Code patterns like this are common, `#` at the line beginning
(https://google.github.io/styleguide/cppguide.html#Preprocessor_Directives),
one space indentation for if/elif/else directives.
```
#if SANITIZER_LINUX
# if defined(__aarch64__)
# endif
#endif
```
However, currently clang-format wants to reformat the code to
```
#if SANITIZER_LINUX
#if defined(__aarch64__)
#endif
#endif
```
This significantly harms readability in my review. Use `IndentPPDirectives:
AfterHash` to defeat the diagnostic. clang-format will now suggest:
```
#if SANITIZER_LINUX
# if defined(__aarch64__)
# endif
#endif
```
Unfortunately there is no clang-format option using indent with 1 for
just preprocessor directives. However, this is still one step forward
from the current behavior.
Reviewed By: #sanitizers, vitalybuka
Differential Revision: https://reviews.llvm.org/D100238
Do not hold the free/live thread list lock longer than necessary.
This change speeds up the following benchmark 10x.
constexpr int kTopThreads = 50;
constexpr int kChildThreads = 20;
constexpr int kChildIterations = 8;
void Thread() {
for (int i = 0; i < kChildIterations; ++i) {
std::vector<std::thread> threads;
for (int i = 0; i < kChildThreads; ++i)
threads.emplace_back([](){});
for (auto& t : threads)
t.join();
}
}
int main() {
std::vector<std::thread> threads;
for (int i = 0; i < kTopThreads; ++i)
threads.emplace_back(Thread);
for (auto& t : threads)
t.join();
}
Differential Revision: https://reviews.llvm.org/D100348
This was reverted by f176803ef1 due to
Ubuntu 16.04 x86-64 glibc 2.23 problems.
This commit additionally calls `__tls_get_addr({modid,0})` to work around the
dlpi_tls_data==NULL issues for glibc<2.25
(https://sourceware.org/bugzilla/show_bug.cgi?id=19826)
GetTls is the range of
* thread control block and optional TLS_PRE_TCB_SIZE
* static TLS blocks plus static TLS surplus
On glibc, lsan requires the range to include
`pthread::{specific_1stblock,specific}` so that allocations only referenced by
`pthread_setspecific` can be scanned.
This patch uses `dl_iterate_phdr` to collect TLS blocks. Find the one
with `dlpi_tls_modid==1` as one of the initially loaded module, then find
consecutive ranges. The boundaries give us addr and size.
This allows us to drop the glibc internal `_dl_get_tls_static_info` and
`InitTlsSize` entirely. Use the simplified method with non-Android Linux for
now, but in theory this can be used with *BSD and potentially other ELF OSes.
This simplification enables D99566 for TLS Variant I architectures.
See https://reviews.llvm.org/D93972#2480556 for analysis on GetTls usage
across various sanitizers.
Differential Revision: https://reviews.llvm.org/D98926
GetTls is the range of
* thread control block and optional TLS_PRE_TCB_SIZE
* static TLS blocks plus static TLS surplus
On glibc, lsan requires the range to include
`pthread::{specific_1stblock,specific}` so that allocations only referenced by
`pthread_setspecific` can be scanned.
This patch uses `dl_iterate_phdr` to collect TLS ranges. Find the one
with `dlpi_tls_modid==1` as one of the initially loaded module, then find
consecutive ranges. The boundaries give us addr and size.
This allows us to drop the glibc internal `_dl_get_tls_static_info` and
`InitTlsSize` entirely. Use the simplified method with non-Android Linux for
now, but in theory this can be used with *BSD and potentially other ELF OSes.
In the future, we can move `ThreadDescriptorSize` code to lsan (and consider
intercepting `pthread_setspecific`) to avoid hacks in generic code.
See https://reviews.llvm.org/D93972#2480556 for analysis on GetTls usage
across various sanitizers.
Differential Revision: https://reviews.llvm.org/D98926
Userspace page aliasing allows us to use middle pointer bits for tags
without untagging them before syscalls or accesses. This should enable
easier experimentation with HWASan on x86_64 platforms.
Currently stack, global, and secondary heap tagging are unsupported.
Only primary heap allocations get tagged.
Note that aliasing mode will not work properly in the presence of
fork(), since heap memory will be shared between the parent and child
processes. This mode is non-ideal; we expect Intel LAM to enable full
HWASan support on x86_64 in the future.
Reviewed By: vitalybuka, eugenis
Differential Revision: https://reviews.llvm.org/D98875
Userspace page aliasing allows us to use middle pointer bits for tags
without untagging them before syscalls or accesses. This should enable
easier experimentation with HWASan on x86_64 platforms.
Currently stack, global, and secondary heap tagging are unsupported.
Only primary heap allocations get tagged.
Note that aliasing mode will not work properly in the presence of
fork(), since heap memory will be shared between the parent and child
processes. This mode is non-ideal; we expect Intel LAM to enable full
HWASan support on x86_64 in the future.
Reviewed By: vitalybuka, eugenis
Differential Revision: https://reviews.llvm.org/D98875
x86_64 aliasing mode will use fewer than 8 bits for tags, so refactor
existing code to remove hard-coded 0xff and 8 values.
