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

Pull vfs fixes from Al Viro:
 "Several fixes for bugs caught while looking through f_pos (ab)users"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  aout32 coredump compat fix
  splice: don't pass the address of ->f_pos to methods
  mconsole: we'd better initialize pos before passing it to vfs_read()...

7 files changed, 43 insertions, 25 deletions

diff --git a/arch/um/drivers/mconsole_kern.c b/arch/um/drivers/mconsole_kern.c
index d7d21851e60c..3df3bd544492 100644
--- a/arch/um/drivers/mconsole_kern.c
+++ b/arch/um/drivers/mconsole_kern.c
@@ -147,7 +147,7 @@ void mconsole_proc(struct mc_request *req)
         }
 
         do {
-                loff_t pos;
+                loff_t pos = file->f_pos;
                 mm_segment_t old_fs = get_fs();
                 set_fs(KERNEL_DS);
                 len = vfs_read(file, buf, PAGE_SIZE - 1, &pos);
diff --git a/arch/x86/ia32/ia32_aout.c b/arch/x86/ia32/ia32_aout.c
index 805078e08013..52ff81cce008 100644
--- a/arch/x86/ia32/ia32_aout.c
+++ b/arch/x86/ia32/ia32_aout.c
@@ -192,7 +192,7 @@ static int aout_core_dump(long signr, struct pt_regs *regs, struct file *file,
         /* struct user */
         DUMP_WRITE(&dump, sizeof(dump));
         /* Now dump all of the user data.  Include malloced stuff as well */
-        DUMP_SEEK(PAGE_SIZE);
+        DUMP_SEEK(PAGE_SIZE - sizeof(dump));
         /* now we start writing out the user space info */
         set_fs(USER_DS);
         /* Dump the data area */
diff --git a/fs/internal.h b/fs/internal.h
index eaa75f75b625..68121584ae37 100644
--- a/fs/internal.h
+++ b/fs/internal.h
@@ -132,6 +132,12 @@ extern struct dentry *__d_alloc(struct super_block *, const struct qstr *);
 extern ssize_t __kernel_write(struct file *, const char *, size_t, loff_t *);
 
 /*
+ * splice.c
+ */
+extern long do_splice_direct(struct file *in, loff_t *ppos, struct file *out,
+                loff_t *opos, size_t len, unsigned int flags);
+
+/*
  * pipe.c
  */
 extern const struct file_operations pipefifo_fops;
diff --git a/fs/read_write.c b/fs/read_write.c
index 03430008704e..2cefa417be34 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -1064,6 +1064,7 @@ static ssize_t do_sendfile(int out_fd, int in_fd, loff_t *ppos,
         struct fd in, out;
         struct inode *in_inode, *out_inode;
         loff_t pos;
+        loff_t out_pos;
         ssize_t retval;
         int fl;
 
@@ -1077,12 +1078,14 @@ static ssize_t do_sendfile(int out_fd, int in_fd, loff_t *ppos,
         if (!(in.file->f_mode & FMODE_READ))
                 goto fput_in;
         retval = -ESPIPE;
-        if (!ppos)
-                ppos = &in.file->f_pos;
-        else
+        if (!ppos) {
+                pos = in.file->f_pos;
+        } else {
+                pos = *ppos;
                 if (!(in.file->f_mode & FMODE_PREAD))
                         goto fput_in;
-        retval = rw_verify_area(READ, in.file, ppos, count);
+        }
+        retval = rw_verify_area(READ, in.file, &pos, count);
         if (retval < 0)
                 goto fput_in;
         count = retval;
@@ -1099,7 +1102,8 @@ static ssize_t do_sendfile(int out_fd, int in_fd, loff_t *ppos,
         retval = -EINVAL;
         in_inode = file_inode(in.file);
         out_inode = file_inode(out.file);
-        retval = rw_verify_area(WRITE, out.file, &out.file->f_pos, count);
+        out_pos = out.file->f_pos;
+        retval = rw_verify_area(WRITE, out.file, &out_pos, count);
         if (retval < 0)
                 goto fput_out;
         count = retval;
@@ -1107,7 +1111,6 @@ static ssize_t do_sendfile(int out_fd, int in_fd, loff_t *ppos,
         if (!max)
                 max = min(in_inode->i_sb->s_maxbytes, out_inode->i_sb->s_maxbytes);
 
