[PATCH v2] x86/boot/e820: Use kmemdup instead of duplicating its function

[PATCH v2] x86/boot/e820: Use kmemdup instead of duplicating its function

[Yi Wang]

From: "Huang Zijiang" <huang.zijiang@zte.com.cn>

changes since v1:
	redo the patch based on suggestions from Boris.
v1 link:https://lkml.org/lkml/2019/1/8/30

kmemdup is the same function as kmalloc() + memcpy().

Signed-off-by: Huang Zijiang <huang.zijiang@zte.com.cn>
---
 arch/x86/kernel/e820.c | 9 +++------
 1 file changed, 3 insertions(+), 6 deletions(-)

diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c
index 50895c2..a687d10 100644
--- a/arch/x86/kernel/e820.c
+++ b/arch/x86/kernel/e820.c
@@ -671,21 +671,18 @@ __init void e820__reallocate_tables(void)
 	int size;
 
 	size = offsetof(struct e820_table, entries) + sizeof(struct e820_entry)*e820_table->nr_entries;
-	n = kmalloc(size, GFP_KERNEL);
+	n = kmemdup(e820_table, size, GFP_KERNEL);
 	BUG_ON(!n);
-	memcpy(n, e820_table, size);
 	e820_table = n;
 
 	size = offsetof(struct e820_table, entries) + sizeof(struct e820_entry)*e820_table_kexec->nr_entries;
-	n = kmalloc(size, GFP_KERNEL);
+	n = kmemdup(e820_table_kexec, size, GFP_KERNEL);
 	BUG_ON(!n);
-	memcpy(n, e820_table_kexec, size);
 	e820_table_kexec = n;
 
 	size = offsetof(struct e820_table, entries) + sizeof(struct e820_entry)*e820_table_firmware->nr_entries;
-	n = kmalloc(size, GFP_KERNEL);
+	n = kmemdup(e820_table_firmware, size, GFP_KERNEL);
 	BUG_ON(!n);
-	memcpy(n, e820_table_firmware, size);
 	e820_table_firmware = n;
 }
 
-- 
1.8.3.1

[tip:x86/cleanups] x86/e820: Replace kmalloc() + memcpy() with kmemdup()

[tip-bot for Huang Zijiang]

Commit-ID:  345dca4ca7e65a46bf0b6e2e6b8ab2e998ec6e91
Gitweb:     https://git.kernel.org/tip/345dca4ca7e65a46bf0b6e2e6b8ab2e998ec6e91
Author:     Huang Zijiang <huang.zijiang@zte.com.cn>
AuthorDate: Sat, 12 Jan 2019 15:16:24 +0800
Committer:  Borislav Petkov <bp@suse.de>
CommitDate: Sun, 13 Jan 2019 15:11:35 +0100

x86/e820: Replace kmalloc() + memcpy() with kmemdup()

Use the equivalent kmemdup() directly instead of kmalloc() + memcpy().

No functional changes.

 [ bp: rewrite commit message. ]

Signed-off-by: Huang Zijiang <huang.zijiang@zte.com.cn>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Joe Perches <joe@perches.com>
Cc: jschoenh@amazon.de
Cc: Masayoshi Mizuma <m.mizuma@jp.fujitsu.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: x86-ml <x86@kernel.org>
Cc: xue.zhihong@zte.com.cn
Link: https://lkml.kernel.org/r/1547277384-22156-1-git-send-email-wang.yi59@zte.com.cn
---
 arch/x86/kernel/e820.c | 9 +++------
 1 file changed, 3 insertions(+), 6 deletions(-)

diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c
index 50895c2f937d..a687d10da417 100644
--- a/arch/x86/kernel/e820.c
+++ b/arch/x86/kernel/e820.c
@@ -671,21 +671,18 @@ __init void e820__reallocate_tables(void)
 	int size;
 
 	size = offsetof(struct e820_table, entries) + sizeof(struct e820_entry)*e820_table->nr_entries;
-	n = kmalloc(size, GFP_KERNEL);
+	n = kmemdup(e820_table, size, GFP_KERNEL);
 	BUG_ON(!n);
-	memcpy(n, e820_table, size);
 	e820_table = n;
 
 	size = offsetof(struct e820_table, entries) + sizeof(struct e820_entry)*e820_table_kexec->nr_entries;
-	n = kmalloc(size, GFP_KERNEL);
+	n = kmemdup(e820_table_kexec, size, GFP_KERNEL);
 	BUG_ON(!n);
-	memcpy(n, e820_table_kexec, size);
 	e820_table_kexec = n;
 
 	size = offsetof(struct e820_table, entries) + sizeof(struct e820_entry)*e820_table_firmware->nr_entries;
-	n = kmalloc(size, GFP_KERNEL);
+	n = kmemdup(e820_table_firmware, size, GFP_KERNEL);
 	BUG_ON(!n);
-	memcpy(n, e820_table_firmware, size);
 	e820_table_firmware = n;
 }