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Documentation and Refactors for Concolic (#243)

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* document symcc_runtime

* rename serialization format expressions to be more concise

* authorship notes

* document dump_constraints

* document smoke test

* tests for serialization format and refactoring

* remove unused bswap message

* remove obselete SymExpr::End

* document and refactor serialization format

* fmt

* more missing docs

* typos

* clippy
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julihoh 2021-08-05 15:01:14 +02:00 committed by GitHub
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16 changed files with 945 additions and 698 deletions
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1
fuzzers/libfuzzer_stb_image_concolic/runtime/Cargo.toml
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@ -2,6 +2,7 @@
name = "example_runtime" name = "example_runtime"
version = "0.1.0" version = "0.1.0"
edition = "2018" edition = "2018"
authors = ["Julius Hohnerlein <julihoh@users.noreply.github.com>"]
[lib] [lib]
# the runtime needs to be a shared object -> cdylib # the runtime needs to be a shared object -> cdylib

2
libafl/src/executors/command.rs
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@ -51,7 +51,7 @@ where
// if this fails, there is not much we can do. let's hope it failed because the process finished // if this fails, there is not much we can do. let's hope it failed because the process finished
// in the meantime. // in the meantime.
drop(child.kill()); drop(child.kill());
// finally, try to wait to properly clean up system ressources. // finally, try to wait to properly clean up system resources.
drop(child.wait()); drop(child.wait());
Ok(ExitKind::Timeout) Ok(ExitKind::Timeout)
} }

166
libafl/src/observers/concolic/mod.rs
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@ -1,300 +1,300 @@
//! # Concolic Tracing
use core::num::NonZeroUsize; use core::num::NonZeroUsize;
#[cfg(feature = "std")] #[cfg(feature = "std")]
use serde::{Deserialize, Serialize}; use serde::{Deserialize, Serialize};
/// A `SymExprRef` identifies a [`SymExpr`] in a trace. Reading a `SymExpr` from a trace will always also yield its
/// `SymExprRef`, which can be used later in the trace to identify the `SymExpr`.
/// It is also never zero, which allows for efficient use of `Option<SymExprRef>`.
///
/// In a trace, `SymExprRef`s are monotonically increasing and start at 1.
/// `SymExprRef`s are not valid across traces.
pub type SymExprRef = NonZeroUsize; pub type SymExprRef = NonZeroUsize;
/// `SymExpr` represents a message in the serialization format.
/// The messages in the format are a perfect mirror of the methods that are called on the runtime during execution.
#[cfg(feature = "std")] #[cfg(feature = "std")]
#[derive(Serialize, Deserialize, Debug)] #[derive(Serialize, Deserialize, Debug, PartialEq)]
pub enum SymExpr { pub enum SymExpr {
GetInputByte { InputByte {
offset: usize, offset: usize,
}, },
BuildInteger { Integer {
value: u64, value: u64,
bits: u8, bits: u8,
}, },
BuildInteger128 { Integer128 {
high: u64, high: u64,
low: u64, low: u64,
}, },
BuildFloat { Float {
value: f64, value: f64,
is_double: bool, is_double: bool,
}, },
BuildNullPointer, NullPointer,
BuildTrue, True,
BuildFalse, False,
BuildBool { Bool {
value: bool, value: bool,
}, },
BuildNeg { Neg {
op: SymExprRef, op: SymExprRef,
}, },
BuildAdd { Add {
a: SymExprRef, a: SymExprRef,
b: SymExprRef, b: SymExprRef,
}, },
BuildSub { Sub {
a: SymExprRef, a: SymExprRef,
b: SymExprRef, b: SymExprRef,
}, },
BuildMul { Mul {
a: SymExprRef, a: SymExprRef,
b: SymExprRef, b: SymExprRef,
}, },
BuildUnsignedDiv { UnsignedDiv {
a: SymExprRef, a: SymExprRef,
b: SymExprRef, b: SymExprRef,
}, },
BuildSignedDiv { SignedDiv {
a: SymExprRef, a: SymExprRef,
b: SymExprRef, b: SymExprRef,
}, },
BuildUnsignedRem { UnsignedRem {
a: SymExprRef, a: SymExprRef,
b: SymExprRef, b: SymExprRef,
}, },
BuildSignedRem { SignedRem {
a: SymExprRef, a: SymExprRef,
b: SymExprRef, b: SymExprRef,
}, },
BuildShiftLeft { ShiftLeft {
a: SymExprRef, a: SymExprRef,
b: SymExprRef, b: SymExprRef,
}, },
BuildLogicalShiftRight { LogicalShiftRight {
a: SymExprRef, a: SymExprRef,
b: SymExprRef, b: SymExprRef,
}, },
BuildArithmeticShiftRight { ArithmeticShiftRight {
a: SymExprRef, a: SymExprRef,
b: SymExprRef, b: SymExprRef,
}, },
BuildSignedLessThan { SignedLessThan {
a: SymExprRef, a: SymExprRef,
b: SymExprRef, b: SymExprRef,
}, },
BuildSignedLessEqual { SignedLessEqual {
a: SymExprRef, a: SymExprRef,
b: SymExprRef, b: SymExprRef,
}, },
BuildSignedGreaterThan { SignedGreaterThan {
a: SymExprRef, a: SymExprRef,
b: SymExprRef, b: SymExprRef,
}, },
BuildSignedGreaterEqual { SignedGreaterEqual {
a: SymExprRef, a: SymExprRef,
b: SymExprRef, b: SymExprRef,
}, },
BuildUnsignedLessThan { UnsignedLessThan {
a: SymExprRef, a: SymExprRef,
b: SymExprRef, b: SymExprRef,
}, },
BuildUnsignedLessEqual { UnsignedLessEqual {
a: SymExprRef, a: SymExprRef,
b: SymExprRef, b: SymExprRef,
}, },
BuildUnsignedGreaterThan { UnsignedGreaterThan {
a: SymExprRef, a: SymExprRef,
b: SymExprRef, b: SymExprRef,
}, },
BuildUnsignedGreaterEqual { UnsignedGreaterEqual {
a: SymExprRef, a: SymExprRef,
b: SymExprRef, b: SymExprRef,
}, },
BuildNot { Not {
op: SymExprRef, op: SymExprRef,
}, },
BuildEqual { Equal {
a: SymExprRef, a: SymExprRef,
b: SymExprRef, b: SymExprRef,
}, },
BuildNotEqual { NotEqual {
a: SymExprRef, a: SymExprRef,
b: SymExprRef, b: SymExprRef,
}, },
BuildBoolAnd { BoolAnd {
a: SymExprRef, a: SymExprRef,
b: SymExprRef, b: SymExprRef,
}, },
BuildBoolOr { BoolOr {
a: SymExprRef, a: SymExprRef,
b: SymExprRef, b: SymExprRef,
}, },
BuildBoolXor { BoolXor {
a: SymExprRef, a: SymExprRef,
b: SymExprRef, b: SymExprRef,
}, },
BuildAnd { And {
a: SymExprRef, a: SymExprRef,
b: SymExprRef, b: SymExprRef,
}, },
BuildOr { Or {
a: SymExprRef, a: SymExprRef,
b: SymExprRef, b: SymExprRef,
}, },
BuildXor { Xor {
a: SymExprRef, a: SymExprRef,
b: SymExprRef, b: SymExprRef,
}, },
BuildFloatOrdered { FloatOrdered {
a: SymExprRef, a: SymExprRef,
b: SymExprRef, b: SymExprRef,
}, },
BuildFloatOrderedGreaterThan { FloatOrderedGreaterThan {
a: SymExprRef, a: SymExprRef,
b: SymExprRef, b: SymExprRef,
}, },
BuildFloatOrderedGreaterEqual { FloatOrderedGreaterEqual {
a: SymExprRef, a: SymExprRef,
b: SymExprRef, b: SymExprRef,
}, },
BuildFloatOrderedLessThan { FloatOrderedLessThan {
a: SymExprRef, a: SymExprRef,
b: SymExprRef, b: SymExprRef,
}, },
BuildFloatOrderedLessEqual { FloatOrderedLessEqual {
a: SymExprRef, a: SymExprRef,
b: SymExprRef, b: SymExprRef,
}, },
BuildFloatOrderedEqual { FloatOrderedEqual {
a: SymExprRef, a: SymExprRef,
b: SymExprRef, b: SymExprRef,
}, },
BuildFloatOrderedNotEqual { FloatOrderedNotEqual {
a: SymExprRef, a: SymExprRef,
b: SymExprRef, b: SymExprRef,
}, },
BuildFloatUnordered { FloatUnordered {
a: SymExprRef, a: SymExprRef,
b: SymExprRef, b: SymExprRef,
}, },
BuildFloatUnorderedGreaterThan { FloatUnorderedGreaterThan {
a: SymExprRef, a: SymExprRef,
b: SymExprRef, b: SymExprRef,
}, },
BuildFloatUnorderedGreaterEqual { FloatUnorderedGreaterEqual {
a: SymExprRef, a: SymExprRef,
b: SymExprRef, b: SymExprRef,
}, },
BuildFloatUnorderedLessThan { FloatUnorderedLessThan {
a: SymExprRef, a: SymExprRef,
b: SymExprRef, b: SymExprRef,
}, },
BuildFloatUnorderedLessEqual { FloatUnorderedLessEqual {
a: SymExprRef, a: SymExprRef,
b: SymExprRef, b: SymExprRef,
}, },
BuildFloatUnorderedEqual { FloatUnorderedEqual {
a: SymExprRef, a: SymExprRef,
b: SymExprRef, b: SymExprRef,
}, },
BuildFloatUnorderedNotEqual { FloatUnorderedNotEqual {
a: SymExprRef, a: SymExprRef,
b: SymExprRef, b: SymExprRef,
}, },
BuildFloatAbs { FloatAbs {
op: SymExprRef, op: SymExprRef,
}, },
BuildFloatAdd { FloatAdd {
a: SymExprRef, a: SymExprRef,
b: SymExprRef, b: SymExprRef,
}, },
BuildFloatSub { FloatSub {
a: SymExprRef, a: SymExprRef,
b: SymExprRef, b: SymExprRef,
}, },
BuildFloatMul { FloatMul {
a: SymExprRef, a: SymExprRef,
b: SymExprRef, b: SymExprRef,
}, },
BuildFloatDiv { FloatDiv {
a: SymExprRef, a: SymExprRef,
b: SymExprRef, b: SymExprRef,
}, },
BuildFloatRem { FloatRem {
a: SymExprRef, a: SymExprRef,
b: SymExprRef, b: SymExprRef,
}, },
BuildSext { Sext {
op: SymExprRef, op: SymExprRef,
bits: u8, bits: u8,
}, },
BuildZext { Zext {
op: SymExprRef, op: SymExprRef,
bits: u8, bits: u8,
}, },
BuildTrunc { Trunc {
op: SymExprRef, op: SymExprRef,
bits: u8, bits: u8,
}, },
BuildIntToFloat { IntToFloat {
op: SymExprRef, op: SymExprRef,
is_double: bool, is_double: bool,
is_signed: bool, is_signed: bool,
}, },
BuildFloatToFloat { FloatToFloat {
op: SymExprRef, op: SymExprRef,
to_double: bool, to_double: bool,
}, },
BuildBitsToFloat { BitsToFloat {
op: SymExprRef, op: SymExprRef,
to_double: bool, to_double: bool,
}, },
BuildFloatToBits { FloatToBits {
op: SymExprRef, op: SymExprRef,
}, },
BuildFloatToSignedInteger { FloatToSignedInteger {
op: SymExprRef, op: SymExprRef,
bits: u8, bits: u8,
}, },
BuildFloatToUnsignedInteger { FloatToUnsignedInteger {
op: SymExprRef, op: SymExprRef,
bits: u8, bits: u8,
}, },
BuildBoolToBits { BoolToBits {
op: SymExprRef, op: SymExprRef,
bits: u8, bits: u8,
}, },
ConcatHelper { Concat {
a: SymExprRef, a: SymExprRef,
b: SymExprRef, b: SymExprRef,
}, },
ExtractHelper { Extract {
op: SymExprRef, op: SymExprRef,
first_bit: usize, first_bit: usize,
last_bit: usize, last_bit: usize,
}, },
BuildExtract { Insert {
op: SymExprRef,
offset: u64,
length: u64,
little_endian: bool,
},
BuildBswap {
op: SymExprRef,
},
BuildInsert {
target: SymExprRef, target: SymExprRef,
to_insert: SymExprRef, to_insert: SymExprRef,
offset: u64, offset: u64,
little_endian: bool, little_endian: bool,
}, },
PushPathConstraint { PathConstraint {
constraint: SymExprRef, constraint: SymExprRef,
taken: bool, taken: bool,
site_id: usize, site_id: usize,
@ -304,8 +304,6 @@ pub enum SymExpr {
ExpressionsUnreachable { ExpressionsUnreachable {
exprs: Vec<SymExprRef>, exprs: Vec<SymExprRef>,
}, },
/// This marks the end of the trace.
End,
} }
#[cfg(feature = "std")] #[cfg(feature = "std")]
@ -317,10 +315,10 @@ pub const HITMAP_ENV_NAME: &str = "LIBAFL_CONCOLIC_HITMAP";
/// The name of the environment variable that contains the byte offsets to be symbolized. /// The name of the environment variable that contains the byte offsets to be symbolized.
pub const SELECTIVE_SYMBOLICATION_ENV_NAME: &str = "LIBAFL_SELECTIVE_SYMBOLICATION"; pub const SELECTIVE_SYMBOLICATION_ENV_NAME: &str = "LIBAFL_SELECTIVE_SYMBOLICATION";
/// The name of the environment variable that contains the byte offsets to be symbolized. /// The name of the environment variable that signals the runtime to concretize floating point operations.
pub const NO_FLOAT_ENV_NAME: &str = "LIBAFL_CONCOLIC_NO_FLOAT"; pub const NO_FLOAT_ENV_NAME: &str = "LIBAFL_CONCOLIC_NO_FLOAT";
/// The name of the environment variable that contains the byte offsets to be symbolized. /// The name of the environment variable that signals the runtime to perform expression pruning.
pub const EXPRESSION_PRUNING: &str = "LIBAFL_CONCOLIC_EXPRESSION_PRUNING"; pub const EXPRESSION_PRUNING: &str = "LIBAFL_CONCOLIC_EXPRESSION_PRUNING";
#[cfg(feature = "std")] #[cfg(feature = "std")]

