Un-inline the core-dump helper functions

Tony Luck reports that the addition of the access_ok() check in commit
0eead9ab41da ("Don't dump task struct in a.out core-dumps") broke the
ia64 compile due to missing the necessary header file includes.

Rather than add yet another include (<asm/unistd.h>) to make everything
happy, just uninline the silly core dump helper functions and move the
bodies to fs/exec.c where they make a lot more sense.

dump_seek() in particular was too big to be an inline function anyway,
and none of them are in any way performance-critical.  And we really
don't need to mess up our include file headers more than they already
are.

Reported-and-tested-by: Tony Luck <tony.luck@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 38 insertions, 0 deletions

diff --git a/fs/exec.c b/fs/exec.c
index 828dd2461d6b..03278c984ba0 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -2014,3 +2014,41 @@ fail_creds:
 fail:
         return;
 }
+
+/*
+ * Core dumping helper functions.  These are the only things you should
+ * do on a core-file: use only these functions to write out all the
+ * necessary info.
+ */
+int dump_write(struct file *file, const void *addr, int nr)
+{
+        return access_ok(VERIFY_READ, addr, nr) && file->f_op->write(file, addr, nr, &file->f_pos) == nr;
+}
+
+int dump_seek(struct file *file, loff_t off)
+{
+        int ret = 1;
+
+        if (file->f_op->llseek && file->f_op->llseek != no_llseek) {
+                if (file->f_op->llseek(file, off, SEEK_CUR) < 0)
+                        return 0;
+        } else {
+                char *buf = (char *)get_zeroed_page(GFP_KERNEL);
+
+                if (!buf)
+                        return 0;
+                while (off > 0) {
+                        unsigned long n = off;
+
+                        if (n > PAGE_SIZE)
+                                n = PAGE_SIZE;
+                        if (!dump_write(file, buf, n)) {
+                                ret = 0;
+                                break;
+                        }
+                        off -= n;
+                }
+                free_page((unsigned long)buf);
+        }
+        return ret;
+}