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-rw-r--r--fs/fcntl.c157
1 files changed, 157 insertions, 0 deletions
diff --git a/fs/fcntl.c b/fs/fcntl.c
index be8fbe289087..8bd81c2e89b2 100644
--- a/fs/fcntl.c
+++ b/fs/fcntl.c
@@ -23,6 +23,7 @@
#include <linux/pid_namespace.h>
#include <linux/user_namespace.h>
#include <linux/shmem_fs.h>
+#include <linux/compat.h>
#include <asm/poll.h>
#include <asm/siginfo.h>
@@ -420,6 +421,162 @@ out:
}
#endif
+#ifdef CONFIG_COMPAT
+static int get_compat_flock(struct flock *kfl, struct compat_flock __user *ufl)
+{
+ if (!access_ok(VERIFY_READ, ufl, sizeof(*ufl)) ||
+ __get_user(kfl->l_type, &ufl->l_type) ||
+ __get_user(kfl->l_whence, &ufl->l_whence) ||
+ __get_user(kfl->l_start, &ufl->l_start) ||
+ __get_user(kfl->l_len, &ufl->l_len) ||
+ __get_user(kfl->l_pid, &ufl->l_pid))
+ return -EFAULT;
+ return 0;
+}
+
+static int put_compat_flock(struct flock *kfl, struct compat_flock __user *ufl)
+{
+ if (!access_ok(VERIFY_WRITE, ufl, sizeof(*ufl)) ||
+ __put_user(kfl->l_type, &ufl->l_type) ||
+ __put_user(kfl->l_whence, &ufl->l_whence) ||
+ __put_user(kfl->l_start, &ufl->l_start) ||
+ __put_user(kfl->l_len, &ufl->l_len) ||
+ __put_user(kfl->l_pid, &ufl->l_pid))
+ return -EFAULT;
+ return 0;
+}
+
+#ifndef HAVE_ARCH_GET_COMPAT_FLOCK64
+static int get_compat_flock64(struct flock *kfl, struct compat_flock64 __user *ufl)
+{
+ if (!access_ok(VERIFY_READ, ufl, sizeof(*ufl)) ||
+ __get_user(kfl->l_type, &ufl->l_type) ||
+ __get_user(kfl->l_whence, &ufl->l_whence) ||
+ __get_user(kfl->l_start, &ufl->l_start) ||
+ __get_user(kfl->l_len, &ufl->l_len) ||
+ __get_user(kfl->l_pid, &ufl->l_pid))
+ return -EFAULT;
+ return 0;
+}
+#endif
+
+#ifndef HAVE_ARCH_PUT_COMPAT_FLOCK64
+static int put_compat_flock64(struct flock *kfl, struct compat_flock64 __user *ufl)
+{
+ if (!access_ok(VERIFY_WRITE, ufl, sizeof(*ufl)) ||
+ __put_user(kfl->l_type, &ufl->l_type) ||
+ __put_user(kfl->l_whence, &ufl->l_whence) ||
+ __put_user(kfl->l_start, &ufl->l_start) ||
+ __put_user(kfl->l_len, &ufl->l_len) ||
+ __put_user(kfl->l_pid, &ufl->l_pid))
+ return -EFAULT;
+ return 0;
+}
+#endif
+
+static unsigned int
+convert_fcntl_cmd(unsigned int cmd)
+{
+ switch (cmd) {
+ case F_GETLK64:
+ return F_GETLK;
+ case F_SETLK64:
+ return F_SETLK;
+ case F_SETLKW64:
+ return F_SETLKW;
+ }
+
+ return cmd;
+}
+
+COMPAT_SYSCALL_DEFINE3(fcntl64, unsigned int, fd, unsigned int, cmd,
+ compat_ulong_t, arg)
+{
+ mm_segment_t old_fs;
+ struct flock f;
+ long ret;
+ unsigned int conv_cmd;
+
+ switch (cmd) {
+ case F_GETLK:
+ case F_SETLK:
+ case F_SETLKW:
+ ret = get_compat_flock(&f, compat_ptr(arg));
+ if (ret != 0)
+ break;
+ old_fs = get_fs();
+ set_fs(KERNEL_DS);
+ ret = sys_fcntl(fd, cmd, (unsigned long)&f);
+ set_fs(old_fs);
+ if (cmd == F_GETLK && ret == 0) {
+ /* GETLK was successful and we need to return the data...
+ * but it needs to fit in the compat structure.
+ * l_start shouldn't be too big, unless the original
+ * start + end is greater than COMPAT_OFF_T_MAX, in which
+ * case the app was asking for trouble, so we return
+ * -EOVERFLOW in that case.
+ * l_len could be too big, in which case we just truncate it,
+ * and only allow the app to see that part of the conflicting
+ * lock that might make sense to it anyway
+ */
+
+ if (f.l_start > COMPAT_OFF_T_MAX)
+ ret = -EOVERFLOW;
+ if (f.l_len > COMPAT_OFF_T_MAX)
+ f.l_len = COMPAT_OFF_T_MAX;
+ if (ret == 0)
+ ret = put_compat_flock(&f, compat_ptr(arg));
+ }
+ break;
+
+ case F_GETLK64:
+ case F_SETLK64:
+ case F_SETLKW64:
+ case F_OFD_GETLK:
+ case F_OFD_SETLK:
+ case F_OFD_SETLKW:
+ ret = get_compat_flock64(&f, compat_ptr(arg));
+ if (ret != 0)
+ break;
+ old_fs = get_fs();
+ set_fs(KERNEL_DS);
+ conv_cmd = convert_fcntl_cmd(cmd);
+ ret = sys_fcntl(fd, conv_cmd, (unsigned long)&f);
+ set_fs(old_fs);
+ if ((conv_cmd == F_GETLK || conv_cmd == F_OFD_GETLK) && ret == 0) {
+ /* need to return lock information - see above for commentary */
+ if (f.l_start > COMPAT_LOFF_T_MAX)
+ ret = -EOVERFLOW;
+ if (f.l_len > COMPAT_LOFF_T_MAX)
+ f.l_len = COMPAT_LOFF_T_MAX;
+ if (ret == 0)
+ ret = put_compat_flock64(&f, compat_ptr(arg));
+ }
+ break;
+
+ default:
+ ret = sys_fcntl(fd, cmd, arg);
+ break;
+ }
+ return ret;
+}
+
+COMPAT_SYSCALL_DEFINE3(fcntl, unsigned int, fd, unsigned int, cmd,
+ compat_ulong_t, arg)
+{
+ switch (cmd) {
+ case F_GETLK64:
+ case F_SETLK64:
+ case F_SETLKW64:
+ case F_OFD_GETLK:
+ case F_OFD_SETLK:
+ case F_OFD_SETLKW:
+ return -EINVAL;
+ }
+ return compat_sys_fcntl64(fd, cmd, arg);
+}
+#endif
+
/* Table to convert sigio signal codes into poll band bitmaps */
static const long band_table[NSIGPOLL] = {