541
libafl/src/observers/concolic/serialization_format.rs
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@ -1,17 +1,64 @@
//! # Concolic Tracing Serialization Format
//! ## Design Goals
//! * The serialization format for concolic tracing was developed with the goal of being space and time efficient.
//! * Additionally, it should be easy to maintain and extend.
//! * It does not have to be compatible with other programming languages.
//! * It should be resilient to crashes. Since we are fuzzing, we are expecting the traced program to crash at some
//! point.
//!
//! The format as implemented fulfils these design goals.
//! Specifically:
//! * it requires only constant memory space for serialization, which allows for tracing complex and/or
//! long-running programs.
//! * the trace itself requires little space. A typical binary operation (such as an add) typically takes just 3 bytes.
//! * it easy to encode. There is no translation between the interface of the runtime itself and the trace it generates.
//! * it is similarly easy to decode and can be easily translated into an in-memory AST without overhead, because
//! expressions are decoded from leaf to root instead of root to leaf.
//! * At its core, it is just [`SymExpr`]s, which can be added to, modified and removed from with ease. The
//! definitions are automatically shared between the runtime and the consuming program, since both depend on the same
//! `LibAFL`.
//!
//! ## Techniques
//! The serialization format applies multiple techniques to achieve its goals.
//! * It uses bincode for efficient binary serialization. Crucially, bincode uses variable length integer encoding,
//! allowing it encode small integers use fewer bytes.
//! * References to previous expressions are stored relative to the current expressions id. The vast majority of
//! expressions refer to other expressions that were defined close to their use. Therefore, encoding relative references
//! keeps references small. Therefore, they make optimal use of bincodes variable length integer encoding.
//! * Ids of expressions ([`SymExprRef`]s) are implicitly derived by their position in the message stream. Effectively,
//! a counter is used to identify expressions.
//! * The current length of the trace in bytes in serialized in a fixed format at the beginning of the trace.
//! This length is updated regularly when the trace is in a consistent state. This allows the reader to avoid reading
//! malformed data if the traced process crashed.
//!
//! ## Example
//! The expression `SymExpr::BoolAnd { a: SymExpr::True, b: SymExpr::False }` would be encoded as:
//! 1. 1 byte to identify `SymExpr::True` (a)
//! 2. 1 byte to identify `SymExpr::False` (b)
//! 3. 1 byte to identify `SymExpr::BoolAnd`
//! 4. 1 byte to reference a
//! 5. 1 byte to reference b
//!
//! ... making for a total of 5 bytes.
#![cfg(feature = "std")] #![cfg(feature = "std")]
use std::io::{self, Read, Seek, SeekFrom, Write}; use std::{
convert::TryFrom,
io::{self, Cursor, Read, Seek, SeekFrom, Write},
};
use bincode::{DefaultOptions, Options}; use bincode::{DefaultOptions, Options};
use super::{SymExpr, SymExprRef}; use super::{SymExpr, SymExprRef};
pub use bincode::ErrorKind; pub use bincode::{ErrorKind, Result};
pub use bincode::Result;
fn serialization_options() -> DefaultOptions { fn serialization_options() -> DefaultOptions {
DefaultOptions::new() DefaultOptions::new()
} }
/// A `MessageFileReader` reads a stream of [`SymExpr`] and their corresponding [`SymExprRef`]s from any [`Read`].
pub struct MessageFileReader<R: Read> { pub struct MessageFileReader<R: Read> {
reader: R, reader: R,
deserializer_config: bincode::DefaultOptions, deserializer_config: bincode::DefaultOptions,
@ -19,6 +66,7 @@ pub struct MessageFileReader<R: Read> {
} }
impl<R: Read> MessageFileReader<R> { impl<R: Read> MessageFileReader<R> {
/// Construct from the given reader.
pub fn from_reader(reader: R) -> Self { pub fn from_reader(reader: R) -> Self {
Self { Self {
reader, reader,
@ -27,15 +75,17 @@ impl<R: Read> MessageFileReader<R> {
} }
} }
/// Parse the next message out of the stream.
/// [`Option::None`] is returned once the stream is depleted.
/// IO and serialization errors are passed to the caller using [`bincode::Result`].
/// Finally, the returned tuple contains the message itself as a [`SymExpr`] and the [`SymExprRef`] associated
/// with this message.
/// The `SymExprRef` may be used by following messages to refer back to this message.
pub fn next_message(&mut self) -> Option<bincode::Result<(SymExprRef, SymExpr)>> { pub fn next_message(&mut self) -> Option<bincode::Result<(SymExprRef, SymExpr)>> {
match self.deserializer_config.deserialize_from(&mut self.reader) { match self.deserializer_config.deserialize_from(&mut self.reader) {
Ok(mut message) => { Ok(mut message) => {
if let SymExpr::End = message { let message_id = self.transform_message(&mut message);
None Some(Ok((message_id, message)))
} else {
let message_id = self.transform_message(&mut message);
Some(Ok((message_id, message)))
}
} }
Err(e) => match *e { Err(e) => match *e {
bincode::ErrorKind::Io(ref io_err) => match io_err.kind() { bincode::ErrorKind::Io(ref io_err) => match io_err.kind() {
@ -47,89 +97,91 @@ impl<R: Read> MessageFileReader<R> {
} }
} }
/// Makes the given `SymExprRef` absolute accoring to the `current_id` counter.
/// See [`MessageFileWriter::make_relative`] for the inverse function.
fn make_absolute(&self, expr: SymExprRef) -> SymExprRef { fn make_absolute(&self, expr: SymExprRef) -> SymExprRef {
SymExprRef::new(self.current_id - expr.get()).unwrap() SymExprRef::new(self.current_id - expr.get()).unwrap()
} }
/// This transforms the given message from it's serialized form into its in-memory form, making relative references
/// absolute and counting the `SymExprRef`s.
fn transform_message(&mut self, message: &mut SymExpr) -> SymExprRef { fn transform_message(&mut self, message: &mut SymExpr) -> SymExprRef {
let ret = self.current_id; let ret = self.current_id;
match message { match message {
SymExpr::GetInputByte { .. } SymExpr::InputByte { .. }
| SymExpr::BuildInteger { .. } | SymExpr::Integer { .. }
| SymExpr::BuildInteger128 { .. } | SymExpr::Integer128 { .. }
| SymExpr::BuildFloat { .. } | SymExpr::Float { .. }
| SymExpr::BuildNullPointer | SymExpr::NullPointer
| SymExpr::BuildTrue | SymExpr::True
| SymExpr::BuildFalse | SymExpr::False
| SymExpr::BuildBool { .. } => { | SymExpr::Bool { .. } => {
self.current_id += 1; self.current_id += 1;
} }
SymExpr::BuildNeg { op } SymExpr::Neg { op }
| SymExpr::BuildFloatAbs { op } | SymExpr::FloatAbs { op }
| SymExpr::BuildNot { op } | SymExpr::Not { op }
| SymExpr::BuildSext { op, .. } | SymExpr::Sext { op, .. }
| SymExpr::BuildZext { op, .. } | SymExpr::Zext { op, .. }
| SymExpr::BuildTrunc { op, .. } | SymExpr::Trunc { op, .. }
| SymExpr::BuildIntToFloat { op, .. } | SymExpr::IntToFloat { op, .. }
| SymExpr::BuildFloatToFloat { op, .. } | SymExpr::FloatToFloat { op, .. }
| SymExpr::BuildBitsToFloat { op, .. } | SymExpr::BitsToFloat { op, .. }
| SymExpr::BuildFloatToBits { op } | SymExpr::FloatToBits { op }
| SymExpr::BuildFloatToSignedInteger { op, .. } | SymExpr::FloatToSignedInteger { op, .. }
| SymExpr::BuildFloatToUnsignedInteger { op, .. } | SymExpr::FloatToUnsignedInteger { op, .. }
| SymExpr::BuildBoolToBits { op, .. } | SymExpr::BoolToBits { op, .. }
| SymExpr::ExtractHelper { op, .. } | SymExpr::Extract { op, .. } => {
| SymExpr::BuildExtract { op, .. }
| SymExpr::BuildBswap { op } => {
*op = self.make_absolute(*op); *op = self.make_absolute(*op);
self.current_id += 1; self.current_id += 1;
} }
SymExpr::BuildAdd { a, b } SymExpr::Add { a, b }
| SymExpr::BuildSub { a, b } | SymExpr::Sub { a, b }
| SymExpr::BuildMul { a, b } | SymExpr::Mul { a, b }
| SymExpr::BuildUnsignedDiv { a, b } | SymExpr::UnsignedDiv { a, b }
| SymExpr::BuildSignedDiv { a, b } | SymExpr::SignedDiv { a, b }
| SymExpr::BuildUnsignedRem { a, b } | SymExpr::UnsignedRem { a, b }
| SymExpr::BuildSignedRem { a, b } | SymExpr::SignedRem { a, b }
| SymExpr::BuildShiftLeft { a, b } | SymExpr::ShiftLeft { a, b }
| SymExpr::BuildLogicalShiftRight { a, b } | SymExpr::LogicalShiftRight { a, b }
| SymExpr::BuildArithmeticShiftRight { a, b } | SymExpr::ArithmeticShiftRight { a, b }
| SymExpr::BuildSignedLessThan { a, b } | SymExpr::SignedLessThan { a, b }
| SymExpr::BuildSignedLessEqual { a, b } | SymExpr::SignedLessEqual { a, b }
| SymExpr::BuildSignedGreaterThan { a, b } | SymExpr::SignedGreaterThan { a, b }
| SymExpr::BuildSignedGreaterEqual { a, b } | SymExpr::SignedGreaterEqual { a, b }
| SymExpr::BuildUnsignedLessThan { a, b } | SymExpr::UnsignedLessThan { a, b }
| SymExpr::BuildUnsignedLessEqual { a, b } | SymExpr::UnsignedLessEqual { a, b }
| SymExpr::BuildUnsignedGreaterThan { a, b } | SymExpr::UnsignedGreaterThan { a, b }
| SymExpr::BuildUnsignedGreaterEqual { a, b } | SymExpr::UnsignedGreaterEqual { a, b }
| SymExpr::BuildEqual { a, b } | SymExpr::Equal { a, b }
| SymExpr::BuildNotEqual { a, b } | SymExpr::NotEqual { a, b }
| SymExpr::BuildBoolAnd { a, b } | SymExpr::BoolAnd { a, b }
| SymExpr::BuildBoolOr { a, b } | SymExpr::BoolOr { a, b }
| SymExpr::BuildBoolXor { a, b } | SymExpr::BoolXor { a, b }
| SymExpr::BuildAnd { a, b } | SymExpr::And { a, b }
| SymExpr::BuildOr { a, b } | SymExpr::Or { a, b }
| SymExpr::BuildXor { a, b } | SymExpr::Xor { a, b }
| SymExpr::BuildFloatOrdered { a, b } | SymExpr::FloatOrdered { a, b }
| SymExpr::BuildFloatOrderedGreaterThan { a, b } | SymExpr::FloatOrderedGreaterThan { a, b }
| SymExpr::BuildFloatOrderedGreaterEqual { a, b } | SymExpr::FloatOrderedGreaterEqual { a, b }
| SymExpr::BuildFloatOrderedLessThan { a, b } | SymExpr::FloatOrderedLessThan { a, b }
| SymExpr::BuildFloatOrderedLessEqual { a, b } | SymExpr::FloatOrderedLessEqual { a, b }
| SymExpr::BuildFloatOrderedEqual { a, b } | SymExpr::FloatOrderedEqual { a, b }
| SymExpr::BuildFloatOrderedNotEqual { a, b } | SymExpr::FloatOrderedNotEqual { a, b }
| SymExpr::BuildFloatUnordered { a, b } | SymExpr::FloatUnordered { a, b }
| SymExpr::BuildFloatUnorderedGreaterThan { a, b } | SymExpr::FloatUnorderedGreaterThan { a, b }
| SymExpr::BuildFloatUnorderedGreaterEqual { a, b } | SymExpr::FloatUnorderedGreaterEqual { a, b }
| SymExpr::BuildFloatUnorderedLessThan { a, b } | SymExpr::FloatUnorderedLessThan { a, b }
| SymExpr::BuildFloatUnorderedLessEqual { a, b } | SymExpr::FloatUnorderedLessEqual { a, b }
| SymExpr::BuildFloatUnorderedEqual { a, b } | SymExpr::FloatUnorderedEqual { a, b }
| SymExpr::BuildFloatUnorderedNotEqual { a, b } | SymExpr::FloatUnorderedNotEqual { a, b }
| SymExpr::BuildFloatAdd { a, b } | SymExpr::FloatAdd { a, b }
| SymExpr::BuildFloatSub { a, b } | SymExpr::FloatSub { a, b }
| SymExpr::BuildFloatMul { a, b } | SymExpr::FloatMul { a, b }
| SymExpr::BuildFloatDiv { a, b } | SymExpr::FloatDiv { a, b }
| SymExpr::BuildFloatRem { a, b } | SymExpr::FloatRem { a, b }
| SymExpr::ConcatHelper { a, b } | SymExpr::Concat { a, b }
| SymExpr::BuildInsert { | SymExpr::Insert {
target: a, target: a,
to_insert: b, to_insert: b,
.. ..
@ -138,7 +190,7 @@ impl<R: Read> MessageFileReader<R> {
*b = self.make_absolute(*b); *b = self.make_absolute(*b);
self.current_id += 1; self.current_id += 1;
} }
SymExpr::PushPathConstraint { constraint: op, .. } => { SymExpr::PathConstraint { constraint: op, .. } => {
*op = self.make_absolute(*op); *op = self.make_absolute(*op);
} }
SymExpr::ExpressionsUnreachable { exprs } => { SymExpr::ExpressionsUnreachable { exprs } => {
@ -146,14 +198,13 @@ impl<R: Read> MessageFileReader<R> {
*expr = self.make_absolute(*expr); *expr = self.make_absolute(*expr);
} }
} }
SymExpr::End => {
panic!("should not pass End message to this function");
}
} }
SymExprRef::new(ret).unwrap() SymExprRef::new(ret).unwrap()
} }
} }
/// A `MessageFileWriter` writes a stream of [`SymExpr`] to any [`Write`]. For each written expression, it returns
/// a [`SymExprRef`] which should be used to refer back to it.
pub struct MessageFileWriter<W: Write> { pub struct MessageFileWriter<W: Write> {
id_counter: usize, id_counter: usize,
writer: W, writer: W,
@ -162,6 +213,7 @@ pub struct MessageFileWriter<W: Write> {
} }
impl<W: Write + Seek> MessageFileWriter<W> { impl<W: Write + Seek> MessageFileWriter<W> {
/// Create a `MessageFileWriter` from the given [`Write`].
pub fn from_writer(mut writer: W) -> io::Result<Self> { pub fn from_writer(mut writer: W) -> io::Result<Self> {
let writer_start_position = writer.stream_position()?; let writer_start_position = writer.stream_position()?;
// write dummy trace length // write dummy trace length
@ -190,7 +242,8 @@ impl<W: Write + Seek> MessageFileWriter<W> {
Ok(()) Ok(())
} }
pub fn end(&mut self) -> io::Result<()> { /// Updates the trace header which stores the total length of the trace in bytes.
pub fn update_trace_header(&mut self) -> io::Result<()> {
self.write_trace_size()?; self.write_trace_size()?;
Ok(()) Ok(())
} }
@ -199,86 +252,86 @@ impl<W: Write + Seek> MessageFileWriter<W> {
SymExprRef::new(self.id_counter - expr.get()).unwrap() SymExprRef::new(self.id_counter - expr.get()).unwrap()
} }
/// Writes a message to the stream and returns the [`SymExprRef`] that should be used to refer back to this message.
