untangle the do_mremap() mess

This backports the following upstream commits all as one patch:
	54f5de709984bae0d31d823ff03de755f9dcac54
	ecc1a8993751de4e82eb18640d631dae1f626bd6
	1a0ef85f84feb13f07b604fcf5b90ef7c2b5c82f
	f106af4e90eadd76cfc0b5325f659619e08fb762
	097eed103862f9c6a97f2e415e21d1134017b135
	935874141df839c706cd6cdc438e85eb69d1525e
	0ec62d290912bb4b989be7563851bc364ec73b56
	c4caa778157dbbf04116f0ac2111e389b5cd7a29
	2ea1d13f64efdf49319e86c87d9ba38c30902782
	570dcf2c15463842e384eb597a87c1e39bead99b
	564b3bffc619dcbdd160de597b0547a7017ea010
	0067bd8a55862ac9dd212bd1c4f6f5bff1ca1301
	f8b7256096a20436f6d0926747e3ac3d64c81d24
	8c7b49b3ecd48923eb64ff57e07a1cdb74782970
	9206de95b1ea68357996ec02be5db0638a0de2c1
	2c6a10161d0b5fc047b5bd81b03693b9af99fab5
	05d72faa6d13c9d857478a5d35c85db9adada685
	bb52d6694002b9d632bb355f64daa045c6293a4e
	e77414e0aad6a1b063ba5e5750c582c75327ea6a
	aa65607373a4daf2010e8c3867b6317619f3c1a3

Backport done by Greg Kroah-Hartman.  Only minor tweaks were needed.

Cc: David S. Miller <davem@davemloft.net>
Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

2 files changed, 5 insertions, 62 deletions

diff --git a/arch/s390/kernel/compat_linux.c b/arch/s390/kernel/compat_linux.c
index 0debcec23a39..9c746c01a7a7 100644
--- a/arch/s390/kernel/compat_linux.c
+++ b/arch/s390/kernel/compat_linux.c
@@ -683,38 +683,6 @@ struct mmap_arg_struct_emu31 {
 	u32	offset;
 };
 
-/* common code for old and new mmaps */
-static inline long do_mmap2(
-	unsigned long addr, unsigned long len,
-	unsigned long prot, unsigned long flags,
-	unsigned long fd, unsigned long pgoff)
-{
-	struct file * file = NULL;
-	unsigned long error = -EBADF;
-
-	flags &= ~(MAP_EXECUTABLE | MAP_DENYWRITE);
-	if (!(flags & MAP_ANONYMOUS)) {
-		file = fget(fd);
-		if (!file)
-			goto out;
-	}
-
-	down_write(&current->mm->mmap_sem);
-	error = do_mmap_pgoff(file, addr, len, prot, flags, pgoff);
-	if (!IS_ERR((void *) error) && error + len >= 0x80000000ULL) {
-		/* Result is out of bounds.  */
-		do_munmap(current->mm, addr, len);
-		error = -ENOMEM;
-	}
-	up_write(&current->mm->mmap_sem);
-
-	if (file)
-		fput(file);
-out:    
-	return error;
-}
-
-
 asmlinkage unsigned long
 old32_mmap(struct mmap_arg_struct_emu31 __user *arg)
 {
@@ -728,7 +696,8 @@ old32_mmap(struct mmap_arg_struct_emu31 __user *arg)
 	if (a.offset & ~PAGE_MASK)
 		goto out;
 
-	error = do_mmap2(a.addr, a.len, a.prot, a.flags, a.fd, a.offset >> PAGE_SHIFT); 
+	error = sys_mmap_pgoff(a.addr, a.len, a.prot, a.flags, a.fd,
+			       a.offset >> PAGE_SHIFT);
 out:
 	return error;
 }
@@ -741,7 +710,7 @@ sys32_mmap2(struct mmap_arg_struct_emu31 __user *arg)
 
 	if (copy_from_user(&a, arg, sizeof(a)))
 		goto out;
-	error = do_mmap2(a.addr, a.len, a.prot, a.flags, a.fd, a.offset);
+	error = sys_mmap_pgoff(a.addr, a.len, a.prot, a.flags, a.fd, a.offset);
 out:
 	return error;
 }
diff --git a/arch/s390/kernel/sys_s390.c b/arch/s390/kernel/sys_s390.c
index e9d94f61d500..86a74c9c9e63 100644
--- a/arch/s390/kernel/sys_s390.c
+++ b/arch/s390/kernel/sys_s390.c
@@ -32,32 +32,6 @@
 #include <asm/uaccess.h>
 #include "entry.h"
 
-/* common code for old and new mmaps */
-static inline long do_mmap2(
-	unsigned long addr, unsigned long len,
-	unsigned long prot, unsigned long flags,
-	unsigned long fd, unsigned long pgoff)
-{
-	long error = -EBADF;
-	struct file * file = NULL;
-
-	flags &= ~(MAP_EXECUTABLE | MAP_DENYWRITE);
-	if (!(flags & MAP_ANONYMOUS)) {
-		file = fget(fd);
-		if (!file)
-			goto out;
-	}
-
-	down_write(&current->mm->mmap_sem);
-	error = do_mmap_pgoff(file, addr, len, prot, flags, pgoff);
-	up_write(&current->mm->mmap_sem);
-
-	if (file)
-		fput(file);
-out:
-	return error;
-}
-
 /*
  * Perform the select(nd, in, out, ex, tv) and mmap() system
  * calls. Linux for S/390 isn't able to handle more than 5
@@ -81,7 +55,7 @@ SYSCALL_DEFINE1(mmap2, struct mmap_arg_struct __user *, arg)
 
 	if (copy_from_user(&a, arg, sizeof(a)))
 		goto out;
-	error = do_mmap2(a.addr, a.len, a.prot, a.flags, a.fd, a.offset);
+	error = sys_mmap_pgoff(a.addr, a.len, a.prot, a.flags, a.fd, a.offset);
 out:
 	return error;
 }
@@ -98,7 +72,7 @@ SYSCALL_DEFINE1(s390_old_mmap, struct mmap_arg_struct __user *, arg)
 	if (a.offset & ~PAGE_MASK)
 		goto out;
 
-	error = do_mmap2(a.addr, a.len, a.prot, a.flags, a.fd, a.offset >> PAGE_SHIFT);
+	error = sys_mmap_pgoff(a.addr, a.len, a.prot, a.flags, a.fd, a.offset >> PAGE_SHIFT);
 out:
 	return error;
 }