Print specific error message on SIGBUS

atomicjets · Jul 12, 2020 · 6d4987e · 6d4987e
1 parent 0a6df32
commit 6d4987e
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Showing 3 changed files with 27 additions and 0 deletions.
diff --git a/Cargo.lock b/Cargo.lock
diff --git a/fortanix-sgx-tools/Cargo.toml b/fortanix-sgx-tools/Cargo.toml
@@ -34,3 +34,5 @@ serde_derive = "1.0.84"    # MIT/Apache-2.0
 serde = "1.0.84"           # MIT/Apache-2.0
 toml = "0.4.10"            # MIT/Apache-2.0
 num_cpus = "1.9.0"         # MIT/Apache-2.0
+libc = "0.2.48"            # MIT/Apache-2.0
+nix = "0.13.0"             # MIT
diff --git a/fortanix-sgx-tools/src/bin/ftxsgx-runner.rs b/fortanix-sgx-tools/src/bin/ftxsgx-runner.rs
@@ -7,10 +7,17 @@
 #[macro_use]
 extern crate clap;
 
+#[cfg(unix)]
+use std::io::{stderr, Write};
+
 use aesm_client::AesmClient;
 use enclave_runner::EnclaveBuilder;
 use failure::{Error, ResultExt};
 #[cfg(unix)]
+use libc::{c_int, c_void, siginfo_t};
+#[cfg(unix)]
+use nix::sys::signal;
+#[cfg(unix)]
 use sgxs_loaders::isgx::Device as IsgxDevice;
 #[cfg(windows)]
 use sgxs_loaders::enclaveapi::Sgx as IsgxDevice;
@@ -26,6 +33,20 @@ arg_enum!{
     }
 }
 
+#[cfg(unix)]
+fn catch_sigbus() {
+    unsafe {
+        extern "C" fn handle_bus(_signo: c_int, _info: *mut siginfo_t, _context: *mut c_void) {
+            eprintln!("SIGBUS triggered: likely caused by stack overflow in enclave.");
+            let _ = stderr().flush();
+        }
+
+        let hdl = signal::SigHandler::SigAction(handle_bus);
+        let sig_action = signal::SigAction::new(hdl, signal::SaFlags::SA_RESETHAND, signal::SigSet::empty());
+        signal::sigaction(signal::SIGBUS, &sig_action).unwrap();
+    }
+}
+
 fn main() -> Result<(), Error> {
     let args = App::new("ftxsgx-runner")
         .arg(
@@ -57,6 +78,8 @@ fn main() -> Result<(), Error> {
 
     let enclave = enclave_builder.build(&mut device).context("While loading SGX enclave")?;
 
+    #[cfg(unix)] catch_sigbus();
+
     enclave.run().map_err(|e| {
         eprintln!("Error while executing SGX enclave.\n{}", e);
         std::process::exit(-1)