Introduce a function __scudo_get_error_info() that may be called to interpret
a crash resulting from a memory error, potentially in another process,
given information extracted from the crashing process. The crash may be
interpreted as a use-after-free, buffer overflow or buffer underflow.
Also introduce a feature to optionally record a stack trace for each
allocation and deallocation. If this feature is enabled, a stack trace for
the allocation and (if applicable) the deallocation will also be available
via __scudo_get_error_info().
Differential Revision: https://reviews.llvm.org/D77283
This lets us remove two pointer indirections (one by removing the pointer,
and another by making the AllocatorPtr declaration hidden) in the C++ wrappers.
Differential Revision: https://reviews.llvm.org/D74356
Summary:
This tweaks some behaviors of the allocator wrt 32-bit, notably
tailoring the size-class map.
I had to remove a `printStats` from `__scudo_print_stats` since when
within Bionic they share the same slot so they can't coexist at the
same time. I have to find a solution for that later, but right now we
are not using the Svelte configuration.
Reviewers: rengolin
Subscribers: #sanitizers, llvm-commits
Tags: #sanitizers, #llvm
Differential Revision: https://reviews.llvm.org/D74178
Summary:
fork() wasn't well (or at all) supported in Scudo. This materialized
in deadlocks in children.
In order to properly support fork, we will lock the allocator pre-fork
and unlock it post-fork in parent and child. This is done via a
`pthread_atfork` call installing the necessary handlers.
A couple of things suck here: this function allocates - so this has to
be done post initialization as our init path is not reentrance, and it
doesn't allow for an extra pointer - so we can't pass the allocator we
are currently working with.
In order to work around this, I added a post-init template parameter
that gets executed once the allocator is initialized for the current
thread. Its job for the C wrappers is to install the atfork handlers.
I reorganized a bit the impacted area and added some tests, courtesy
of cferris@ that were deadlocking prior to this fix.
Subscribers: jfb, #sanitizers, llvm-commits
Tags: #sanitizers, #llvm
Differential Revision: https://reviews.llvm.org/D72470
Peter Collingbourne