Ignore SigPipe by default (#1741)

* Ignore SigPipe by default

* Fix no_std

* fmt

libafl/Cargo.toml

@@ -56,6 +56,8 @@ fork = ["libafl_bolts/derive"]
 ## Collected stats to decide if observers must be serialized or not (which should reduce mem use and increase speed)
 adaptive_serialization = []
 
+## If this feature is set, `LibAFL` targets (and the fuzzer) will crash on `SIGPIPE` on unix systems.
+handle_sigpipe = []
 
 #! ## Additional Components
 

libafl/src/executors/inprocess.rs

@@ -5,7 +5,7 @@
 #![allow(clippy::needless_pass_by_value)]
 
 use alloc::boxed::Box;
-#[cfg(all(unix, feature = "std"))]
+#[cfg(unix)]
 use alloc::vec::Vec;
 #[cfg(all(feature = "std", unix, target_os = "linux"))]
 use core::ptr::addr_of_mut;
@@ -28,8 +28,10 @@ use std::intrinsics::transmute;
 
 #[cfg(all(unix, not(miri)))]
 use libafl_bolts::os::unix_signals::setup_signal_handler;
+#[cfg(unix)]
+use libafl_bolts::os::unix_signals::Signal;
 #[cfg(all(feature = "std", unix))]
-use libafl_bolts::os::unix_signals::{ucontext_t, Handler, Signal};
+use libafl_bolts::os::unix_signals::{ucontext_t, Handler};
 #[cfg(all(windows, feature = "std"))]
 use libafl_bolts::os::windows_exceptions::setup_exception_handler;
 #[cfg(all(feature = "std", unix))]
@@ -276,6 +278,24 @@ pub struct InProcessHandlers {
     pub timeout_handler: *const c_void,
 }
 
+/// The common signals we want to handle
+#[cfg(unix)]
+#[inline]
+fn common_signals() -> Vec<Signal> {
+    vec![
+        Signal::SigAlarm,
+        Signal::SigUser2,
+        Signal::SigAbort,
+        Signal::SigBus,
+        #[cfg(feature = "handle_sigpipe")]
+        Signal::SigPipe,
+        Signal::SigFloatingPointException,
+        Signal::SigIllegalInstruction,
+        Signal::SigSegmentationFault,
+        Signal::SigTrap,
+    ]
+}
+
 impl InProcessHandlers {
     /// Call before running a target.
     #[allow(clippy::unused_self)]
@@ -683,6 +703,7 @@ pub mod unix_signal_handler {
     use libafl_bolts::os::unix_signals::{ucontext_t, Handler, Signal};
     use libc::siginfo_t;
 
+    use super::common_signals;
     #[cfg(feature = "std")]
     use crate::inputs::Input;
     use crate::{
@@ -743,17 +764,7 @@ pub mod unix_signal_handler {
         }
 
         fn signals(&self) -> Vec<Signal> {
-            vec![
+            common_signals()
-                Signal::SigAlarm,
-                Signal::SigUser2,
-                Signal::SigAbort,
-                Signal::SigBus,
-                Signal::SigPipe,
-                Signal::SigFloatingPointException,
-                Signal::SigIllegalInstruction,
-                Signal::SigSegmentationFault,
-                Signal::SigTrap,
-            ]
         }
     }
 
@@ -1541,17 +1552,7 @@ impl Handler for InProcessForkExecutorGlobalData {
     }
 
     fn signals(&self) -> Vec<Signal> {
-        vec![
+        common_signals()
-            Signal::SigAlarm,
-            Signal::SigUser2,
-            Signal::SigAbort,
-            Signal::SigBus,
-            Signal::SigPipe,
-            Signal::SigFloatingPointException,
-            Signal::SigIllegalInstruction,
-            Signal::SigSegmentationFault,
-            Signal::SigTrap,
-        ]
     }
 }
 

libafl_bolts/src/os/unix_signals.rs

@@ -331,16 +331,6 @@ impl From<Signal> for nix::sys::signal::Signal {
     }
 }
 
-/// A list of crashing signals
-pub static CRASH_SIGNALS: &[Signal] = &[
-    Signal::SigAbort,
-    Signal::SigBus,
-    Signal::SigFloatingPointException,
-    Signal::SigIllegalInstruction,
-    Signal::SigPipe,
-    Signal::SigSegmentationFault,
-];
-
 impl PartialEq for Signal {
     fn eq(&self, other: &Self) -> bool {
         *self as i32 == *other as i32