The `_DYNAMIC` reference from `AsanDoesNotSupportStaticLinkage` ensures
that `clang++ -fsanitize=address -static` gets a linker error.
`MemprofDoesNotSupportStaticLinkage` is similar for `-fmemory-profile`.
Move the functions to sanitizer_common.h to be used by more sanitizers
on ELF platforms.
Fuchsia does not use interposition and opts out the check (its
`AsanDoesNotSupportStaticLinkage` is a no-op).
Issue #72639
The commit at 020cdaf broke build of asan on macOS with GCC. GCC does
not support the Apple blocks extension (yet). Uses of blocks in other
parts of the sanitisers are protected by MISSING_BLOCKS_SUPPORT. But the
type definition is not.
_This applies FX's patch from the issue._
Co-authored-by: FX Coudert <fxcoudert@gmail.com>
When enabling DriverKit, Address Sanitizer was unable to
intercept thread creation directly for dispatch workerthreads.
Because of this calls to GetStackTraceFromID failed and ASan was
unable to capture a meaningful stack trace.
This patch adds an interceptor for a dispatch function as a proxy
that is "close enough" to thread creation so that ASan is able
to meaningfully capture and register the dispatched thread.
Note: I propose not adding a test for this change.
Because this change is only meaningful in such a narrow usecase on Darwin
and is incredibly difficult to add a meaningful test.
Differential Revision: https://reviews.llvm.org/D154753
ClearShadowMemoryForContextStack assumes that context contains the stack
bounds. This is not true for a context from getcontext or oucp of
swapcontext.
Reviewed By: kstoimenov
Differential Revision: https://reviews.llvm.org/D130218
This is a follow up to [Sanitizers][Darwin] Rename Apple macro SANITIZER_MAC -> SANITIZER_APPLE (D125816)
Performed a global search/replace as in title against LLVM sources
Differential Revision: https://reviews.llvm.org/D126263
This CL allows asan allocator in fuchsia to decommit shadow memory
for memory allocated using mmap.
Big allocations in asan end up being allocated via `mmap` and freed with
`munmap`. However, when that memory is freed, asan returns the
corresponding shadow memory back to the OS via a call to
`ReleaseMemoryPagesToOs`.
In fuchsia, `ReleaseMemoryPagesToOs` is a no-op: to be able to free
memory back to the OS, you have to hold a handle to the vmo you want to
modify, which is tricky at the ReleaseMemoryPagesToOs level as that
function is not exclusively used for shadow memory.
The function `__sanitizer_fill_shadow` fills a given shadow memory range
with a specific value, and if that value is 0 (unpoison) and the memory
range is bigger than a threshold parameter, it will decommit that memory
if it is all zeroes.
This CL modifies the `FlushUnneededASanShadowMemory` function in
`asan_poisoning.cpp` to add a call to `__sanitizer_fill_shadow` with
value and threshold = 0. This way, all the unneeded shadow memory gets
returned back to the OS.
A test for this behavior can be found in fxrev.dev/391974
Differential Revision: https://reviews.llvm.org/D80355
Change-Id: Id6dd85693e78a222f0329d5b2201e0da753e01c0
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
