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>

fs/coredump.c

@@ -40,7 +40,6 @@
 
 #include <trace/events/task.h>
 #include "internal.h"
-#include "coredump.h"
 
 #include <trace/events/sched.h>
 

fs/coredump.h

@@ -1,6 +0,0 @@
-#ifndef _FS_COREDUMP_H
-#define _FS_COREDUMP_H
-
-extern int __get_dumpable(unsigned long mm_flags);
-
-#endif

fs/exec.c

@@ -62,7 +62,6 @@
 
 #include <trace/events/task.h>
 #include "internal.h"
-#include "coredump.h"
 
 #include <trace/events/sched.h>
 
@@ -1609,7 +1608,6 @@ void set_binfmt(struct linux_binfmt *new)
 	if (new)
 		__module_get(new->module);
 }
-
 EXPORT_SYMBOL(set_binfmt);
 
 /*
@@ -1628,22 +1626,6 @@ void set_dumpable(struct mm_struct *mm, int value)
 	} while (cmpxchg(&mm->flags, old, new) != old);
 }
 
-int __get_dumpable(unsigned long mm_flags)
-{
-	return mm_flags & MMF_DUMPABLE_MASK;
-}
-
-/*
- * 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.
- */
-int get_dumpable(struct mm_struct *mm)
-{
-	return __get_dumpable(mm->flags);
-}
-
 SYSCALL_DEFINE3(execve,
 		const char __user *, filename,
 		const char __user *const __user *, argv,

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