[PATCH 1/2] um: add uml_kmalloc_array() helper to avoid potential

[iamhswang@gmail.com]

From: Haisu Wang <iamhswang@gmail.com>

Add uml_kmalloc_array to avoid potential dynamic multiplication
overflow. Since in Documentation/process/deprecated.rst,
the preferred way is avoid the open-coded arithmetic.

Signed-off-by: Haisu Wang <wanghs18@chinatelecom.cn>
---
 arch/um/include/shared/um_malloc.h | 1 +
 arch/um/kernel/mem.c               | 5 +++++
 2 files changed, 6 insertions(+)

diff --git a/arch/um/include/shared/um_malloc.h b/arch/um/include/shared/um_malloc.h
index 815dd03e8707..a55a81131e10 100644
--- a/arch/um/include/shared/um_malloc.h
+++ b/arch/um/include/shared/um_malloc.h
@@ -9,6 +9,7 @@
 #include <generated/asm-offsets.h>
 
 extern void *uml_kmalloc(int size, int flags);
+extern void *uml_kmalloc_array(int count, int size, int flags);
 extern void kfree(const void *ptr);
 
 extern void *vmalloc_noprof(unsigned long size);
diff --git a/arch/um/kernel/mem.c b/arch/um/kernel/mem.c
index 39c4a7e21c6f..3bf9e9bef3bf 100644
--- a/arch/um/kernel/mem.c
+++ b/arch/um/kernel/mem.c
@@ -126,6 +126,11 @@ void *uml_kmalloc(int size, int flags)
 	return kmalloc(size, flags);
 }
 
+void *uml_kmalloc_array(int count, int size, int flags)
+{
+	return kmalloc_array(count, size, flags);
+}
+
 static const pgprot_t protection_map[16] = {
 	[VM_NONE]					= PAGE_NONE,
 	[VM_READ]					= PAGE_READONLY,
-- 
2.52.0