Summary:
In order to avoid starting a separate thread to return unused memory to
the system (the thread interferes with process startup on Android,
Zygota waits for all threads to exit before fork, but this thread never
exits), try to return it right after free.
Reviewers: eugenis
Subscribers: cryptoad, filcab, danalbert, kubabrecka, llvm-commits
Patch by Aleksey Shlyapnikov.
Differential Revision: https://reviews.llvm.org/D27003
llvm-svn: 288091
When running with start_deactivated=1 in ASAN_OPTIONS, heap redzones
are not poisoned until the first instrumented module is loaded. This
can cause false negatives even on memory allocated after activation,
because redzones are normally poisoned only once when a new allocator
region is mapped.
This change attempts to fix it by iterating over all existing
allocator chunks and poisoning their redzones.
llvm-svn: 281364
Summary:
Replacement for part of D23518
This deals with heap addresses, and renames DescribeHeapAddress.
Requires D23520, which moves code around to make it accessible in asan_describers.cc (and still accessible in asan_report.cc if needed).
Reviewers: kcc, samsonov
Subscribers: kubabrecka, llvm-commits
Differential Revision: https://reviews.llvm.org/D23569
llvm-svn: 278917
that makes allocation fail. "UL" is 32-bit and shift by 40 will make
the value overflow and become 0.
Patch by Wei Wang
Differential Revision: http://reviews.llvm.org/D21310
llvm-svn: 272689
Summary:
This (partially) implements the check mentioned at
http://kristerw.blogspot.co.uk/2016/04/dangling-pointers-and-undefined-behavior.html
(via John Regehr)
Quoting:
"That the behavior is undefined follows from C11 6.2.4 "Storage
durations of objects"
The lifetime of an object is the portion of program execution during
which storage is guaranteed to be reserved for it. An object exists, has
a constant address, and retains its last-stored value throughout its
lifetime. If an object is referred to outside of its lifetime, the
behavior is undefined. The value of a pointer becomes indeterminate when
the object it points to (or just past) reaches the end of its lifetime.
and 7.22.3 "Memory management functions" that says that free ends the
lifetime of objects
The lifetime of an allocated object extends from the allocation until
the deallocation.
"
We can probably implement this for stack variables too, but I think this
is a good start to see if there's interest in this check.
We can also hide this behind a flag, too.
Reviewers: samsonov, kcc, rsmith, regehr
Subscribers: kubabrecka, llvm-commits
Differential Revision: http://reviews.llvm.org/D19691
llvm-svn: 268097
With -fsized-deallocation, new[] vs delete mismatch is reported as
new-delete-type-mismatch. This is technically true, but
alloc-dealloc-mismatch describes it better.
llvm-svn: 266246
ucrtbase.dll appears to be built with some kind of cross-module
inlining, because there are calls to imported Heap* routines sprinkled
throughout the code. This inlining defeats our attempts to hotpatch
malloc, _malloc_base, and related functions. Failing to intercept an
allocation or deallocation results in a crash when the program attempts
to deallocate or reallocate memory with the wrong allocator.
This change patches the IAT of ucrtbase.dll to replace the addresses of
the imported Heap* functions with implementations provided by ASan. We
don't globally intercept the win32 Heap* functions because they are
typically used by system DLLs that run before ASan initializes.
Eventually, we may want to intercept them, but for now I think this is
the minimal change that will keep ASan stable.
Reviewers: samsonov
Differential Revision: http://reviews.llvm.org/D18413
llvm-svn: 264327
- Trim spaces.
- Use nullptr in place of 0 for pointer variables.
- Use '!p' in place of 'p == 0' for null pointer checks.
- Add blank lines to separate function definitions.
- Add 'extern "C"' or 'namespace foo' comments after the appropriate
closing brackets
This is a continuation of work from 409b7b82. The focus here is on the
various sanitizers (not sanitizer_common, as before).
Patch by Eugene Zelenko!
Differential Revision: http://reviews.llvm.org/D13225
llvm-svn: 248966
Now ASan deactivation doesn't modify common or ASan-specific runtime
flags. Flags stay constant after initialization, and "deactivation"
instead stashes initialized runtime state, and deactivates the
runtime. Activation then just restores the original state (possibly,
overriden by some activation flags provided in system property on
Android).
llvm-svn: 224614
Summary:
Reduce the dependency of allocator code on runtime flags. Instead,
pass a bunch of options that configure allocator behavior at
initialization or re-initialization. That would allow us to
cleaner modify allocator behavior during a program execution
when ASan is activated or de-activated.
Test Plan: regression test suite
Reviewers: kcc
Subscribers: llvm-commits, eugenis
Differential Revision: http://reviews.llvm.org/D6711
llvm-svn: 224605
Introduce "Allocator" object, which contains all the bits and pieces
ASan allocation machinery actually use: allocator from sanitizer_common,
quarantine, fallback allocator and quarantine caches, fallback mutex.
This step is a preparation to adding more state to this object. We want
to reduce dependency of Allocator on commandline flags and be able to
"safely" modify its behavior (such as the size of the redzone) at
runtime.
llvm-svn: 224406
In case of partial right OOB, ASan was reporting
X is located 0 bytes to the right of [A, B)
where X was actually inside [A, B).
With this change, ASan will report B as the error address in such case.
llvm-svn: 174373
Evgeniy Stepanov