Changeset bfcf6b9 for libcfa/src/concurrency/kernel/startup.cfa

Timestamp:

Dec 10, 2020, 3:20:33 PM (4 years ago)

Author:

Thierry Delisle <tdelisle@…>

Branches:

ADT, arm-eh, ast-experimental, enum, forall-pointer-decay, jacob/cs343-translation, master, new-ast-unique-expr, pthread-emulation, qualifiedEnum

Children:

297cf18

Parents:

c920317

Message:

Stacks are always created with mmap to control page permission

File:

• libcfa/src/concurrency/kernel/startup.cfa (modified) (5 diffs)

libcfa/src/concurrency/kernel/startup.cfa

@@ -29 +29 @@
 #include "kernel_private.hfa"
 #include "startup.hfa"          // STARTUP_PRIORITY_XXX
+#include "math.hfa"
 
 //-----------------------------------------------------------------------------
@@ -539 +540 @@
 }
 
+extern size_t __page_size;
 void ^?{}(processor & this) with( this ){
         if( ! __atomic_load_n(&do_terminate, __ATOMIC_ACQUIRE) ) {
@@ -550 +552 @@
         }
 
-        int err = pthread_join( kernel_thread, 0p );
-        if( err != 0 ) abort("KERNEL ERROR: joining processor %p caused error %s\n", &this, strerror(err));
-
-        free( this.stack );
+        __destroy_pthread( kernel_thread, this.stack, 0p );
 
         disable_interrupts();
@@ -678 +677 @@
 
         void * stack;
-        __cfaabi_dbg_debug_do(
-                stack = memalign( __page_size, stacksize + __page_size );
-                // pthread has no mechanism to create the guard page in user supplied stack.
-                if ( mprotect( stack, __page_size, PROT_NONE ) == -1 ) {
-                        abort( "mprotect : internal error, mprotect failure, error(%d) %s.", errno, strerror( errno ) );
-                } // if
-        );
-        __cfaabi_dbg_no_debug_do(
-                stack = malloc( stacksize );
-        );
+        #warning due to the thunk problem, stack creation uses mmap, revert to malloc once this goes away
+        // __cfaabi_dbg_debug_do(
+        //      stack = memalign( __page_size, stacksize + __page_size );
+        //      // pthread has no mechanism to create the guard page in user supplied stack.
+        //      if ( mprotect( stack, __page_size, PROT_NONE ) == -1 ) {
+        //              abort( "mprotect : internal error, mprotect failure, error(%d) %s.", errno, strerror( errno ) );
+        //      } // if
+        // );
+        // __cfaabi_dbg_no_debug_do(
+        //      stack = malloc( stacksize );
+        // );
+        stacksize = ceiling( stacksize, __page_size ) + __page_size;
+        stack = mmap(0p, stacksize, PROT_EXEC | PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, 0, 0);
+        if(stack == ((void*)-1)) {
+                abort( "pthread stack creation : internal error, mmap failure, error(%d) %s.", errno, strerror( errno ) );
+        }
+        if ( mprotect( stack, __page_size, PROT_NONE ) == -1 ) {
+                abort( "pthread stack creation : internal error, mprotect failure, error(%d) %s.", errno, strerror( errno ) );
+        } // if
 
         check( pthread_attr_setstack( &attr, stack, stacksize ), "pthread_attr_setstack" );
@@ -694 +702 @@
         return stack;
 }
+
+void __destroy_pthread( pthread_t pthread, void * stack, void ** retval ) {
+        int err = pthread_join( pthread, retval );
+        if( err != 0 ) abort("KERNEL ERROR: joining pthread %p caused error %s\n", (void*)pthread, strerror(err));
+
+        pthread_attr_t attr;
+
+        check( pthread_attr_init( &attr ), "pthread_attr_init" ); // initialize attribute
+
+        size_t stacksize;
+        // default stack size, normally defined by shell limit
+        check( pthread_attr_getstacksize( &attr, &stacksize ), "pthread_attr_getstacksize" );
+        assert( stacksize >= PTHREAD_STACK_MIN );
+        stacksize += __page_size;
+
+        if(munmap(stack, stacksize) == -1) {
+                abort( "pthread stack destruction : internal error, munmap failure, error(%d) %s.", errno, strerror( errno ) );
+        }
+}
+
 
 #if defined(__CFA_WITH_VERIFY__)