diff --git a/fs/pstore/ram_core.c b/fs/pstore/ram_core.c
index e11672a..ecdb3ba 100644
--- a/fs/pstore/ram_core.c
+++ b/fs/pstore/ram_core.c
@@ -421,7 +421,12 @@
 	vaddr = vmap(pages, page_count, VM_MAP, prot);
 	kfree(pages);
 
-	return vaddr;
+	/*
+	 * Since vmap() uses page granularity, we must add the offset
+	 * into the page here, to get the byte granularity address
+	 * into the mapping to represent the actual "start" location.
+	 */
+	return vaddr + offset_in_page(start);
 }
 
 static void *persistent_ram_iomap(phys_addr_t start, size_t size,
@@ -440,6 +445,11 @@
 	else
 		va = ioremap_wc(start, size);
 
+	/*
+	 * Since request_mem_region() and ioremap() are byte-granularity
+	 * there is no need handle anything special like we do when the
+	 * vmap() case in persistent_ram_vmap() above.
+	 */
 	return va;
 }
 
@@ -460,7 +470,7 @@
 		return -ENOMEM;
 	}
 
-	prz->buffer = prz->vaddr + offset_in_page(start);
+	prz->buffer = prz->vaddr;
 	prz->buffer_size = size - sizeof(struct persistent_ram_buffer);
 
 	return 0;
@@ -507,7 +517,8 @@
 
 	if (prz->vaddr) {
 		if (pfn_valid(prz->paddr >> PAGE_SHIFT)) {
-			vunmap(prz->vaddr);
+			/* We must vunmap() at page-granularity. */
+			vunmap(prz->vaddr - offset_in_page(prz->paddr));
 		} else {
 			iounmap(prz->vaddr);
 			release_mem_region(prz->paddr, prz->size);