Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull vfs changes from Al Viro.
 "A lot of misc stuff.  The obvious groups:
   * Miklos' atomic_open series; kills the damn abuse of
     ->d_revalidate() by NFS, which was the major stumbling block for
     all work in that area.
   * ripping security_file_mmap() and dealing with deadlocks in the
     area; sanitizing the neighborhood of vm_mmap()/vm_munmap() in
     general.
   * ->encode_fh() switched to saner API; insane fake dentry in
     mm/cleancache.c gone.
   * assorted annotations in fs (endianness, __user)
   * parts of Artem's ->s_dirty work (jff2 and reiserfs parts)
   * ->update_time() work from Josef.
   * other bits and pieces all over the place.

  Normally it would've been in two or three pull requests, but
  signal.git stuff had eaten a lot of time during this cycle ;-/"

Fix up trivial conflicts in Documentation/filesystems/vfs.txt (the
'truncate_range' inode method was removed by the VM changes, the VFS
update adds an 'update_time()' method), and in fs/btrfs/ulist.[ch] (due
to sparse fix added twice, with other changes nearby).

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (95 commits)
  nfs: don't open in ->d_revalidate
  vfs: retry last component if opening stale dentry
  vfs: nameidata_to_filp(): don't throw away file on error
  vfs: nameidata_to_filp(): inline __dentry_open()
  vfs: do_dentry_open(): don't put filp
  vfs: split __dentry_open()
  vfs: do_last() common post lookup
  vfs: do_last(): add audit_inode before open
  vfs: do_last(): only return EISDIR for O_CREAT
  vfs: do_last(): check LOOKUP_DIRECTORY
  vfs: do_last(): make ENOENT exit RCU safe
  vfs: make follow_link check RCU safe
  vfs: do_last(): use inode variable
  vfs: do_last(): inline walk_component()
  vfs: do_last(): make exit RCU safe
  vfs: split do_lookup()
  Btrfs: move over to use ->update_time
  fs: introduce inode operation ->update_time
  reiserfs: get rid of resierfs_sync_super
  reiserfs: mark the superblock as dirty a bit later
  ...

7 files changed, 80 insertions, 72 deletions

diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c
index 032daab449b0..8ea39aabe948 100644
--- a/security/apparmor/lsm.c
+++ b/security/apparmor/lsm.c
@@ -490,17 +490,9 @@ static int common_mmap(int op, struct file *file, unsigned long prot,
         return common_file_perm(op, file, mask);
 }
 
-static int apparmor_file_mmap(struct file *file, unsigned long reqprot,
-                              unsigned long prot, unsigned long flags,
-                              unsigned long addr, unsigned long addr_only)
+static int apparmor_mmap_file(struct file *file, unsigned long reqprot,
+                              unsigned long prot, unsigned long flags)
 {
-        int rc = 0;
-
-        /* do DAC check */
-        rc = cap_file_mmap(file, reqprot, prot, flags, addr, addr_only);
-        if (rc || addr_only)
-                return rc;
-
         return common_mmap(OP_FMMAP, file, prot, flags);
 }
 
@@ -646,7 +638,8 @@ static struct security_operations apparmor_ops = {
         .file_permission =              apparmor_file_permission,
         .file_alloc_security =          apparmor_file_alloc_security,
         .file_free_security =           apparmor_file_free_security,
-        .file_mmap =                    apparmor_file_mmap,
+        .mmap_file =                    apparmor_mmap_file,
+        .mmap_addr =                    cap_mmap_addr,
         .file_mprotect =                apparmor_file_mprotect,
         .file_lock =                    apparmor_file_lock,
 
diff --git a/security/capability.c b/security/capability.c
index fca889676c5e..61095df8b89a 100644
--- a/security/capability.c
+++ b/security/capability.c
@@ -949,7 +949,8 @@ void __init security_fixup_ops(struct security_operations *ops)
         set_to_cap_if_null(ops, file_alloc_security);
         set_to_cap_if_null(ops, file_free_security);
         set_to_cap_if_null(ops, file_ioctl);
-        set_to_cap_if_null(ops, file_mmap);
+        set_to_cap_if_null(ops, mmap_addr);
+        set_to_cap_if_null(ops, mmap_file);
         set_to_cap_if_null(ops, file_mprotect);
         set_to_cap_if_null(ops, file_lock);
         set_to_cap_if_null(ops, file_fcntl);
diff --git a/security/commoncap.c b/security/commoncap.c
index e771cb1b2d79..6dbae4650abe 100644
--- a/security/commoncap.c
+++ b/security/commoncap.c
@@ -958,22 +958,15 @@ int cap_vm_enough_memory(struct mm_struct *mm, long pages)
 }
 
