Merge branch 'rbd-sysfs' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph...

[pandora-kernel.git] / fs / compat.c

diff --git a/fs/compat.c b/fs/compat.c
index 52cfeb6..eb1740a 100644 (file)
--- a/fs/compat.c
+++ b/fs/compat.c
@@ -49,6 +49,7 @@
 #include <linux/eventpoll.h>
 #include <linux/fs_struct.h>
 #include <linux/slab.h>
+#include <linux/pagemap.h>
 
 #include <asm/uaccess.h>
 #include <asm/mmu_context.h>
@@ -606,14 +607,14 @@ ssize_t compat_rw_copy_check_uvector(int type,
        /*
         * Single unix specification:
         * We should -EINVAL if an element length is not >= 0 and fitting an
-        * ssize_t.  The total length is fitting an ssize_t
+        * ssize_t.
         *
-        * Be careful here because iov_len is a size_t not an ssize_t
+        * In Linux, the total length is limited to MAX_RW_COUNT, there is
+        * no overflow possibility.
         */
        tot_len = 0;
        ret = -EINVAL;
        for (seg = 0; seg < nr_segs; seg++) {
-               compat_ssize_t tmp = tot_len;
                compat_uptr_t buf;
                compat_ssize_t len;
 
@@ -624,13 +625,13 @@ ssize_t compat_rw_copy_check_uvector(int type,
                }
                if (len < 0)    /* size_t not fitting in compat_ssize_t .. */
                        goto out;
-               tot_len += len;
-               if (tot_len < tmp) /* maths overflow on the compat_ssize_t */
-                       goto out;
                if (!access_ok(vrfy_dir(type), compat_ptr(buf), len)) {
                        ret = -EFAULT;
                        goto out;
                }
+               if (len > MAX_RW_COUNT - tot_len)
+                       len = MAX_RW_COUNT - tot_len;
+               tot_len += len;
                iov->iov_base = compat_ptr(buf);
                iov->iov_len = (compat_size_t) len;
                uvector++;
@@ -1349,6 +1350,10 @@ static int compat_count(compat_uptr_t __user *argv, int max)
                        argv++;
                        if (i++ >= max)
                                return -E2BIG;
+
+                       if (fatal_signal_pending(current))
+                               return -ERESTARTNOHAND;
+                       cond_resched();
                }
        }
        return i;
@@ -1390,6 +1395,12 @@ static int compat_copy_strings(int argc, compat_uptr_t __user *argv,
                while (len > 0) {
                        int offset, bytes_to_copy;
 
+                       if (fatal_signal_pending(current)) {
+                               ret = -ERESTARTNOHAND;
+                               goto out;
+                       }
+                       cond_resched();
+
                        offset = pos % PAGE_SIZE;
                        if (offset == 0)
                                offset = PAGE_SIZE;
@@ -1406,18 +1417,8 @@ static int compat_copy_strings(int argc, compat_uptr_t __user *argv,
                        if (!kmapped_page || kpos != (pos & PAGE_MASK)) {
                                struct page *page;
 
-#ifdef CONFIG_STACK_GROWSUP
-                               ret = expand_stack_downwards(bprm->vma, pos);
-                               if (ret < 0) {
-                                       /* We've exceed the stack rlimit. */
-                                       ret = -E2BIG;
-                                       goto out;
-                               }
-#endif
-                               ret = get_user_pages(current, bprm->mm, pos,
-                                                    1, 1, 1, &page, NULL);
-                               if (ret <= 0) {
-                                       /* We've exceed the stack rlimit. */
+                               page = get_arg_page(bprm, pos, 1);
+                               if (!page) {
                                        ret = -E2BIG;
                                        goto out;
                                }
@@ -1538,8 +1539,10 @@ int compat_do_execve(char * filename,
        return retval;
 
 out:
-       if (bprm->mm)
+       if (bprm->mm) {
+               acct_arg_size(bprm, 0);
                mmput(bprm->mm);
+       }
 
 out_file:
        if (bprm->file) {