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authorAl Viro <viro@zeniv.linux.org.uk>2010-01-14 11:39:39 -0800
committerGreg Kroah-Hartman <gregkh@suse.de>2010-01-18 10:19:11 -0800
commit1f51eb3a881359e97dc2c228e55c83fba598e349 (patch)
treed408fd227f329d2df0007b7677d27b64375b1ccb /mm
parentc3a8e0eaafb438d5a7e6ca55c09b921291fcc1b1 (diff)
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>
Diffstat (limited to 'mm')
-rw-r--r--mm/mmap.c42
-rw-r--r--mm/mremap.c241
-rw-r--r--mm/util.c44
3 files changed, 211 insertions, 116 deletions
diff --git a/mm/mmap.c b/mm/mmap.c
index 73f5e4b64010..ae197468b352 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -932,13 +932,9 @@ unsigned long do_mmap_pgoff(struct file *file, unsigned long addr,
if (!(flags & MAP_FIXED))
addr = round_hint_to_min(addr);
- error = arch_mmap_check(addr, len, flags);
- if (error)
- return error;
-
/* Careful about overflows.. */
len = PAGE_ALIGN(len);
- if (!len || len > TASK_SIZE)
+ if (!len)
return -ENOMEM;
/* offset overflow? */
@@ -949,24 +945,6 @@ unsigned long do_mmap_pgoff(struct file *file, unsigned long addr,
if (mm->map_count > sysctl_max_map_count)
return -ENOMEM;
- if (flags & MAP_HUGETLB) {
- struct user_struct *user = NULL;
- if (file)
- return -EINVAL;
-
- /*
- * VM_NORESERVE is used because the reservations will be
- * taken when vm_ops->mmap() is called
- * A dummy user value is used because we are not locking
- * memory so no accounting is necessary
- */
- len = ALIGN(len, huge_page_size(&default_hstate));
- file = hugetlb_file_setup(HUGETLB_ANON_FILE, len, VM_NORESERVE,
- &user, HUGETLB_ANONHUGE_INODE);
- if (IS_ERR(file))
- return PTR_ERR(file);
- }
-
/* Obtain the address to map to. we verify (or select) it and ensure
* that it represents a valid section of the address space.
*/
@@ -1459,6 +1437,14 @@ get_unmapped_area(struct file *file, unsigned long addr, unsigned long len,
unsigned long (*get_area)(struct file *, unsigned long,
unsigned long, unsigned long, unsigned long);
+ unsigned long error = arch_mmap_check(addr, len, flags);
+ if (error)
+ return error;
+
+ /* Careful about overflows.. */
+ if (len > TASK_SIZE)
+ return -ENOMEM;
+
get_area = current->mm->get_unmapped_area;
if (file && file->f_op && file->f_op->get_unmapped_area)
get_area = file->f_op->get_unmapped_area;
@@ -2003,20 +1989,14 @@ unsigned long do_brk(unsigned long addr, unsigned long len)
if (!len)
return addr;
- if ((addr + len) > TASK_SIZE || (addr + len) < addr)
- return -EINVAL;
-
- if (is_hugepage_only_range(mm, addr, len))
- return -EINVAL;
-
error = security_file_mmap(NULL, 0, 0, 0, addr, 1);
if (error)
return error;
flags = VM_DATA_DEFAULT_FLAGS | VM_ACCOUNT | mm->def_flags;
- error = arch_mmap_check(addr, len, flags);
- if (error)
+ error = get_unmapped_area(NULL, addr, len, 0, MAP_FIXED);
+ if (error & ~PAGE_MASK)
return error;
/*
diff --git a/mm/mremap.c b/mm/mremap.c
index 97bff2547719..845190898d59 100644
--- a/mm/mremap.c
+++ b/mm/mremap.c
@@ -261,6 +261,137 @@ static unsigned long move_vma(struct vm_area_struct *vma,
return new_addr;
}
+static struct vm_area_struct *vma_to_resize(unsigned long addr,
+ unsigned long old_len, unsigned long new_len, unsigned long *p)
+{
+ struct mm_struct *mm = current->mm;
+ struct vm_area_struct *vma = find_vma(mm, addr);
+
+ if (!vma || vma->vm_start > addr)
+ goto Efault;
+
+ if (is_vm_hugetlb_page(vma))
+ goto Einval;
+
