aio/vfs: cleanup of rw_copy_check_uvector() and compat_rw_copy_check_uvector()

A cleanup of rw_copy_check_uvector and compat_rw_copy_check_uvector after
changes made to support CMA in an earlier patch.

Rather than having an additional check_access parameter to these
functions, the first paramater type is overloaded to allow the caller to
specify CHECK_IOVEC_ONLY which means check that the contents of the iovec
are valid, but do not check the memory that they point to.  This is used
by process_vm_readv/writev where we need to validate that a iovec passed
to the syscall is valid but do not want to check the memory that it points
to at this point because it refers to an address space in another process.

Signed-off-by: Chris Yeoh <yeohc@au1.ibm.com>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/fs/aio.c b/fs/aio.c
index 67a6db3e1b6f83677009d2323c54dccd38dea63d..acb3312804e20503f5e1ad8303b6a7c98d05faa9 100644 (file)
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -1446,13 +1446,13 @@ static ssize_t aio_setup_vectored_rw(int type, struct kiocb *kiocb, bool compat)
                ret = compat_rw_copy_check_uvector(type,
                                (struct compat_iovec __user *)kiocb->ki_buf,
                                kiocb->ki_nbytes, 1, &kiocb->ki_inline_vec,
-                               &kiocb->ki_iovec, 1);
+                               &kiocb->ki_iovec);
        else
 #endif
                ret = rw_copy_check_uvector(type,
                                (struct iovec __user *)kiocb->ki_buf,
                                kiocb->ki_nbytes, 1, &kiocb->ki_inline_vec,
-                               &kiocb->ki_iovec, 1);
+                               &kiocb->ki_iovec);
        if (ret < 0)
                goto out;
 

diff --git a/fs/compat.c b/fs/compat.c
index 1426a516af4545f3e9cfe95bf9ac8310b0b4703a..b01e042aa8014a04b7fbace042611d8702394d0e 100644 (file)
--- a/fs/compat.c
+++ b/fs/compat.c
@@ -532,7 +532,7 @@ out:
 ssize_t compat_rw_copy_check_uvector(int type,
                const struct compat_iovec __user *uvector, unsigned long nr_segs,
                unsigned long fast_segs, struct iovec *fast_pointer,
-               struct iovec **ret_pointer, int check_access)
+               struct iovec **ret_pointer)
 {
        compat_ssize_t tot_len;
        struct iovec *iov = *ret_pointer = fast_pointer;
@@ -579,7 +579,7 @@ ssize_t compat_rw_copy_check_uvector(int type,
                }
                if (len < 0)    /* size_t not fitting in compat_ssize_t .. */
                        goto out;
-               if (check_access &&
+               if (type >= 0 &&
                    !access_ok(vrfy_dir(type), compat_ptr(buf), len)) {
                        ret = -EFAULT;
                        goto out;
@@ -1089,7 +1089,7 @@ static ssize_t compat_do_readv_writev(int type, struct file *file,
                goto out;
 
        tot_len = compat_rw_copy_check_uvector(type, uvector, nr_segs,
-                                              UIO_FASTIOV, iovstack, &iov, 1);
+                                              UIO_FASTIOV, iovstack, &iov);
        if (tot_len == 0) {
                ret = 0;
                goto out;

diff --git a/fs/read_write.c b/fs/read_write.c
index ffc99d22e0a3656711f14ac7e094cc954d1d90bd..c20614f86c01ed88ed36a65e9dfafdabfd3ba4d3 100644 (file)
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -633,8 +633,7 @@ ssize_t do_loop_readv_writev(struct file *filp, struct iovec *iov,
 ssize_t rw_copy_check_uvector(int type, const struct iovec __user * uvector,
                              unsigned long nr_segs, unsigned long fast_segs,
                              struct iovec *fast_pointer,
-                             struct iovec **ret_pointer,
-                             int check_access)
+                             struct iovec **ret_pointer)
 {
        unsigned long seg;
        ssize_t ret;
@@ -690,7 +689,7 @@ ssize_t rw_copy_check_uvector(int type, const struct iovec __user * uvector,
                        ret = -EINVAL;
                        goto out;
                }
-               if (check_access
+               if (type >= 0
                    && unlikely(!access_ok(vrfy_dir(type), buf, len))) {
                        ret = -EFAULT;
                        goto out;
@@ -723,7 +722,7 @@ static ssize_t do_readv_writev(int type, struct file *file,
        }
 
        ret = rw_copy_check_uvector(type, uvector, nr_segs,
-                                   ARRAY_SIZE(iovstack), iovstack, &iov, 1);
+                                   ARRAY_SIZE(iovstack), iovstack, &iov);
        if (ret <= 0)
                goto out;
 

diff --git a/include/linux/compat.h b/include/linux/compat.h
index 5d46217f84adfaab0dbe679a7612da7062bb72c6..4e890394ef996e709c490439be23f0c6fe24292f 100644 (file)
--- a/include/linux/compat.h
+++ b/include/linux/compat.h
@@ -577,8 +577,7 @@ extern ssize_t compat_rw_copy_check_uvector(int type,
                const struct compat_iovec __user *uvector,
                unsigned long nr_segs,
                unsigned long fast_segs, struct iovec *fast_pointer,
-               struct iovec **ret_pointer,
-               int check_access);
+               struct iovec **ret_pointer);
 
 extern void __user *compat_alloc_user_space(unsigned long len);
 

diff --git a/include/linux/fs.h b/include/linux/fs.h
index 685f567f9d69d56d5d0cdc7525161e93c07230cd..73a40283229ae61ac96cc852af1d7d8c256320d4 100644 (file)
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -173,6 +173,15 @@ struct inodes_stat_t {
 #define WRITE_FUA              (WRITE | REQ_SYNC | REQ_NOIDLE | REQ_FUA)
 #define WRITE_FLUSH_FUA                (WRITE | REQ_SYNC | REQ_NOIDLE | REQ_FLUSH | REQ_FUA)
 
