[PATCH] pstore: fix incorrect persistent ram buffer mapping

[Bin Yang]

persistent_ram_vmap() returns the page start vaddr.
persistent_ram_iomap() supports non-page-aligned mapping.

persistent_ram_buffer_map() always adds offset-in-page to the vaddr
returned from these two functions, which causes incorrect mapping of
non-page-aligned persistent ram buffer.

Signed-off-by: Bin Yang <bin.y...@intel.com>
---
 fs/pstore/ram_core.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/fs/pstore/ram_core.c b/fs/pstore/ram_core.c
index 951a14e..7c05fdd 100644
--- a/fs/pstore/ram_core.c
+++ b/fs/pstore/ram_core.c
@@ -429,7 +429,7 @@ static void *persistent_ram_vmap(phys_addr_t start, size_t 
size,
        vaddr = vmap(pages, page_count, VM_MAP, prot);
        kfree(pages);
 
-       return vaddr;
+       return vaddr + offset_in_page(start);
 }
 
 static void *persistent_ram_iomap(phys_addr_t start, size_t size,
@@ -468,7 +468,7 @@ static int persistent_ram_buffer_map(phys_addr_t start, 
phys_addr_t size,
                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;
@@ -515,7 +515,7 @@ void persistent_ram_free(struct persistent_ram_zone *prz)
 
        if (prz->vaddr) {
                if (pfn_valid(prz->paddr >> PAGE_SHIFT)) {
-                       vunmap(prz->vaddr);
+                       vunmap(prz->vaddr - offset_in_page(prz->paddr));
                } else {
                        iounmap(prz->vaddr);
                        release_mem_region(prz->paddr, prz->size);
-- 
2.7.4