/// May error when the underlying `Write` errors or when there is a serialization error.
#[allow(clippy::too_many_lines)] #[allow(clippy::too_many_lines)]
pub fn write_message(&mut self, mut message: SymExpr) -> bincode::Result<SymExprRef> { pub fn write_message(&mut self, mut message: SymExpr) -> bincode::Result<SymExprRef> {
let current_id = self.id_counter; let current_id = self.id_counter;
match &mut message { match &mut message {
SymExpr::GetInputByte { .. } SymExpr::InputByte { .. }
| SymExpr::BuildInteger { .. } | SymExpr::Integer { .. }
| SymExpr::BuildInteger128 { .. } | SymExpr::Integer128 { .. }
| SymExpr::BuildFloat { .. } | SymExpr::Float { .. }
| SymExpr::BuildNullPointer | SymExpr::NullPointer
| SymExpr::BuildTrue | SymExpr::True
| SymExpr::BuildFalse | SymExpr::False
| SymExpr::BuildBool { .. } => { | SymExpr::Bool { .. } => {
self.id_counter += 1; self.id_counter += 1;
} }
SymExpr::BuildNeg { op } SymExpr::Neg { op }
| SymExpr::BuildFloatAbs { op } | SymExpr::FloatAbs { op }
| SymExpr::BuildNot { op } | SymExpr::Not { op }
| SymExpr::BuildSext { op, .. } | SymExpr::Sext { op, .. }
| SymExpr::BuildZext { op, .. } | SymExpr::Zext { op, .. }
| SymExpr::BuildTrunc { op, .. } | SymExpr::Trunc { op, .. }
| SymExpr::BuildIntToFloat { op, .. } | SymExpr::IntToFloat { op, .. }
| SymExpr::BuildFloatToFloat { op, .. } | SymExpr::FloatToFloat { op, .. }
| SymExpr::BuildBitsToFloat { op, .. } | SymExpr::BitsToFloat { op, .. }
| SymExpr::BuildFloatToBits { op } | SymExpr::FloatToBits { op }
| SymExpr::BuildFloatToSignedInteger { op, .. } | SymExpr::FloatToSignedInteger { op, .. }
| SymExpr::BuildFloatToUnsignedInteger { op, .. } | SymExpr::FloatToUnsignedInteger { op, .. }
| SymExpr::BuildBoolToBits { op, .. } | SymExpr::BoolToBits { op, .. }
| SymExpr::ExtractHelper { op, .. } | SymExpr::Extract { op, .. } => {
| SymExpr::BuildExtract { op, .. }
| SymExpr::BuildBswap { op } => {
*op = self.make_relative(*op); *op = self.make_relative(*op);
self.id_counter += 1; self.id_counter += 1;
} }
SymExpr::BuildAdd { a, b } SymExpr::Add { a, b }
| SymExpr::BuildSub { a, b } | SymExpr::Sub { a, b }
| SymExpr::BuildMul { a, b } | SymExpr::Mul { a, b }
| SymExpr::BuildUnsignedDiv { a, b } | SymExpr::UnsignedDiv { a, b }
| SymExpr::BuildSignedDiv { a, b } | SymExpr::SignedDiv { a, b }
| SymExpr::BuildUnsignedRem { a, b } | SymExpr::UnsignedRem { a, b }
| SymExpr::BuildSignedRem { a, b } | SymExpr::SignedRem { a, b }
| SymExpr::BuildShiftLeft { a, b } | SymExpr::ShiftLeft { a, b }
| SymExpr::BuildLogicalShiftRight { a, b } | SymExpr::LogicalShiftRight { a, b }
| SymExpr::BuildArithmeticShiftRight { a, b } | SymExpr::ArithmeticShiftRight { a, b }
| SymExpr::BuildSignedLessThan { a, b } | SymExpr::SignedLessThan { a, b }
| SymExpr::BuildSignedLessEqual { a, b } | SymExpr::SignedLessEqual { a, b }
| SymExpr::BuildSignedGreaterThan { a, b } | SymExpr::SignedGreaterThan { a, b }
| SymExpr::BuildSignedGreaterEqual { a, b } | SymExpr::SignedGreaterEqual { a, b }
| SymExpr::BuildUnsignedLessThan { a, b } | SymExpr::UnsignedLessThan { a, b }
| SymExpr::BuildUnsignedLessEqual { a, b } | SymExpr::UnsignedLessEqual { a, b }
| SymExpr::BuildUnsignedGreaterThan { a, b } | SymExpr::UnsignedGreaterThan { a, b }
| SymExpr::BuildUnsignedGreaterEqual { a, b } | SymExpr::UnsignedGreaterEqual { a, b }
| SymExpr::BuildEqual { a, b } | SymExpr::Equal { a, b }
| SymExpr::BuildNotEqual { a, b } | SymExpr::NotEqual { a, b }
| SymExpr::BuildBoolAnd { a, b } | SymExpr::BoolAnd { a, b }
| SymExpr::BuildBoolOr { a, b } | SymExpr::BoolOr { a, b }
| SymExpr::BuildBoolXor { a, b } | SymExpr::BoolXor { a, b }
| SymExpr::BuildAnd { a, b } | SymExpr::And { a, b }
| SymExpr::BuildOr { a, b } | SymExpr::Or { a, b }
| SymExpr::BuildXor { a, b } | SymExpr::Xor { a, b }
| SymExpr::BuildFloatOrdered { a, b } | SymExpr::FloatOrdered { a, b }
| SymExpr::BuildFloatOrderedGreaterThan { a, b } | SymExpr::FloatOrderedGreaterThan { a, b }
| SymExpr::BuildFloatOrderedGreaterEqual { a, b } | SymExpr::FloatOrderedGreaterEqual { a, b }
| SymExpr::BuildFloatOrderedLessThan { a, b } | SymExpr::FloatOrderedLessThan { a, b }
| SymExpr::BuildFloatOrderedLessEqual { a, b } | SymExpr::FloatOrderedLessEqual { a, b }
| SymExpr::BuildFloatOrderedEqual { a, b } | SymExpr::FloatOrderedEqual { a, b }
| SymExpr::BuildFloatOrderedNotEqual { a, b } | SymExpr::FloatOrderedNotEqual { a, b }
| SymExpr::BuildFloatUnordered { a, b } | SymExpr::FloatUnordered { a, b }
| SymExpr::BuildFloatUnorderedGreaterThan { a, b } | SymExpr::FloatUnorderedGreaterThan { a, b }
| SymExpr::BuildFloatUnorderedGreaterEqual { a, b } | SymExpr::FloatUnorderedGreaterEqual { a, b }
| SymExpr::BuildFloatUnorderedLessThan { a, b } | SymExpr::FloatUnorderedLessThan { a, b }
| SymExpr::BuildFloatUnorderedLessEqual { a, b } | SymExpr::FloatUnorderedLessEqual { a, b }
| SymExpr::BuildFloatUnorderedEqual { a, b } | SymExpr::FloatUnorderedEqual { a, b }
| SymExpr::BuildFloatUnorderedNotEqual { a, b } | SymExpr::FloatUnorderedNotEqual { a, b }
| SymExpr::BuildFloatAdd { a, b } | SymExpr::FloatAdd { a, b }
| SymExpr::BuildFloatSub { a, b } | SymExpr::FloatSub { a, b }
| SymExpr::BuildFloatMul { a, b } | SymExpr::FloatMul { a, b }
| SymExpr::BuildFloatDiv { a, b } | SymExpr::FloatDiv { a, b }
| SymExpr::BuildFloatRem { a, b } | SymExpr::FloatRem { a, b }
| SymExpr::ConcatHelper { a, b } | SymExpr::Concat { a, b }
| SymExpr::BuildInsert { | SymExpr::Insert {
target: a, target: a,
to_insert: b, to_insert: b,
.. ..
@ -287,7 +340,7 @@ impl<W: Write + Seek> MessageFileWriter<W> {
*b = self.make_relative(*b); *b = self.make_relative(*b);
self.id_counter += 1; self.id_counter += 1;
} }
SymExpr::PushPathConstraint { constraint: op, .. } => { SymExpr::PathConstraint { constraint: op, .. } => {
*op = self.make_relative(*op); *op = self.make_relative(*op);
} }
SymExpr::ExpressionsUnreachable { exprs } => { SymExpr::ExpressionsUnreachable { exprs } => {
@ -295,74 +348,142 @@ impl<W: Write + Seek> MessageFileWriter<W> {
*expr = self.make_relative(*expr); *expr = self.make_relative(*expr);
} }
} }
SymExpr::End => {}
} }
self.serialization_options self.serialization_options
.serialize_into(&mut self.writer, &message)?; .serialize_into(&mut self.writer, &message)?;
// for every path constraint, make sure we can later decode it in case we crash by updating the trace header // for every path constraint, make sure we can later decode it in case we crash by updating the trace header
if let SymExpr::PushPathConstraint { .. } = &message { if let SymExpr::PathConstraint { .. } = &message {
self.write_trace_size()?; self.write_trace_size()?;
} }
Ok(SymExprRef::new(current_id).unwrap()) Ok(SymExprRef::new(current_id).unwrap())
} }
} }
pub mod shared_memory { #[cfg(test)]
use std::{ mod serialization_tests {
convert::TryFrom, use std::io::Cursor;
io::{self, Cursor, Read},
};
use crate::bolts::shmem::{ShMem, ShMemCursor, ShMemProvider, StdShMemProvider}; use super::{MessageFileReader, MessageFileWriter, SymExpr};
use super::{MessageFileReader, MessageFileWriter}; /// This test intends to ensure that the serialization format can efficiently encode the required information.
/// This is mainly useful to fail if any changes should be made in the future that (inadvertently) reduce
pub const DEFAULT_ENV_NAME: &str = "SHARED_MEMORY_MESSAGES"; /// serialization efficiency.
pub const DEFAULT_SIZE: usize = 1024 * 1024 * 1024; #[test]
fn efficient_serialization() {
impl<'buffer> MessageFileReader<Cursor<&'buffer [u8]>> { let mut buf = Vec::new();
#[must_use] {
pub fn from_buffer(buffer: &'buffer [u8]) -> Self { let mut cursor = Cursor::new(&mut buf);
Self::from_reader(Cursor::new(buffer)) let mut writer = MessageFileWriter::from_writer(&mut cursor).unwrap();
} let a = writer.write_message(SymExpr::True).unwrap();
let b = writer.write_message(SymExpr::True).unwrap();
pub fn from_length_prefixed_buffer(mut buffer: &'buffer [u8]) -> io::Result<Self> { writer.write_message(SymExpr::And { a, b }).unwrap();
let mut len_buf = 0u64.to_le_bytes(); writer.update_trace_header().unwrap();
buffer.read_exact(&mut len_buf)?;
let buffer_len = u64::from_le_bytes(len_buf);
assert!(usize::try_from(buffer_len).is_ok());
let buffer_len = buffer_len as usize;
let (buffer, _) = buffer.split_at(buffer_len);
Ok(Self::from_buffer(buffer))
}
#[must_use]
pub fn get_buffer(&self) -> &[u8] {
self.reader.get_ref()
} }
let expected_size = 8 + // the header takes 8 bytes to encode the length of the trace
1 + // tag to create SymExpr::True (a)
1 + // tag to create SymExpr::True (b)
1 + // tag to create SymExpr::And
1 + // reference to a
1; // reference to b
assert_eq!(buf.len(), expected_size);
} }
impl<T: ShMem> MessageFileWriter<ShMemCursor<T>> { /// This test intends to verify that a trace written by [`MessageFileWriter`] can indeed be read back by
pub fn from_shmem(shmem: T) -> io::Result<Self> { /// [`MessageFileReader`].
Self::from_writer(ShMemCursor::new(shmem)) #[test]
fn serialization_roundtrip() {
let mut buf = Vec::new();
{
let mut cursor = Cursor::new(&mut buf);
let mut writer = MessageFileWriter::from_writer(&mut cursor).unwrap();
let a = writer.write_message(SymExpr::True).unwrap();
let b = writer.write_message(SymExpr::True).unwrap();
writer.write_message(SymExpr::And { a, b }).unwrap();
writer.update_trace_header().unwrap();
} }
let mut reader = MessageFileReader::from_length_prefixed_buffer(&buf).unwrap();
let (first_bool_id, first_bool) = reader.next_message().unwrap().unwrap();
assert_eq!(first_bool, SymExpr::True);
let (second_bool_id, second_bool) = reader.next_message().unwrap().unwrap();
assert_eq!(second_bool, SymExpr::True);
let (_, and) = reader.next_message().unwrap().unwrap();
assert_eq!(
and,
SymExpr::And {
a: first_bool_id,
b: second_bool_id
}
);
assert!(reader.next_message().is_none());
} }
impl MessageFileWriter<ShMemCursor<<StdShMemProvider as ShMemProvider>::Mem>> {
pub fn from_stdshmem_env_with_name(env_name: impl AsRef<str>) -> io::Result<Self> {
Self::from_shmem(
StdShMemProvider::new()
.expect("unable to initialize StdShMemProvider")
.existing_from_env(env_name.as_ref())
.expect("unable to get shared memory from env"),
)
}
pub fn from_stdshmem_default_env() -> io::Result<Self> {
Self::from_stdshmem_env_with_name(DEFAULT_ENV_NAME)
}
}
pub type StdShMemMessageFileWriter =
MessageFileWriter<ShMemCursor<<StdShMemProvider as ShMemProvider>::Mem>>;
} }
use crate::bolts::shmem::{ShMem, ShMemCursor, ShMemProvider, StdShMemProvider};
/// The default environment variable name to use for the shared memory used by the concolic tracing
pub const DEFAULT_ENV_NAME: &str = "SHARED_MEMORY_MESSAGES";
/// The default shared memory size used by the concolic tracing.
///
/// This amounts to 1GiB of memory, which is considered to be enough for any reasonable trace. It is also assumed
/// that the memory will not be phsyically mapped until accessed, alleviating reource concerns.
pub const DEFAULT_SIZE: usize = 1024 * 1024 * 1024;
impl<'buffer> MessageFileReader<Cursor<&'buffer [u8]>> {
/// Creates a new `MessageFileReader` from the given buffer.
/// It is expected that trace in this buffer is not length prefixed and the buffer itself should have the exact
/// length of the trace (ie. contain no partial message).
/// See also [`MessageFileReader::from_length_prefixed_buffer`].
#[must_use]
pub fn from_buffer(buffer: &'buffer [u8]) -> Self {
Self::from_reader(Cursor::new(buffer))
}
/// Creates a new `MessageFileReader` from the given buffer, expecting the contained trace to be prefixed by the
/// trace length (as generated by the [`MessageFileWriter`]).
/// See also [`MessageFileReader::from_buffer`].
pub fn from_length_prefixed_buffer(mut buffer: &'buffer [u8]) -> io::Result<Self> {
let mut len_buf = 0u64.to_le_bytes();
buffer.read_exact(&mut len_buf)?;
let buffer_len = u64::from_le_bytes(len_buf);
assert!(usize::try_from(buffer_len).is_ok());
let buffer_len = buffer_len as usize;
let (buffer, _) = buffer.split_at(buffer_len);
Ok(Self::from_buffer(buffer))
}
/// Gets the currently used buffer. If the buffer was length prefixed, the returned buffer does not contain the
/// prefix and is exactly as many bytes long as the prefix specified. Effectively, the length prefix is removed and
/// used to limit the buffer.
#[must_use]
pub fn get_buffer(&self) -> &[u8] {
self.reader.get_ref()
}
}
impl<T: ShMem> MessageFileWriter<ShMemCursor<T>> {
/// Creates a new `MessageFileWriter` from the given [`ShMemCursor`].
pub fn from_shmem(shmem: T) -> io::Result<Self> {
Self::from_writer(ShMemCursor::new(shmem))
}
}
impl MessageFileWriter<ShMemCursor<<StdShMemProvider as ShMemProvider>::Mem>> {
/// Creates a new `MessageFileWriter` by reading a [`StdShMem`] from the given environment variable.
pub fn from_stdshmem_env_with_name(env_name: impl AsRef<str>) -> io::Result<Self> {
Self::from_shmem(
StdShMemProvider::new()
.expect("unable to initialize StdShMemProvider")
.existing_from_env(env_name.as_ref())
.expect("unable to get shared memory from env"),
)
}
/// Creates a new `MessageFileWriter` by reading a [`StdShMem`] using [`DEFAULT_ENV_NAME`].
pub fn from_stdshmem_default_env() -> io::Result<Self> {
Self::from_stdshmem_env_with_name(DEFAULT_ENV_NAME)
}
}
pub type StdShMemMessageFileWriter =
MessageFileWriter<ShMemCursor<<StdShMemProvider as ShMemProvider>::Mem>>;

