Enable building PTH with address sanitizer (#1)

* Enable building PTH with address sanitizer, on both GCC and Clang.
Clang also has the option to use annotations to enable the sanitizer to switch stacks.

* Adds convenience script for building & installing.
* Adds gitignore file for convenience
* Fix typo in PTH_DEBUG macro when --enable-debug is set

.gitignore

@@ -0,0 +1,23 @@
+*.o
+*.lo
+*.la
+.libs/
+bin/
+include/
+lib/
+man/
+share/
+test_*
+config.log
+config.status
+libtool
+pth_p.h
+pth.h
+.done-all
+.done-test
+.gdb*
+Makefile
+pth-config
+pth_acdef.h
+pth_acmac.h
+tags

build_pth.sh

@@ -0,0 +1,8 @@
+#!/bin/bash
+# USE: This configures/installs pth locally in $HOME/lib and $HOME/include. 
+# MANDATORY: Set env variables CC and CXX before running this script
+# On the parsa cluster, you should use /home/parsacom/tools/gcc-qflex/path/to/bin/gcc and g++
+./configure --with-pic --enable-shared --disable-static --prefix=$HOME
+make -j
+make test
+#make install

configure

@@ -1096,6 +1096,7 @@ Optional Features:
   --enable-FEATURE[=ARG]  include FEATURE [ARG=yes]
   --enable-subdir         enable local building as subdirectory (default=no)
   --enable-debug          build for debugging (default=no)
+  --enable-asan           build with address sanitizer (default=no)
   --enable-profile        build for profiling (default=no)
   --enable-optimize       build with optimization (default=no)
   --enable-shared[=PKGS]
@@ -2883,6 +2884,34 @@ echo "${ECHO_T}no" >&6
   SET_MAKE="MAKE=${MAKE-make}"
 fi
 
+# Check whether --enable-asan was requested
+if test "${enable_asan+set}" = set; then
+    echo "$as_me:$LINENO: checking whether compiler supports asan" >&5
+    echo $ECHO_N "checking whether compiler supports asan... $ECHO_C" >&6
+    enableval="$enable_asan"
+cat >conftest.$ac_ext <<EOF
+int main() { return 0; }
+EOF
+    ${CC-cc} -c $CFLAGS $CPPFLAGS -fsanitize=address conftest.$ac_ext 1>conftest.out 2>conftest.err
+    if test $? -ne 0 -o -s conftest.err; then
+        ac_cv_compiler_option_asan=no
+    else
+        ac_cv_compiler_option_asan=yes
+    fi
+    rm -f conftest.$ac_ext conftest.out conftest.err
+
+    if test ".$ac_cv_compiler_option_asan" = .yes; then
+        echo "$as_me:$LINENO: result: yes" >&5
+        echo "${ECHO_T}yes" >&6
+        CXXFLAGS="$CFLAGS -fsanitize=address"
+        CFLAGS="$CFLAGS -fsanitize=address"
+        LDFLAGS="$LDFLAGS -fsanitize=address"
+    else
+        echo "$as_me:$LINENO: result: no" >&5
+        echo "${ECHO_T}no" >&6
+    fi
+fi
+
 # Check whether --enable-debug or --disable-debug was given.
 if test "${enable_debug+set}" = set; then
   enableval="$enable_debug"
@@ -3020,7 +3049,6 @@ cat >>confdefs.h <<\_ACEOF
 #define PTH_DEBUG 1
 _ACEOF
 
-
 else
 
 if test ".$ac_cv_c_compiler_gnu" = ".yes"; then

pth_lib.c

@@ -128,8 +128,14 @@ int pth_init(void)
      * function to find the scheduler.
      */
     pth_current = pth_sched;
-    pth_mctx_switch(&pth_main->mctx, &pth_sched->mctx);
 
+    /* Msutherl: annotations for Clang api. Nothing happens under the hood if
+     * support not detected by autoconf. 
+     * */
+    wrapper_start_fiber_switch(pth_sched->stack,pth_sched->stacksize);
+    pth_mctx_switch(&pth_main->mctx, &pth_sched->mctx);
+    wrapper_finish_fiber_switch();
+    pth_debug5("Finished switch back to pth_init stack 0x%p, size %u, FROM stack 0x%p, size %u",pth_main->stack,pth_main->stacksize,from_stack,from_stacksize);
     /* came back, so let's go home... */
     pth_debug1("pth_init: leave");
     return TRUE;
@@ -212,6 +218,11 @@ static void pth_spawn_trampoline(void)
 {
     void *data;
 
+    /* Msutherl: Call the finish fiber switch here before jumping into the
+     * thread's execution function. Prevents all user code from needing to call
+     * an external sanitizer API. */
+    wrapper_finish_fiber_switch();
+
     /* just jump into the start routine */
     data = (*pth_current->start_func)(pth_current->start_arg);
 
