[Soot-list] Problem Instrumenting Kotlin data class

[Marc Miltenberger]

Hello Dr. Gambi,

I see one issue in this line:
$r0 := @caughtexception

This does not seem right since $r0 is of type
com.orgzly.android.util.Encoding. This should actually be some sort of
throwable.

Best regards,
Marc Miltenberger



Am Mo., 22. März 2021 um 18:24 Uhr schrieb Alessio Gambi <
alessio.gambi at uni-passau.de>:

> Dear All,
>
> I am facing a weird problem while instrumenting a Kotlin data class using
> soot [1].
>
> The problem is that after instrumenting the class, the byte code verifier
> rejects the class.
>
> The method causing this seems to be “copy” that contains those units:
>
> r0 := @this: com.orgzly.android.util.Encoding
> $r1 := @parameter0: java.lang.String
> $r2 := @parameter1: java.lang.String
> $r3 := @parameter2: java.lang.String
> staticinvoke <kotlin.jvm.internal.Intrinsics: void
> checkNotNullParameter(java.lang.Object,java.lang.String)>($r1, "used")
> r0 = new com.orgzly.android.util.Encoding
> specialinvoke r0.<com.orgzly.android.util.Encoding: void
> <init>(java.lang.String,java.lang.String,java.lang.String)>($r1, $r2, $r3)
> return r0
>
> The same method after the instrumentation looks like the one reported
> below (I simplified it), where the units marked with ** are the code
> injected via soot.
>
> The instrumentations
> - encapsulates all the parameters of method calls into generic arrays of
> objects
> - invokes a Monitor class to track method invocations (before/after) and
> captures return values
> - wraps the method with a generic try-catch-all where the catch block logs
> the captured exception before rethrowing it
>
> Now the weirdness (IMHO) is that r0 is assigned first to @this and then to
> something different (r0 = new com.orgzly.android.util.Encoding).
> This is part of the original code (see above), but I am afraid it might
> break the instrumented code because we pass r0 as parameter to other
> invocations in the catch block,
> under the assumption it points to “this”, while in reality it points to
> another instance of the same type.
> Consequently, the bytecode verifier reports the first call using it  in
> the catch block (staticinvoke <Monitor: void onAppMethodCaptureException)
>  as invalid (with type conflict)
>
> Maybe someone has experiences something similar and/or can suggest a work
> around? Assuming this is indeed the problem, the only option I see at the
> moment
>  is to assign the return of  r0 = new com.orgzly.android.util.Encoding to
> a fresh local variable (rX)
>
> Any help is appreciated !
>
> Best
>
> — Dr. Alessio Gambi
> Chair for SE 2
> University of Passau
>
>
> —————
> [1]
> https://github.com/orgzly/orgzly-android/blob/master/app/src/main/java/com/orgzly/android/util/Encoding.kt
>
> INSTRUMENTED CODE:
>                  r0 := @this: com.orgzly.android.util.Encoding
>                  $r1 := @parameter0: java.lang.String
>                  $r2 := @parameter1: java.lang.String
>                  $r3 := @parameter2: java.lang.String
> **               $r5 = newarray (java.lang.Object)[3]
> **               $r5[0] = $r1
> **               $r5[1] = $r2
> **               $r5[2] = $r3
> **               staticinvoke <Monitor: void
> onAppMethodCall(java.lang.String,java.lang.Object,java.lang.String,java.lang.Object[])>("com.orgzly",
> r0, "<com.orgzly.android.util.Encoding: com.orgzly.android.util.Encoding
> copy(java.lang.String,java.lang.String,java.lang.String)>", $r5)
> **               $r6 = newarray (java.lang.Object)[2]
> **               $r6[0] = $r1
> **               $r6[1] = "used"
> **               staticinvoke <Monitor: void
> onLibMethodCall(java.lang.Object,java.lang.String,java.lang.String,java.lang.Object[])>(null,
> "<kotlin.jvm.internal.Intrinsics: void
> checkNotNullParameter(java.lang.Object,java.lang.String)>",
> "<com.orgzly.android.util.Encoding: com.orgzly.android.util.Encoding
> copy(java.lang.String,java.lang.String,java.lang.String)>", $r6)
>                  staticinvoke <kotlin.jvm.internal.Intrinsics: void
> checkNotNullParameter(java.lang.Object,java.lang.String)>($r1, "used")
> **               staticinvoke <Monitor: void
> onLibMethodReturnNormally(java.lang.Object,java.lang.String,java.lang.String,java.lang.Object)>(null,
> "<kotlin.jvm.internal.Intrinsics: void
> checkNotNullParameter(java.lang.Object,java.lang.String)>",
> "<com.orgzly.android.util.Encoding: com.orgzly.android.util.Encoding
> copy(java.lang.String,java.lang.String,java.lang.String)>", null)
>
>                  r0 = new com.orgzly.android.util.Encoding
>                  specialinvoke r0.<com.orgzly.android.util.Encoding: void
> <init>(java.lang.String,java.lang.String,java.lang.String)>($r1, $r2, $r3)
> **               staticinvoke <Monitor: void
> onAppMethodReturnNormally(java.lang.Object,java.lang.String,java.lang.String,java.lang.Object)>(r0,
> "<com.orgzly.android.util.Encoding: com.orgzly.android.util.Encoding
> copy(java.lang.String,java.lang.String,java.lang.String)>",
> "<com.orgzly.android.util.Encoding: com.orgzly.android.util.Encoding
> copy(java.lang.String,java.lang.String,java.lang.String)>", r0)
>                  return r0
>
> **               $r0 := @caughtexception
> **               $r7 = $r0
> **               staticinvoke <Monitor: void
> onAppMethodCaptureException(java.lang.Object,java.lang.String,java.lang.String,java.lang.Object)>(r0,
> "<com.orgzly.android.util.Encoding: com.orgzly.android.util.Encoding
> copy(java.lang.String,java.lang.String,java.lang.String)>",
> "<com.orgzly.android.util.Encoding: com.orgzly.android.util.Encoding
> copy(java.lang.String,java.lang.String,java.lang.String)>", $r0)
> **               $r4 = $r0
> **               staticinvoke <Monitor: void
> onAppMethodThrowException(java.lang.Object,java.lang.String,java.lang.String,java.lang.Object)>(r0,
> "<com.orgzly.android.util.Encoding: com.orgzly.android.util.Encoding
> copy(java.lang.String,java.lang.String,java.lang.String)>",
> "<com.orgzly.android.util.Encoding: com.orgzly.android.util.Encoding
> copy(java.lang.String,java.lang.String,java.lang.String)>", $r4)
> **               staticinvoke <Monitor: void
> onAppMethodReturnExceptionally(java.lang.Object,java.lang.String,java.lang.String,java.lang.Object)>(r0,
> "<com.orgzly.android.util.Encoding: com.orgzly.android.util.Encoding
> copy(java.lang.String,java.lang.String,java.lang.String)>",
> "<com.orgzly.android.util.Encoding: com.orgzly.android.util.Encoding
> copy(java.lang.String,java.lang.String,java.lang.String)>", $r4)
> **               throw $r4
>
>
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