106
libafl/src/stages/concolic.rs
View File

@ -159,39 +159,39 @@ fn generate_mutations(iter: impl Iterator<Item = (SymExprRef, SymExpr)>) -> Vec<
for (id, msg) in iter { for (id, msg) in iter {
let z3_expr: Option<Dynamic> = match msg { let z3_expr: Option<Dynamic> = match msg {
SymExpr::GetInputByte { offset } => { SymExpr::InputByte { offset } => {
Some(BV::new_const(&ctx, Symbol::Int(offset as u32), 8).into()) Some(BV::new_const(&ctx, Symbol::Int(offset as u32), 8).into())
} }
SymExpr::BuildInteger { value, bits } => { SymExpr::Integer { value, bits } => {
Some(BV::from_u64(&ctx, value, u32::from(bits)).into()) Some(BV::from_u64(&ctx, value, u32::from(bits)).into())
} }
SymExpr::BuildInteger128 { high: _, low: _ } => todo!(), SymExpr::Integer128 { high: _, low: _ } => todo!(),
SymExpr::BuildNullPointer => { SymExpr::NullPointer => {
Some(BV::from_u64(&ctx, 0, (8 * size_of::<usize>()) as u32).into()) Some(BV::from_u64(&ctx, 0, (8 * size_of::<usize>()) as u32).into())
} }
SymExpr::BuildTrue => Some(Bool::from_bool(&ctx, true).into()), SymExpr::True => Some(Bool::from_bool(&ctx, true).into()),
SymExpr::BuildFalse => Some(Bool::from_bool(&ctx, false).into()), SymExpr::False => Some(Bool::from_bool(&ctx, false).into()),
SymExpr::BuildBool { value } => Some(Bool::from_bool(&ctx, value).into()), SymExpr::Bool { value } => Some(Bool::from_bool(&ctx, value).into()),
SymExpr::BuildNeg { op } => Some(bv!(op).bvneg().into()), SymExpr::Neg { op } => Some(bv!(op).bvneg().into()),
SymExpr::BuildAdd { a, b } => bv_binop!(a bvadd b), SymExpr::Add { a, b } => bv_binop!(a bvadd b),
SymExpr::BuildSub { a, b } => bv_binop!(a bvsub b), SymExpr::Sub { a, b } => bv_binop!(a bvsub b),
SymExpr::BuildMul { a, b } => bv_binop!(a bvmul b), SymExpr::Mul { a, b } => bv_binop!(a bvmul b),
SymExpr::BuildUnsignedDiv { a, b } => bv_binop!(a bvudiv b), SymExpr::UnsignedDiv { a, b } => bv_binop!(a bvudiv b),
SymExpr::BuildSignedDiv { a, b } => bv_binop!(a bvsdiv b), SymExpr::SignedDiv { a, b } => bv_binop!(a bvsdiv b),
SymExpr::BuildUnsignedRem { a, b } => bv_binop!(a bvurem b), SymExpr::UnsignedRem { a, b } => bv_binop!(a bvurem b),
SymExpr::BuildSignedRem { a, b } => bv_binop!(a bvsrem b), SymExpr::SignedRem { a, b } => bv_binop!(a bvsrem b),
SymExpr::BuildShiftLeft { a, b } => bv_binop!(a bvshl b), SymExpr::ShiftLeft { a, b } => bv_binop!(a bvshl b),
SymExpr::BuildLogicalShiftRight { a, b } => bv_binop!(a bvlshr b), SymExpr::LogicalShiftRight { a, b } => bv_binop!(a bvlshr b),
SymExpr::BuildArithmeticShiftRight { a, b } => bv_binop!(a bvashr b), SymExpr::ArithmeticShiftRight { a, b } => bv_binop!(a bvashr b),
SymExpr::BuildSignedLessThan { a, b } => bv_binop!(a bvslt b), SymExpr::SignedLessThan { a, b } => bv_binop!(a bvslt b),
SymExpr::BuildSignedLessEqual { a, b } => bv_binop!(a bvsle b), SymExpr::SignedLessEqual { a, b } => bv_binop!(a bvsle b),
SymExpr::BuildSignedGreaterThan { a, b } => bv_binop!(a bvsgt b), SymExpr::SignedGreaterThan { a, b } => bv_binop!(a bvsgt b),
SymExpr::BuildSignedGreaterEqual { a, b } => bv_binop!(a bvsge b), SymExpr::SignedGreaterEqual { a, b } => bv_binop!(a bvsge b),
SymExpr::BuildUnsignedLessThan { a, b } => bv_binop!(a bvult b), SymExpr::UnsignedLessThan { a, b } => bv_binop!(a bvult b),
SymExpr::BuildUnsignedLessEqual { a, b } => bv_binop!(a bvule b), SymExpr::UnsignedLessEqual { a, b } => bv_binop!(a bvule b),
SymExpr::BuildUnsignedGreaterThan { a, b } => bv_binop!(a bvugt b), SymExpr::UnsignedGreaterThan { a, b } => bv_binop!(a bvugt b),
SymExpr::BuildUnsignedGreaterEqual { a, b } => bv_binop!(a bvuge b), SymExpr::UnsignedGreaterEqual { a, b } => bv_binop!(a bvuge b),
SymExpr::BuildNot { op } => { SymExpr::Not { op } => {
let translated = &translation[&op]; let translated = &translation[&op];
Some(if let Some(bv) = translated.as_bv() { Some(if let Some(bv) = translated.as_bv() {
bv.bvnot().into() bv.bvnot().into()
@ -204,22 +204,18 @@ fn generate_mutations(iter: impl Iterator<Item = (SymExprRef, SymExpr)>) -> Vec<
) )
}) })
} }
SymExpr::BuildEqual { a, b } => Some(translation[&a]._eq(&translation[&b]).into()), SymExpr::Equal { a, b } => Some(translation[&a]._eq(&translation[&b]).into()),
SymExpr::BuildNotEqual { a, b } => { SymExpr::NotEqual { a, b } => Some(translation[&a]._eq(&translation[&b]).not().into()),
Some(translation[&a]._eq(&translation[&b]).not().into()) SymExpr::BoolAnd { a, b } => Some(Bool::and(&ctx, &[&bool!(a), &bool!(b)]).into()),
} SymExpr::BoolOr { a, b } => Some(Bool::or(&ctx, &[&bool!(a), &bool!(b)]).into()),
SymExpr::BuildBoolAnd { a, b } => Some(Bool::and(&ctx, &[&bool!(a), &bool!(b)]).into()), SymExpr::BoolXor { a, b } => Some(bool!(a).xor(&bool!(b)).into()),
SymExpr::BuildBoolOr { a, b } => Some(Bool::or(&ctx, &[&bool!(a), &bool!(b)]).into()), SymExpr::And { a, b } => bv_binop!(a bvand b),
SymExpr::BuildBoolXor { a, b } => Some(bool!(a).xor(&bool!(b)).into()), SymExpr::Or { a, b } => bv_binop!(a bvor b),
SymExpr::BuildAnd { a, b } => bv_binop!(a bvand b), SymExpr::Xor { a, b } => bv_binop!(a bvxor b),
SymExpr::BuildOr { a, b } => bv_binop!(a bvor b), SymExpr::Sext { op, bits } => Some(bv!(op).sign_ext(u32::from(bits)).into()),
SymExpr::BuildXor { a, b } => bv_binop!(a bvxor b), SymExpr::Zext { op, bits } => Some(bv!(op).zero_ext(u32::from(bits)).into()),
SymExpr::BuildSext { op, bits } => Some(bv!(op).sign_ext(u32::from(bits)).into()), SymExpr::Trunc { op, bits } => Some(bv!(op).extract(u32::from(bits - 1), 0).into()),
SymExpr::BuildZext { op, bits } => Some(bv!(op).zero_ext(u32::from(bits)).into()), SymExpr::BoolToBits { op, bits } => Some(
SymExpr::BuildTrunc { op, bits } => {
Some(bv!(op).extract(u32::from(bits - 1), 0).into())
}
SymExpr::BuildBoolToBits { op, bits } => Some(
bool!(op) bool!(op)
.ite( .ite(
&BV::from_u64(&ctx, 1, u32::from(bits)), &BV::from_u64(&ctx, 1, u32::from(bits)),
@ -227,29 +223,13 @@ fn generate_mutations(iter: impl Iterator<Item = (SymExprRef, SymExpr)>) -> Vec<
) )
.into(), .into(),
), ),
SymExpr::ConcatHelper { a, b } => bv_binop!(a concat b), SymExpr::Concat { a, b } => bv_binop!(a concat b),
SymExpr::ExtractHelper { SymExpr::Extract {
op, op,
first_bit, first_bit,
last_bit, last_bit,
} => Some(bv!(op).extract(first_bit as u32, last_bit as u32).into()), } => Some(bv!(op).extract(first_bit as u32, last_bit as u32).into()),
SymExpr::BuildExtract { SymExpr::Insert {
op,
offset,
length,
little_endian,
} => Some(build_extract(&(bv!(op)), offset, length, little_endian).into()),
SymExpr::BuildBswap { op } => {
let bv = bv!(op);
let bits = bv.get_size();
assert_eq!(
bits % 16,
0,
"bswap is only compatible with an even number of bvytes in the BV"
);
Some(build_extract(&bv, 0, u64::from(bits) / 8, true).into())
}
SymExpr::BuildInsert {
target, target,
to_insert, to_insert,
offset, offset,
@ -297,7 +277,7 @@ fn generate_mutations(iter: impl Iterator<Item = (SymExprRef, SymExpr)>) -> Vec<
}; };
if let Some(expr) = z3_expr { if let Some(expr) = z3_expr {
translation.insert(id, expr); translation.insert(id, expr);
} else if let SymExpr::PushPathConstraint { } else if let SymExpr::PathConstraint {
constraint, constraint,
site_id: _, site_id: _,
taken, taken,

