[PATCH] fix memory leak while coredumping

[IWAMOTO Toshihiro <iwamoto@valinux.co.jp>]

Hi,

with some help of coworker, I found a bug in binfmt_elf.c.
The bug exists in linux-2.6.1 and linux-2.6.2-rc2-mm2.

This patch fixes a memory leak that happens when a core file hits the
process's resource limit.
I've tested the DUMP_WRITE case only a little, and the DUMP_SEEK case
is only compile tested.

--- old/fs/binfmt_elf.c	Fri Jan 16 12:12:24 2004
+++ new/fs/binfmt_elf.c	Mon Feb  2 19:31:42 2004
@@ -1441,12 +1441,22 @@
 				DUMP_SEEK (file->f_pos + PAGE_SIZE);
 			} else {
 				if (page == ZERO_PAGE(addr)) {
-					DUMP_SEEK (file->f_pos + PAGE_SIZE);
+					if (!dump_seek(file,
+					    file->f_pos + PAGE_SIZE)) {
+						page_cache_release(page);
+						goto end_coredump;
+					}
 				} else {
 					void *kaddr;
 					flush_cache_page(vma, addr);
 					kaddr = kmap(page);
-					DUMP_WRITE(kaddr, PAGE_SIZE);
+					if ((size += PAGE_SIZE) > limit ||
+					    !dump_write(file, kaddr,
+					    PAGE_SIZE)) {
+						kunmap(page);
+						page_cache_release(page);
+						goto end_coredump;
+					}
 					kunmap(page);
 				}
 				page_cache_release(page);