+
+/*
+ * Flag for rw_copy_check_uvector and compat_rw_copy_check_uvector
+ * that indicates that they should check the contents of the iovec are
+ * valid, but not check the memory that the iovec elements
+ * points too.
+ */
+#define CHECK_IOVEC_ONLY -1
+
 #define SEL_IN         1
 #define SEL_OUT                2
 #define SEL_EX         4
@@ -1673,8 +1682,7 @@ struct seq_file;
 ssize_t rw_copy_check_uvector(int type, const struct iovec __user * uvector,
                              unsigned long nr_segs, unsigned long fast_segs,
                              struct iovec *fast_pointer,
-                             struct iovec **ret_pointer,
-                             int check_access);
+                             struct iovec **ret_pointer);
 
 extern ssize_t vfs_read(struct file *, char __user *, size_t, loff_t *);
 extern ssize_t vfs_write(struct file *, const char __user *, size_t, loff_t *);

diff --git a/mm/process_vm_access.c b/mm/process_vm_access.c
index c20ff48994c29050953c79fcdb0633e690bb653e..926b466497492f3f8463ebc623adc4fbddf9547a 100644 (file)
--- a/mm/process_vm_access.c
+++ b/mm/process_vm_access.c
@@ -371,15 +371,15 @@ static ssize_t process_vm_rw(pid_t pid,
        /* Check iovecs */
        if (vm_write)
                rc = rw_copy_check_uvector(WRITE, lvec, liovcnt, UIO_FASTIOV,
-                                          iovstack_l, &iov_l, 1);
+                                          iovstack_l, &iov_l);
        else
                rc = rw_copy_check_uvector(READ, lvec, liovcnt, UIO_FASTIOV,
-                                          iovstack_l, &iov_l, 1);
+                                          iovstack_l, &iov_l);
        if (rc <= 0)
                goto free_iovecs;
 
-       rc = rw_copy_check_uvector(READ, rvec, riovcnt, UIO_FASTIOV,
-                                  iovstack_r, &iov_r, 0);
+       rc = rw_copy_check_uvector(CHECK_IOVEC_ONLY, rvec, riovcnt, UIO_FASTIOV,
+                                  iovstack_r, &iov_r);
        if (rc <= 0)
                goto free_iovecs;
 
@@ -438,16 +438,16 @@ compat_process_vm_rw(compat_pid_t pid,
        if (vm_write)
                rc = compat_rw_copy_check_uvector(WRITE, lvec, liovcnt,
                                                  UIO_FASTIOV, iovstack_l,
-                                                 &iov_l, 1);
+                                                 &iov_l);
        else
                rc = compat_rw_copy_check_uvector(READ, lvec, liovcnt,
                                                  UIO_FASTIOV, iovstack_l,
-                                                 &iov_l, 1);
+                                                 &iov_l);
        if (rc <= 0)
                goto free_iovecs;
-       rc = compat_rw_copy_check_uvector(READ, rvec, riovcnt,
+       rc = compat_rw_copy_check_uvector(CHECK_IOVEC_ONLY, rvec, riovcnt,
                                          UIO_FASTIOV, iovstack_r,
-                                         &iov_r, 0);
+                                         &iov_r);
        if (rc <= 0)
                goto free_iovecs;
 

diff --git a/security/keys/compat.c b/security/keys/compat.c
index 4c48e13448f84e0df200ab0a2f0895d0eb5a709c..338b510e90275b1da873ed83aa907c404997d353 100644 (file)
--- a/security/keys/compat.c
+++ b/security/keys/compat.c
@@ -38,7 +38,7 @@ long compat_keyctl_instantiate_key_iov(
 
        ret = compat_rw_copy_check_uvector(WRITE, _payload_iov, ioc,
                                           ARRAY_SIZE(iovstack),
-                                          iovstack, &iov, 1);
+                                          iovstack, &iov);
        if (ret < 0)
                return ret;
        if (ret == 0)

diff --git a/security/keys/keyctl.c b/security/keys/keyctl.c
index 788cfc6965d2558b039748823ba1e993451fb10f..a3498f85f9632bb71fbad738b45750cd413b0ec7 100644 (file)
--- a/security/keys/keyctl.c
+++ b/security/keys/keyctl.c
@@ -1079,7 +1079,7 @@ long keyctl_instantiate_key_iov(key_serial_t id,
                goto no_payload;
 
        ret = rw_copy_check_uvector(WRITE, _payload_iov, ioc,
-                                   ARRAY_SIZE(iovstack), iovstack, &iov, 1);
+                                   ARRAY_SIZE(iovstack), iovstack, &iov);
        if (ret < 0)
                return ret;
        if (ret == 0)