1
libafl_concolic/symcc_runtime/Cargo.toml
View File

@ -2,6 +2,7 @@
name = "symcc_runtime" name = "symcc_runtime"
version = "0.1.0" version = "0.1.0"
edition = "2018" edition = "2018"
authors = ["Julius Hohnerlein <julihoh@users.noreply.github.com>"]
# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html

253
libafl_concolic/symcc_runtime/src/filter.rs
View File

@ -1,12 +1,21 @@
//! [`Filter`]s are ergonomic abstractions over [`Runtime`] that facilitate filtering expressions.
use std::collections::HashSet; use std::collections::HashSet;
#[allow(clippy::wildcard_imports)] #[allow(clippy::wildcard_imports)]
use crate::*; use crate::*;
mod coverage;
pub use coverage::{CallStackCoverage, HitmapFilter};
// creates the method declaration and default implementations for the filter trait
macro_rules! rust_filter_function_declaration { macro_rules! rust_filter_function_declaration {
// expression_unreachable is not supported for filters
(pub fn expression_unreachable(expressions: *mut RSymExpr, num_elements: usize), $c_name:ident;) => { (pub fn expression_unreachable(expressions: *mut RSymExpr, num_elements: usize), $c_name:ident;) => {
}; };
// push_path_constraint is not caught by the following case (because it has not return value),
// but still needs to return something
(pub fn push_path_constraint($( $arg:ident : $type:ty ),*$(,)?), $c_name:ident;) => { (pub fn push_path_constraint($( $arg:ident : $type:ty ),*$(,)?), $c_name:ident;) => {
#[allow(unused_variables)] #[allow(unused_variables)]
fn push_path_constraint(&mut self, $($arg : $type),*) -> bool { fn push_path_constraint(&mut self, $($arg : $type),*) -> bool {
@ -25,18 +34,46 @@ macro_rules! rust_filter_function_declaration {
}; };
} }
/// A [`Filter`] can decide for each expression whether the expression should be trace symbolically or be /// A [`Filter`] can decide for each expression whether the expression should be traced symbolically or be
/// concretized. This allows to implement filtering mechanisms that reduce the amount of traced expressions by /// concretized. This allows to implement filtering mechanisms that reduce the amount of traced expressions by
/// concretizing uninteresting expressions. /// concretizing uninteresting expressions.
/// If a filter concretizes an expression that would have later been used as part of another expression that /// If a filter concretizes an expression that would have later been used as part of another expression that
/// is still symbolic, a concrete instead of a symbolic value is received. /// is still symbolic, a concrete instead of a symbolic value is received.
/// ///
/// The interface for a filter matches [`Runtime`] with all methods returning `bool` instead of returning [`Option<RSymExpr>`].
/// Returning `true` indicates that the expression should _continue_ to be processed.
/// Returning `false` indicates that the expression should _not_ be processed any further and its result should be _concretized_.
///
/// For example: /// For example:
/// Suppose there are symbolic expressions `a` and `b`. Expression `a` is concretized, `b` is still symbolic. If an add /// Suppose there are symbolic expressions `a` and `b`. Expression `a` is concretized, `b` is still symbolic. If an add
/// operation between `a` and `b` is encountered, it will receive `a`'s concrete value and `b` as a symbolic expression. /// operation between `a` and `b` is encountered, it will receive `a`'s concrete value and `b` as a symbolic expression.
/// ///
/// An expression filter also receives code locations (`visit_*` methods) as they are visited in between operations /// An expression filter also receives code locations (`visit_*` methods) as they are visited in between operations
/// and these code locations are typically used to decide whether an expression should be concretized. /// and these code locations are typically used to decide whether an expression should be concretized.
///
/// ## How to use
/// To create your own filter, implement this trait for a new struct.
/// All methods of this trait have default implementations, so you can just implement those methods which you may want
/// to filter.
///
/// Use a [`FilterRuntime`] to compose your filter with a [`Runtime`].
/// ## Example
/// As an example, the following filter concretizes all variables (and, therefore, expressions based on these variables) that are not part of a predetermined set of variables.
/// It is also available to use as [`SelectiveSymbolication`].
/// ```no_run
/// # use symcc_runtime::filter::Filter;
/// # use std::collections::HashSet;
/// struct SelectiveSymbolication {
/// bytes_to_symbolize: HashSet<usize>,
/// }
///
/// impl Filter for SelectiveSymbolication {
/// fn get_input_byte(&mut self, offset: usize) -> bool {
/// self.bytes_to_symbolize.contains(&offset)
/// }
/// // Note: No need to implement methods that we are not interested in!
/// }
/// ```
pub trait Filter { pub trait Filter {
invoke_macro_with_rust_runtime_exports!(rust_filter_function_declaration;); invoke_macro_with_rust_runtime_exports!(rust_filter_function_declaration;);
} }
@ -186,217 +223,3 @@ impl Filter for NoFloat {
false false
} }
} }
pub mod coverage {
use std::{
collections::hash_map::DefaultHasher,
convert::TryInto,
hash::{BuildHasher, BuildHasherDefault, Hash, Hasher},
marker::PhantomData,
};
use libafl::bolts::shmem::ShMem;
use super::Filter;
const MAP_SIZE: usize = 65536;
/// A coverage-based [`Filter`] based on the expression pruning from [`QSym`](https://github.com/sslab-gatech/qsym)
/// [here](https://github.com/sslab-gatech/qsym/blob/master/qsym/pintool/call_stack_manager.cpp).
struct CallStackCoverage<
THasher: Hasher = DefaultHasher,
THashBuilder: BuildHasher = BuildHasherDefault<THasher>,
> {
call_stack: Vec<usize>,
call_stack_hash: u64,
is_interesting: bool,
bitmap: Vec<u16>,
pending: bool,
last_location: usize,
hasher_builder: THashBuilder,
hasher_phantom: PhantomData<THasher>,
}
impl Default for CallStackCoverage<DefaultHasher, BuildHasherDefault<DefaultHasher>> {
fn default() -> Self {
Self {
call_stack: Vec::new(),
call_stack_hash: 0,
is_interesting: true,
bitmap: vec![0; MAP_SIZE],
pending: false,
last_location: 0,
hasher_builder: BuildHasherDefault::default(),
hasher_phantom: PhantomData,
}
}
}
impl<THasher: Hasher, THashBuilder: BuildHasher> CallStackCoverage<THasher, THashBuilder> {
pub fn visit_call(&mut self, location: usize) {
self.call_stack.push(location);
self.update_call_stack_hash();
}
pub fn visit_ret(&mut self, location: usize) {
if self.call_stack.is_empty() {
return;
}
let num_elements_to_remove = self
.call_stack
.iter()
.rev()
.take_while(|&&loc| loc != location)
.count()
+ 1;
self.call_stack
.truncate(self.call_stack.len() - num_elements_to_remove);
self.update_call_stack_hash();
}
pub fn visit_basic_block(&mut self, location: usize) {
self.last_location = location;
self.pending = true;
}
pub fn is_interesting(&self) -> bool {
self.is_interesting
}
pub fn update_bitmap(&mut self) {
if self.pending {
self.pending = false;
let mut hasher = self.hasher_builder.build_hasher();
self.last_location.hash(&mut hasher);
self.call_stack_hash.hash(&mut hasher);
let hash = hasher.finish();
let index: usize = (hash % MAP_SIZE as u64).try_into().unwrap();
let value = self.bitmap[index] / 8;
self.is_interesting = value == 0 || value.is_power_of_two();
*self.bitmap.get_mut(index).unwrap() += 1;
}
}
fn update_call_stack_hash(&mut self) {
let mut hasher = self.hasher_builder.build_hasher();
self.call_stack
.iter()
.for_each(|&loc| loc.hash(&mut hasher));
self.call_stack_hash = hasher.finish();
}
}
macro_rules! call_stack_coverage_filter_function_implementation {
(pub fn expression_unreachable(expressions: *mut RSymExpr, num_elements: usize), $c_name:ident;) => {
};
(pub fn notify_basic_block(site_id: usize), $c_name:ident;) => {
fn notify_basic_block(&mut self, site_id: usize) {
self.visit_basic_block(site_id);
}
};
(pub fn notify_call(site_id: usize), $c_name:ident;) => {
fn notify_call(&mut self, site_id: usize) {
self.visit_call(site_id);
}
};
(pub fn notify_ret(site_id: usize), $c_name:ident;) => {
fn notify_ret(&mut self, site_id: usize) {
self.visit_ret(site_id);
}
};
(pub fn push_path_constraint($( $arg:ident : $type:ty ),*$(,)?), $c_name:ident;) => {
fn push_path_constraint(&mut self, $( _ : $type ),*) -> bool {
self.update_bitmap();
self.is_interesting()
}
};
(pub fn $name:ident($( $arg:ident : $type:ty ),*$(,)?) -> $ret:ty, $c_name:ident;) => {
fn $name(&mut self, $( _ : $type),*) -> bool {
self.update_bitmap();
self.is_interesting()
}
};
(pub fn $name:ident($( $arg:ident : $type:ty ),*$(,)?), $c_name:ident;) => {
fn $name(&mut self, $( _ : $type),*) {
}
};
}
#[allow(clippy::wildcard_imports)]
use crate::*;
impl<THasher: Hasher, THashBuilder: BuildHasher> Filter
for CallStackCoverage<THasher, THashBuilder>
{
invoke_macro_with_rust_runtime_exports!(call_stack_coverage_filter_function_implementation;);
}
/// A [`Filter`] that just observers Basic Block locations and updates a given Hitmap as a [`ShMem`].
pub struct HitmapFilter<M, BH: BuildHasher = BuildHasherDefault<DefaultHasher>> {
hitcounts_map: M,
build_hasher: BH,
}
impl<M> HitmapFilter<M, BuildHasherDefault<DefaultHasher>>
where
M: ShMem,
{
/// Creates a new `HitmapFilter` using the given map and the [`DefaultHasher`].
pub fn new(hitcounts_map: M) -> Self {
Self::new_with_default_hasher_builder(hitcounts_map)
}
}
impl<M, H> HitmapFilter<M, BuildHasherDefault<H>>
where
M: ShMem,
H: Hasher + Default,
{
/// Creates a new `HitmapFilter` using the given map and [`Hasher`] (as type argument) using the [`BuildHasherDefault`].
pub fn new_with_default_hasher_builder(hitcounts_map: M) -> Self {
Self::new_with_build_hasher(hitcounts_map, BuildHasherDefault::default())
}
}
impl<M, BH> HitmapFilter<M, BH>
where
M: ShMem,
BH: BuildHasher,
{
/// Creates a new `HitmapFilter` using the given map and [`BuildHasher`] (as type argument).
pub fn new_with_build_hasher(hitcounts_map: M, build_hasher: BH) -> Self {
Self {
hitcounts_map,
build_hasher,
}
}
fn register_location_on_hitmap(&mut self, location: usize) {
let mut hasher = self.build_hasher.build_hasher();
location.hash(&mut hasher);
let hash = (hasher.finish() % usize::MAX as u64) as usize;
let val = unsafe {
// SAFETY: the index is modulo by the length, therefore it is always in bounds
let len = self.hitcounts_map.len();
self.hitcounts_map.map_mut().get_unchecked_mut(hash % len)
};
*val = val.saturating_add(1);
}
}
impl<M, BH> Filter for HitmapFilter<M, BH>
where
M: ShMem,
BH: BuildHasher,
{
fn notify_basic_block(&mut self, location_id: usize) {
self.register_location_on_hitmap(location_id);
}
}
}

