Don't include sys/personality.h in linux-low.cc anymore

[deliverable/binutils-gdb.git] / gdb / nat / linux-namespaces.c

diff --git a/gdb/nat/linux-namespaces.c b/gdb/nat/linux-namespaces.c
index 98ae104ffb873f9203a51e338122af673e2dc28d..801a81b5f8c22b3b5c087727def0c88c39d28daa 100644 (file)
--- a/gdb/nat/linux-namespaces.c
+++ b/gdb/nat/linux-namespaces.c
@@ -1,6 +1,6 @@
 /* Linux namespaces(7) support.
 
-   Copyright (C) 2015 Free Software Foundation, Inc.
+   Copyright (C) 2015-2021 Free Software Foundation, Inc.
 
    This file is part of GDB.
 
@@ -17,34 +17,54 @@
    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
 
-#include "common-defs.h"
+#include "gdbsupport/common-defs.h"
 #include "nat/linux-namespaces.h"
-#include "filestuff.h"
+#include "gdbsupport/filestuff.h"
 #include <fcntl.h>
 #include <sys/syscall.h>
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <sys/socket.h>
-#include "gdb_wait.h"
+#include "gdbsupport/gdb_wait.h"
 #include <signal.h>
 #include <sched.h>
+#include "gdbsupport/scope-exit.h"
 
 /* See nat/linux-namespaces.h.  */
-int debug_linux_namespaces;
+bool debug_linux_namespaces;
+
+/* Handle systems without fork.  */
+
+static inline pid_t
+do_fork (void)
+{
+#ifdef HAVE_FORK
+  return fork ();
+#else
+  errno = ENOSYS;
+  return -1;
+#endif
+}
 
 /* Handle systems without setns.  */
 
-#ifndef HAVE_SETNS
-static int
-setns (int fd, int nstype)
+static inline int
+do_setns (int fd, int nstype)
 {
-#ifdef __NR_setns
+#ifdef HAVE_SETNS
+  return setns (fd, nstype);
+#elif defined __NR_setns
   return syscall (__NR_setns, fd, nstype);
 #else
   errno = ENOSYS;
   return -1;
 #endif
 }
+
+/* Handle systems without MSG_CMSG_CLOEXEC.  */
+
+#ifndef MSG_CMSG_CLOEXEC
+#define MSG_CMSG_CLOEXEC 0
 #endif
 
 /* A Linux namespace.  */
@@ -187,12 +207,12 @@ linux_ns_same (pid_t pid, enum linux_ns_type type)
    - TYPE (enum mnsh_msg_type, always sent) - the message type.
    - INT1 and
    - INT2 (int, always sent, though not always used) - two
-           values whose meaning is message-type-dependent.
+          values whose meaning is message-type-dependent.
           See enum mnsh_msg_type documentation below.
    - FD (int, optional, sent using SCM_RIGHTS) - an open file
-         descriptor.
+        descriptor.
    - BUF (unstructured data, optional) - some data with message-
-          type-dependent meaning.
+         type-dependent meaning.
 
    Note that the helper process is the child of a call to fork,
    so all code in the helper must be async-signal-safe.  */
@@ -374,7 +394,7 @@ mnsh_send_message (int sock, enum mnsh_msg_type type,
     {
       debug_printf ("mnsh: send: ");
       mnsh_debug_print_message (type, fd, int1, int2, buf, bufsiz);
-      debug_printf (" -> %ld\n", size);
+      debug_printf (" -> %s\n", pulongest (size));
     }
 
   return size;
@@ -426,7 +446,8 @@ mnsh_recv_message (int sock, enum mnsh_msg_type *type,
   if (size < 0)
     {
       if (debug_linux_namespaces)
-       debug_printf ("namespace-helper: recv failed (%ld)\n", size);
+       debug_printf ("namespace-helper: recv failed (%s)\n",
+                     pulongest (size));
 
       mnsh_maybe_mourn_peer ();
 