Reviewed By: vitalybuka, eugenis
Differential Revision: https://reviews.llvm.org/D98072
InternalScopedString uses InternalMmapVector internally
so it can be resized dynamically as needed.
Reviewed By: eugenis
Differential Revision: https://reviews.llvm.org/D98751
When adding this function in https://reviews.llvm.org/D68794 I did not
notice that internal_prctl has the API of the syscall to prctl rather
than the API of the glibc (posix) wrapper.
This means that the error return value is not necessarily -1 and that
errno is not set by the call.
For InitPrctl this means that the checks do not catch running on a
kernel *without* the required ABI (not caught since I only tested this
function correctly enables the ABI when it exists).
This commit updates the two calls which check for an error condition to
use internal_iserror. That function sets a provided integer to an
equivalent errno value and returns a boolean to indicate success or not.
Tested by running on a kernel that has this ABI and on one that does
not. Verified that running on the kernel without this ABI the current
code prints the provided error message and does not attempt to run the
program. Verified that running on the kernel with this ABI the current
code does not print an error message and turns on the ABI.
This done on an x86 kernel (where the ABI does not exist), an AArch64
kernel without this ABI, and an AArch64 kernel with this ABI.
In order to keep running the testsuite on kernels that do not provide
this new ABI we add another option to the HWASAN_OPTIONS environment
variable, this option determines whether the library kills the process
if it fails to enable the relaxed syscall ABI or not.
This new flag is `fail_without_syscall_abi`.
The check-hwasan testsuite results do not change with this patch on
either x86, AArch64 without a kernel supporting this ABI, and AArch64
with a kernel supporting this ABI.
Differential Revision: https://reviews.llvm.org/D96964
When adding this function in https://reviews.llvm.org/D68794 I did not
notice that internal_prctl has the API of the syscall to prctl rather
than the API of the glibc (posix) wrapper.
This means that the error return value is not necessarily -1 and that
errno is not set by the call.
For InitPrctl this means that the checks do not catch running on a
kernel *without* the required ABI (not caught since I only tested this
function correctly enables the ABI when it exists).
This commit updates the two calls which check for an error condition to
use `internal_iserror`. That function sets a provided integer to an
equivalent errno value and returns a boolean to indicate success or not.
Tested by running on a kernel that has this ABI and on one that does
not. Verified that running on the kernel without this ABI the current
code prints the provided error message and does not attempt to run the
program. Verified that running on the kernel with this ABI the current
code does not print an error message and turns on the ABI.
All tests done on an AArch64 Linux machine.
Reviewed By: eugenis
Differential Revision: https://reviews.llvm.org/D94425
Similar to __asan_set_error_report_callback, pass the entire report to a
user provided callback function.
Differential Revision: https://reviews.llvm.org/D91825
HwasanThreadList::DontNeedThread clobbers Thread::next_,
Breaking the freelist. As a result, only the top of the freelist ever
gets reused, and the rest of it is lost.
Since the Thread object with its associated ring buffer is only 8Kb, this is
typically only noticable in long running processes, such as fuzzers.
Fix the problem by switching from an intrusive linked list to a vector.
Differential Revision: https://reviews.llvm.org/D91392
In `GetGlobalSizeFromDescriptor` we use `dladdr` to get info on the the
current address. `dladdr` returns 0 if it failed.
During testing on Linux this returned 0 to indicate failure, and
populated the `info` structure with a NULL pointer which was
dereferenced later.
This patch checks for `dladdr` returning 0, and in that case returns 0
from `GetGlobalSizeFromDescriptor` to indicate failure of identifying
the address.
This occurs when `GetModuleNameAndOffsetForPC` succeeds for some address
not in a dynamically loaded library. One example is when the found
"module" is '[stack]' having come from parsing /proc/self/maps.
Differential Revision: https://reviews.llvm.org/D91344
HwasanThreadList::DontNeedThread clobbers Thread::next_, breaking the
freelist. As a result, only the top of the freelist ever gets reused,
and the rest of it is lost.
Since the Thread object its associated ring buffer is only 8Kb, this is
typically only noticable in long running processes, such as fuzzers.
Fix the problem by switching from an intrusive linked list to a vector.
Differential Revision: https://reviews.llvm.org/D91208
It turns out that we can't remove the operator new and delete
interceptors on Android without breaking ABI, so bring them back
as forwards to the malloc and free functions.
Differential Revision: https://reviews.llvm.org/D91219
While sanitizers don't use C++ standard library, we could still end
up accidentally including or linking it just by the virtue of using
the C++ compiler. Pass -nostdinc++ and -nostdlib++ to avoid these
accidental dependencies.
Differential Revision: https://reviews.llvm.org/D88922
Adds a check to avoid symbolization when printing stack traces if the
stack_trace_format flag does not need it. While there is a symbolize
flag that can be turned off to skip some of the symbolization,
SymbolizePC() still unconditionally looks up the module name and offset.
Avoid invoking SymbolizePC() at all if not needed.
This is an efficiency improvement when dumping all stack traces as part
of the memory profiler in D87120, for large stripped apps where we want
to symbolize as a post pass.
