow fast unwinder selection from the caller
and doesn't take any arguments that would leak that abstraction (i.e.,
arguments like stack_top/stack_bottom).
GetStackTrace will become an implementation detail (private method) of
the BufferedStackTrace class.
Reviewers: vitalybuka
Differential Revision: https://reviews.llvm.org/D58741
llvm-svn: 355168
We already independently declare GetStackTrace in all (except TSan)
sanitizer runtime headers. Lets move it to sanitizer_stacktrace.h to
have one canonical way to fill in a BufferedStackFrame. Also enables us
to use it in sanitizer_common itself.
This patch defines GetStackTrace for TSan and moves the function from
ubsan_diag.cc to ubsan_diag_standalone.cc to avoid duplicate symbols
for the UBSan-ASan runtime.
Other than that this patch just moves the code out of headers and into
the correct namespace.
Reviewers: vitalybuka
Differential Revision: https://reviews.llvm.org/D58651
llvm-svn: 355039
This function initializes enough of the runtime to be able to run
instrumented code in a statically linked executable. It replaces
__hwasan_shadow_init() which wasn't doing enough initialization for
instrumented code that uses either TLS or IFUNC to work.
Differential Revision: https://reviews.llvm.org/D57490
llvm-svn: 352816
to reflect the new license.
We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.
Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.
llvm-svn: 351636
The Android dynamic loader has a non-standard feature that allows
libraries such as the hwasan runtime to interpose symbols even after
the symbol already has a value. The new value of the symbol is used to
relocate libraries loaded after the interposing library, but existing
libraries keep the old value. This behaviour is activated by the
DF_1_GLOBAL flag in DT_FLAGS_1, which is set by passing -z global to
the linker, which is what we already do to link the hwasan runtime.
What this means in practice is that if we have .so files that depend
on interceptor-mode hwasan without the main executable depending on
it, some of the libraries in the process will be using the hwasan
allocator and some will be using the system allocator, and these
allocators need to interact somehow. For example, if an instrumented
library calls a function such as strdup that allocates memory on
behalf of the caller, the instrumented library can reasonably expect
to be able to call free to deallocate the memory.
We can handle that relatively easily with hwasan by using tag 0 to
represent allocations from the system allocator. If hwasan's realloc
or free functions are passed a pointer with tag 0, the system allocator
is called.
One limitation is that this scheme doesn't work in reverse: if an
instrumented library allocates memory, it must free the memory itself
and cannot pass ownership to a system library. In a future change,
we may want to expose an API for calling the system allocator so
that instrumented libraries can safely transfer ownership of memory
to system libraries.
Differential Revision: https://reviews.llvm.org/D55986
llvm-svn: 350427
Summary:
Add a check that TLS_SLOT_TSAN / TLS_SLOT_SANITIZER, whichever
android_get_tls_slot is using, is not conflicting with
TLS_SLOT_DLERROR.
Reviewers: rprichard, vitalybuka
Subscribers: srhines, kubamracek, llvm-commits
Differential Revision: https://reviews.llvm.org/D55587
llvm-svn: 348979
Summary:
When reporting a fatal error, collect and add the entire report text to
android_set_abort_message so that it can be found in the tombstone.
Reviewers: kcc, vitalybuka
Subscribers: srhines, kubamracek, llvm-commits
Differential Revision: https://reviews.llvm.org/D54284
llvm-svn: 346557
Summary:
Display a list of recent stack frames (not a stack trace!) when
tag-mismatch is detected on a stack address.
The implementation uses alignment tricks to get both the address of
the history buffer, and the base address of the shadow with a single
8-byte load. See the comment in hwasan_thread_list.h for more
details.
Developed in collaboration with Kostya Serebryany.
Reviewers: kcc
Subscribers: srhines, kubamracek, mgorny, hiraditya, jfb, llvm-commits
Differential Revision: https://reviews.llvm.org/D52249
llvm-svn: 342923
Summary:
Display a list of recent stack frames (not a stack trace!) when
tag-mismatch is detected on a stack address.
The implementation uses alignment tricks to get both the address of
the history buffer, and the base address of the shadow with a single
8-byte load. See the comment in hwasan_thread_list.h for more
details.
Developed in collaboration with Kostya Serebryany.
Reviewers: kcc
Subscribers: srhines, kubamracek, mgorny, hiraditya, jfb, llvm-commits
Differential Revision: https://reviews.llvm.org/D52249
llvm-svn: 342921
Summary:
The idea behind this change is to allow sanitization of libc. We are prototyping on Bionic,
but the tool interface will be general enough (or at least generalizable) to support any other libc.
When libc depends on libclang_rt.hwasan, the latter can not interpose libc functions.
In fact, majority of interceptors become unnecessary when libc code is instrumented.
This change gets rid of most hwasan interceptors and provides interface for libc to notify
hwasan about thread creation and destruction events. Some interceptors (pthread_create)
are kept under #ifdef to enable testing with uninstrumented libc. They are expressed in
terms of the new libc interface.
The new cmake switch, COMPILER_RT_HWASAN_WITH_INTERCEPTORS, ON by default, builds testing
version of the library with the aforementioned pthread_create interceptor.
