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Fix for #1881, ProbabilitySamplingScheduler seems to be inverted (#1884)

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* Fix for #1881, ProbabilitySamplingScheduler seems to be inverted

* Run 'cargo +nightly fmt'

* Added debug_assert as negative and infinite probability values would break the current implementation of next()

---------

Co-authored-by: Dan Blackwell <danblackwell@eduroam-int-dhcp-97-192-218.ucl.ac.uk>
Co-authored-by: Dan Blackwell <danblackwell@ML-W0NYVW4XCK.local>
Co-authored-by: Dongjia "toka" Zhang <tokazerkje@outlook.com>
This commit is contained in:
Dan Blackwell 2024-03-05 18:04:13 +00:00 committed by GitHub
parent e3f837d712
commit cd8003ee69
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1 changed files with 46 additions and 9 deletions
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55
libafl/src/schedulers/probabilistic_sampling.rs
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@ -9,9 +9,9 @@ use libafl_bolts::rands::Rand;
use serde::{Deserialize, Serialize};
use crate::{
corpus::{Corpus, CorpusId, HasTestcase},
corpus::{Corpus, CorpusId, HasTestcase, Testcase},
inputs::UsesInput,
schedulers::{Scheduler, TestcaseScore},
schedulers::{RemovableScheduler, Scheduler, TestcaseScore},
state::{HasCorpus, HasMetadata, HasRand, State, UsesState},
Error,
};
@ -74,23 +74,60 @@ where
#[allow(clippy::cast_precision_loss)]
#[allow(clippy::unused_self)]
pub fn store_probability(&self, state: &mut S, idx: CorpusId) -> Result<(), Error> {
let factor = F::compute(state, &mut *state.corpus().get(idx)?.borrow_mut())?;
if factor == 0.0 {
return Err(Error::illegal_state(
"Infinity probability calculated for probabilistic sampling scheduler",
));
}
let prob = F::compute(state, &mut *state.corpus().get(idx)?.borrow_mut())?;
debug_assert!(
prob >= 0.0 && prob.is_finite(),
"scheduler probability is {prob}; to work correctly it must be >= 0.0 and finite"
);
let meta = state
.metadata_map_mut()
.get_mut::<ProbabilityMetadata>()
.unwrap();
let prob = 1.0 / factor;
meta.map.insert(idx, prob);
meta.total_probability += prob;
Ok(())
}
}
impl<F, S> RemovableScheduler for ProbabilitySamplingScheduler<F, S>
where
F: TestcaseScore<S>,
S: HasCorpus + HasMetadata + HasRand + HasTestcase + State,
{
fn on_remove(
&mut self,
state: &mut Self::State,
idx: CorpusId,
_testcase: &Option<Testcase<<Self::State as UsesInput>::Input>>,
) -> Result<(), Error> {
let meta = state
.metadata_map_mut()
.get_mut::<ProbabilityMetadata>()
.unwrap();
if let Some(prob) = meta.map.remove(&idx) {
meta.total_probability -= prob;
}
Ok(())
}
fn on_replace(
&mut self,
state: &mut Self::State,
idx: CorpusId,
_prev: &Testcase<<Self::State as UsesInput>::Input>,
) -> Result<(), Error> {
let meta = state
.metadata_map_mut()
.get_mut::<ProbabilityMetadata>()
.unwrap();
if let Some(prob) = meta.map.remove(&idx) {
meta.total_probability -= prob;
}
self.store_probability(state, idx)
}
}
impl<F, S> UsesState for ProbabilitySamplingScheduler<F, S>
where
S: State + HasTestcase,