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| author | Rodrigo Kumpera <kumpera@gmail.com> | 2017-09-12 01:53:14 +0300 |
|---|---|---|
| committer | Rodrigo Kumpera <kumpera@gmail.com> | 2017-09-12 01:53:14 +0300 |
| commit | 8493513ad3876e73163f64ecab0299bd5e6e0346 (patch) | |
| tree | 8d7ac0264c50e69678a3830bdbf0903c14445c40 /tools | |
| parent | 4a20e930afc89aba911f43fb14cce2feeeab65cc (diff) | |
[verifier] Implement verification of byref returns.
The verification algorithm is inspired on internal specs by the Roslyn team but adapted to what it generates today.
Here's how this patch works:
We introduce a new verification type, SAFE_BYREF, that's used for a byref value that is safe to return from the stack.
It's unverifiable to return a byref value that is not marked SAFE_BYREF.
We mark the following values are SAFE_BYREF:
- byref arguments, unless it's the `this` arg of a valuetype instance method
- return values of method calls when all byref arguments have SAFE_BYREF values - the this arg is ignored.
- the address of a static field (LDSFLDA)
- the address of an array element (LDELEMA)
- the address of a field if the receiver is either a SAFE_BYREF value or a reference
Notoriously from the above is the value of local variables. We took a conservative approach of unsafe tainting.
We do this by associating 3 states to a local: unassigned (initial value of zero), assigned and safe (SAFE_BYREF_LOCAL), assigned and unsafe (UNSAFE_BYREF_LOCAL)
When loading a local, we set its value as SAFE_BYREF if the local is in the SAFE_BYREF_LOCAL state.
When storing to a local, we set it to SAFE_BYREF_LOCAL if, only if, it's not marked as UNSAFE_BYREF_LOCAL and the value is SAFE_BYREF.
If we store a non-safe value to a local, we mark it as UNSAFE_BYREF_LOCAL.
If we store a non-safe value to a SAFE_BYREF_LOCAL local, we mark the method as unverifiable.
This algorithm makes sure we don't mix safe and unsafe byref and side with safety in case of control-flow dependent values.
Diffstat (limited to 'tools')
| -rw-r--r-- | tools/pedump/Makefile.am | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/tools/pedump/Makefile.am b/tools/pedump/Makefile.am index 7a2776c8514..788704a9cb9 100644 --- a/tools/pedump/Makefile.am +++ b/tools/pedump/Makefile.am @@ -28,3 +28,8 @@ pedump_LDADD = \ if HOST_DARWIN pedump_LDFLAGS=-framework CoreFoundation -framework Foundation endif + +#Helper target to rebuild metadata as well, it's useful when working on the verifier as its source still on metadata +md: + make -C ../../mono/metadata all + make -C . all
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