coredump: setuid core dump cleanups

index 7bdea79..60b4080 100644
@@ -1723,8 +1723,6 @@ int do_coredump(long signr, int exit_code, struct pt_regs * regs)
 	struct inode * inode;
 	struct file * file;
 	int retval = 0;
-	int fsuid = current->fsuid;
-	int flag = 0;
 	int ispipe = 0;
 
 	audit_core_dumps(signr);

@@ -1737,16 +1735,6 @@ int do_coredump(long signr, int exit_code, struct pt_regs * regs)
 		up_write(&mm->mmap_sem);
 		goto fail;
 	}
-
-	/*
-	 *	We cannot trust fsuid as being the "true" uid of the
-	 *	process nor do we know its entire history. We only know it
-	 *	was tainted so we dump it as root in mode 2.
-	 */
-	if (get_dumpable(mm) == 2) {	/* Setuid core dump mode */
-		flag = O_EXCL;		/* Stop rewrite attacks */
-		current->fsuid = 0;	/* Dump root private */
-	}
 	set_dumpable(mm, 0);
 
 	retval = coredump_wait(exit_code);

@@ -1778,8 +1766,7 @@ int do_coredump(long signr, int exit_code, struct pt_regs * regs)
  		}
  	} else
  		file = filp_open(corename,
-				 O_CREAT | 2 | O_NOFOLLOW | O_LARGEFILE | flag,
-				 0600);
+				 O_CREAT | 2 | O_NOFOLLOW | O_LARGEFILE, 0600);
 	if (IS_ERR(file))
 		goto fail_unlock;
 	inode = file->f_path.dentry->d_inode;

@@ -1806,7 +1793,6 @@ int do_coredump(long signr, int exit_code, struct pt_regs * regs)
 close_fail:
 	filp_close(file, NULL);
 fail_unlock:
-	current->fsuid = fsuid;
 	complete_all(&mm->core_done);
 fail:
 	return retval;

index 91c8c07..ca75ee4 100644
@@ -81,9 +81,6 @@ extern int search_binary_handler(struct linux_binprm *,struct pt_regs *);
 extern int flush_old_exec(struct linux_binprm * bprm);
 
 extern int suid_dumpable;
-#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 */
 
 /* Stack area protections */
 #define EXSTACK_DEFAULT   0	/* Whatever the arch defaults to */

index 60b4080..0f30b94 100644
@@ -1666,53 +1666,21 @@ fail:
 }
 
 /*
- * set_dumpable converts traditional three-value dumpable to two flags and
- * stores them into mm->flags.  It modifies lower two bits of mm->flags, but
- * these bits are not changed atomically.  So get_dumpable can observe the
- * intermediate state.  To avoid doing unexpected behavior, get get_dumpable
- * return either old dumpable or new one by paying attention to the order of
- * modifying the bits.
- *
- * dumpable |   mm->flags (binary)
- * old  new | initial interim  final
- * ---------+-----------------------
- *  0    1  |   00      01      01
- *  0    2  |   00      10(*)   11
- *  1    0  |   01      00      00
- *  1    2  |   01      11      11
- *  2    0  |   11      10(*)   00
- *  2    1  |   11      11      01
- *
- * (*) get_dumpable regards interim value of 10 as 11.
+ * set_dumpable converts traditional two-value dumpable to one flag and
+ * stores it in mm->flags. It modifies the lower bit of mm->flags.
  */
 void set_dumpable(struct mm_struct *mm, int value)
 {
-	switch (value) {
-	case 0:
+	if (value == 0)
 		clear_bit(MMF_DUMPABLE, &mm->flags);
-		smp_wmb();
-		clear_bit(MMF_DUMP_SECURELY, &mm->flags);
-		break;
-	case 1:
-		set_bit(MMF_DUMPABLE, &mm->flags);
-		smp_wmb();
-		clear_bit(MMF_DUMP_SECURELY, &mm->flags);
-		break;
-	case 2:
-		set_bit(MMF_DUMP_SECURELY, &mm->flags);
-		smp_wmb();
+	else if (value == 1)
 		set_bit(MMF_DUMPABLE, &mm->flags);
-		break;
-	}
 }
 EXPORT_SYMBOL_GPL(set_dumpable);
 
 int get_dumpable(struct mm_struct *mm)
 {
-	int ret;
-
-	ret = mm->flags & 0x3;
-	return (ret >= 2) ? 2 : ret;
+	return (mm->flags & 0x1);
 }
 
 int do_coredump(long signr, int exit_code, struct pt_regs * regs)

index 2e49027..8a0092d 100644
@@ -350,15 +350,14 @@ extern int get_dumpable(struct mm_struct *mm);
 
 /* mm flags */
 /* dumpable bits */
-#define MMF_DUMPABLE      0  /* core dump is permitted */
-#define MMF_DUMP_SECURELY 1  /* core file is readable only by root */
-#define MMF_DUMPABLE_BITS 2
+#define MMF_DUMPABLE		0  /* core dump is permitted */
+#define MMF_DUMPABLE_BITS	1
 
 /* coredump filter bits */
-#define MMF_DUMP_ANON_PRIVATE	2
-#define MMF_DUMP_ANON_SHARED	3
-#define MMF_DUMP_MAPPED_PRIVATE	4
-#define MMF_DUMP_MAPPED_SHARED	5
+#define MMF_DUMP_ANON_PRIVATE	1
+#define MMF_DUMP_ANON_SHARED	2
+#define MMF_DUMP_MAPPED_PRIVATE	3
+#define MMF_DUMP_MAPPED_SHARED	4
 #define MMF_DUMP_FILTER_SHIFT	MMF_DUMPABLE_BITS
 #define MMF_DUMP_FILTER_BITS	4
 #define MMF_DUMP_FILTER_MASK \