Differential Revision: https://reviews.llvm.org/D88361
D28596 added SANITIZER_INTERFACE_WEAK_DEF which can guarantee `*_default_options` are always defined.
The weak attributes on the `__{asan,lsan,msan,ubsan}_default_options` declarations can thus be removed.
`MaybeCall*DefaultOptions` no longer need nullptr checks, so their call sites can just be replaced by `__*_default_options`.
Reviewed By: #sanitizers, vitalybuka
Differential Revision: https://reviews.llvm.org/D87175
Summary:
This refactors some common support related to shadow memory setup from
asan and hwasan into sanitizer_common. This should not only reduce code
duplication but also make these facilities available for new compiler-rt
uses (e.g. heap profiling).
In most cases the separate copies of the code were either identical, or
at least functionally identical. A few notes:
In ProtectGap, the asan version checked the address against an upper
bound (kZeroBaseMaxShadowStart, which is (2^18). I have created a copy
of kZeroBaseMaxShadowStart in hwasan_mapping.h, with the same value, as
it isn't clear why that code should not do the same check. If it
shouldn't, I can remove this and guard this check so that it only
happens for asan.
In asan's InitializeShadowMemory, in the dynamic shadow case it was
setting __asan_shadow_memory_dynamic_address to 0 (which then sets both
macro SHADOW_OFFSET as well as macro kLowShadowBeg to 0) before calling
FindDynamicShadowStart(). AFAICT this is only needed because
FindDynamicShadowStart utilizes kHighShadowEnd to
get the shadow size, and kHighShadowEnd is a macro invoking
MEM_TO_SHADOW(kHighMemEnd) which in turn invokes:
(((kHighMemEnd) >> SHADOW_SCALE) + (SHADOW_OFFSET))
I.e. it computes the shadow space needed by kHighMemEnd (the shift), and
adds the offset. Since we only want the shadow space here, the earlier
setting of SHADOW_OFFSET to 0 via __asan_shadow_memory_dynamic_address
accomplishes this. In the hwasan version, it simply gets the shadow
space via "MemToShadowSize(kHighMemEnd)", where MemToShadowSize just
does the shift. I've simplified the asan handling to do the same
thing, and therefore was able to remove the setting of the SHADOW_OFFSET
via __asan_shadow_memory_dynamic_address to 0.
Reviewers: vitalybuka, kcc, eugenis
Subscribers: dberris, #sanitizers, llvm-commits, davidxl
Tags: #sanitizers
Differential Revision: https://reviews.llvm.org/D83247
Summary: Refactor the current global header iteration to be callback-based, and add a feature that reports the size of the global variable during reporting. This allows binaries without symbols to still report the size of the global variable, which is always available in the HWASan globals PT_NOTE metadata.
Reviewers: eugenis, pcc
Reviewed By: pcc
Subscribers: mgorny, llvm-commits, #sanitizers
Tags: #sanitizers, #llvm
Differential Revision: https://reviews.llvm.org/D80599
Summary: Non-zero malloc fill is causing way too many hard to debug issues.
Reviewers: kcc, pcc, hctim
Subscribers: #sanitizers, llvm-commits
Tags: #sanitizers
Differential Revision: https://reviews.llvm.org/D81284
Summary:
This is necessary to handle calls to free() after __hwasan_thread_exit,
which is possible in glibc.
Also, add a null check to GetCurrentThread, otherwise the logic in
GetThreadByBufferAddress turns it into a non-null value. This means that
all of the checks for GetCurrentThread() != nullptr do not have any
effect at all right now!
Reviewers: pcc, hctim
Subscribers: #sanitizers, llvm-commits
Tags: #sanitizers
Differential Revision: https://reviews.llvm.org/D79608
Summary:
Fix parsing of mangled stack trace lines where the address has been
replaced with "0x", literally.
Reviewers: vitalybuka
Subscribers: #sanitizers, llvm-commits
Tags: #sanitizers, #llvm
Differential Revision: https://reviews.llvm.org/D73823
Summary:
A script to symbolize hwasan reports after the fact using unstripped
binaries. Supports stack-based reports. Requires llvm-symbolizer
(addr2line is not an option).
Reviewers: pcc, hctim
Subscribers: mgorny, #sanitizers, llvm-commits
Tags: #sanitizers, #llvm
Differential Revision: https://reviews.llvm.org/D71148
Shadow memory (and short granules) are not prepended with memory
address and arrow at the end of line is removed.
Differential Revision: https://reviews.llvm.org/D70707
This was an experiment made possible by a non-standard feature of the
Android dynamic loader.
It required introducing a flag to tell the compiler which ABI was being
targeted.
This flag is no longer needed, since the generated code now works for
both ABI's.
We leave that flag untouched for backwards compatibility. This also
means that if we need to distinguish between targeted ABI's again
we can do that without disturbing any existing workflows.
We leave a comment in the source code and mention in the help text to
explain this for any confused person reading the code in the future.
Patch by Matthew Malcomson
Differential Revision: https://reviews.llvm.org/D69574
Fangrui Song