1 files changed, 41 insertions, 26 deletions

diff --git a/arch/x86/kernel/crash_dump_64.c b/arch/x86/kernel/crash_dump_64.c
index afa64adb75ee..32d710f7eb84 100644
--- a/arch/x86/kernel/crash_dump_64.c
+++ b/arch/x86/kernel/crash_dump_64.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  *	Memory preserving reboot related code.
  *
@@ -7,43 +8,57 @@
 
 #include <linux/errno.h>
 #include <linux/crash_dump.h>
-#include <linux/uaccess.h>
+#include <linux/uio.h>
 #include <linux/io.h>
+#include <linux/cc_platform.h>
 
-/**
- * copy_oldmem_page - copy one page from "oldmem"
- * @pfn: page frame number to be copied
- * @buf: target memory address for the copy; this can be in kernel address
- *	space or user address space (see @userbuf)
- * @csize: number of bytes to copy
- * @offset: offset in bytes into the page (based on pfn) to begin the copy
- * @userbuf: if set, @buf is in user address space, use copy_to_user(),
- *	otherwise @buf is in kernel address space, use memcpy().
- *
- * Copy a page from "oldmem". For this page, there is no pte mapped
- * in the current kernel. We stitch up a pte, similar to kmap_atomic.
- */
-ssize_t copy_oldmem_page(unsigned long pfn, char *buf,
-		size_t csize, unsigned long offset, int userbuf)
+static ssize_t __copy_oldmem_page(struct iov_iter *iter, unsigned long pfn,
+				  size_t csize, unsigned long offset,
+				  bool encrypted)
 {
 	void  *vaddr;
 
 	if (!csize)
 		return 0;
 
-	vaddr = ioremap_cache(pfn << PAGE_SHIFT, PAGE_SIZE);
+	if (encrypted)
+		vaddr = (__force void *)ioremap_encrypted(pfn << PAGE_SHIFT, PAGE_SIZE);
+	else
+		vaddr = (__force void *)ioremap_cache(pfn << PAGE_SHIFT, PAGE_SIZE);
+
 	if (!vaddr)
 		return -ENOMEM;
 
-	if (userbuf) {
-		if (copy_to_user(buf, vaddr + offset, csize)) {
-			iounmap(vaddr);
-			return -EFAULT;
-		}
-	} else
-		memcpy(buf, vaddr + offset, csize);
+	csize = copy_to_iter(vaddr + offset, csize, iter);
 
-	set_iounmap_nonlazy();
-	iounmap(vaddr);
+	iounmap((void __iomem *)vaddr);
 	return csize;
 }
+
+ssize_t copy_oldmem_page(struct iov_iter *iter, unsigned long pfn, size_t csize,
+			 unsigned long offset)
+{
+	return __copy_oldmem_page(iter, pfn, csize, offset, false);
+}
+
+/*
+ * copy_oldmem_page_encrypted - same as copy_oldmem_page() above but ioremap the
+ * memory with the encryption mask set to accommodate kdump on SME-enabled
+ * machines.
+ */
+ssize_t copy_oldmem_page_encrypted(struct iov_iter *iter, unsigned long pfn,
+				   size_t csize, unsigned long offset)
+{
+	return __copy_oldmem_page(iter, pfn, csize, offset, true);
+}
+
+ssize_t elfcorehdr_read(char *buf, size_t count, u64 *ppos)
+{
+	struct kvec kvec = { .iov_base = buf, .iov_len = count };
+	struct iov_iter iter;
+
+	iov_iter_kvec(&iter, ITER_DEST, &kvec, 1, count);
+
+	return read_from_oldmem(&iter, count, ppos,
+				cc_platform_has(CC_ATTR_GUEST_MEM_ENCRYPT));
+}