backport-include: backport kvmalloc and kvmalloc_array

Signed-off-by: Felix Fietkau <nbd@nbd.name>

diff --git a/backport/backport-include/linux/mm.h b/backport/backport-include/linux/mm.h
index 3234b37d40c1c0f2b9c3ab64da299f933c236280..6ee5c7d8743e9efc33d5ea93016b3524afc19777 100644 (file)
--- a/backport/backport-include/linux/mm.h
+++ b/backport/backport-include/linux/mm.h
@@ -3,6 +3,9 @@
 #include_next <linux/mm.h>
 #include <linux/page_ref.h>
 #include <linux/sched.h>
+#include <linux/overflow.h>
+#include <linux/vmalloc.h>
+#include <linux/slab.h>
 
 #ifndef VM_NODUMP
 /*
@@ -123,4 +126,36 @@ static inline bool page_is_pfmemalloc(struct page *page)
 }
 #endif /* < 4.2 */
 
+#if LINUX_VERSION_IS_LESS(4,12,0)
+#define kvmalloc LINUX_BACKPORT(kvmalloc)
+static inline void *kvmalloc(size_t size, gfp_t flags)
+{
+       gfp_t kmalloc_flags = flags;
+       void *ret;
+
+       if ((flags & GFP_KERNEL) != GFP_KERNEL)
+               return kmalloc(size, flags);
+
+       if (size > PAGE_SIZE)
+               kmalloc_flags |= __GFP_NOWARN | __GFP_NORETRY;
+
+       ret = kmalloc(size, flags);
+       if (ret || size < PAGE_SIZE)
+               return ret;
+
+       return vmalloc(size);
+}
+
+#define kvmalloc_array LINUX_BACKPORT(kvmalloc_array)
+static inline void *kvmalloc_array(size_t n, size_t size, gfp_t flags)
+{
+       size_t bytes;
+
+       if (unlikely(check_mul_overflow(n, size, &bytes)))
+               return NULL;
+
+       return kvmalloc(bytes, flags);
+}
+#endif
+
 #endif /* __BACKPORT_MM_H */