radix_tree_tag_get() is not as safe as the docs make out [ver #2]

[safe/jmp/linux-2.6] / lib / cpumask.c

diff --git a/lib/cpumask.c b/lib/cpumask.c
index 8d03f22..05d6aca 100644 (file)
--- a/lib/cpumask.c
+++ b/lib/cpumask.c
@@ -1,3 +1,4 @@
+#include <linux/slab.h>
 #include <linux/kernel.h>
 #include <linux/bitops.h>
 #include <linux/cpumask.h>
@@ -76,39 +77,100 @@ int cpumask_any_but(const struct cpumask *mask, unsigned int cpu)
 
 /* These are not inline because of header tangles. */
 #ifdef CONFIG_CPUMASK_OFFSTACK
-bool alloc_cpumask_var(cpumask_var_t *mask, gfp_t flags)
+/**
+ * alloc_cpumask_var_node - allocate a struct cpumask on a given node
+ * @mask: pointer to cpumask_var_t where the cpumask is returned
+ * @flags: GFP_ flags
+ *
+ * Only defined when CONFIG_CPUMASK_OFFSTACK=y, otherwise is
+ * a nop returning a constant 1 (in <linux/cpumask.h>)
+ * Returns TRUE if memory allocation succeeded, FALSE otherwise.
+ *
+ * In addition, mask will be NULL if this fails.  Note that gcc is
+ * usually smart enough to know that mask can never be NULL if
+ * CONFIG_CPUMASK_OFFSTACK=n, so does code elimination in that case
+ * too.
+ */
+bool alloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags, int node)
 {
-       if (likely(slab_is_available()))
-               *mask = kmalloc(cpumask_size(), flags);
-       else {
-#ifdef CONFIG_DEBUG_PER_CPU_MAPS
-               printk(KERN_ERR
-                       "=> alloc_cpumask_var: kmalloc not available!\n");
-               dump_stack();
-#endif
-               *mask = NULL;
-       }
+       *mask = kmalloc_node(cpumask_size(), flags, node);
+
 #ifdef CONFIG_DEBUG_PER_CPU_MAPS
        if (!*mask) {
                printk(KERN_ERR "=> alloc_cpumask_var: failed!\n");
                dump_stack();
        }
 #endif
+       /* FIXME: Bandaid to save us from old primitives which go to NR_CPUS. */
+       if (*mask) {
+               unsigned char *ptr = (unsigned char *)cpumask_bits(*mask);
+               unsigned int tail;
+               tail = BITS_TO_LONGS(NR_CPUS - nr_cpumask_bits) * sizeof(long);
+               memset(ptr + cpumask_size() - tail, 0, tail);
+       }
+
        return *mask != NULL;
 }
+EXPORT_SYMBOL(alloc_cpumask_var_node);
+
+bool zalloc_cpumask_var_node(cpumask_var_t *mask, gfp_t flags, int node)
+{
+       return alloc_cpumask_var_node(mask, flags | __GFP_ZERO, node);
+}
+EXPORT_SYMBOL(zalloc_cpumask_var_node);
+
+/**
+ * alloc_cpumask_var - allocate a struct cpumask
+ * @mask: pointer to cpumask_var_t where the cpumask is returned
+ * @flags: GFP_ flags
+ *
+ * Only defined when CONFIG_CPUMASK_OFFSTACK=y, otherwise is
+ * a nop returning a constant 1 (in <linux/cpumask.h>).
+ *
+ * See alloc_cpumask_var_node.
+ */
+bool alloc_cpumask_var(cpumask_var_t *mask, gfp_t flags)
+{
+       return alloc_cpumask_var_node(mask, flags, numa_node_id());
+}
 EXPORT_SYMBOL(alloc_cpumask_var);
 
+bool zalloc_cpumask_var(cpumask_var_t *mask, gfp_t flags)
+{
+       return alloc_cpumask_var(mask, flags | __GFP_ZERO);
+}
+EXPORT_SYMBOL(zalloc_cpumask_var);
+
+/**
+ * alloc_bootmem_cpumask_var - allocate a struct cpumask from the bootmem arena.
+ * @mask: pointer to cpumask_var_t where the cpumask is returned
+ *
+ * Only defined when CONFIG_CPUMASK_OFFSTACK=y, otherwise is
+ * a nop (in <linux/cpumask.h>).
+ * Either returns an allocated (zero-filled) cpumask, or causes the
+ * system to panic.
+ */
 void __init alloc_bootmem_cpumask_var(cpumask_var_t *mask)
 {
        *mask = alloc_bootmem(cpumask_size());
 }
 
+/**
+ * free_cpumask_var - frees memory allocated for a struct cpumask.
+ * @mask: cpumask to free
+ *
+ * This is safe on a NULL mask.
+ */
 void free_cpumask_var(cpumask_var_t mask)
 {
        kfree(mask);
 }
 EXPORT_SYMBOL(free_cpumask_var);
 
+/**
+ * free_bootmem_cpumask_var - frees result of alloc_bootmem_cpumask_var
+ * @mask: cpumask to free
+ */
 void __init free_bootmem_cpumask_var(cpumask_var_t mask)
 {
        free_bootmem((unsigned long)mask, cpumask_size());