Summary:
The reasoning behind this change is twofold:
- the current combined allocator (sanitizer_allocator_combined.h) implements
features that are not relevant for Scudo, making some code redundant, and
some restrictions not pertinent (alignments for example). This forced us to
do some weird things between the frontend and our secondary to make things
work;
- we have enough information to be able to know if a chunk will be serviced by
the Primary or Secondary, allowing us to avoid extraneous calls to functions
such as `PointerIsMine` or `CanAllocate`.
As a result, the new scudo-specific combined allocator is very straightforward,
and allows us to remove some now unnecessary code both in the frontend and the
secondary. Unused functions have been left in as unimplemented for now.
It turns out to also be a sizeable performance gain (3% faster in some Android
memory_replay benchmarks, doing some more on other platforms).
Reviewers: alekseyshl, kcc, dvyukov
Reviewed By: alekseyshl
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D33007
llvm-svn: 302830
This breaks several tests because we don't always have
access to __cxa_guard functions
This reverts commit 45eb470c3e9e8f6993a204e247c33d4092237efe.
llvm-svn: 302693
Summary:
This bug is caused by the incorrect handling of return-value registers.
According to OpenPOWER 64-Bit ELF V2 ABI 2.2.5, up to 2 general-purpose
registers are going to be used for return values, and up to 8 floating
point registers or vector registers are going to be used for return
values.
Reviewers: dberris, echristo
Subscribers: nemanjai, llvm-commits
Differential Revision: https://reviews.llvm.org/D33027
llvm-svn: 302691
Summary:
The test fails on PPC, because the address of a function may vary
depending on whether the "taker" shares the same ToC (roughly, in the
same "module") as the function.
Therefore the addresses of the functions taken in func-id-utils.cc may be
different from the addresses taken in xray runtime.
Change the test to be permissive on address comparison.
Reviewers: dberris, echristo
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D33026
llvm-svn: 302686
Disable building enable_execute_stack.c for targets that do not have
support for mprotect().
Differential Revision: https://reviews.llvm.org/D33018
llvm-svn: 302680
Summary:
Sanitizer procmaps uses dyld apis to iterate over the list of images
in the process. This is much more performan than manually recursing
over all of the memory regions in the process, however, dyld does
not report itself in the list of images. In order to prevent reporting
leaks from dyld globals and to symbolize dyld functions in stack traces,
this patch special-cases dyld and ensures that it is added to the
list of modules.
This is accomplished by recursing through the memory map of the process
until a dyld Mach header is found. While this recursion is expensive,
it is run before the full set of images has been loaded in the process,
so only a few calls are required. The result is cached so that it never
needs to be searched for when the full process memory map exists, as this
would be incredibly slow, on the order of minutes for leak sanitizer with
only 25 or so libraries loaded.
Reviewers: alekseyshl, kubamracek
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D32968
llvm-svn: 302673
Some configuration (for instance default docker ubuntu images) uses
a default empty and invalid /etc/fstab configuration file. It makes
any call to getmntent return NULL and it leads to failures on
Msan-aarch64{-with-call}-Test/MemorySanitizer.getmntent{_r}.
This patch fixes it by creating a temporary file with some valid
entries (although not valid for the system) to use along with
setmntent/getmntent.
llvm-svn: 302639
By default glibc writes its diagnostics directly to tty so the `2>&1 |`
redirection in the test doesn't catch the *** stack smashing detected ***
message, which in turn breaks printing the lit's progress bar. By defining
the LIBC_FATAL_STDERR_ environment variable we force glibc to direct
diagnostic messages to stderr.
Differential Revision: https://reviews.llvm.org/D32599
llvm-svn: 302628
This commit made ubsan use the fast unwinder. On SystemZ this requires
test cases to be compiled with -mbackchain. That was already done for
asan, but not ubsan. Add the flag for ubsan as well.
llvm-svn: 302562
Summary:
This change optimizes several aspects of the checksum used for chunk headers.
First, there is no point in checking the weak symbol `computeHardwareCRC32`
everytime, it will either be there or not when we start, so check it once
during initialization and set the checksum type accordingly.
Then, the loading of `HashAlgorithm` for SSE versions (and ARM equivalent) was
not optimized out, while not necessary. So I reshuffled that part of the code,
which duplicates a tiny bit of code, but ends up in a much cleaner assembly
(and faster as we avoid an extraneous load and some calls).
