[PATCH] Get core dump code to work...

The file based core dump code was broken by pipe changes - a relative
llseek returns the absolute file position on success, not the relative
one, so dump_seek() always failed when invoked with non-zero current
position.

Only success/failure can be tested with relative lseek, we have to trust
kernel that on success we've got right file offset.  With this fix in
place I have finally real core files instead of 1KB fragments...
Signed-off-by: NPetr Vandrovec <petr@vandrovec.name>
[ Cleaned it up a bit while here - use SEEK_CUR instead of hardcoding 1 ]
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

fs/binfmt_elf.c

@@ -1152,7 +1152,7 @@ static int dump_write(struct file *file, const void *addr, int nr)
 static int dump_seek(struct file *file, loff_t off)
 {
 	if (file->f_op->llseek && file->f_op->llseek != no_llseek) {
-		if (file->f_op->llseek(file, off, 1) != off)
+		if (file->f_op->llseek(file, off, SEEK_CUR) < 0)
 			return 0;
 	} else {
 		char *buf = (char *)get_zeroed_page(GFP_KERNEL);