+ /* We can't remap across vm area boundaries */
+ if (old_len > vma->vm_end - addr)
+ goto Efault;
+
+ if (vma->vm_flags & (VM_DONTEXPAND | VM_PFNMAP)) {
+ if (new_len > old_len)
+ goto Efault;
+ }
+
+ if (vma->vm_flags & VM_LOCKED) {
+ unsigned long locked, lock_limit;
+ locked = mm->locked_vm << PAGE_SHIFT;
+ lock_limit = current->signal->rlim[RLIMIT_MEMLOCK].rlim_cur;
+ locked += new_len - old_len;
+ if (locked > lock_limit && !capable(CAP_IPC_LOCK))
+ goto Eagain;
+ }
+
+ if (!may_expand_vm(mm, (new_len - old_len) >> PAGE_SHIFT))
+ goto Enomem;
+
+ if (vma->vm_flags & VM_ACCOUNT) {
+ unsigned long charged = (new_len - old_len) >> PAGE_SHIFT;
+ if (security_vm_enough_memory(charged))
+ goto Efault;
+ *p = charged;
+ }
+
+ return vma;
+
+Efault: /* very odd choice for most of the cases, but... */
+ return ERR_PTR(-EFAULT);
+Einval:
+ return ERR_PTR(-EINVAL);
+Enomem:
+ return ERR_PTR(-ENOMEM);
+Eagain:
+ return ERR_PTR(-EAGAIN);
+}
+
+static unsigned long mremap_to(unsigned long addr,
+ unsigned long old_len, unsigned long new_addr,
+ unsigned long new_len)
+{
+ struct mm_struct *mm = current->mm;
+ struct vm_area_struct *vma;
+ unsigned long ret = -EINVAL;
+ unsigned long charged = 0;
+ unsigned long map_flags;
+
+ if (new_addr & ~PAGE_MASK)
+ goto out;
+
+ if (new_len > TASK_SIZE || new_addr > TASK_SIZE - new_len)
+ goto out;
+
+ /* Check if the location we're moving into overlaps the
+ * old location at all, and fail if it does.
+ */
+ if ((new_addr <= addr) && (new_addr+new_len) > addr)
+ goto out;
+
+ if ((addr <= new_addr) && (addr+old_len) > new_addr)
+ goto out;
+
+ ret = security_file_mmap(NULL, 0, 0, 0, new_addr, 1);
+ if (ret)
+ goto out;
+
+ ret = do_munmap(mm, new_addr, new_len);
+ if (ret)
+ goto out;
+
+ if (old_len >= new_len) {
+ ret = do_munmap(mm, addr+new_len, old_len - new_len);
+ if (ret && old_len != new_len)
+ goto out;
+ old_len = new_len;
+ }
+
+ vma = vma_to_resize(addr, old_len, new_len, &charged);
+ if (IS_ERR(vma)) {
+ ret = PTR_ERR(vma);
+ goto out;
+ }
+
+ map_flags = MAP_FIXED;
+ if (vma->vm_flags & VM_MAYSHARE)
+ map_flags |= MAP_SHARED;
+
+ ret = get_unmapped_area(vma->vm_file, new_addr, new_len, vma->vm_pgoff +
+ ((addr - vma->vm_start) >> PAGE_SHIFT),
+ map_flags);
+ if (ret & ~PAGE_MASK)
+ goto out1;
+
+ ret = move_vma(vma, addr, old_len, new_len, new_addr);
+ if (!(ret & ~PAGE_MASK))
+ goto out;
+out1:
+ vm_unacct_memory(charged);
+
+out:
+ return ret;
+}
+
+static int vma_expandable(struct vm_area_struct *vma, unsigned long delta)
+{
+ unsigned long end = vma->vm_end + delta;
+ if (end < vma->vm_end) /* overflow */
+ return 0;
+ if (vma->vm_next && vma->vm_next->vm_start < end) /* intersection */
+ return 0;
+ if (get_unmapped_area(NULL, vma->vm_start, end - vma->vm_start,
+ 0, MAP_FIXED) & ~PAGE_MASK)
+ return 0;
+ return 1;
+}
+
/*
* Expand (or shrink) an existing mapping, potentially moving it at the
* same time (controlled by the MREMAP_MAYMOVE flag and available VM space)
@@ -294,32 +425,10 @@ unsigned long do_mremap(unsigned long addr,
if (!new_len)
goto out;
- /* new_addr is only valid if MREMAP_FIXED is specified */
if (flags & MREMAP_FIXED) {
- if (new_addr & ~PAGE_MASK)
- goto out;
- if (!(flags & MREMAP_MAYMOVE))
- goto out;
-
- if (new_len > TASK_SIZE || new_addr > TASK_SIZE - new_len)
- goto out;
-
- /* Check if the location we're moving into overlaps the
- * old location at all, and fail if it does.
