use clear_page()/copy_page() in favor of memset()/memcpy() on whole pages
Jan Beulich [Tue, 26 Oct 2010 21:22:27 +0000 (14:22 -0700)]
After all that's what they are intended for.

Signed-off-by: Jan Beulich <jbeulich@novell.com>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/fuse/dev.c
kernel/kexec.c
kernel/power/snapshot.c
kernel/power/swap.c
mm/memory.c

index cde755c..6903711 100644 (file)
@@ -811,7 +811,7 @@ static int fuse_copy_page(struct fuse_copy_state *cs, struct page **pagep,
 
        if (page && zeroing && count < PAGE_SIZE) {
                void *mapaddr = kmap_atomic(page, KM_USER1);
-               memset(mapaddr, 0, PAGE_SIZE);
+               clear_page(mapaddr);
                kunmap_atomic(mapaddr, KM_USER1);
        }
        while (count) {
index c0613f7..b55045b 100644 (file)
@@ -816,7 +816,7 @@ static int kimage_load_normal_segment(struct kimage *image,
 
                ptr = kmap(page);
                /* Start with a clear page */
-               memset(ptr, 0, PAGE_SIZE);
+               clear_page(ptr);
                ptr += maddr & ~PAGE_MASK;
                mchunk = PAGE_SIZE - (maddr & ~PAGE_MASK);
                if (mchunk > mbytes)
index 9e3581f..0dac75e 100644 (file)
@@ -993,7 +993,7 @@ static void copy_data_page(unsigned long dst_pfn, unsigned long src_pfn)
                         */
                        safe_copy_page(buffer, s_page);
                        dst = kmap_atomic(d_page, KM_USER0);
-                       memcpy(dst, buffer, PAGE_SIZE);
+                       copy_page(dst, buffer);
                        kunmap_atomic(dst, KM_USER0);
                } else {
                        safe_copy_page(page_address(d_page), s_page);
@@ -1687,7 +1687,7 @@ int snapshot_read_next(struct snapshot_handle *handle)
                memory_bm_position_reset(&orig_bm);
                memory_bm_position_reset(&copy_bm);
        } else if (handle->cur <= nr_meta_pages) {
-               memset(buffer, 0, PAGE_SIZE);
+               clear_page(buffer);
                pack_pfns(buffer, &orig_bm);
        } else {
                struct page *page;
@@ -1701,7 +1701,7 @@ int snapshot_read_next(struct snapshot_handle *handle)
                        void *kaddr;
 
                        kaddr = kmap_atomic(page, KM_USER0);
-                       memcpy(buffer, kaddr, PAGE_SIZE);
+                       copy_page(buffer, kaddr);
                        kunmap_atomic(kaddr, KM_USER0);
                        handle->buffer = buffer;
                } else {
@@ -1984,7 +1984,7 @@ static void copy_last_highmem_page(void)
                void *dst;
 
                dst = kmap_atomic(last_highmem_page, KM_USER0);
-               memcpy(dst, buffer, PAGE_SIZE);
+               copy_page(dst, buffer);
                kunmap_atomic(dst, KM_USER0);
                last_highmem_page = NULL;
        }
@@ -2270,9 +2270,9 @@ swap_two_pages_data(struct page *p1, struct page *p2, void *buf)
 
        kaddr1 = kmap_atomic(p1, KM_USER0);
        kaddr2 = kmap_atomic(p2, KM_USER1);
-       memcpy(buf, kaddr1, PAGE_SIZE);
-       memcpy(kaddr1, kaddr2, PAGE_SIZE);
-       memcpy(kaddr2, buf, PAGE_SIZE);
+       copy_page(buf, kaddr1);
+       copy_page(kaddr1, kaddr2);
+       copy_page(kaddr2, buf);
        kunmap_atomic(kaddr2, KM_USER1);
        kunmap_atomic(kaddr1, KM_USER0);
 }
index 916eaa7..a0e4a86 100644 (file)
@@ -251,7 +251,7 @@ static int write_page(void *buf, sector_t offset, struct bio **bio_chain)
        if (bio_chain) {
                src = (void *)__get_free_page(__GFP_WAIT | __GFP_HIGH);
                if (src) {
-                       memcpy(src, buf, PAGE_SIZE);
+                       copy_page(src, buf);
                } else {
                        WARN_ON_ONCE(1);
                        bio_chain = NULL;       /* Go synchronous */
@@ -325,7 +325,7 @@ static int swap_write_page(struct swap_map_handle *handle, void *buf,
                error = write_page(handle->cur, handle->cur_swap, NULL);
                if (error)
                        goto out;
-               memset(handle->cur, 0, PAGE_SIZE);
+               clear_page(handle->cur);
                handle->cur_swap = offset;
                handle->k = 0;
        }
@@ -910,7 +910,7 @@ int swsusp_check(void)
        hib_resume_bdev = open_by_devnum(swsusp_resume_device, FMODE_READ);
        if (!IS_ERR(hib_resume_bdev)) {
                set_blocksize(hib_resume_bdev, PAGE_SIZE);
-               memset(swsusp_header, 0, PAGE_SIZE);
+               clear_page(swsusp_header);
                error = hib_bio_read_page(swsusp_resume_block,
                                        swsusp_header, NULL);
                if (error)
index 861f798..02e48aa 100644 (file)
@@ -2080,7 +2080,7 @@ static inline void cow_user_page(struct page *dst, struct page *src, unsigned lo
                 * zeroes.
                 */
                if (__copy_from_user_inatomic(kaddr, uaddr, PAGE_SIZE))
-                       memset(kaddr, 0, PAGE_SIZE);
+                       clear_page(kaddr);
                kunmap_atomic(kaddr, KM_USER0);
                flush_dcache_page(dst);
        } else