[PATCH] uml: change memcpy to memmove

Replace one memcpy() call with overlapping source and dest arguments with
one call to memmove(), to avoid data corruption.

Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/arch/um/kernel/irq_user.c b/arch/um/kernel/irq_user.c
index 6d6f948..b3074cb 100644 (file)
--- a/arch/um/kernel/irq_user.c
+++ b/arch/um/kernel/irq_user.c
@@ -236,9 +236,15 @@ static void free_irq_by_cb(int (*test)(struct irq_fd *, void *), void *arg)
                                       (*prev)->fd, pollfds[i].fd);
                                goto out;
                        }
-                       memcpy(&pollfds[i], &pollfds[i + 1],
-                              (pollfds_num - i - 1) * sizeof(pollfds[0]));
+
                        pollfds_num--;
+
+                       /* This moves the *whole* array after pollfds[i] (though
+                        * it doesn't spot as such)! */
+
+                       memmove(&pollfds[i], &pollfds[i + 1],
+                              (pollfds_num - i) * sizeof(pollfds[0]));
+
                        if(last_irq_ptr == &old_fd->next) 
                                last_irq_ptr = prev;
                        *prev = (*prev)->next;