Commit Graph

10 Commits

Author SHA1 Message Date
Nikita Popov 41d5033eb1 [IR] Enable opaque pointers by default
This enabled opaque pointers by default in LLVM. The effect of this
is twofold:

* If IR that contains *neither* explicit ptr nor %T* types is passed
  to tools, we will now use opaque pointer mode, unless
  -opaque-pointers=0 has been explicitly passed.
* Users of LLVM as a library will now default to opaque pointers.
  It is possible to opt-out by calling setOpaquePointers(false) on
  LLVMContext.

A cmake option to toggle this default will not be provided. Frontends
or other tools that want to (temporarily) keep using typed pointers
should disable opaque pointers via LLVMContext.

Differential Revision: https://reviews.llvm.org/D126689
2022-06-02 09:40:56 +02:00
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 6b7b53f5b9 [dfsan] Remove hard-coded shadow width in more tests
As a preparation step for fast8 support, we need to update the tests
to pass in both modes. That requires generalizing the shadow width
and remove any hard coded references that assume it's always 2 bytes.

Reviewed By: stephan.yichao.zhao

Differential Revision: https://reviews.llvm.org/D97884
2021-03-03 15:05:16 -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
Cameron McInally 7aa898e61e [DFSan] Add UnaryOperator visitor to DataFlowSanitizer
Differential Revision: https://reviews.llvm.org/D62815

llvm-svn: 363814
2019-06-19 15:11:41 +00:00
Peter Collingbourne e67e4e821d Add target triples to all dfsan tests.
llvm-svn: 223536
2014-12-05 22:32:30 +00:00
Peter Collingbourne a96296f3ab DataFlowSanitizer: correctly combine labels in the case where they are equal.
llvm-svn: 189133
2013-08-23 18:45:06 +00:00
Peter Collingbourne 59b1262d01 DataFlowSanitizer: Prefix the name of each instrumented function with "dfs$".
DFSan changes the ABI of each function in the module.  This makes it possible
for a function with the native ABI to be called with the instrumented ABI,
or vice versa, thus possibly invoking undefined behavior.  A simple way
of statically detecting instances of this problem is to prepend the prefix
"dfs$" to the name of each instrumented-ABI function.

This will not catch every such problem; in particular function pointers passed
across the instrumented-native barrier cannot be used on the other side.
These problems could potentially be caught dynamically.

Differential Revision: http://llvm-reviews.chandlerc.com/D1373

llvm-svn: 189052
2013-08-22 20:08:08 +00:00
Peter Collingbourne e5d5b0c71e DataFlowSanitizer; LLVM changes.
DataFlowSanitizer is a generalised dynamic data flow analysis.

Unlike other Sanitizer tools, this tool is not designed to detect a
specific class of bugs on its own.  Instead, it provides a generic
dynamic data flow analysis framework to be used by clients to help
detect application-specific issues within their own code.

Differential Revision: http://llvm-reviews.chandlerc.com/D965

llvm-svn: 187923
2013-08-07 22:47:18 +00:00