@@ -449,7 +460,14 @@ void pth_exit(void *value)
         pth_current->join_arg = value;
         pth_current->state = PTH_STATE_DEAD;
         pth_debug2("pth_exit: switching from thread \"%s\" to scheduler", pth_current->name);
+
+        /* Msutherl: annotations for Clang api. Nothing happens under the hood if
+         * support not detected by autoconf. 
+         */
+        wrapper_start_fiber_switch(pth_sched->stack,pth_sched->stacksize);
         pth_mctx_switch(&pth_current->mctx, &pth_sched->mctx);
+        wrapper_finish_fiber_switch();
+        pth_debug5("Finished switch back to pth_sched stack 0x%p, size %u, FROM stack 0x%p, size %u",pth_sched->stack,pth_sched->stacksize,from_stack,from_stacksize);
     }
     else {
         /*
@@ -522,9 +540,15 @@ int pth_yield(pth_t to)
                    "in favour of thread \"%s\"", to->name);
     else
         pth_debug1("pth_yield: give up control to scheduler");
+
+    /* Msutherl: annotations for Clang api. Nothing happens under the hood if
+     * support not detected by autoconf. 
+     * */
+    wrapper_start_fiber_switch(pth_sched->stack,pth_sched->stacksize);
     pth_mctx_switch(&pth_current->mctx, &pth_sched->mctx);
+    wrapper_finish_fiber_switch();
+    pth_debug5("Finished switch back to pth_sched stack 0x%p, size %u, FROM stack 0x%p, size %u",pth_sched->stack,pth_sched->stacksize,from_stack,from_stacksize);
     pth_debug1("pth_yield: got back control from scheduler");
-
     pth_debug2("pth_yield: leave to thread \"%s\"", pth_current->name);
     return TRUE;
 }

pth_mctx.c

@@ -60,6 +60,17 @@ struct pth_mctx_st {
     int error;
 };
 
+/* Msutherl: Parameters to swap out when compiled using address sanitizer 
+ * These params are only used when --enable-asan requested from autoconf. */
+void *fake_stack_save;
+const void *from_stack;
+size_t from_stacksize;
+
+/* Functions that wrap __sanitizer_start_fiber_switch as well as __sanitizer_end_fiber_switch,
+ * as well as debugging prints if compiled in
+ */
+void wrapper_start_fiber_switch(const void *new_stack, const size_t new_stacksize);
+void wrapper_finish_fiber_switch(void);
 /*
 ** ____ MACHINE STATE SWITCHING ______________________________________
 */
@@ -119,7 +130,7 @@ struct pth_mctx_st {
  * switch from one machine context to another
  */
 #define SWITCH_DEBUG_LINE \
-        "==== THREAD CONTEXT SWITCH ==========================================="
+        "================== THREAD CONTEXT SWITCH ==========================================="
 #ifdef PTH_DEBUG
 #define  _pth_mctx_switch_debug pth_debug(NULL, 0, 1, SWITCH_DEBUG_LINE);
 #else
@@ -141,6 +152,40 @@ struct pth_mctx_st {
 
 #endif /* cpp */
 
+/* Msutherl: Include sanitizer API */
+#if defined(__clang__)
+#if defined(__has_feature)
+#if __has_feature(address_sanitizer)
+#include <sanitizer/common_interface_defs.h>
+#endif // endif support for Clang ASAN API
+#endif // endif has_feature
+#endif
+
+/* Msutherl: functions to wrap sanitizer API. They only do anything 
+ * when called by other PTH functions if compiled under ASAN */
+intern void wrapper_start_fiber_switch(const void *new_stack, const size_t new_stacksize) {
+#if defined(__clang__)
+#if defined(__has_feature)
+#if __has_feature(address_sanitizer)
+    pth_debug3("WRAPPER: Switching fiber to new stack 0x%p, size %u",new_stack,new_stacksize);
+    __sanitizer_start_switch_fiber(NULL,new_stack,new_stacksize);
+#endif // endif support for Clang ASAN API
+#endif // endif has_feature
+#endif
+}
+
+intern void wrapper_finish_fiber_switch(void) {
+#if defined(__clang__)
+#if defined(__has_feature)
+#if __has_feature(address_sanitizer)
+    pth_debug3("WRAPPER: Finished fiber switch FROM stack 0x%p, size %u",from_stack,from_stacksize);
+    __sanitizer_finish_switch_fiber(NULL,&from_stack,&from_stacksize);
+#endif // endif support for Clang ASAN API
+#endif // endif has_feature
+#endif
+}
+
+
 /*
 ** ____ MACHINE STATE INITIALIZATION ________________________________
 */
@@ -558,4 +603,3 @@ pth_mctx_set(pth_mctx_t *mctx, void (*func)(void),
 #else
 #error "unknown mctx method"
 #endif
-

pth_sched.c

@@ -163,6 +163,8 @@ intern void *pth_scheduler(void *dummy)
     int sig;
     pth_t t;
 
+    pth_debug5("Finished switch to pth_scheduler first time 0x%p, size %u, FROM stack 0x%p, size %u",pth_sched->stack,pth_sched->stacksize,from_stack,from_stacksize);
+
     /*
      * bootstrapping
      */
@@ -248,7 +250,15 @@ intern void *pth_scheduler(void *dummy)
 
         /* ** ENTERING THREAD ** - by switching the machine context */
         pth_current->dispatches++;
+
+        /* Msutherl: annotations for Clang api. Nothing happens under the hood if
+         * support not detected by autoconf. 
+         */
+        wrapper_start_fiber_switch(pth_current->stack,pth_current->stacksize);
         pth_mctx_switch(&pth_sched->mctx, &pth_current->mctx);
+        wrapper_finish_fiber_switch();
+        pth_debug5("Finished switch back to pth_sched stack 0x%p, size %u, FROM stack 0x%p, size %u",
+                pth_sched->stack,pth_sched->stacksize,from_stack,from_stacksize);
 
         /* update scheduler times */
         pth_time_set(&snapshot, PTH_TIME_NOW);