With the OFF setting, the library becomes more of a libc plugin.
Reviewers: vitalybuka, kcc, jfb
Subscribers: srhines, kubamracek, mgorny, jfb, llvm-commits
Differential Revision: https://reviews.llvm.org/D50922
llvm-svn: 340216
Summary:
Provide __hwasan_shadow_init that can be used to initialize shadow w/o touching libc.
It can be used to bootstrap an unusual case of fully-static executable with
hwasan-instrumented libc, which needs to run hwasan code before it is ready to serve
user calls like madvise().
Reviewers: vitalybuka, kcc
Subscribers: kubamracek, llvm-commits
Differential Revision: https://reviews.llvm.org/D50581
llvm-svn: 339606
Summary:
Currently many allocator specific errors (OOM, for example) are reported as
a text message and CHECK(0) termination, not stack, no details, not too
helpful nor informative. To improve the situation, detailed and
structured errors were defined and reported under the appropriate conditions.
Reviewers: eugenis
Subscribers: kubamracek, delcypher, llvm-commits, #sanitizers
Differential Revision: https://reviews.llvm.org/D47798
llvm-svn: 334248
Retire the fixed shadow memory mapping to avoid conflicts with default
process memory mapping (currently manifests on Android).
Tests on AArch64 show <1% performance loss and code size increase,
making it possible to use dynamic shadow memory by default.
Keep the fixed shadow memory mapping around to be able to run
performance comparison tests later.
Re-commiting D45847 with fixed shadow for x86-64.
llvm-svn: 330624
This commit causes internal errors with ld.bfd 2.24. My guess is that
the ifunc usage in this commit is causing problems. This is the default
system linker on Trusty Tahr, which is from 2014. I claim it's still in
our support window. Maybe we will decide to drop support for it, but
let's get the bots green while we do the investigation and have that
discussion.
Discovered here: https://crbug.com/835864
llvm-svn: 330619
Summary:
Retire the fixed shadow memory mapping to avoid conflicts with default
process memory mapping (currently manifests on Android).
Tests on AArch64 show <1% performance loss and code size increase,
making it possible to use dynamic shadow memory by default.
For the simplicity and unifirmity sake, use dynamic shadow memory mapping
with base address accessed via ifunc resolver on all supported platforms.
Keep the fixed shadow memory mapping around to be able to run
performance comparison tests later.
Complementing D45840.
Reviewers: eugenis
Subscribers: srhines, kubamracek, dberris, mgorny, kristof.beyls, delcypher, #sanitizers, llvm-commits
Differential Revision: https://reviews.llvm.org/D45847
llvm-svn: 330474
Summary:
Porting HWASan to Linux x86-64, first of the three patches, compiler-rt part.
The approach is similar to ARM case, trap signal is used to communicate
memory tag check failure. int3 instruction is used to generate a signal,
access parameters are stored in nop [eax + offset] instruction immediately
following the int3 one
Had to add HWASan init on malloc because, due to much less interceptors
defined (most other sanitizers intercept much more and get initalized
via one of those interceptors or don't care about malloc), HWASan was not
initialized yet when libstdc++ was trying to allocate memory for its own
fixed-size heap, which led to CHECK-fail in AllocateFromLocalPool.
Also added the CHECK() failure handler with more detailed message and
stack reporting.
Reviewers: eugenis
Subscribers: kubamracek, dberris, mgorny, kristof.beyls, delcypher, #sanitizers, llvm-commits
Differential Revision: https://reviews.llvm.org/D44705
llvm-svn: 328385
Summary:
Very basic stack instrumentation using tagged pointers.
Tag for N'th alloca in a function is built as XOR of:
* base tag for the function, which is just some bits of SP (poor
man's random)
* small constant which is a function of N.
Allocas are aligned to 16 bytes. On every ReturnInst allocas are
re-tagged to catch use-after-return.
This implementation has a bunch of issues that will be taken care of
later:
1. lifetime intrinsics referring to tagged pointers are not
recognized in SDAG. This effectively disables stack coloring.
2. Generated code is quite inefficient. There is one extra
instruction at each memory access that adds the base tag to the
untagged alloca address. It would be better to keep tagged SP in a
callee-saved register and address allocas as an offset of that XOR
retag, but that needs better coordination between hwasan
instrumentation pass and prologue/epilogue insertion.
3. Lifetime instrinsics are ignored and use-after-scope is not
implemented. This would be harder to do than in ASan, because we
need to use a differently tagged pointer depending on which
lifetime.start / lifetime.end the current instruction is dominated
/ post-dominated.
Reviewers: kcc, alekseyshl
Subscribers: srhines, kubamracek, javed.absar, hiraditya, llvm-commits
Differential Revision: https://reviews.llvm.org/D41602
llvm-svn: 322324
Summary: This brings CPU overhead on bzip2 down from 5.5x to 2x.
Reviewers: kcc, alekseyshl
Subscribers: kubamracek, hiraditya, llvm-commits
Differential Revision: https://reviews.llvm.org/D41137
llvm-svn: 320538