 /*
- * cap_file_mmap - check if able to map given addr
- * @file: unused
- * @reqprot: unused
- * @prot: unused
- * @flags: unused
+ * cap_mmap_addr - check if able to map given addr
  * @addr: address attempting to be mapped
- * @addr_only: unused
  *
  * If the process is attempting to map memory below dac_mmap_min_addr they need
  * CAP_SYS_RAWIO.  The other parameters to this function are unused by the
  * capability security module.  Returns 0 if this mapping should be allowed
  * -EPERM if not.
  */
-int cap_file_mmap(struct file *file, unsigned long reqprot,
-                  unsigned long prot, unsigned long flags,
-                  unsigned long addr, unsigned long addr_only)
+int cap_mmap_addr(unsigned long addr)
 {
         int ret = 0;
 
@@ -986,3 +979,9 @@ int cap_file_mmap(struct file *file, unsigned long reqprot,
         }
         return ret;
 }
+
+int cap_mmap_file(struct file *file, unsigned long reqprot,
+                  unsigned long prot, unsigned long flags)
+{
+        return 0;
+}
diff --git a/security/security.c b/security/security.c
index 5497a57fba01..3efc9b12aef4 100644
--- a/security/security.c
+++ b/security/security.c
@@ -20,6 +20,9 @@
 #include <linux/ima.h>
 #include <linux/evm.h>
 #include <linux/fsnotify.h>
+#include <linux/mman.h>
+#include <linux/mount.h>
+#include <linux/personality.h>
 #include <net/flow.h>
 
 #define MAX_LSM_EVM_XATTR       2
@@ -657,18 +660,56 @@ int security_file_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
         return security_ops->file_ioctl(file, cmd, arg);
 }
 
-int security_file_mmap(struct file *file, unsigned long reqprot,
-                        unsigned long prot, unsigned long flags,
-                        unsigned long addr, unsigned long addr_only)
+static inline unsigned long mmap_prot(struct file *file, unsigned long prot)
 {
-        int ret;
+        /*
+         * Does we have PROT_READ and does the application expect
+         * it to imply PROT_EXEC?  If not, nothing to talk about...
+         */
+        if ((prot & (PROT_READ | PROT_EXEC)) != PROT_READ)
+                return prot;
+        if (!(current->personality & READ_IMPLIES_EXEC))
+                return prot;
+        /*
+         * if that's an anonymous mapping, let it.
+         */
+        if (!file)
+                return prot | PROT_EXEC;
+        /*
+         * ditto if it's not on noexec mount, except that on !MMU we need
+         * BDI_CAP_EXEC_MMAP (== VM_MAYEXEC) in this case
+         */
+        if (!(file->f_path.mnt->mnt_flags & MNT_NOEXEC)) {
+#ifndef CONFIG_MMU
+                unsigned long caps = 0;
+                struct address_space *mapping = file->f_mapping;
+                if (mapping && mapping->backing_dev_info)
+                        caps = mapping->backing_dev_info->capabilities;
+                if (!(caps & BDI_CAP_EXEC_MAP))
+                        return prot;
+#endif
+                return prot | PROT_EXEC;
+        }
+        /* anything on noexec mount won't get PROT_EXEC */
+        return prot;
+}
 
-        ret = security_ops->file_mmap(file, reqprot, prot, flags, addr, addr_only);
+int security_mmap_file(struct file *file, unsigned long prot,
+                        unsigned long flags)
+{
+        int ret;
+        ret = security_ops->mmap_file(file, prot,
+                                        mmap_prot(file, prot), flags);
         if (ret)
                 return ret;
         return ima_file_mmap(file, prot);
 }
 
+int security_mmap_addr(unsigned long addr)
+{
+        return security_ops->mmap_addr(addr);
+}
+
 int security_file_mprotect(struct vm_area_struct *vma, unsigned long reqprot,
                             unsigned long prot)
 {
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index fa2341b68331..372ec6502aa8 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -3083,9 +3083,7 @@ error:
         return rc;
 }
 
-static int selinux_file_mmap(struct file *file, unsigned long reqprot,
-                             unsigned long prot, unsigned long flags,
-                             unsigned long addr, unsigned long addr_only)
+static int selinux_mmap_addr(unsigned long addr)
 {
         int rc = 0;
         u32 sid = current_sid();
@@ -3104,10 +3102,12 @@ static int selinux_file_mmap(struct file *file, unsigned long reqprot,
         }
 
         /* do DAC check on address space usage */
-        rc = cap_file_mmap(file, reqprot, prot, flags, addr, addr_only);
-        if (rc || addr_only)
-                return rc;
+        return cap_mmap_addr(addr);
+}
 
+static int selinux_mmap_file(struct file *file, unsigned long reqprot,
+                             unsigned long prot, unsigned long flags)
+{
         if (selinux_checkreqprot)
                 prot = reqprot;
 