@@ -437,8 +458,8 @@ mnsh_recv_message (int sock, enum mnsh_msg_type *type,
   if (size < fixed_size || (msg.msg_flags & (MSG_TRUNC | MSG_CTRUNC)))
     {
       if (debug_linux_namespaces)
-       debug_printf ("namespace-helper: recv truncated (%ld 0x%x)\n",
-                     size, msg.msg_flags);
+       debug_printf ("namespace-helper: recv truncated (%s 0x%x)\n",
+                     pulongest (size), msg.msg_flags);
 
       mnsh_maybe_mourn_peer ();
 
@@ -488,7 +509,7 @@ mnsh_recv_message (int sock, enum mnsh_msg_type *type,
 static ssize_t
 mnsh_handle_setns (int sock, int fd, int nstype)
 {
-  int result = setns (fd, nstype);
+  int result = do_setns (fd, nstype);
 
   return mnsh_return_int (sock, result, errno);
 }
@@ -541,7 +562,7 @@ mnsh_main (int sock)
   while (1)
     {
       enum mnsh_msg_type type;
-      int fd, int1, int2;
+      int fd = -1, int1, int2;
       char buf[PATH_MAX];
       ssize_t size, response = -1;
 
@@ -637,7 +658,7 @@ linux_mntns_get_helper (void)
       if (gdb_socketpair_cloexec (AF_UNIX, SOCK_STREAM, 0, sv) < 0)
        return NULL;
 
-      h.pid = fork ();
+      h.pid = do_fork ();
       if (h.pid < 0)
        {
          int saved_errno = errno;
@@ -867,12 +888,11 @@ enum mnsh_fs_code
 static enum mnsh_fs_code
 linux_mntns_access_fs (pid_t pid)
 {
-  struct cleanup *old_chain;
   struct linux_ns *ns;
   struct stat sb;
   struct linux_mnsh *helper;
   ssize_t size;
-  int fd, saved_errno;
+  int fd;
 
   if (pid == getpid ())
     return MNSH_FS_DIRECT;
@@ -881,27 +901,26 @@ linux_mntns_access_fs (pid_t pid)
   if (ns == NULL)
     return MNSH_FS_DIRECT;
 
-  old_chain = make_cleanup (null_cleanup, NULL);
-
   fd = gdb_open_cloexec (linux_ns_filename (ns, pid), O_RDONLY, 0);
   if (fd < 0)
-    goto error;
+    return MNSH_FS_ERROR;
 
-  old_chain = make_cleanup_close (fd);
+  SCOPE_EXIT
+    {
+      int save_errno = errno;
+      close (fd);
+      errno = save_errno;
+    };
 
   if (fstat (fd, &sb) != 0)
-    goto error;
+    return MNSH_FS_ERROR;
 
   if (sb.st_ino == ns->id)
-    {
-      do_cleanups (old_chain);
-
-      return MNSH_FS_DIRECT;
-    }
+    return MNSH_FS_DIRECT;
 
   helper = linux_mntns_get_helper ();
   if (helper == NULL)
-    goto error;
+    return MNSH_FS_ERROR;
 
   if (sb.st_ino != helper->nsid)
     {
@@ -909,10 +928,10 @@ linux_mntns_access_fs (pid_t pid)
 
       size = mnsh_send_setns (helper, fd, 0);
       if (size < 0)
-       goto error;
+       return MNSH_FS_ERROR;
 
       if (mnsh_recv_int (helper, &result, &error) != 0)
-       goto error;
+       return MNSH_FS_ERROR;
 
       if (result != 0)
        {
@@ -925,23 +944,13 @@ linux_mntns_access_fs (pid_t pid)
            error = ENOTSUP;
 
          errno = error;
-         goto error;
+         return MNSH_FS_ERROR;
        }
 
       helper->nsid = sb.st_ino;
     }
 
-  do_cleanups (old_chain);
-
   return MNSH_FS_HELPER;
-
-error:
-  saved_errno = errno;
-
-  do_cleanups (old_chain);
-
-  errno = saved_errno;
-  return MNSH_FS_ERROR;
 }
 
 /* See nat/linux-namespaces.h.  */