x86: check for ioremap() failure in copy_oldmem_page()

Add a check for ioremap() failure in copy_oldmem_page().
This patch also includes small coding style fixes.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 4 insertions, 2 deletions

diff --git a/arch/x86/kernel/crash_dump_64.c b/arch/x86/kernel/crash_dump_64.c
index 15e6c6bc4a46..280d6ef3af02 100644
--- a/arch/x86/kernel/crash_dump_64.c
+++ b/arch/x86/kernel/crash_dump_64.c
@@ -33,14 +33,16 @@ ssize_t copy_oldmem_page(unsigned long pfn, char *buf,
                 return 0;
 
         vaddr = ioremap(pfn << PAGE_SHIFT, PAGE_SIZE);
+        if (!vaddr)
+                return -ENOMEM;
 
         if (userbuf) {
-                if (copy_to_user(buf, (vaddr + offset), csize)) {
+                if (copy_to_user(buf, vaddr + offset, csize)) {
                         iounmap(vaddr);
                         return -EFAULT;
                 }
         } else
-        memcpy(buf, (vaddr + offset), csize);
+                memcpy(buf, vaddr + offset, csize);
 
         iounmap(vaddr);
         return csize;