xnu-1228.5.18.tar.gz

[apple/xnu.git] / osfmk / kern / stack.c

diff --git a/osfmk/kern/stack.c b/osfmk/kern/stack.c
index f9fb6682c9680c55a074ca5a2aecdbf48158659d..68cdcabc0fd54b111f3e4e5defec347eb069a776 100644 (file)
--- a/osfmk/kern/stack.c
+++ b/osfmk/kern/stack.c
@@ -1,5 +1,5 @@
 /*
 /*

- * Copyright (c) 2003-2004 Apple Computer, Inc. All rights reserved.
+ * Copyright (c) 2003-2007 Apple Inc. All rights reserved.

  *
  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
  * 
  *
  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
  * 


@@ -58,7 +58,6 @@ decl_simple_lock_data(static,stack_lock_data)
 
 #define STACK_CACHE_SIZE       2
 
 
 #define STACK_CACHE_SIZE       2
 

-static vm_map_t                        stack_map;

 static vm_offset_t             stack_free_list;
 
 static unsigned int            stack_free_count, stack_free_hiwat;             /* free list count */
 static vm_offset_t             stack_free_list;
 
 static unsigned int            stack_free_count, stack_free_hiwat;             /* free list count */


@@ -81,27 +80,12 @@ static vm_offset_t          stack_addr_mask;
 void
 stack_init(void)
 {
 void
 stack_init(void)
 {

-       vm_offset_t                     stacks, boundary;
-       vm_map_offset_t         map_addr;
-

        simple_lock_init(&stack_lock_data, 0);
        
        if (KERNEL_STACK_SIZE < round_page(KERNEL_STACK_SIZE))
                panic("stack_init: stack size %d not a multiple of page size %d\n",     KERNEL_STACK_SIZE, PAGE_SIZE);
        
        simple_lock_init(&stack_lock_data, 0);
        
        if (KERNEL_STACK_SIZE < round_page(KERNEL_STACK_SIZE))
                panic("stack_init: stack size %d not a multiple of page size %d\n",     KERNEL_STACK_SIZE, PAGE_SIZE);
        

-       for (boundary = PAGE_SIZE; boundary <= KERNEL_STACK_SIZE; )
-               boundary <<= 1;
-
-       stack_addr_mask = boundary - 1;
-
-       if (kmem_suballoc(kernel_map, &stacks, (boundary * (2 * THREAD_MAX + 64)),
-                                                               FALSE, VM_FLAGS_ANYWHERE, &stack_map) != KERN_SUCCESS)
-               panic("stack_init: kmem_suballoc");
-
-       map_addr = vm_map_min(stack_map);
-       if (vm_map_enter(stack_map, &map_addr, vm_map_round_page(PAGE_SIZE), 0, (VM_MAKE_TAG(VM_MEMORY_STACK) | VM_FLAGS_FIXED),
-                                               VM_OBJECT_NULL, 0, FALSE, VM_PROT_NONE, VM_PROT_NONE, VM_INHERIT_DEFAULT) != KERN_SUCCESS)
-               panic("stack_init: vm_map_enter");
+       stack_addr_mask = KERNEL_STACK_SIZE - 1;

 }
 
 /*
 }
 
 /*


@@ -116,6 +100,7 @@ stack_alloc(
 {
        vm_offset_t             stack;
        spl_t                   s;
 {
        vm_offset_t             stack;
        spl_t                   s;

+       int                     guard_flags;

 
        assert(thread->kernel_stack == 0);
 
 
        assert(thread->kernel_stack == 0);
 


@@ -136,8 +121,27 @@ stack_alloc(
        splx(s);
                
        if (stack == 0) {
        splx(s);
                
        if (stack == 0) {

-               if (kernel_memory_allocate(stack_map, &stack, KERNEL_STACK_SIZE, stack_addr_mask, KMA_KOBJECT) != KERN_SUCCESS)
+
+               /*
+                * Request guard pages on either side of the stack.  Ask
+                * kernel_memory_allocate() for two extra pages to account
+                * for these.
+                */
+
+               guard_flags = KMA_GUARD_FIRST | KMA_GUARD_LAST;
+               if (kernel_memory_allocate(kernel_map, &stack,
+                                          KERNEL_STACK_SIZE + (2*PAGE_SIZE),
+                                          stack_addr_mask,
+                                          KMA_KOBJECT | guard_flags)
+                   != KERN_SUCCESS)

                        panic("stack_alloc: kernel_memory_allocate");
                        panic("stack_alloc: kernel_memory_allocate");

+
+               /*
+                * The stack address that comes back is the address of the lower
+                * guard page.  Skip past it to get the actual stack base address.
+                */
+
+               stack += PAGE_SIZE;

        }
 
        machine_stack_attach(thread, stack);
        }
 
        machine_stack_attach(thread, stack);


@@ -155,28 +159,8 @@ stack_free(
     vm_offset_t                stack = machine_stack_detach(thread);
 
        assert(stack);
     vm_offset_t                stack = machine_stack_detach(thread);
 
        assert(stack);

-       if (stack != thread->reserved_stack) {
-               struct stack_cache      *cache;
-               spl_t                           s;
-
-               s = splsched();
-               cache = &PROCESSOR_DATA(current_processor(), stack_cache);
-               if (cache->count < STACK_CACHE_SIZE) {
-                       stack_next(stack) = cache->free;
-                       cache->free = stack;
-                       cache->count++;
-               }
-               else {
-                       stack_lock();
-                       stack_next(stack) = stack_free_list;
-                       stack_free_list = stack;
-                       if (++stack_free_count > stack_free_hiwat)
-                               stack_free_hiwat = stack_free_count;
-                       stack_free_delta++;
-                       stack_unlock();
-               }
-               splx(s);
-       }
+       if (stack != thread->reserved_stack)
+               stack_free_stack(stack);

