The current naming scheme adds the `dfs$` prefix to all
DFSan-instrumented functions. This breaks mangling and prevents stack
trace printers and other tools from automatically demangling function
names.
This new naming scheme is mangling-compatible, with the `.dfsan`
suffix being a vendor-specific suffix:
https://itanium-cxx-abi.github.io/cxx-abi/abi.html#mangling-structure
With this fix, demangling utils would work out-of-the-box.
Reviewed By: stephan.yichao.zhao
Differential Revision: https://reviews.llvm.org/D104494
Complete support for fast8:
- amend shadow size and mapping in runtime
- remove fast16 mode and -dfsan-fast-16-labels flag
- remove legacy mode and make fast8 mode the default
- remove dfsan-fast-8-labels flag
- remove functions in dfsan interface only applicable to legacy
- remove legacy-related instrumentation code and tests
- update documentation.
Reviewed By: stephan.yichao.zhao, browneee
Differential Revision: https://reviews.llvm.org/D103745
Needs to be discussed more.
This reverts commit 255a5c1baa6020c009934b4fa342f9f6dbbcc46
This reverts commit df2056ff3730316f376f29d9986c9913b95ceb1
This reverts commit faff79b7ca144e505da6bc74aa2b2f7cffbbf23
This reverts commit d2a9020785c6e02afebc876aa2778fa64c5cafd
Calls must properly match argument ABI attributes with the callee.
Found via D103412.
Reviewed By: morehouse
Differential Revision: https://reviews.llvm.org/D103414
The first version of origin tracking tracks only memory stores. Although
this is sufficient for understanding correct flows, it is hard to figure
out where an undefined value is read from. To find reading undefined values,
we still have to do a reverse binary search from the last store in the chain
with printing and logging at possible code paths. This is
quite inefficient.
Tracking memory load instructions can help this case. The main issues of
tracking loads are performance and code size overheads.
With tracking only stores, the code size overhead is 38%,
memory overhead is 1x, and cpu overhead is 3x. In practice #load is much
larger than #store, so both code size and cpu overhead increases. The
first blocker is code size overhead: link fails if we inline tracking
loads. The workaround is using external function calls to propagate
metadata. This is also the workaround ASan uses. The cpu overhead
is ~10x. This is a trade off between debuggability and performance,
and will be used only when debugging cases that tracking only stores
is not enough.
Reviewed By: gbalats
Differential Revision: https://reviews.llvm.org/D100967
George Balatsouras