- */
- if ((new_addr <= addr) && (new_addr+new_len) > addr)
- goto out;
-
- if ((addr <= new_addr) && (addr+old_len) > new_addr)
- goto out;
-
- ret = security_file_mmap(NULL, 0, 0, 0, new_addr, 1);
- if (ret)
- goto out;
-
- ret = do_munmap(mm, new_addr, new_len);
- if (ret)
- goto out;
+ if (flags & MREMAP_MAYMOVE)
+ ret = mremap_to(addr, old_len, new_addr, new_len);
+ goto out;
}
/*
@@ -332,60 +441,23 @@ unsigned long do_mremap(unsigned long addr,
if (ret && old_len != new_len)
goto out;
ret = addr;
- if (!(flags & MREMAP_FIXED) || (new_addr == addr))
- goto out;
- old_len = new_len;
+ goto out;
}
/*
- * Ok, we need to grow.. or relocate.
+ * Ok, we need to grow..
*/
- ret = -EFAULT;
- vma = find_vma(mm, addr);
- if (!vma || vma->vm_start > addr)
- goto out;
- if (is_vm_hugetlb_page(vma)) {
- ret = -EINVAL;
- goto out;
- }
- /* We can't remap across vm area boundaries */
- if (old_len > vma->vm_end - addr)
- goto out;
- if (vma->vm_flags & (VM_DONTEXPAND | VM_PFNMAP)) {
- if (new_len > old_len)
- goto out;
- }
- if (vma->vm_flags & VM_LOCKED) {
- unsigned long locked, lock_limit;
- locked = mm->locked_vm << PAGE_SHIFT;
- lock_limit = current->signal->rlim[RLIMIT_MEMLOCK].rlim_cur;
- locked += new_len - old_len;
- ret = -EAGAIN;
- if (locked > lock_limit && !capable(CAP_IPC_LOCK))
- goto out;
- }
- if (!may_expand_vm(mm, (new_len - old_len) >> PAGE_SHIFT)) {
- ret = -ENOMEM;
+ vma = vma_to_resize(addr, old_len, new_len, &charged);
+ if (IS_ERR(vma)) {
+ ret = PTR_ERR(vma);
goto out;
}
- if (vma->vm_flags & VM_ACCOUNT) {
- charged = (new_len - old_len) >> PAGE_SHIFT;
- if (security_vm_enough_memory(charged))
- goto out_nc;
- }
-
/* old_len exactly to the end of the area..
- * And we're not relocating the area.