 }
 
 void
 }
 
 void


@@ -278,9 +262,24 @@ stack_collect(void)
                        stack_unlock();
                        splx(s);
 
                        stack_unlock();
                        splx(s);
 

-                       if (vm_map_remove(stack_map, vm_map_trunc_page(stack),
-                                                               vm_map_round_page(stack + KERNEL_STACK_SIZE), VM_MAP_REMOVE_KUNWIRE) != KERN_SUCCESS)
+                       /*
+                        * Get the stack base address, then decrement by one page
+                        * to account for the lower guard page.  Add two extra pages
+                        * to the size to account for the guard pages on both ends
+                        * that were originally requested when the stack was allocated
+                        * back in stack_alloc().
+                        */
+
+                       stack = vm_map_trunc_page(stack);
+                       stack -= PAGE_SIZE;
+                       if (vm_map_remove(
+                                   kernel_map,
+                                   stack,
+                                   stack + KERNEL_STACK_SIZE+(2*PAGE_SIZE),
+                                   VM_MAP_REMOVE_KUNWIRE)
+                           != KERN_SUCCESS)

                                panic("stack_collect: vm_map_remove");
                                panic("stack_collect: vm_map_remove");

+                       stack = 0;

 
                        s = splsched();
                        stack_lock();
 
                        s = splsched();
                        stack_lock();


@@ -383,7 +382,7 @@ processor_set_stack_usage(
        vm_size_t maxusage;
        vm_offset_t maxstack;
 
        vm_size_t maxusage;
        vm_offset_t maxstack;
 

-       register thread_t *threads;
+       register thread_t *thread_list;

        register thread_t thread;
 
        unsigned int actual;    /* this many things */
        register thread_t thread;
 
        unsigned int actual;    /* this many things */


@@ -392,19 +391,16 @@ processor_set_stack_usage(
        vm_size_t size, size_needed;
        void *addr;
 
        vm_size_t size, size_needed;
        void *addr;
 

-       if (pset == PROCESSOR_SET_NULL)
+       if (pset == PROCESSOR_SET_NULL || pset != &pset0)

                return KERN_INVALID_ARGUMENT;
 
                return KERN_INVALID_ARGUMENT;
 

-       size = 0; addr = 0;
+       size = 0;
+       addr = NULL;

 
        for (;;) {
 
        for (;;) {

-               pset_lock(pset);
-               if (!pset->active) {
-                       pset_unlock(pset);
-                       return KERN_INVALID_ARGUMENT;
-               }
+               mutex_lock(&tasks_threads_lock);

 
 

-               actual = pset->thread_count;
+               actual = threads_count;

 
                /* do we have the memory we need? */
 
 
                /* do we have the memory we need? */
 


@@ -412,8 +408,7 @@ processor_set_stack_usage(
                if (size_needed <= size)
                        break;
 
                if (size_needed <= size)
                        break;
 

-               /* unlock the pset and allocate more memory */
-               pset_unlock(pset);
+               mutex_unlock(&tasks_threads_lock);

 
                if (size != 0)
                        kfree(addr, size);
 
                if (size != 0)
                        kfree(addr, size);


@@ -426,18 +421,17 @@ processor_set_stack_usage(
                        return KERN_RESOURCE_SHORTAGE;
        }
 
                        return KERN_RESOURCE_SHORTAGE;
        }
 

-       /* OK, have memory and the processor_set is locked & active */
-       threads = (thread_t *) addr;
-       for (i = 0, thread = (thread_t) queue_first(&pset->threads);
-                                       !queue_end(&pset->threads, (queue_entry_t) thread);
-                                       thread = (thread_t) queue_next(&thread->pset_threads)) {
+       /* OK, have memory and list is locked */
+       thread_list = (thread_t *) addr;
+       for (i = 0, thread = (thread_t) queue_first(&threads);
+                                       !queue_end(&threads, (queue_entry_t) thread);
+                                       thread = (thread_t) queue_next(&thread->threads)) {

                thread_reference_internal(thread);
                thread_reference_internal(thread);

-               threads[i++] = thread;
+               thread_list[i++] = thread;

        }
        assert(i <= actual);
 
        }
        assert(i <= actual);
 

-       /* can unlock processor set now that we have the thread refs */
-       pset_unlock(pset);
+       mutex_unlock(&tasks_threads_lock);

 
        /* calculate maxusage and free thread references */
 
 
        /* calculate maxusage and free thread references */
 


@@ -445,7 +439,7 @@ processor_set_stack_usage(
        maxusage = 0;
        maxstack = 0;
        while (i > 0) {
        maxusage = 0;
        maxstack = 0;
        while (i > 0) {

-               thread_t threadref = threads[--i];
+               thread_t threadref = thread_list[--i];

 
                if (threadref->kernel_stack != 0)
                        total++;
 
                if (threadref->kernel_stack != 0)
                        total++;


@@ -467,10 +461,10 @@ processor_set_stack_usage(
 
 vm_offset_t min_valid_stack_address(void)
 {
 
 vm_offset_t min_valid_stack_address(void)
 {

-       return vm_map_min(stack_map);
+       return vm_map_min(kernel_map);

 }
 
 vm_offset_t max_valid_stack_address(void)
 {
 }
 
 vm_offset_t max_valid_stack_address(void)
 {

-       return vm_map_max(stack_map);
+       return vm_map_max(kernel_map);

 }
 }