@@ -5570,7 +5570,8 @@ static struct security_operations selinux_ops = {
         .file_alloc_security =          selinux_file_alloc_security,
         .file_free_security =           selinux_file_free_security,
         .file_ioctl =                   selinux_file_ioctl,
-        .file_mmap =                    selinux_file_mmap,
+        .mmap_file =                    selinux_mmap_file,
+        .mmap_addr =                    selinux_mmap_addr,
         .file_mprotect =                selinux_file_mprotect,
         .file_lock =                    selinux_file_lock,
         .file_fcntl =                   selinux_file_fcntl,
diff --git a/security/selinux/selinuxfs.c b/security/selinux/selinuxfs.c
index 4e93f9ef970b..3ad290251288 100644
--- a/security/selinux/selinuxfs.c
+++ b/security/selinux/selinuxfs.c
@@ -1259,12 +1259,8 @@ static int sel_make_bools(void)
                 if (!inode)
                         goto out;
 
-                ret = -EINVAL;
-                len = snprintf(page, PAGE_SIZE, "/%s/%s", BOOL_DIR_NAME, names[i]);
-                if (len < 0)
-                        goto out;
-
                 ret = -ENAMETOOLONG;
+                len = snprintf(page, PAGE_SIZE, "/%s/%s", BOOL_DIR_NAME, names[i]);
                 if (len >= PAGE_SIZE)
                         goto out;
 
@@ -1557,19 +1553,10 @@ static inline u32 sel_ino_to_perm(unsigned long ino)
 static ssize_t sel_read_class(struct file *file, char __user *buf,
                                 size_t count, loff_t *ppos)
 {
-        ssize_t rc, len;
-        char *page;
         unsigned long ino = file->f_path.dentry->d_inode->i_ino;
-
-        page = (char *)__get_free_page(GFP_KERNEL);
-        if (!page)
-                return -ENOMEM;
-
-        len = snprintf(page, PAGE_SIZE, "%d", sel_ino_to_class(ino));
-        rc = simple_read_from_buffer(buf, count, ppos, page, len);
-        free_page((unsigned long)page);
-
-        return rc;
+        char res[TMPBUFLEN];
+        ssize_t len = snprintf(res, sizeof(res), "%d", sel_ino_to_class(ino));
+        return simple_read_from_buffer(buf, count, ppos, res, len);
 }
 
 static const struct file_operations sel_class_ops = {
@@ -1580,19 +1567,10 @@ static const struct file_operations sel_class_ops = {
 static ssize_t sel_read_perm(struct file *file, char __user *buf,
                                 size_t count, loff_t *ppos)
 {
-        ssize_t rc, len;
-        char *page;
         unsigned long ino = file->f_path.dentry->d_inode->i_ino;
-
-        page = (char *)__get_free_page(GFP_KERNEL);
-        if (!page)
-                return -ENOMEM;
-
-        len = snprintf(page, PAGE_SIZE, "%d", sel_ino_to_perm(ino));
-        rc = simple_read_from_buffer(buf, count, ppos, page, len);
-        free_page((unsigned long)page);
-
-        return rc;
+        char res[TMPBUFLEN];
+        ssize_t len = snprintf(res, sizeof(res), "%d", sel_ino_to_perm(ino));
+        return simple_read_from_buffer(buf, count, ppos, res, len);
 }
 
 static const struct file_operations sel_perm_ops = {
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index d583c0545808..ee0bb5735f35 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -1171,7 +1171,7 @@ static int smack_file_fcntl(struct file *file, unsigned int cmd,
 }
 
 /**
- * smack_file_mmap :
+ * smack_mmap_file :
  * Check permissions for a mmap operation.  The @file may be NULL, e.g.
  * if mapping anonymous memory.
  * @file contains the file structure for file to map (may be NULL).
@@ -1180,10 +1180,9 @@ static int smack_file_fcntl(struct file *file, unsigned int cmd,
  * @flags contains the operational flags.
  * Return 0 if permission is granted.
  */
-static int smack_file_mmap(struct file *file,
+static int smack_mmap_file(struct file *file,
                            unsigned long reqprot, unsigned long prot,
-                           unsigned long flags, unsigned long addr,
-                           unsigned long addr_only)
+                           unsigned long flags)
 {
         struct smack_known *skp;
         struct smack_rule *srp;
@@ -1198,11 +1197,6 @@ static int smack_file_mmap(struct file *file,
         int tmay;
         int rc;
 
-        /* do DAC check on address space usage */
-        rc = cap_file_mmap(file, reqprot, prot, flags, addr, addr_only);
-        if (rc || addr_only)
-                return rc;
-
         if (file == NULL || file->f_dentry == NULL)
                 return 0;
 
@@ -3482,7 +3476,8 @@ struct security_operations smack_ops = {
         .file_ioctl =                   smack_file_ioctl,
         .file_lock =                    smack_file_lock,
         .file_fcntl =                   smack_file_fcntl,
-        .file_mmap =                    smack_file_mmap,
+        .mmap_file =                    smack_mmap_file,
+        .mmap_addr =                    cap_mmap_addr,
         .file_set_fowner =              smack_file_set_fowner,
         .file_send_sigiotask =          smack_file_send_sigiotask,
         .file_receive =                 smack_file_receive,