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, 6 insertions, 80 deletions

diff --git a/arch/ia64/ia32/sys_ia32.c b/arch/ia64/ia32/sys_ia32.c
index 625ed8f76fce..e031ee8ecb05 100644
--- a/arch/ia64/ia32/sys_ia32.c
+++ b/arch/ia64/ia32/sys_ia32.c
@@ -858,6 +858,9 @@ ia32_do_mmap (struct file *file, unsigned long addr, unsigned long len, int prot
 
 	prot = get_prot32(prot);
 
+	if (flags & MAP_HUGETLB)
+		return -ENOMEM;
+
 #if PAGE_SHIFT > IA32_PAGE_SHIFT
 	mutex_lock(&ia32_mmap_mutex);
 	{
diff --git a/arch/ia64/kernel/sys_ia64.c b/arch/ia64/kernel/sys_ia64.c
index 92ed83f34036..609d50056a6c 100644
--- a/arch/ia64/kernel/sys_ia64.c
+++ b/arch/ia64/kernel/sys_ia64.c
@@ -100,51 +100,7 @@ sys_getpagesize (void)
 asmlinkage unsigned long
 ia64_brk (unsigned long brk)
 {
-	unsigned long rlim, retval, newbrk, oldbrk;
-	struct mm_struct *mm = current->mm;
-
-	/*
-	 * Most of this replicates the code in sys_brk() except for an additional safety
-	 * check and the clearing of r8.  However, we can't call sys_brk() because we need
-	 * to acquire the mmap_sem before we can do the test...
-	 */
-	down_write(&mm->mmap_sem);
-
-	if (brk < mm->end_code)
-		goto out;
-	newbrk = PAGE_ALIGN(brk);
-	oldbrk = PAGE_ALIGN(mm->brk);
-	if (oldbrk == newbrk)
-		goto set_brk;
-
-	/* Always allow shrinking brk. */
-	if (brk <= mm->brk) {
-		if (!do_munmap(mm, newbrk, oldbrk-newbrk))
-			goto set_brk;
-		goto out;
-	}
-
-	/* Check against unimplemented/unmapped addresses: */
-	if ((newbrk - oldbrk) > RGN_MAP_LIMIT || REGION_OFFSET(newbrk) > RGN_MAP_LIMIT)
-		goto out;
-
-	/* Check against rlimit.. */
-	rlim = current->signal->rlim[RLIMIT_DATA].rlim_cur;
-	if (rlim < RLIM_INFINITY && brk - mm->start_data > rlim)
-		goto out;
-
-	/* Check against existing mmap mappings. */
-	if (find_vma_intersection(mm, oldbrk, newbrk+PAGE_SIZE))
-		goto out;
-
-	/* Ok, looks good - let it rip. */
-	if (do_brk(oldbrk, newbrk-oldbrk) != oldbrk)
-		goto out;
-set_brk:
-	mm->brk = brk;
-out:
-	retval = mm->brk;
-	up_write(&mm->mmap_sem);
+	unsigned long retval = sys_brk(brk);
 	force_successful_syscall_return();
 	return retval;
 }
@@ -185,39 +141,6 @@ int ia64_mmap_check(unsigned long addr, unsigned long len,
 	return 0;
 }
 
-static inline unsigned long
-do_mmap2 (unsigned long addr, unsigned long len, int prot, int flags, int fd, unsigned long pgoff)
-{
-	struct file *file = NULL;
-
-	flags &= ~(MAP_EXECUTABLE | MAP_DENYWRITE);
-	if (!(flags & MAP_ANONYMOUS)) {
-		file = fget(fd);
-		if (!file)
-			return -EBADF;
-
-		if (!file->f_op || !file->f_op->mmap) {
-			addr = -ENODEV;
-			goto out;
-		}
-	}
-
-	/* Careful about overflows.. */
-	len = PAGE_ALIGN(len);
-	if (!len || len > TASK_SIZE) {
-		addr = -EINVAL;
-		goto out;
-	}
-
-	down_write(&current->mm->mmap_sem);
-	addr = do_mmap_pgoff(file, addr, len, prot, flags, pgoff);
-	up_write(&current->mm->mmap_sem);
-
-out:	if (file)
-		fput(file);
-	return addr;
-}
-
 /*
  * mmap2() is like mmap() except that the offset is expressed in units
  * of PAGE_SIZE (instead of bytes).  This allows to mmap2() (pieces
@@ -226,7 +149,7 @@ out:	if (file)
 asmlinkage unsigned long
 sys_mmap2 (unsigned long addr, unsigned long len, int prot, int flags, int fd, long pgoff)
 {
-	addr = do_mmap2(addr, len, prot, flags, fd, pgoff);
+	addr = sys_mmap_pgoff(addr, len, prot, flags, fd, pgoff);
 	if (!IS_ERR((void *) addr))
 		force_successful_syscall_return();
 	return addr;
@@ -238,7 +161,7 @@ sys_mmap (unsigned long addr, unsigned long len, int prot, int flags, int fd, lo
 	if (offset_in_page(off) != 0)
 		return -EINVAL;
 
-	addr = do_mmap2(addr, len, prot, flags, fd, off >> PAGE_SHIFT);
+	addr = sys_mmap_pgoff(addr, len, prot, flags, fd, off >> PAGE_SHIFT);
 	if (!IS_ERR((void *) addr))
 		force_successful_syscall_return();
 	return addr;