-        pos = *ppos;
         if (unlikely(pos + count > max)) {
                 retval = -EOVERFLOW;
                 if (pos >= max)
@@ -1126,18 +1129,23 @@ static ssize_t do_sendfile(int out_fd, int in_fd, loff_t *ppos,
         if (in.file->f_flags & O_NONBLOCK)
                 fl = SPLICE_F_NONBLOCK;
 #endif
-        retval = do_splice_direct(in.file, ppos, out.file, count, fl);
+        retval = do_splice_direct(in.file, &pos, out.file, &out_pos, count, fl);
 
         if (retval > 0) {
                 add_rchar(current, retval);
                 add_wchar(current, retval);
                 fsnotify_access(in.file);
                 fsnotify_modify(out.file);
+                out.file->f_pos = out_pos;
+                if (ppos)
+                        *ppos = pos;
+                else
+                        in.file->f_pos = pos;
         }
 
         inc_syscr(current);
         inc_syscw(current);
-        if (*ppos > max)
+        if (pos > max)
                 retval = -EOVERFLOW;
 
 fput_out:
diff --git a/fs/splice.c b/fs/splice.c
index e6b25598c8c4..9eca476227d5 100644
--- a/fs/splice.c
+++ b/fs/splice.c
@@ -1274,7 +1274,7 @@ static int direct_splice_actor(struct pipe_inode_info *pipe,
 {
         struct file *file = sd->u.file;
 
-        return do_splice_from(pipe, file, &file->f_pos, sd->total_len,
+        return do_splice_from(pipe, file, sd->opos, sd->total_len,
                               sd->flags);
 }
 
@@ -1294,7 +1294,7 @@ static int direct_splice_actor(struct pipe_inode_info *pipe,
  *
  */
 long do_splice_direct(struct file *in, loff_t *ppos, struct file *out,
-                      size_t len, unsigned int flags)
+                      loff_t *opos, size_t len, unsigned int flags)
 {
         struct splice_desc sd = {
                 .len            = len,
@@ -1302,6 +1302,7 @@ long do_splice_direct(struct file *in, loff_t *ppos, struct file *out,
                 .flags          = flags,
                 .pos            = *ppos,
                 .u.file         = out,
+                .opos           = opos,
         };
         long ret;
 
@@ -1325,7 +1326,7 @@ static long do_splice(struct file *in, loff_t __user *off_in,
 {
         struct pipe_inode_info *ipipe;
         struct pipe_inode_info *opipe;
-        loff_t offset, *off;
+        loff_t offset;
         long ret;
 
         ipipe = get_pipe_info(in);
@@ -1356,13 +1357,15 @@ static long do_splice(struct file *in, loff_t __user *off_in,
                                 return -EINVAL;
                         if (copy_from_user(&offset, off_out, sizeof(loff_t)))
                                 return -EFAULT;
-                        off = &offset;
-                } else
-                        off = &out->f_pos;
+                } else {
+                        offset = out->f_pos;
+                }
 
-                ret = do_splice_from(ipipe, out, off, len, flags);
+                ret = do_splice_from(ipipe, out, &offset, len, flags);
 
-                if (off_out && copy_to_user(off_out, off, sizeof(loff_t)))
+                if (!off_out)
+                        out->f_pos = offset;
+                else if (copy_to_user(off_out, &offset, sizeof(loff_t)))
                         ret = -EFAULT;
 
                 return ret;
@@ -1376,13 +1379,15 @@ static long do_splice(struct file *in, loff_t __user *off_in,
                                 return -EINVAL;
                         if (copy_from_user(&offset, off_in, sizeof(loff_t)))
                                 return -EFAULT;
-                        off = &offset;
-                } else
-                        off = &in->f_pos;
+                } else {
+                        offset = in->f_pos;
+                }
 
-                ret = do_splice_to(in, off, opipe, len, flags);
+                ret = do_splice_to(in, &offset, opipe, len, flags);
 
-                if (off_in && copy_to_user(off_in, off, sizeof(loff_t)))
+                if (!off_in)
+                        in->f_pos = offset;
+                else if (copy_to_user(off_in, &offset, sizeof(loff_t)))
                         ret = -EFAULT;
 
                 return ret;
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 43db02e9c9fa..65c2be22b601 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -2414,8 +2414,6 @@ extern ssize_t generic_file_splice_write(struct pipe_inode_info *,
                 struct file *, loff_t *, size_t, unsigned int);
 extern ssize_t generic_splice_sendpage(struct pipe_inode_info *pipe,
                 struct file *out, loff_t *, size_t len, unsigned int flags);
-extern long do_splice_direct(struct file *in, loff_t *ppos, struct file *out,
-                size_t len, unsigned int flags);
 
 extern void
 file_ra_state_init(struct file_ra_state *ra, struct address_space *mapping);
diff --git a/include/linux/splice.h b/include/linux/splice.h
index 09a545a7dfa3..74575cbf2d6f 100644
--- a/include/linux/splice.h
+++ b/include/linux/splice.h
@@ -35,6 +35,7 @@ struct splice_desc {
                 void *data;             /* cookie */
         } u;
         loff_t pos;                     /* file position */
+        loff_t *opos;                   /* sendfile: output position */
         size_t num_spliced;             /* number of bytes already spliced */
         bool need_wakeup;               /* need to wake up writer */
 };