bolts: support dump_registers for x86 linux (#1694)

* bolts: support dump_registers for x86 linux

* bolts: fix write_crash fault addr for linux/x86

libafl_bolts/src/minibsod.rs

@@ -50,6 +50,33 @@ pub fn dump_registers<W: Write>(
     Ok(())
 }
 
+/// Write the content of all important registers
+#[cfg(all(any(target_os = "linux", target_os = "android"), target_arch = "x86"))]
+#[allow(clippy::similar_names)]
+pub fn dump_registers<W: Write>(
+    writer: &mut BufWriter<W>,
+    ucontext: &ucontext_t,
+) -> Result<(), std::io::Error> {
+    use libc::{
+        REG_EAX, REG_EBP, REG_EBX, REG_ECX, REG_EDI, REG_EDX, REG_EFL, REG_EIP, REG_ESI, REG_ESP,
+    };
+
+    let mcontext = &ucontext.uc_mcontext;
+
+    write!(writer, "eax: {:#016x}, ", mcontext.gregs[REG_EAX as usize])?;
+    write!(writer, "ebx: {:#016x}, ", mcontext.gregs[REG_EBX as usize])?;
+    write!(writer, "ecx: {:#016x}, ", mcontext.gregs[REG_ECX as usize])?;
+    writeln!(writer, "edx: {:#016x}, ", mcontext.gregs[REG_EDX as usize])?;
+    write!(writer, "edi: {:#016x}, ", mcontext.gregs[REG_EDI as usize])?;
+    write!(writer, "esi: {:#016x}, ", mcontext.gregs[REG_ESI as usize])?;
+    write!(writer, "esp: {:#016x}, ", mcontext.gregs[REG_ESP as usize])?;
+    writeln!(writer, "ebp: {:#016x}, ", mcontext.gregs[REG_EBP as usize])?;
+    write!(writer, "eip: {:#016x}, ", mcontext.gregs[REG_EIP as usize])?;
+    writeln!(writer, "efl: {:#016x}, ", mcontext.gregs[REG_EFL as usize])?;
+
+    Ok(())
+}
+
 /// Write the content of all important registers
 #[cfg(all(
     any(target_os = "linux", target_os = "android"),
@@ -478,7 +505,7 @@ fn write_crash<W: Write>(
         "Received signal {} at {:#08x}, fault address: {:#08x}",
         signal,
         ucontext.uc_mcontext.gregs[libc::REG_EIP as usize],
-        ucontext.uc_mcontext.gregs[libc::REG_ERR as usize]
+        ucontext.uc_mcontext.cr2
     )?;
 
     Ok(())