212
libafl_concolic/symcc_runtime/src/filter/coverage.rs Normal file
View File

@ -0,0 +1,212 @@
use std::{
collections::hash_map::DefaultHasher,
convert::TryInto,
hash::{BuildHasher, BuildHasherDefault, Hash, Hasher},
marker::PhantomData,
};
use libafl::bolts::shmem::ShMem;
use super::Filter;
const MAP_SIZE: usize = 65536;
/// A coverage-based [`Filter`] based on the
/// [expression pruning](https://github.com/sslab-gatech/qsym/blob/master/qsym/pintool/call_stack_manager.cpp) from
/// [`QSym`](https://github.com/sslab-gatech/qsym).
pub struct CallStackCoverage<
THasher: Hasher = DefaultHasher,
THashBuilder: BuildHasher = BuildHasherDefault<THasher>,
> {
call_stack: Vec<usize>,
call_stack_hash: u64,
is_interesting: bool,
bitmap: Vec<u16>,
pending: bool,
last_location: usize,
hasher_builder: THashBuilder,
hasher_phantom: PhantomData<THasher>,
}
impl Default for CallStackCoverage<DefaultHasher, BuildHasherDefault<DefaultHasher>> {
fn default() -> Self {
Self {
call_stack: Vec::new(),
call_stack_hash: 0,
is_interesting: true,
bitmap: vec![0; MAP_SIZE],
pending: false,
last_location: 0,
hasher_builder: BuildHasherDefault::default(),
hasher_phantom: PhantomData,
}
}
}
impl<THasher: Hasher, THashBuilder: BuildHasher> CallStackCoverage<THasher, THashBuilder> {
pub fn visit_call(&mut self, location: usize) {
self.call_stack.push(location);
self.update_call_stack_hash();
}
pub fn visit_ret(&mut self, location: usize) {
if self.call_stack.is_empty() {
return;
}
let num_elements_to_remove = self
.call_stack
.iter()
.rev()
.take_while(|&&loc| loc != location)
.count()
+ 1;
self.call_stack
.truncate(self.call_stack.len() - num_elements_to_remove);
self.update_call_stack_hash();
}
pub fn visit_basic_block(&mut self, location: usize) {
self.last_location = location;
self.pending = true;
}
pub fn is_interesting(&self) -> bool {
self.is_interesting
}
pub fn update_bitmap(&mut self) {
if self.pending {
self.pending = false;
let mut hasher = self.hasher_builder.build_hasher();
self.last_location.hash(&mut hasher);
self.call_stack_hash.hash(&mut hasher);
let hash = hasher.finish();
let index: usize = (hash % MAP_SIZE as u64).try_into().unwrap();
let value = self.bitmap[index] / 8;
self.is_interesting = value == 0 || value.is_power_of_two();
*self.bitmap.get_mut(index).unwrap() += 1;
}
}
fn update_call_stack_hash(&mut self) {
let mut hasher = self.hasher_builder.build_hasher();
self.call_stack
.iter()
.for_each(|&loc| loc.hash(&mut hasher));
self.call_stack_hash = hasher.finish();
}
}
macro_rules! call_stack_coverage_filter_function_implementation {
(pub fn expression_unreachable(expressions: *mut RSymExpr, num_elements: usize), $c_name:ident;) => {
};
(pub fn notify_basic_block(site_id: usize), $c_name:ident;) => {
fn notify_basic_block(&mut self, site_id: usize) {
self.visit_basic_block(site_id);
}
};
(pub fn notify_call(site_id: usize), $c_name:ident;) => {
fn notify_call(&mut self, site_id: usize) {
self.visit_call(site_id);
}
};
(pub fn notify_ret(site_id: usize), $c_name:ident;) => {
fn notify_ret(&mut self, site_id: usize) {
self.visit_ret(site_id);
}
};
(pub fn push_path_constraint($( $arg:ident : $type:ty ),*$(,)?), $c_name:ident;) => {
fn push_path_constraint(&mut self, $( _ : $type ),*) -> bool {
self.update_bitmap();
self.is_interesting()
}
};
(pub fn $name:ident($( $arg:ident : $type:ty ),*$(,)?) -> $ret:ty, $c_name:ident;) => {
fn $name(&mut self, $( _ : $type),*) -> bool {
self.update_bitmap();
self.is_interesting()
}
};
(pub fn $name:ident($( $arg:ident : $type:ty ),*$(,)?), $c_name:ident;) => {
fn $name(&mut self, $( _ : $type),*) {
}
};
}
#[allow(clippy::wildcard_imports)]
use crate::*;
impl<THasher: Hasher, THashBuilder: BuildHasher> Filter
for CallStackCoverage<THasher, THashBuilder>
{
invoke_macro_with_rust_runtime_exports!(call_stack_coverage_filter_function_implementation;);
}
/// A [`Filter`] that just observes Basic Block locations and updates a given Hitmap as a [`ShMem`].
pub struct HitmapFilter<M, BH: BuildHasher = BuildHasherDefault<DefaultHasher>> {
hitcounts_map: M,
build_hasher: BH,
}
impl<M> HitmapFilter<M, BuildHasherDefault<DefaultHasher>>
where
M: ShMem,
{
/// Creates a new `HitmapFilter` using the given map and the [`DefaultHasher`].
pub fn new(hitcounts_map: M) -> Self {
Self::new_with_default_hasher_builder(hitcounts_map)
}
}
impl<M, H> HitmapFilter<M, BuildHasherDefault<H>>
where
M: ShMem,
H: Hasher + Default,
{
/// Creates a new `HitmapFilter` using the given map and [`Hasher`] (as type argument) using the [`BuildHasherDefault`].
pub fn new_with_default_hasher_builder(hitcounts_map: M) -> Self {
Self::new_with_build_hasher(hitcounts_map, BuildHasherDefault::default())
}
}
impl<M, BH> HitmapFilter<M, BH>
where
M: ShMem,
BH: BuildHasher,
{
/// Creates a new `HitmapFilter` using the given map and [`BuildHasher`] (as type argument).
pub fn new_with_build_hasher(hitcounts_map: M, build_hasher: BH) -> Self {
Self {
hitcounts_map,
build_hasher,
}
}
fn register_location_on_hitmap(&mut self, location: usize) {
let mut hasher = self.build_hasher.build_hasher();
location.hash(&mut hasher);
let hash = (hasher.finish() % usize::MAX as u64) as usize;
let val = unsafe {
// SAFETY: the index is modulo by the length, therefore it is always in bounds
let len = self.hitcounts_map.len();
self.hitcounts_map.map_mut().get_unchecked_mut(hash % len)
};
*val = val.saturating_add(1);
}
}
impl<M, BH> Filter for HitmapFilter<M, BH>
where
M: ShMem,
BH: BuildHasher,
{
fn notify_basic_block(&mut self, location_id: usize) {
self.register_location_on_hitmap(location_id);
}
}

