Merge #268

268: Print specific error message on SIGBUS r=AdrianCX a=jethrogb Co-authored-by: Jethro Beekman <[email protected]>
fortanix · Jul 16, 2020 · 981505f · 981505f
2 parents 0eaff6c + 6d4987e
commit 981505f
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Showing 4 changed files with 38 additions and 14 deletions.
diff --git a/Cargo.lock b/Cargo.lock
diff --git a/fortanix-sgx-tools/Cargo.toml b/fortanix-sgx-tools/Cargo.toml
@@ -15,6 +15,7 @@ documentation = "https://edp.fortanix.com/docs/"
 homepage = "https://edp.fortanix.com/"
 keywords = ["sgx", "enclave", "ftxsgx-runner"]
 categories = ["development-tools::build-utils", "command-line-utilities"]
+edition = "2018"
 
 [dependencies]
 # Project dependencies
@@ -33,3 +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-elf2sgxs.rs b/fortanix-sgx-tools/src/bin/ftxsgx-elf2sgxs.rs
@@ -108,7 +108,7 @@ impl Splice {
 pub struct LayoutInfo<'a> {
     elf: ElfFile<'a>,
     sym: Symbols<'a>,
-    dyn: Option<Dynamic<'a>>,
+    dynamic: Option<Dynamic<'a>>,
     ssaframesize: u32,
     heap_size: u64,
     stack_size: u64,
@@ -299,8 +299,8 @@ impl<'a> LayoutInfo<'a> {
         let mut rela = None;
         let mut relacount = None;
 
-        for dyn in dyns {
-            match dyn.get_tag().map_err(err_msg)? {
+        for dynamic in dyns {
+            match dynamic.get_tag().map_err(err_msg)? {
                 // Some entries for PLT/GOT checking are currently
                 // commented out. I *think* that if there were an actual
                 // PLT/GOT problem, that would be caught by the remaining
@@ -313,10 +313,10 @@ impl<'a> LayoutInfo<'a> {
                     bail!("Unsupported dynamic entry: .fini functions"),
                 Rel | RelSize | RelEnt | DT_RELCOUNT =>
                     bail!("Unsupported dynamic entry: relocations with implicit addend"),
-                Rela => if replace(&mut rela, Some(dyn)).is_some() {
+                Rela => if replace(&mut rela, Some(dynamic)).is_some() {
                     bail!("Found dynamic entry twice: DT_RELA")
                 },
-                DT_RELACOUNT => if replace(&mut relacount, Some(dyn)).is_some() {
+                DT_RELACOUNT => if replace(&mut relacount, Some(dynamic)).is_some() {
                     bail!("Found dynamic entry twice: DT_RELACOUNT")
                 },
                 _ => {}
@@ -396,16 +396,16 @@ impl<'a> LayoutInfo<'a> {
         }
         Self::check_toolchain_version(&elf)?;
         let sym = Self::check_symbols(&elf)?;
-        let dyn = Self::check_dynamic(&elf)?;
-        Self::check_relocs(&elf, dyn.as_ref())?;
+        let dynamic = Self::check_dynamic(&elf)?;
+        Self::check_relocs(&elf, dynamic.as_ref())?;
         let ehfrm = Self::check_section(&elf, ".eh_frame")?;
         let ehfrm_hdr = Self::check_section(&elf, ".eh_frame_hdr")?;
         let text = Self::check_section(&elf, ".text")?;
 
         Ok(LayoutInfo {
             elf,
             sym,
-            dyn,
+            dynamic,
             ssaframesize,
             heap_size,
             stack_size,
@@ -432,15 +432,15 @@ impl<'a> LayoutInfo<'a> {
             Splice::for_sym_u64(self.sym.HEAP_SIZE, self.heap_size),
             Splice::for_sym_u64(
                 self.sym.RELA,               
-                self.dyn
+                self.dynamic
                     .as_ref()
                     .and_then(|d| d.rela.get_ptr().ok())
                     .unwrap_or(0),
 
             ),
             Splice::for_sym_u64(
                 self.sym.RELACOUNT,
-                self.dyn
+                self.dynamic
                     .as_ref()
                     .and_then(|d| d.relacount.get_val().ok())
                     .unwrap_or(0),

diff --git a/fortanix-sgx-tools/src/bin/ftxsgx-runner.rs b/fortanix-sgx-tools/src/bin/ftxsgx-runner.rs
@@ -4,17 +4,20 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
-extern crate aesm_client;
-extern crate enclave_runner;
-extern crate sgxs_loaders;
-extern crate failure;
 #[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;
@@ -30,6 +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(
@@ -61,6 +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)