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>

5 files changed, 9 insertions, 58 deletions

diff --git a/arch/arm/include/asm/mman.h b/arch/arm/include/asm/mman.h
index 8eebf89f5ab..41f99c573b9 100644
--- a/arch/arm/include/asm/mman.h
+++ b/arch/arm/include/asm/mman.h
@@ -1 +1,4 @@
 #include <asm-generic/mman.h>
+
+#define arch_mmap_check(addr, len, flags) \
+	(((flags) & MAP_FIXED && (addr) < FIRST_USER_ADDRESS) ? -EINVAL : 0)
diff --git a/arch/arm/kernel/calls.S b/arch/arm/kernel/calls.S
index fafce1b5c69..4f07168cf33 100644
--- a/arch/arm/kernel/calls.S
+++ b/arch/arm/kernel/calls.S
@@ -172,7 +172,7 @@
 /* 160 */	CALL(sys_sched_get_priority_min)
 		CALL(sys_sched_rr_get_interval)
 		CALL(sys_nanosleep)
-		CALL(sys_arm_mremap)
+		CALL(sys_mremap)
 		CALL(sys_setresuid16)
 /* 165 */	CALL(sys_getresuid16)
 		CALL(sys_ni_syscall)		/* vm86 */
diff --git a/arch/arm/kernel/entry-common.S b/arch/arm/kernel/entry-common.S
index f0fe95b7085..2c1db77d784 100644
--- a/arch/arm/kernel/entry-common.S
+++ b/arch/arm/kernel/entry-common.S
@@ -416,12 +416,12 @@ sys_mmap2:
 		tst	r5, #PGOFF_MASK
 		moveq	r5, r5, lsr #PAGE_SHIFT - 12
 		streq	r5, [sp, #4]
-		beq	do_mmap2
+		beq	sys_mmap_pgoff
 		mov	r0, #-EINVAL
 		mov	pc, lr
 #else
 		str	r5, [sp, #4]
-		b	do_mmap2
+		b	sys_mmap_pgoff
 #endif
 ENDPROC(sys_mmap2)
 
diff --git a/arch/arm/kernel/sys_arm.c b/arch/arm/kernel/sys_arm.c
index 78ecaac6520..ae4027bd01b 100644
--- a/arch/arm/kernel/sys_arm.c
+++ b/arch/arm/kernel/sys_arm.c
@@ -28,41 +28,6 @@
 #include <linux/ipc.h>
 #include <linux/uaccess.h>
 
-extern unsigned long do_mremap(unsigned long addr, unsigned long old_len,
-			       unsigned long new_len, unsigned long flags,
-			       unsigned long new_addr);
-
-/* common code for old and new mmaps */
-inline long do_mmap2(
-	unsigned long addr, unsigned long len,
-	unsigned long prot, unsigned long flags,
-	unsigned long fd, unsigned long pgoff)
-{
-	int error = -EINVAL;
-	struct file * file = NULL;
-
-	flags &= ~(MAP_EXECUTABLE | MAP_DENYWRITE);
-
-	if (flags & MAP_FIXED && addr < FIRST_USER_ADDRESS)
-		goto out;
-
-	error = -EBADF;
-	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;
-}
-
 struct mmap_arg_struct {
 	unsigned long addr;
 	unsigned long len;
@@ -84,29 +49,11 @@ asmlinkage int 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;
 }
 
-asmlinkage unsigned long
-sys_arm_mremap(unsigned long addr, unsigned long old_len,
-	       unsigned long new_len, unsigned long flags,
-	       unsigned long new_addr)
-{
-	unsigned long ret = -EINVAL;
-
-	if (flags & MREMAP_FIXED && new_addr < FIRST_USER_ADDRESS)
-		goto out;
-
-	down_write(&current->mm->mmap_sem);
-	ret = do_mremap(addr, old_len, new_len, flags, new_addr);
-	up_write(&current->mm->mmap_sem);
-
-out:
-	return ret;
-}
-
 /*
  * Perform the select(nd, in, out, ex, tv) and mmap() system
  * calls.
diff --git a/arch/arm/mm/mmap.c b/arch/arm/mm/mmap.c
index 2b7996401b0..f5abc51c5a0 100644
--- a/arch/arm/mm/mmap.c
+++ b/arch/arm/mm/mmap.c
@@ -54,7 +54,8 @@ arch_get_unmapped_area(struct file *filp, unsigned long addr,
 	 * We enforce the MAP_FIXED case.
 	 */
 	if (flags & MAP_FIXED) {
-		if (aliasing && flags & MAP_SHARED && addr & (SHMLBA - 1))
+		if (aliasing && flags & MAP_SHARED &&
+		    (addr - (pgoff << PAGE_SHIFT)) & (SHMLBA - 1))
 			return -EINVAL;
 		return addr;
 	}