110
libafl_concolic/symcc_runtime/src/lib.rs
View File

@ -1,6 +1,36 @@
//! # `SymCC` Runtime Bindings
//! This crate contains bindings to the [`SymCC`](https://github.com/eurecom-s3/symcc) [runtime interface](https://github.com/eurecom-s3/symcc/blob/master/runtime/RuntimeCommon.h) to be used from Rust.
//! A `SymCC` runtime can be used with either `SymCC` or [`SymQEMU`](https://github.com/eurecom-s3/symqemu) to trace the execution of a target program.
//!
//! ## How to use
//! On a high level, users of this crate can implement the [`Runtime`] trait and export the runtime interface as a `cdylib` using the [`export_runtime`] macro.
//! On a technical level, a `SymCC` runtime is a dynamic library (/shared object) that exposes a set of symbols that the instrumentation layer of `SymCC` calls into during execution of the target.
//! Therefore, to create a runtime, a separate crate for the runtime is required, because this is the only way to create a separate dynamic library using cargo.
//!
//! ## Goodies
//! To facilitate common use cases, this crate also contains some pre-built functionality in the form of a [`tracing::TracingRuntime`] that traces the execution to a shared memory region.
//! It also contains a separate abstraction to easily filter the expressions that make up such a trace in the [`filter`] module.
//! For example, it contains a [`filter::NoFloat`] filter that concretizes all floating point operations in the trace, because those are usually more difficult to handle than discrete constraints.
//!
//! ## Crate setup
//! Your runtime crate should have the following keys set in its `Cargo.toml`:
//! ```toml
//! [profile.release]
//! # this is somewhat important to ensure the runtime does not unwind into the target program.
//! panic = "abort"
//! [profile.debug]
//! panic = "abort"
//!
//! [lib]
//! # this is required for the output to be a shared object (.so file)
//! crate-type = ["cdylib"]
//! # SymCC and SymQEMU expect to runtime file to be called `libSymRuntime.so`. Setting the name to `SymRuntime` achieves this.
//! name = "SymRuntime"
//! ```
pub mod filter; pub mod filter;
pub mod tracing; pub mod tracing;
// The following exports are used by the `export_runtime` macro. They are therefore exported, but hidden from docs, as they are not supposed to be used directly by the user.
#[doc(hidden)] #[doc(hidden)]
#[cfg(target_os = "linux")] #[cfg(target_os = "linux")]
pub mod cpp_runtime { pub mod cpp_runtime {
@ -49,8 +79,31 @@ macro_rules! rust_runtime_function_declaration {
}; };
} }
/// Values of this type identify an expression. They can be thought of as references to expressions.
///
/// All values of this type are produced by the `build_*` methods on [`Runtime`] and subsequently consumed by the runtime.
/// Therefore, how these values are interpreted is entirely up to the runtime.
/// They are pointer-sized and are required to be non-zero.
/// Therefore this type resolves to [`core::num::NonZeroUsize`].
pub type RSymExpr = concolic::SymExprRef; pub type RSymExpr = concolic::SymExprRef;
/// This trait encapsulates the full interface of a runtime.
/// The individual methods of this trait are not documented, but follow a simple rules:
///
/// 1. methods starting with `build_` or end in `_helper` create new expressions in the trace
/// 2. `Runtime::get_input_byte` creates variable expressions
/// 3. methods starting with `notify_` trace give an indication as to where in the code the execution is at (using random, but stable identifiers)
/// 4. `Runtime::push_path_constraint` creates a root expression (no other expressions can reference this) and marks a path constraint in the execution of the target
/// 5. `Runtime::expression_unreachable` is called regularly to with [`RSymExpr`]'s that won't be referenced in future calls to the runtime (because they are not reachable anymore)
///
/// All methods that create new expressions return `Option<RSymExpr>`. Returning `Option::None` will concretize the result of the expression.
/// For example, returning `None` from `Runtime::build_udiv` will concretize the result of all unsidned integer division operations.
/// Filtering expressions like this is also facilitated by [`filter::Filter`].
///
/// ## Drop
/// The code generated from `export_runtime` will attempt to drop your runtime.
/// In the context of fuzzing it is expected that the process may crash and in this case, the runtime will not be dropped.
/// Therefore, any runtime should make sure to handle this case properly (for example by flushing buffers regularly).
pub trait Runtime { pub trait Runtime {
invoke_macro_with_rust_runtime_exports!(rust_runtime_function_declaration;); invoke_macro_with_rust_runtime_exports!(rust_runtime_function_declaration;);
} }
@ -73,9 +126,11 @@ macro_rules! unwrap_option {
}; };
} }
/// Creates an exported extern C function for the given runtime function declaration, forwarding to the runtime as obtained by $rt_cb (which should be `fn (fn (&mut impl Runtime))`).
#[doc(hidden)] #[doc(hidden)]
#[macro_export] #[macro_export]
macro_rules! export_rust_runtime_fn { macro_rules! export_rust_runtime_fn {
// special case for expression_unreachable, because we need to be convert pointer+length to slice
(pub fn expression_unreachable(expressions: *mut RSymExpr, num_elements: usize), $c_name:ident; $rt_cb:path) => { (pub fn expression_unreachable(expressions: *mut RSymExpr, num_elements: usize), $c_name:ident; $rt_cb:path) => {
#[allow(clippy::missing_safety_doc)] #[allow(clippy::missing_safety_doc)]
#[no_mangle] #[no_mangle]
@ -86,6 +141,7 @@ macro_rules! export_rust_runtime_fn {
}) })
} }
}; };
// special case for push_path_constraint, we are not returning a new expression while taking an expression as argument
(pub fn push_path_constraint(constraint: RSymExpr, taken: bool, site_id: usize), $c_name:ident; $rt_cb:path) => { (pub fn push_path_constraint(constraint: RSymExpr, taken: bool, site_id: usize), $c_name:ident; $rt_cb:path) => {
#[allow(clippy::missing_safety_doc)] #[allow(clippy::missing_safety_doc)]
#[no_mangle] #[no_mangle]
@ -97,6 +153,7 @@ macro_rules! export_rust_runtime_fn {
} }
} }
}; };
// all other methods are handled by this
(pub fn $name:ident($( $arg:ident : $(::)?$($type:ident)::+ ),*$(,)?)$( -> $($ret:ident)::+)?, $c_name:ident; $rt_cb:path) => { (pub fn $name:ident($( $arg:ident : $(::)?$($type:ident)::+ ),*$(,)?)$( -> $($ret:ident)::+)?, $c_name:ident; $rt_cb:path) => {
#[allow(clippy::missing_safety_doc)] #[allow(clippy::missing_safety_doc)]
#[no_mangle] #[no_mangle]
@ -109,7 +166,9 @@ macro_rules! export_rust_runtime_fn {
}; };
} }
/// implements the [`NopRuntime`] methods by returning [`Default::default`] from all methods.
macro_rules! impl_nop_runtime_fn { macro_rules! impl_nop_runtime_fn {
// special case for expression_unreachable, because it has a different signature in our runtime trait than in the c interface.
(pub fn expression_unreachable(expressions: *mut RSymExpr, num_elements: usize), $c_name:ident;) => { (pub fn expression_unreachable(expressions: *mut RSymExpr, num_elements: usize), $c_name:ident;) => {
#[allow(clippy::default_trait_access)] #[allow(clippy::default_trait_access)]
fn expression_unreachable(&mut self, _exprs: &[RSymExpr]) {std::default::Default::default()} fn expression_unreachable(&mut self, _exprs: &[RSymExpr]) {std::default::Default::default()}
@ -121,36 +180,79 @@ macro_rules! impl_nop_runtime_fn {
}; };
} }
/// This runtime does nothing and concretizes all expressions. Intended for testing purposes.
pub struct NopRuntime; pub struct NopRuntime;
impl Runtime for NopRuntime { impl Runtime for NopRuntime {
invoke_macro_with_rust_runtime_exports!(impl_nop_runtime_fn;); invoke_macro_with_rust_runtime_exports!(impl_nop_runtime_fn;);
} }
/// This macro allows you to export your runtime from your crate. It is necessary to call this macro in your crate to get a functional runtime.
///
/// ## Simple form
/// The simplest invocation of this macro looks like this:
/// ```no_run
/// # #[macro_use] extern crate symcc_runtime;
/// # use symcc_runtime::{NopRuntime, Runtime};
/// export_runtime!(NopRuntime => NopRuntime);
/// ```
/// The first argument is an expression that constructs your `Runtime` type and the second argument is the name of your `Runtime` type.
/// For example, to construct a tracing runtime, the invocation would look like this:
/// ```no_run
/// # #[macro_use] extern crate symcc_runtime;
/// # use symcc_runtime::{tracing::TracingRuntime, Runtime};
/// export_runtime!(TracingRuntime::new(todo!()) => TracingRuntime);
/// ```
///
/// ## Runtime composition using `Filter`s
/// If you're not a fan of macro magic, you should stop reading here.
///
/// To construct a runtime that is composed of [`filter::Filter`]s, you can save some boilerplate code by using the extended form of this macro.
/// The gist of it is that you can prepend any number of `constructor => type` statements (separated by `;`) to your final runtime statement and the result of this macro will wrap your final runtime with the given filters.
/// Filters are applied from left to right.
///
/// Example:
/// ```no_run
/// # #[macro_use] extern crate symcc_runtime;
/// # use symcc_runtime::{tracing::TracingRuntime, Runtime, filter::NoFloat};
/// export_runtime!(NoFloat => NoFloat; TracingRuntime::new(todo!()) => TracingRuntime);
/// ```
/// This will construct a runtime that is first filtered by [`filter::NoFloat`] and then traced by the tracing runtime.
///
/// You can achieve the same effect by constructing [`filter::FilterRuntime`] manually, but as you add more filters, the types become tedious to write out.
#[macro_export] #[macro_export]
macro_rules! export_runtime { macro_rules! export_runtime {
($filter_constructor:expr => $filter:ty ; $($constructor:expr => $rt:ty);+) => { // Simple version: just export this runtime
export_runtime!(@final export_runtime!(@combine_constructor $filter_constructor; $($constructor);+) => export_runtime!(@combine_type $filter; $($rt);+));
};
($constructor:expr => $rt:ty) => { ($constructor:expr => $rt:ty) => {
export_runtime!(@final $constructor => $rt); export_runtime!(@final $constructor => $rt);
}; };
// Compositional version: export this chain of filters and a final runtime
($filter_constructor:expr => $filter:ty ; $($constructor:expr => $rt:ty);+) => {
export_runtime!(@final export_runtime!(@combine_constructor $filter_constructor; $($constructor);+) => export_runtime!(@combine_type $filter; $($rt);+));
};
// combines a chain of filter constructor expressions
// recursive case: wrap the constructor expression in a `filter::FilterRuntime::new`
(@combine_constructor $filter_constructor:expr ; $($constructor:expr);+) => { (@combine_constructor $filter_constructor:expr ; $($constructor:expr);+) => {
$crate::filter::FilterRuntime::new($filter_constructor, export_runtime!(@combine_constructor $($constructor);+)) $crate::filter::FilterRuntime::new($filter_constructor, export_runtime!(@combine_constructor $($constructor);+))
}; };
// base case
(@combine_constructor $constructor:expr) => { (@combine_constructor $constructor:expr) => {
$constructor $constructor
}; };
// combines a chain of filter type expressions
// recursive case: wrap the type in a `filter::FilterRuntime`
(@combine_type $filter:ty ; $($rt:ty);+) => { (@combine_type $filter:ty ; $($rt:ty);+) => {
$crate::filter::FilterRuntime<$filter, export_runtime!(@combine_type $($rt);+)> $crate::filter::FilterRuntime<$filter, export_runtime!(@combine_type $($rt);+)>
}; };
// base case
(@combine_type $rt:ty) => { (@combine_type $rt:ty) => {
$rt $rt
}; };
// finally, generate the necessary code for the given runtime
(@final $constructor:expr => $rt:ty) => { (@final $constructor:expr => $rt:ty) => {
// We are creating a piece of shared mutable state here for our runtime, which is used unsafely. // We are creating a piece of shared mutable state here for our runtime, which is used unsafely.
// The correct solution here would be to either use a mutex or have per-thread state, // The correct solution here would be to either use a mutex or have per-thread state,

