Fix some bugs with multithreaded tests:

* kmod tests must run exclusively, because they load and unload a module
  with a constant name.
* A few tests were doing some variant of chdir, but weren't taking the
  CWD_MTX.
* The kmod tests read files by path relative to CWD, so they need the
  CWD_MTX.  But they don't need it exclusively, so convert the CWD_MTX
  into an RwLock.
* Tests that do change the cwd need to change it back when they're done.

1 files changed, 14 insertions, 0 deletions

diff --git a/test/test_kmod/mod.rs b/test/test_kmod/mod.rs
index 86558d1b..ad406357 100644
--- a/test/test_kmod/mod.rs
+++ b/test/test_kmod/mod.rs
@@ -41,6 +41,8 @@ use std::io::Read;
 #[test]
 fn test_finit_and_delete_module() {
     require_capability!(CAP_SYS_MODULE);
+    let _m0 = ::KMOD_MTX.lock().expect("Mutex got poisoned by another test");
+    let _m1 = ::CWD_LOCK.read().expect("Mutex got poisoned by another test");
 
     let (kmod_path, kmod_name, _kmod_dir) = compile_kernel_module();
 
@@ -57,6 +59,8 @@ fn test_finit_and_delete_module() {
 #[test]
 fn test_finit_and_delete_modul_with_params() {
     require_capability!(CAP_SYS_MODULE);
+    let _m0 = ::KMOD_MTX.lock().expect("Mutex got poisoned by another test");
+    let _m1 = ::CWD_LOCK.read().expect("Mutex got poisoned by another test");
 
     let (kmod_path, kmod_name, _kmod_dir) = compile_kernel_module();
 
@@ -76,6 +80,8 @@ fn test_finit_and_delete_modul_with_params() {
 #[test]
 fn test_init_and_delete_module() {
     require_capability!(CAP_SYS_MODULE);
+    let _m0 = ::KMOD_MTX.lock().expect("Mutex got poisoned by another test");
+    let _m1 = ::CWD_LOCK.read().expect("Mutex got poisoned by another test");
 
     let (kmod_path, kmod_name, _kmod_dir) = compile_kernel_module();
 
@@ -94,6 +100,8 @@ fn test_init_and_delete_module() {
 #[test]
 fn test_init_and_delete_module_with_params() {
     require_capability!(CAP_SYS_MODULE);
+    let _m0 = ::KMOD_MTX.lock().expect("Mutex got poisoned by another test");
+    let _m1 = ::CWD_LOCK.read().expect("Mutex got poisoned by another test");
 
     let (kmod_path, kmod_name, _kmod_dir) = compile_kernel_module();
 
@@ -113,6 +121,8 @@ fn test_init_and_delete_module_with_params() {
 #[test]
 fn test_finit_module_invalid() {
     require_capability!(CAP_SYS_MODULE);
+    let _m0 = ::KMOD_MTX.lock().expect("Mutex got poisoned by another test");
+    let _m1 = ::CWD_LOCK.read().expect("Mutex got poisoned by another test");
 
     let kmod_path = "/dev/zero";
 
@@ -125,6 +135,8 @@ fn test_finit_module_invalid() {
 #[test]
 fn test_finit_module_twice_and_delete_module() {
     require_capability!(CAP_SYS_MODULE);
+    let _m0 = ::KMOD_MTX.lock().expect("Mutex got poisoned by another test");
+    let _m1 = ::CWD_LOCK.read().expect("Mutex got poisoned by another test");
 
     let (kmod_path, kmod_name, _kmod_dir) = compile_kernel_module();
 
@@ -145,6 +157,8 @@ fn test_finit_module_twice_and_delete_module() {
 #[test]
 fn test_delete_module_not_loaded() {
     require_capability!(CAP_SYS_MODULE);
+    let _m0 = ::KMOD_MTX.lock().expect("Mutex got poisoned by another test");
+    let _m1 = ::CWD_LOCK.read().expect("Mutex got poisoned by another test");
 
     let result = delete_module(&CString::new("hello").unwrap(), DeleteModuleFlags::empty());