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-rw-r--r--mm/slab_common.c101
1 files changed, 101 insertions, 0 deletions
diff --git a/mm/slab_common.c b/mm/slab_common.c
index d31c4bacc6a2..d319502b2403 100644
--- a/mm/slab_common.c
+++ b/mm/slab_common.c
@@ -19,6 +19,8 @@
#include <asm/tlbflush.h>
#include <asm/page.h>
#include <linux/memcontrol.h>
+
+#define CREATE_TRACE_POINTS
#include <trace/events/kmem.h>
#include "slab.h"
@@ -787,3 +789,102 @@ static int __init slab_proc_init(void)
}
module_init(slab_proc_init);
#endif /* CONFIG_SLABINFO */
+
+static __always_inline void *__do_krealloc(const void *p, size_t new_size,
+ gfp_t flags)
+{
+ void *ret;
+ size_t ks = 0;
+
+ if (p)
+ ks = ksize(p);
+
+ if (ks >= new_size)
+ return (void *)p;
+
+ ret = kmalloc_track_caller(new_size, flags);
+ if (ret && p)
+ memcpy(ret, p, ks);
+
+ return ret;
+}
+
+/**
+ * __krealloc - like krealloc() but don't free @p.
+ * @p: object to reallocate memory for.
+ * @new_size: how many bytes of memory are required.
+ * @flags: the type of memory to allocate.
+ *
+ * This function is like krealloc() except it never frees the originally
+ * allocated buffer. Use this if you don't want to free the buffer immediately
+ * like, for example, with RCU.
+ */
+void *__krealloc(const void *p, size_t new_size, gfp_t flags)
+{
+ if (unlikely(!new_size))
+ return ZERO_SIZE_PTR;
+
+ return __do_krealloc(p, new_size, flags);
+
+}
+EXPORT_SYMBOL(__krealloc);
+
+/**
+ * krealloc - reallocate memory. The contents will remain unchanged.
+ * @p: object to reallocate memory for.
+ * @new_size: how many bytes of memory are required.
+ * @flags: the type of memory to allocate.
+ *
+ * The contents of the object pointed to are preserved up to the
+ * lesser of the new and old sizes. If @p is %NULL, krealloc()
+ * behaves exactly like kmalloc(). If @new_size is 0 and @p is not a
+ * %NULL pointer, the object pointed to is freed.
+ */
+void *krealloc(const void *p, size_t new_size, gfp_t flags)
+{
+ void *ret;
+
+ if (unlikely(!new_size)) {
+ kfree(p);
+ return ZERO_SIZE_PTR;
+ }
+
+ ret = __do_krealloc(p, new_size, flags);
+ if (ret && p != ret)
+ kfree(p);
+
+ return ret;
+}
+EXPORT_SYMBOL(krealloc);
+
+/**
+ * kzfree - like kfree but zero memory
+ * @p: object to free memory of
+ *
+ * The memory of the object @p points to is zeroed before freed.
+ * If @p is %NULL, kzfree() does nothing.
+ *
+ * Note: this function zeroes the whole allocated buffer which can be a good
+ * deal bigger than the requested buffer size passed to kmalloc(). So be
+ * careful when using this function in performance sensitive code.
+ */
+void kzfree(const void *p)
+{
+ size_t ks;
+ void *mem = (void *)p;
+
+ if (unlikely(ZERO_OR_NULL_PTR(mem)))
+ return;
+ ks = ksize(mem);
+ memset(mem, 0, ks);
+ kfree(mem);
+}
+EXPORT_SYMBOL(kzfree);
+
+/* Tracepoints definitions. */
+EXPORT_TRACEPOINT_SYMBOL(kmalloc);
+EXPORT_TRACEPOINT_SYMBOL(kmem_cache_alloc);
+EXPORT_TRACEPOINT_SYMBOL(kmalloc_node);
+EXPORT_TRACEPOINT_SYMBOL(kmem_cache_alloc_node);
+EXPORT_TRACEPOINT_SYMBOL(kfree);
+EXPORT_TRACEPOINT_SYMBOL(kmem_cache_free);