The following code is the checksum at the end of `scudoMalloc` for x86_64 with
full SSE 4.2, before:
```
mov rax, 0FFFFFFFFFFFFFFh
shl r10, 38h
mov edi, dword ptr cs:_ZN7__scudoL6CookieE ; __scudo::Cookie
and r14, rax
lea rsi, [r13-10h]
movzx eax, cs:_ZN7__scudoL13HashAlgorithmE ; __scudo::HashAlgorithm
or r14, r10
mov rbx, r14
xor bx, bx
call _ZN7__scudo20computeHardwareCRC32Ejm ; __scudo::computeHardwareCRC32(uint,ulong)
mov rsi, rbx
mov edi, eax
call _ZN7__scudo20computeHardwareCRC32Ejm ; __scudo::computeHardwareCRC32(uint,ulong)
mov r14w, ax
mov rax, r13
mov [r13-10h], r14
```
After:
```
mov rax, cs:_ZN7__scudoL6CookieE ; __scudo::Cookie
lea rcx, [rbx-10h]
mov rdx, 0FFFFFFFFFFFFFFh
and r14, rdx
shl r9, 38h
or r14, r9
crc32 eax, rcx
mov rdx, r14
xor dx, dx
mov eax, eax
crc32 eax, rdx
mov r14w, ax
mov rax, rbx
mov [rbx-10h], r14
```
Reviewers: dvyukov, alekseyshl, kcc
Reviewed By: alekseyshl
Subscribers: aemerson, rengolin, llvm-commits
Differential Revision: https://reviews.llvm.org/D32971
llvm-svn: 302538
Summary: This should significantly improve darwin lsan performance in cases where root regions are not used.
Reviewers: alekseyshl, kubamracek
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D32966
llvm-svn: 302530
Summary:
This change adds Android support to the allocator (but doesn't yet enable it in
the cmake config), and should be the last fragment of the rewritten change
D31947.
Android has more memory constraints than other platforms, so the idea of a
unique context per thread would not have worked. The alternative chosen is to
allocate a set of contexts based on the number of cores on the machine, and
share those contexts within the threads. Contexts can be dynamically reassigned
to threads to prevent contention, based on a scheme suggested by @dvyuokv in
the initial review.
Additionally, given that Android doesn't support ELF TLS (only emutls for now),
we use the TSan TLS slot to make things faster: Scudo is mutually exclusive
with other sanitizers so this shouldn't cause any problem.
An additional change made here, is replacing `thread_local` by `THREADLOCAL`
and using the initial-exec thread model in the non-Android version to prevent
extraneous weak definition and checks on the relevant variables.
Reviewers: kcc, dvyukov, alekseyshl
Reviewed By: alekseyshl
Subscribers: srhines, mgorny, llvm-commits
Differential Revision: https://reviews.llvm.org/D32649
llvm-svn: 302300
Follow-up on D32846 to simplify testing and not rely on FileCheck to
test boundary conditions, and instead do all the testing in code
instead.
llvm-svn: 302212
Summary:
This change allows us to provide users and implementers of XRay handlers
a means of converting XRay function id's to addresses. This, in
combination with the facilities provided in D32695, allows users to find
out:
- How many function id's there are defined in the current binary.
- Get the address of the function associated with this function id.
- Patch only specific functions according to their requirements.
While we don't directly provide symbolization support in XRay, having
the function's address lets users determine this information easily
either during runtime, or offline with tools like 'addr2line'.
Reviewers: dblaikie, echristo, pelikan
Subscribers: kpw, llvm-commits
Differential Revision: https://reviews.llvm.org/D32846
llvm-svn: 302210
Summary:
glibc on Linux calls __longjmp_chk instead of longjmp (or _longjmp) when
_FORTIFY_SOURCE is defined. Ensure that an ASAN-instrumented program
intercepts this function when a system library calls it, otherwise the
stack might remain poisoned and result in CHECK failures and false
positives.
Fixes https://github.com/google/sanitizers/issues/721
Reviewed By: eugenis
Differential Revision: https://reviews.llvm.org/D32408
llvm-svn: 302152
Match the builtins that GCC provides for IEEE754 quad precision
on MIPS64. Also, enable building them with clang as PR20098 is resolved.
Disable tests for xf and xc modes as MIPS doesn't support that mode in
hardware or software.
Reviewers: slthakur
Differential Revision: https://reviews.llvm.org/D32794
llvm-svn: 302147
Summary:
This change allows us to patch/unpatch specific functions using the
function ID. This is useful in cases where implementations might want to
do coverage-style, or more fine-grained control of which functions to
patch or un-patch at runtime.
Depends on D32693.
Reviewers: dblaikie, echristo, kpw
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D32695
llvm-svn: 302112
This patch allows the Swift compiler to emit calls to `__tsan_external_write` before starting any modifying access, which will cause TSan to detect races on arrays, dictionaries and other classes defined in non-instrumented modules. Races on collections from the Swift standard library and user-defined structs and a frequent cause of subtle bugs and it's important that TSan detects those on top of existing LLVM IR instrumentation, which already detects races in direct memory accesses.
Differential Revision: https://reviews.llvm.org/D31630
llvm-svn: 302050
This patch marks a few ASan tests as unsupported on iOS. These are mostly tests that use files or paths that are invalid/inaccessible on iOS or the simulator. We currently don't have a good way of propagating/copying secondary files that individual tests need. The same problem exists on Android, so I'm just marking the tests as UNSUPPORTED now.
Differential Revision: https://reviews.llvm.org/D32632
llvm-svn: 301966
Kostya Kortchinsky