coredump: make __get_dumpable/get_dumpable inline, kill fs/coredump.h

1. Remove fs/coredump.h. It is not clear why do we need it,
   it only declares __get_dumpable(), signal.c includes it
   for no reason.

2. Now that get_dumpable() and __get_dumpable() are really
   trivial make them inline in linux/sched.h.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Alex Kelly <alex.page.kelly@gmail.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Petr Matousek <pmatouse@redhat.com>
Cc: Vasily Kulikov <segoon@openwall.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 17 insertions, 4 deletions

diff --git a/include/linux/sched.h b/include/linux/sched.h
index 124430ba569b..cf9e414dbb9e 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -391,10 +391,6 @@ arch_get_unmapped_area_topdown(struct file *filp, unsigned long addr,
 static inline void arch_pick_mmap_layout(struct mm_struct *mm) {}
 #endif
 
-
-extern void set_dumpable(struct mm_struct *mm, int value);
-extern int get_dumpable(struct mm_struct *mm);
-
 #define SUID_DUMP_DISABLE       0       /* No setuid dumping */
 #define SUID_DUMP_USER          1       /* Dump as user of process */
 #define SUID_DUMP_ROOT          2       /* Dump as root */
@@ -405,6 +401,23 @@ extern int get_dumpable(struct mm_struct *mm);
 #define MMF_DUMPABLE_BITS 2
 #define MMF_DUMPABLE_MASK ((1 << MMF_DUMPABLE_BITS) - 1)
 
+extern void set_dumpable(struct mm_struct *mm, int value);
+/*
+ * This returns the actual value of the suid_dumpable flag. For things
+ * that are using this for checking for privilege transitions, it must
+ * test against SUID_DUMP_USER rather than treating it as a boolean
+ * value.
+ */
+static inline int __get_dumpable(unsigned long mm_flags)
+{
+        return mm_flags & MMF_DUMPABLE_MASK;
+}
+
+static inline int get_dumpable(struct mm_struct *mm)
+{
+        return __get_dumpable(mm->flags);
+}
+
 /* coredump filter bits */
 #define MMF_DUMP_ANON_PRIVATE   2
 #define MMF_DUMP_ANON_SHARED    3