Commit Graph

6 Commits

Author SHA1 Message Date
George Balatsouras c6b5a25eeb [dfsan] Replace dfs$ prefix with .dfsan suffix
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
2021-06-17 22:42:47 -07:00
George Balatsouras 5b4dda550e [dfsan] Add full fast8 support
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
2021-06-07 17:20:54 -07:00
George Balatsouras d10f173f34 [dfsan] Add -dfsan-fast-8-labels flag
This is only adding support to the dfsan instrumentation pass but not
to the runtime.

Added more RUN lines for testing: for each instrumentation test that
had a -dfsan-fast-16-labels invocation, a new invocation was added
using fast8.

Reviewed By: stephan.yichao.zhao

Differential Revision: https://reviews.llvm.org/D98734
2021-03-18 16:28:42 -07:00
George Balatsouras bd99f23260 [dfsan] Increase coverage of vector and select tests
Add more expectations in vector.ll and select.ll based on command-line option combinations.
Also, remove hard-coded shadow width references to enable fast8 transition.

Reviewed By: stephan.yichao.zhao

Differential Revision: https://reviews.llvm.org/D97903
2021-03-04 12:56:55 -08:00
Jianzhou Zhao 80e326a8c4 [dfsan] Support passing non-i16 shadow values in TLS mode
This is a child diff of D92261.

It extended TLS arg/ret to work with aggregate types.

For a function
  t foo(t1 a1, t2 a2, ... tn an)
Its arguments shadow are saved in TLS args like
  a1_s, a2_s, ..., an_s
TLS ret simply includes r_s. By calculating the type size of each shadow
value, we can get their offset.

This is similar to what MSan does. See __msan_retval_tls and __msan_param_tls
from llvm/lib/Transforms/Instrumentation/MemorySanitizer.cpp.

Note that this change does not add test cases for overflowed TLS
arg/ret because this is hard to test w/o supporting aggregate shdow
types. We will be adding them after supporting that.

Reviewed-by: morehouse

Differential Revision: https://reviews.llvm.org/D92440
2020-12-04 02:45:07 +00:00
Jianzhou Zhao 0dd87825db Add a flag to control whether to propagate labels from condition values to results
Before the change, DFSan always does the propagation. W/o
origin tracking, it is harder to understand such flows. After
the change, the flag is off by default.

Reviewed-by: morehouse
Differential Revision: https://reviews.llvm.org/D91234
2020-11-11 20:41:42 +00:00