This guarantees that we will detect a buffer overflow or underflow
that overwrites an adjacent block. This spatial guarantee is similar
to the temporal guarantee that we provide for immediate use-after-free.
Enabling odd/even tags involves a tradeoff between use-after-free
detection and buffer overflow detection. Odd/even tags make it more
likely for buffer overflows to be detected by increasing the size of
the guaranteed "red zone" around the allocation, but on the other
hand use-after-free is less likely to be detected because the tag
space for any particular chunk is cut in half. Therefore we introduce
a tuning setting to control whether odd/even tags are enabled.
Differential Revision: https://reviews.llvm.org/D84361
Summary:
This is a redo of D63612.
Two problems came up on some bots:
- `__builtin_umull_overflow` was not declared. This is likely due to an
older clang or gcc, so add a guard with `__has_builtin` and fallback
to a division in the event the builtin doesn't exist;
- contradicting definition for `malloc`, etc. This is AFAIU due to the
fact that we ended up transitively including `stdlib.h` in the `.inc`
due to it being the flags parser header: so move the include to the
cc instead.
This should fix the issues, but since those didn't come up in my local
tests it's mostly guesswork.
Rest is the same!
Reviewers: morehouse, hctim, eugenis, vitalybuka, dyung, hans
Reviewed By: morehouse, dyung, hans
Subscribers: srhines, mgorny, delcypher, jfb, #sanitizers, llvm-commits
Tags: #llvm, #sanitizers
Differential Revision: https://reviews.llvm.org/D63831
llvm-svn: 364547
Makes the build fail with e.g.
llvm/projects/compiler-rt/lib/scudo/standalone/wrappers_c.inc:20:68: error:
declaration of 'void* calloc(size_t, size_t)' has a different exception
specifier
INTERFACE WEAK void *SCUDO_PREFIX(calloc)(size_t nmemb, size_t size) {
^
See llvm-commits thread.
> Summary:
> This CL adds C & C++ wrappers and associated tests. Those use default
> configurations for a Scudo combined allocator that will likely be
> tweaked in the future.
>
> This is the final CL required to have a functional C & C++ allocator
> based on Scudo.
>
> The structure I have chosen is to define the core C allocation
> primitives in an `.inc` file that can be customized through defines.
> This allows to easily have 2 (or more) sets of wrappers backed by
> different combined allocators, as demonstrated by the `Bionic`
> wrappers: one set for the "default" allocator, one set for the "svelte"
> allocator.
>
> Currently all the tests added have been gtests, but I am planning to
> add some more lit tests as well.
>
> Reviewers: morehouse, eugenis, vitalybuka, hctim, rengolin
>
> Reviewed By: morehouse
>
> Subscribers: srhines, mgorny, delcypher, jfb, #sanitizers, llvm-commits
>
> Tags: #llvm, #sanitizers
>
> Differential Revision: https://reviews.llvm.org/D63612
llvm-svn: 364400
Summary:
This CL adds C & C++ wrappers and associated tests. Those use default
configurations for a Scudo combined allocator that will likely be
tweaked in the future.
This is the final CL required to have a functional C & C++ allocator
based on Scudo.
The structure I have chosen is to define the core C allocation
primitives in an `.inc` file that can be customized through defines.
This allows to easily have 2 (or more) sets of wrappers backed by
different combined allocators, as demonstrated by the `Bionic`
wrappers: one set for the "default" allocator, one set for the "svelte"
allocator.
Currently all the tests added have been gtests, but I am planning to
add some more lit tests as well.
Reviewers: morehouse, eugenis, vitalybuka, hctim, rengolin
Reviewed By: morehouse
Subscribers: srhines, mgorny, delcypher, jfb, #sanitizers, llvm-commits
Tags: #llvm, #sanitizers
Differential Revision: https://reviews.llvm.org/D63612
llvm-svn: 364332
Peter Collingbourne