*/
- if (old_len == vma->vm_end - addr &&
- !((flags & MREMAP_FIXED) && (addr != new_addr)) &&
- (old_len != new_len || !(flags & MREMAP_MAYMOVE))) {
- unsigned long max_addr = TASK_SIZE;
- if (vma->vm_next)
- max_addr = vma->vm_next->vm_start;
+ if (old_len == vma->vm_end - addr) {
/* can we just expand the current mapping? */
- if (max_addr - addr >= new_len) {
+ if (vma_expandable(vma, new_len - old_len)) {
int pages = (new_len - old_len) >> PAGE_SHIFT;
vma_adjust(vma, vma->vm_start,
@@ -409,28 +481,27 @@ unsigned long do_mremap(unsigned long addr,
*/
ret = -ENOMEM;
if (flags & MREMAP_MAYMOVE) {
- if (!(flags & MREMAP_FIXED)) {
- unsigned long map_flags = 0;
- if (vma->vm_flags & VM_MAYSHARE)
- map_flags |= MAP_SHARED;
-
- new_addr = get_unmapped_area(vma->vm_file, 0, new_len,
- vma->vm_pgoff, map_flags);
- if (new_addr & ~PAGE_MASK) {
- ret = new_addr;
- goto out;
- }
-
- ret = security_file_mmap(NULL, 0, 0, 0, new_addr, 1);
- if (ret)
- goto out;
+ unsigned long map_flags = 0;
+ if (vma->vm_flags & VM_MAYSHARE)
+ map_flags |= MAP_SHARED;
+
+ new_addr = get_unmapped_area(vma->vm_file, 0, new_len,
+ vma->vm_pgoff +
+ ((addr - vma->vm_start) >> PAGE_SHIFT),
+ map_flags);
+ if (new_addr & ~PAGE_MASK) {
+ ret = new_addr;
+ goto out;
}
+
+ ret = security_file_mmap(NULL, 0, 0, 0, new_addr, 1);
+ if (ret)
+ goto out;
ret = move_vma(vma, addr, old_len, new_len, new_addr);
}
out:
if (ret & ~PAGE_MASK)
vm_unacct_memory(charged);
-out_nc:
return ret;
}
diff --git a/mm/util.c b/mm/util.c
index 7c35ad95f927..b377ce430803 100644
--- a/mm/util.c
+++ b/mm/util.c
@@ -4,6 +4,10 @@
#include <linux/module.h>
#include <linux/err.h>
#include <linux/sched.h>
+#include <linux/hugetlb.h>
+#include <linux/syscalls.h>
+#include <linux/mman.h>
+#include <linux/file.h>
#include <asm/uaccess.h>
#define CREATE_TRACE_POINTS
@@ -268,6 +272,46 @@ int __attribute__((weak)) get_user_pages_fast(unsigned long start,
}
EXPORT_SYMBOL_GPL(get_user_pages_fast);
+SYSCALL_DEFINE6(mmap_pgoff, unsigned long, addr, unsigned long, len,
+ unsigned long, prot, unsigned long, flags,
+ unsigned long, fd, unsigned long, pgoff)
+{
+ struct file * file = NULL;
+ unsigned long retval = -EBADF;
+
+ if (!(flags & MAP_ANONYMOUS)) {
+ if (unlikely(flags & MAP_HUGETLB))
+ return -EINVAL;
+ file = fget(fd);
+ if (!file)
+ goto out;
+ } else if (flags & MAP_HUGETLB) {
+ struct user_struct *user = NULL;
+ /*
+ * VM_NORESERVE is used because the reservations will be
+ * taken when vm_ops->mmap() is called
+ * A dummy user value is used because we are not locking
+ * memory so no accounting is necessary
+ */
+ len = ALIGN(len, huge_page_size(&default_hstate));
+ file = hugetlb_file_setup(HUGETLB_ANON_FILE, len, VM_NORESERVE,
+ &user, HUGETLB_ANONHUGE_INODE);
+ if (IS_ERR(file))
+ return PTR_ERR(file);
+ }
+
+ flags &= ~(MAP_EXECUTABLE | MAP_DENYWRITE);
+
+ down_write(&current->mm->mmap_sem);
+ retval = do_mmap_pgoff(file, addr, len, prot, flags, pgoff);
+ up_write(&current->mm->mmap_sem);
+
+ if (file)
+ fput(file);
+out:
+ return retval;
+}
+
/* Tracepoints definitions. */
EXPORT_TRACEPOINT_SYMBOL(kmalloc);
EXPORT_TRACEPOINT_SYMBOL(kmem_cache_alloc);