Summary:
We supported globals as sources before, but we did so by allowing ClangTrace etc. to match against any access path in the footprint of the trace.
This is very powerful/flexible, but it's ultimately not a good idea because it leads to traces that are hard to read.
This is because a footprint source doesn't have any information about its provenance: we might know that the value came from a global, but we don't know where the read occurred.
The mechanism for handling procedure calls as sources already knows how to solve this problem.
This diff implements globals as sources as a special case of procedure call sources instead.
This will give us much nicer traces with full provenance of the read from the global.
Reviewed By: mbouaziz
Differential Revision: D5772299
fbshipit-source-id: 491ae81
Summary:
We now represent the footprint with an access trie, so this code is no longer required.
This lets us simplify things a bit
Reviewed By: jberdine
Differential Revision: D5664484
fbshipit-source-id: c35edf2
Summary:
In looking at summaries that Quandary took a long time to compute, one thing I notice frequently is redundancy in the footprint sources (e.g., I might see `Footprint(x), Footprint(x.f), Footprint(x*)`).
`sudo perf top` indicates that joining big sets of sources is a major performance bottleneck, and a large number of footprint sources is surely a big part of this (since we expect the number of non-footprint sources to be small).
This diff addresses the redundancy issue by using a more complex representation for a set of sources. The "known" sources are still in a set, but the footprint sources are now represented as a set of access paths (via an access trie).
The access path trie is a minimal representation of a set of access paths, so it would represent the example above as a simple `x*`.
This should make join/widen/<= faster and improve performance
Reviewed By: jberdine
Differential Revision: D5663980
fbshipit-source-id: 9fb66f8
Summary:
It's nice to have "raw" as the default kind of access path, since it's used much more often than the abstraction.
This is also a prereq for supporting index expressions in access paths, since we'll need mutual recursion between accesses and access paths.
Reviewed By: jeremydubreil
Differential Revision: D5529807
fbshipit-source-id: cb3f521
Summary: This gives us more expressive power when defining sources--we can use heuristics like "`foo(o)` only returns a source when `o` is not a constant".
Reviewed By: jvillard
Differential Revision: D5467935
fbshipit-source-id: f3d581d
Summary:
Conversion and reformat of infer source using ocamlformat
auto-formatting tool.
Current status:
- Because Reason does not handle docstrings, the output of the
conversion is not 'Warning 50'-clean, meaning that there are
docstrings with ambiguous placement. I'll need to manually fix
them just before landing.
Reviewed By: jvillard
Differential Revision: D5225546
fbshipit-source-id: 3bd2786
Summary:
First step toward addressing bad traces that happen in examples like
```
void sourceMethod() {
Obj source = (Obj) InferTaint.inferSecretSource();
callSameSink(null, source); // index: 1
}
void callSameSink(Obj o1, Obj o2) {
callMySink1(o1); // flows via o1 ~= index 0, don't expand
callMySink2(o2); // flows via o2 ~= index 1, can expand
}
void callMySink1(Obj o) {
... // maybe interesting something happens here that doesn't happen in callMySink2
InferTaint.inferSensitiveSink(o); // flows via o ~= index 0, can expand
}
void callMySink2(Obj o) {
InferTaint.inferSensitiveSink(o); // flows via o ~= index 0, can expand
}
```
The issue is that when we recreate a trace to the sink starting from `sourceMethod`, we don't know which of the calls to `callMySink` to expand/include in the trace.
If we expand the call to `callMySink(o1)`, we'll get a bogus trace.
In this example that's not such a big deal, but imagine the case where the first call to `callMySink` is a different function that transitively calls the sink through some long and confusing path.
Remembering the index at which taint flows into each sink will let us choose which sinks are safe to expand.
This diff just adds indexes to the API; it's not actually propagating the index info or using it during expansion yet.
Reviewed By: jeremydubreil
Differential Revision: D5170563
fbshipit-source-id: ba4b096
Summary: We were almost always using `~report_reachable:true`, and in the cases where we weren't it is fine to do so. In general, a sink could read any state from its parameters, so it makes sense to complain if anything reachable from them is tainted.
Reviewed By: mbouaziz
Differential Revision: D5169067
fbshipit-source-id: ea7d659
Summary: Being forced to separately define `pp_element`/`pp_key` is uneccessary and makes it more cumbersome to create a set/map from an existing module that already defines `pp`.
Reviewed By: jeremydubreil
Differential Revision: D4517308
fbshipit-source-id: 9b17c9c
Summary:
Remove the remaining uses of polymorphic equality `=`.
In case of basic types, this is replaced by String.equal or Int.equal.
In case of `= []`, this is replaced by `List.is_empty`.
In case of `= None`, this is replaced by `is_none`.
In case of a datatype definition such as `type a = A | B`,
a `compare_a` function is defined by adding `type a = A | B [@deriving compare]`
and a `equal_a` function is defined as `let equal_a = [%compare.equal : a]`.
In case of comparison with a polymorphic variant `= `Yes`, the equality
defined in `PVariant.(=)` is used. Typically, `open! Pvariant` is added
at the beginning of the file to cover all the uses.
Reviewed By: jberdine
Differential Revision: D4456129
fbshipit-source-id: f31c433
Summary:
There's a lot of boilerplate work to be done when adding a new kind of source.
This diff tries to reduce the boilerplate by making a functor do all the work.
The functor:
(1) adds a notion of "footprint kind" to the source
(2) packages the source with a call site
Reviewed By: jvillard
Differential Revision: D4349224
fbshipit-source-id: 5e1701a
Summary:
We currently can only model the return values of functions as sources.
In order to model inputs of endpoints as sources, we need the capability to treat the formals of certain functions as sources too.
This diff adds that capability by adding a function for getting the tainted sources to the source module, then using that info in the analysis.
Reviewed By: jeremydubreil
Differential Revision: D4314738
fbshipit-source-id: dd7d423
Summary:
Utils contains definitions intended to be in the global namespace for
all of the infer code-base, as well as pretty-printing functions, and
assorted utility functions mostly for dealing with files and processes.
This diff changes the module opened into the global namespace to
IStd (Std conflict with extlib), and moves the pretty-printing
definitions from Utils to Pp.
Reviewed By: jvillard
Differential Revision: D4232457
fbshipit-source-id: 1e070e0
Summary:
There's not really a concept of callee here, so s/callee/callsite/, and "to"
suggests we get the callee whereas we update it, so s/to/with/.
Feel free to bikeshed further.
Reviewed By: sblackshear
Differential Revision: D4153426
fbshipit-source-id: 6ea762c
Summary: A must-have for reporting taint errors and any other interprocedural error where the trace is sufficiently complex.
Reviewed By: jvillard
Differential Revision: D4124072
fbshipit-source-id: 26b3b2b
Summary: A must-have for reporting taint errors and any other interprocedural error where the trace is sufficiently complex.
Reviewed By: jvillard
Differential Revision: D4106352
fbshipit-source-id: b2677e6
Summary:
Previously, we recorded direct sinks as sinks and transitive sinks as passthroughs. This makes it difficult to create an expanded interprocedural trace when recording an error because we can't distinguish between sinks (which we want to expand) and passthroughs (which we don't). This diff changes recording of sinks so that a sink is now the *last* function in a trace to call a sink. To find out what the original sink was, the summary for the transitive sink in the trace will now need to be (recursively) expanded until we bottom out in the original sink.
Will do the same for sources in a follow-up diff.
Reviewed By: cristianoc
Differential Revision: D4103759
fbshipit-source-id: 6f435f5
Sam Blackshear
Josh Berdine
Andrzej Kotulski
Cristiano Calcagno
Jules Villard