162
libafl_concolic/symcc_runtime/src/tracing.rs
View File

@ -1,14 +1,18 @@
pub use libafl::observers::concolic::{ //! Tracing of expressions in a serialized form.
serialization_format::shared_memory::StdShMemMessageFileWriter, SymExpr,
}; pub use libafl::observers::concolic::serialization_format::StdShMemMessageFileWriter;
use libafl::observers::concolic::SymExpr;
use crate::{RSymExpr, Runtime}; use crate::{RSymExpr, Runtime};
/// Traces the expressions according to the format described in [`libafl::observers::concolic::serialization_format`].
/// The format can be read from elsewhere to perform processing of the expressions outside of the runtime.
pub struct TracingRuntime { pub struct TracingRuntime {
writer: StdShMemMessageFileWriter, writer: StdShMemMessageFileWriter,
} }
impl TracingRuntime { impl TracingRuntime {
/// Creates the runtime, tracing using the given writer.
#[must_use] #[must_use]
pub fn new(writer: StdShMemMessageFileWriter) -> Self { pub fn new(writer: StdShMemMessageFileWriter) -> Self {
Self { writer } Self { writer }
@ -52,101 +56,92 @@ macro_rules! binary_expression_builder {
} }
impl Runtime for TracingRuntime { impl Runtime for TracingRuntime {
expression_builder!(get_input_byte(offset: usize) => GetInputByte); expression_builder!(get_input_byte(offset: usize) => InputByte);
expression_builder!(build_integer(value: u64, bits: u8) => BuildInteger); expression_builder!(build_integer(value: u64, bits: u8) => Integer);
expression_builder!(build_integer128(high: u64, low: u64) => BuildInteger128); expression_builder!(build_integer128(high: u64, low: u64) => Integer128);
expression_builder!(build_float(value: f64, is_double: bool) => BuildFloat); expression_builder!(build_float(value: f64, is_double: bool) => Float);
expression_builder!(build_null_pointer() => BuildNullPointer); expression_builder!(build_null_pointer() => NullPointer);
expression_builder!(build_true() => BuildTrue); expression_builder!(build_true() => True);
expression_builder!(build_false() => BuildFalse); expression_builder!(build_false() => False);
expression_builder!(build_bool(value: bool) => BuildBool); expression_builder!(build_bool(value: bool) => Bool);
unary_expression_builder!(build_neg, BuildNeg); unary_expression_builder!(build_neg, Neg);
binary_expression_builder!(build_add, BuildAdd); binary_expression_builder!(build_add, Add);
binary_expression_builder!(build_sub, BuildSub); binary_expression_builder!(build_sub, Sub);
binary_expression_builder!(build_mul, BuildMul); binary_expression_builder!(build_mul, Mul);
binary_expression_builder!(build_unsigned_div, BuildUnsignedDiv); binary_expression_builder!(build_unsigned_div, UnsignedDiv);
binary_expression_builder!(build_signed_div, BuildSignedDiv); binary_expression_builder!(build_signed_div, SignedDiv);
binary_expression_builder!(build_unsigned_rem, BuildUnsignedRem); binary_expression_builder!(build_unsigned_rem, UnsignedRem);
binary_expression_builder!(build_signed_rem, BuildSignedRem); binary_expression_builder!(build_signed_rem, SignedRem);
binary_expression_builder!(build_shift_left, BuildShiftLeft); binary_expression_builder!(build_shift_left, ShiftLeft);
binary_expression_builder!(build_logical_shift_right, BuildLogicalShiftRight); binary_expression_builder!(build_logical_shift_right, LogicalShiftRight);
binary_expression_builder!(build_arithmetic_shift_right, BuildArithmeticShiftRight); binary_expression_builder!(build_arithmetic_shift_right, ArithmeticShiftRight);
binary_expression_builder!(build_signed_less_than, BuildSignedLessThan); binary_expression_builder!(build_signed_less_than, SignedLessThan);
binary_expression_builder!(build_signed_less_equal, BuildSignedLessEqual); binary_expression_builder!(build_signed_less_equal, SignedLessEqual);
binary_expression_builder!(build_signed_greater_than, BuildSignedGreaterThan); binary_expression_builder!(build_signed_greater_than, SignedGreaterThan);
binary_expression_builder!(build_signed_greater_equal, BuildSignedGreaterEqual); binary_expression_builder!(build_signed_greater_equal, SignedGreaterEqual);
binary_expression_builder!(build_unsigned_less_than, BuildUnsignedLessThan); binary_expression_builder!(build_unsigned_less_than, UnsignedLessThan);
binary_expression_builder!(build_unsigned_less_equal, BuildUnsignedLessEqual); binary_expression_builder!(build_unsigned_less_equal, UnsignedLessEqual);
binary_expression_builder!(build_unsigned_greater_than, BuildUnsignedGreaterThan); binary_expression_builder!(build_unsigned_greater_than, UnsignedGreaterThan);
binary_expression_builder!(build_unsigned_greater_equal, BuildUnsignedGreaterEqual); binary_expression_builder!(build_unsigned_greater_equal, UnsignedGreaterEqual);
binary_expression_builder!(build_and, BuildAnd); binary_expression_builder!(build_and, And);
binary_expression_builder!(build_or, BuildOr); binary_expression_builder!(build_or, Or);
binary_expression_builder!(build_xor, BuildXor); binary_expression_builder!(build_xor, Xor);
binary_expression_builder!(build_float_ordered, BuildFloatOrdered); binary_expression_builder!(build_float_ordered, FloatOrdered);
binary_expression_builder!( binary_expression_builder!(build_float_ordered_greater_than, FloatOrderedGreaterThan);
build_float_ordered_greater_than, binary_expression_builder!(build_float_ordered_greater_equal, FloatOrderedGreaterEqual);
BuildFloatOrderedGreaterThan binary_expression_builder!(build_float_ordered_less_than, FloatOrderedLessThan);
); binary_expression_builder!(build_float_ordered_less_equal, FloatOrderedLessEqual);
binary_expression_builder!( binary_expression_builder!(build_float_ordered_equal, FloatOrderedEqual);
build_float_ordered_greater_equal, binary_expression_builder!(build_float_ordered_not_equal, FloatOrderedNotEqual);
BuildFloatOrderedGreaterEqual
);
binary_expression_builder!(build_float_ordered_less_than, BuildFloatOrderedLessThan);
binary_expression_builder!(build_float_ordered_less_equal, BuildFloatOrderedLessEqual);
binary_expression_builder!(build_float_ordered_equal, BuildFloatOrderedEqual);
binary_expression_builder!(build_float_ordered_not_equal, BuildFloatOrderedNotEqual);
binary_expression_builder!(build_float_unordered, BuildFloatUnordered); binary_expression_builder!(build_float_unordered, FloatUnordered);
binary_expression_builder!( binary_expression_builder!(
build_float_unordered_greater_than, build_float_unordered_greater_than,
BuildFloatUnorderedGreaterThan FloatUnorderedGreaterThan
); );
binary_expression_builder!( binary_expression_builder!(
build_float_unordered_greater_equal, build_float_unordered_greater_equal,
BuildFloatUnorderedGreaterEqual FloatUnorderedGreaterEqual
); );
binary_expression_builder!(build_float_unordered_less_than, BuildFloatUnorderedLessThan); binary_expression_builder!(build_float_unordered_less_than, FloatUnorderedLessThan);
binary_expression_builder!( binary_expression_builder!(build_float_unordered_less_equal, FloatUnorderedLessEqual);
build_float_unordered_less_equal, binary_expression_builder!(build_float_unordered_equal, FloatUnorderedEqual);
BuildFloatUnorderedLessEqual binary_expression_builder!(build_float_unordered_not_equal, FloatUnorderedNotEqual);
);
binary_expression_builder!(build_float_unordered_equal, BuildFloatUnorderedEqual);
binary_expression_builder!(build_float_unordered_not_equal, BuildFloatUnorderedNotEqual);
binary_expression_builder!(build_fp_add, BuildFloatAdd); binary_expression_builder!(build_fp_add, FloatAdd);
binary_expression_builder!(build_fp_sub, BuildFloatSub); binary_expression_builder!(build_fp_sub, FloatSub);
binary_expression_builder!(build_fp_mul, BuildFloatMul); binary_expression_builder!(build_fp_mul, FloatMul);
binary_expression_builder!(build_fp_div, BuildFloatDiv); binary_expression_builder!(build_fp_div, FloatDiv);
binary_expression_builder!(build_fp_rem, BuildFloatRem); binary_expression_builder!(build_fp_rem, FloatRem);
unary_expression_builder!(build_fp_abs, BuildFloatAbs); unary_expression_builder!(build_fp_abs, FloatAbs);
unary_expression_builder!(build_not, BuildNot); unary_expression_builder!(build_not, Not);
binary_expression_builder!(build_equal, BuildEqual); binary_expression_builder!(build_equal, Equal);
binary_expression_builder!(build_not_equal, BuildNotEqual); binary_expression_builder!(build_not_equal, NotEqual);
binary_expression_builder!(build_bool_and, BuildBoolAnd); binary_expression_builder!(build_bool_and, BoolAnd);
binary_expression_builder!(build_bool_or, BuildBoolOr); binary_expression_builder!(build_bool_or, BoolOr);
binary_expression_builder!(build_bool_xor, BuildBoolXor); binary_expression_builder!(build_bool_xor, BoolXor);
expression_builder!(build_sext(op: RSymExpr, bits: u8) => BuildSext); expression_builder!(build_sext(op: RSymExpr, bits: u8) => Sext);
expression_builder!(build_zext(op: RSymExpr, bits: u8) => BuildZext); expression_builder!(build_zext(op: RSymExpr, bits: u8) => Zext);
expression_builder!(build_trunc(op: RSymExpr, bits: u8) => BuildTrunc); expression_builder!(build_trunc(op: RSymExpr, bits: u8) => Trunc);
expression_builder!(build_int_to_float(op: RSymExpr, is_double: bool, is_signed: bool) => BuildIntToFloat); expression_builder!(build_int_to_float(op: RSymExpr, is_double: bool, is_signed: bool) => IntToFloat);
expression_builder!(build_float_to_float(op: RSymExpr, to_double: bool) => BuildFloatToFloat); expression_builder!(build_float_to_float(op: RSymExpr, to_double: bool) => FloatToFloat);
expression_builder!(build_bits_to_float(op: RSymExpr, to_double: bool) => BuildBitsToFloat); expression_builder!(build_bits_to_float(op: RSymExpr, to_double: bool) => BitsToFloat);
expression_builder!(build_float_to_bits(op: RSymExpr) => BuildFloatToBits); expression_builder!(build_float_to_bits(op: RSymExpr) => FloatToBits);
expression_builder!(build_float_to_signed_integer(op: RSymExpr, bits: u8) => BuildFloatToSignedInteger); expression_builder!(build_float_to_signed_integer(op: RSymExpr, bits: u8) => FloatToSignedInteger);
expression_builder!(build_float_to_unsigned_integer(op: RSymExpr, bits: u8) => BuildFloatToUnsignedInteger); expression_builder!(build_float_to_unsigned_integer(op: RSymExpr, bits: u8) => FloatToUnsignedInteger);
expression_builder!(build_bool_to_bits(op: RSymExpr, bits: u8) => BuildBoolToBits); expression_builder!(build_bool_to_bits(op: RSymExpr, bits: u8) => BoolToBits);
binary_expression_builder!(concat_helper, ConcatHelper); binary_expression_builder!(concat_helper, Concat);
expression_builder!(extract_helper(op: RSymExpr, first_bit:usize, last_bit:usize) => ExtractHelper); expression_builder!(extract_helper(op: RSymExpr, first_bit:usize, last_bit:usize) => Extract);
fn notify_call(&mut self, _site_id: usize) {} fn notify_call(&mut self, _site_id: usize) {}
@ -161,7 +156,7 @@ impl Runtime for TracingRuntime {
} }
fn push_path_constraint(&mut self, constraint: RSymExpr, taken: bool, site_id: usize) { fn push_path_constraint(&mut self, constraint: RSymExpr, taken: bool, site_id: usize) {
self.write_message(SymExpr::PushPathConstraint { self.write_message(SymExpr::PathConstraint {
constraint, constraint,
taken, taken,
site_id, site_id,
@ -171,6 +166,9 @@ impl Runtime for TracingRuntime {
impl Drop for TracingRuntime { impl Drop for TracingRuntime {
fn drop(&mut self) { fn drop(&mut self) {
self.writer.end().expect("failed to shut down writer"); // manually end the writer to update the length prefix
self.writer
.update_trace_header()
.expect("failed to shut down writer");
} }
} }

9
libafl_concolic/test/README.md Normal file
View File

@ -0,0 +1,9 @@
This folder contains all the code necessary to run a smoke test of the whole concolic tracing setup.
This is achieved by
1. Compiling SymCC. Dependencies are installed via `smoke_test_ubuntu_deps.sh`.
2. Compiling a custom runtime with tracing capability (`runtime_test`).
3. Compiling a test program using SymCC that instruments using the custom runtime.
4. Capturing an execution trace of the instrumented target using `dump_constraints` and a fixed input (`if_test_input`).
5. Snapshot-testing the captured trace against our expectation (`expected_constraints.txt`).
This whole process is orchestrated by `smoke_test.sh`.

1
libafl_concolic/test/dump_constraints/Cargo.toml
View File

@ -2,6 +2,7 @@
name = "dump_constraints" name = "dump_constraints"
version = "0.1.0" version = "0.1.0"
edition = "2018" edition = "2018"
authors = ["Julius Hohnerlein <julihoh@users.noreply.github.com>"]
# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html

16
libafl_concolic/test/dump_constraints/src/main.rs
View File

@ -1,3 +1,7 @@
//! This is a straight-forward command line utility that can dump constraints written by a tracing runtime.
//! It achieves this by running an instrumented target program with the necessary environment variables set.
//! When the program has finished executing, it dumps the traced constraints to a file.
use std::{ use std::{
ffi::OsString, ffi::OsString,
fs::File, fs::File,
@ -12,11 +16,8 @@ use structopt::StructOpt;
use libafl::{ use libafl::{
bolts::shmem::{ShMem, ShMemProvider, StdShMemProvider}, bolts::shmem::{ShMem, ShMemProvider, StdShMemProvider},
observers::concolic::{ observers::concolic::{
serialization_format::{ serialization_format::{MessageFileReader, MessageFileWriter, DEFAULT_ENV_NAME},
shared_memory::DEFAULT_ENV_NAME, MessageFileReader, MessageFileWriter, EXPRESSION_PRUNING, HITMAP_ENV_NAME, NO_FLOAT_ENV_NAME, SELECTIVE_SYMBOLICATION_ENV_NAME,
},
SymExpr, EXPRESSION_PRUNING, HITMAP_ENV_NAME, NO_FLOAT_ENV_NAME,
SELECTIVE_SYMBOLICATION_ENV_NAME,
}, },
}; };
@ -113,7 +114,7 @@ fn main() {
} }
} }
// open a new scope to ensure our ressources get dropped before the exit call at the end // open a new scope to ensure our resources get dropped before the exit call at the end
let output_file_path = opt.output.unwrap_or_else(|| "trace".into()); let output_file_path = opt.output.unwrap_or_else(|| "trace".into());
let mut output_file = let mut output_file =
BufWriter::new(File::create(output_file_path).expect("unable to open output file")); BufWriter::new(File::create(output_file_path).expect("unable to open output file"));
@ -140,9 +141,6 @@ fn main() {
break; break;
} }
} }
writer
.write_message(SymExpr::End)
.expect("unable to write end message");
} }
} }

60
libafl_concolic/test/expected_constraints.txt
View File

@ -1,30 +1,30 @@
1 GetInputByte { offset: 0 } 1 InputByte { offset: 0 }
2 GetInputByte { offset: 1 } 2 InputByte { offset: 1 }
3 GetInputByte { offset: 2 } 3 InputByte { offset: 2 }
4 GetInputByte { offset: 3 } 4 InputByte { offset: 3 }
5 ConcatHelper { a: 2, b: 1 } 5 Concat { a: 2, b: 1 }
6 ConcatHelper { a: 3, b: 5 } 6 Concat { a: 3, b: 5 }
7 ConcatHelper { a: 4, b: 6 } 7 Concat { a: 4, b: 6 }
8 ConcatHelper { a: 2, b: 1 } 8 Concat { a: 2, b: 1 }
9 ConcatHelper { a: 3, b: 8 } 9 Concat { a: 3, b: 8 }
10 ConcatHelper { a: 4, b: 9 } 10 Concat { a: 4, b: 9 }
11 ExtractHelper { op: 10, first_bit: 7, last_bit: 0 } 11 Extract { op: 10, first_bit: 7, last_bit: 0 }
12 ExtractHelper { op: 10, first_bit: 15, last_bit: 8 } 12 Extract { op: 10, first_bit: 15, last_bit: 8 }
13 ExtractHelper { op: 10, first_bit: 23, last_bit: 16 } 13 Extract { op: 10, first_bit: 23, last_bit: 16 }
14 ExtractHelper { op: 10, first_bit: 31, last_bit: 24 } 14 Extract { op: 10, first_bit: 31, last_bit: 24 }
15 ConcatHelper { a: 12, b: 11 } 15 Concat { a: 12, b: 11 }
16 ConcatHelper { a: 13, b: 15 } 16 Concat { a: 13, b: 15 }
17 ConcatHelper { a: 14, b: 16 } 17 Concat { a: 14, b: 16 }
18 BuildInteger { value: 2, bits: 32 } 18 Integer { value: 2, bits: 32 }
19 BuildMul { a: 18, b: 17 } 19 Mul { a: 18, b: 17 }
20 BuildInteger { value: 7, bits: 32 } 20 Integer { value: 7, bits: 32 }
21 BuildSignedLessThan { a: 19, b: 20 } 21 SignedLessThan { a: 19, b: 20 }
22 PushPathConstraint { constraint: 21, taken: false, site_id: 11229456 } 22 PathConstraint { constraint: 21, taken: false, site_id: 11229456 }
22 ConcatHelper { a: 12, b: 11 } 22 Concat { a: 12, b: 11 }
23 ConcatHelper { a: 13, b: 22 } 23 Concat { a: 13, b: 22 }
24 ConcatHelper { a: 14, b: 23 } 24 Concat { a: 14, b: 23 }
25 BuildInteger { value: 7, bits: 32 } 25 Integer { value: 7, bits: 32 }
26 BuildSignedRem { a: 24, b: 25 } 26 SignedRem { a: 24, b: 25 }
27 BuildInteger { value: 0, bits: 32 } 27 Integer { value: 0, bits: 32 }
28 BuildNotEqual { a: 26, b: 27 } 28 NotEqual { a: 26, b: 27 }
29 PushPathConstraint { constraint: 28, taken: true, site_id: 11122032 } 29 PathConstraint { constraint: 28, taken: true, site_id: 11122032 }

1
libafl_concolic/test/runtime_test/Cargo.toml
View File

@ -2,6 +2,7 @@
name = "runtime_test" name = "runtime_test"
version = "0.1.0" version = "0.1.0"
edition = "2018" edition = "2018"
authors = ["Julius Hohnerlein <julihoh@users.noreply.github.com>"]
[lib] [lib]
crate-type = ["cdylib"] crate-type = ["cdylib"]

2
libafl_concolic/test/runtime_test/src/lib.rs
View File

@ -1,3 +1,5 @@
//! Just a small runtime to be used in the smoke test.
use symcc_runtime::{ use symcc_runtime::{
export_runtime, export_runtime,
filter::NoFloat, filter::NoFloat,