Address comments

8 files changed, 72 insertions, 29 deletions

diff --git a/.topmsg b/.topmsg
index fd15d3d6a1..755717e443 100644
--- a/.topmsg
+++ b/.topmsg
@@ -6,10 +6,37 @@ Subject: [PATCH] Implement SysV shared memory for GNU/Hurd.
         * hurd/Makefile (routines): Add sysvshm.
         * hurd/sysvshm.h: New file.
         * hurd/sysvshm.c: New file.
-        * sysdeps/mach/hurd/bits/stat.h (S_IMMAP0): New macro.
-        (S_ISPARE): Unset the S_IMMAP0 flag.
         * sysdeps/mach/hurd/ftok.c: New file.
         * sysdeps/mach/hurd/shmat.c: New file.
         * sysdeps/mach/hurd/shmctl.c: New file.
         * sysdeps/mach/hurd/shmdt.c: New file.
+        * sysdeps/mach/hurd/shmget.c: New file.
         * sysdeps/mach/hurd/bits/posix_opt.h: Define _XOPEN_SHM to 1.
+
+TODO:
+“
+> +  char filename[sizeof (SHM_DIR) - 1 + SHM_NAMEMAX];
+> +  struct stat statbuf;
+> +
+> +  sprintf (filename, SHM_DIR SHM_NAMEPRI, id);
+> +  /* SysV requires read access for IPC_STAT.  */
+> +  fd = __open (filename, O_NORW);
+> +  if (fd < 0)
+> +    {
+> +      if (errno == ENOENT)
+> +     errno = EINVAL;
+> +      return -1;
+> +    }
+
+Since this is repeated in more than one function, put it into an
+internal subroutine.  Then we have only one place doing the
+name-generation logic.
+”
+
+“
+> +    case IPC_RMID:
+> +      res = __unlink (filename);
+> +      /* FIXME: Check error (mapping ENOENT to EINVAL).  */
+
+Fix it.
+”
diff --git a/hurd/sysvshm.c b/hurd/sysvshm.c
index 945ac1c24e..5d538a6373 100644
--- a/hurd/sysvshm.c
+++ b/hurd/sysvshm.c
@@ -1,4 +1,5 @@
-/* Copyright (C) 2005-2015 Free Software Foundation, Inc.
+/* SysV shared memory for Hurd.
+   Copyright (C) 2005-2015 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
 
    The GNU C Library is free software; you can redistribute it and/or
@@ -41,7 +42,7 @@ struct sysvshm_attach
 };
 
 /* List of attachments.  */
-static struct sysvshm_attach *attach_list;
+static struct sysvshm_attach *sysvshm_list;
 
 /* A lock to protect the linked list of shared memory attachments.  */
 static struct mutex sysvshm_lock = MUTEX_INITIALIZER;
@@ -54,30 +55,30 @@ __sysvshm_add (void *addr, size_t size)
   struct sysvshm_attach *shm;
 
   shm = malloc (sizeof (*shm));
-  if (!shm)
+  if (shm == NULL)
     return errno;
 
   __mutex_lock (&sysvshm_lock);
   shm->addr = addr;
   shm->size = size;
-  shm->next = attach_list;
-  attach_list = shm;
+  shm->next = sysvshm_list;
+  sysvshm_list = shm;
   __mutex_unlock (&sysvshm_lock);
 
   return 0;
 }
 
-/* Removes a segment attachment.  Returns its size if found, or EINVAL
-   otherwise.  */
+/* Removes a segment attachment.  On success, returns 0 and sets *SIZE to its
+   size. Returns EINVAL if not found.  */
 error_t
 __sysvshm_remove (void *addr, size_t *size)
 {
   struct sysvshm_attach *shm;
-  struct sysvshm_attach **pshm = &attach_list;
+  struct sysvshm_attach **pshm = &sysvshm_list;
 
   __mutex_lock (&sysvshm_lock);
-  shm = attach_list;
-  while (shm)
+  shm = sysvshm_list;
+  while (shm != NULL)
     {
       shm = *pshm;
       if (shm->addr == addr)
@@ -85,6 +86,7 @@ __sysvshm_remove (void *addr, size_t *size)
 	  *pshm = shm->next;
 	  *size = shm->size;
 	  __mutex_unlock (&sysvshm_lock);
+	  free (shm);
 	  return 0;
 	}
       pshm = &shm->next;
diff --git a/hurd/sysvshm.h b/hurd/sysvshm.h
index 5faa0f005f..8b9c29ff46 100644
--- a/hurd/sysvshm.h
+++ b/hurd/sysvshm.h
@@ -1,4 +1,5 @@
-/* Copyright (C) 2005-2015 Free Software Foundation, Inc.
+/* SysV shared memory for Hurd.
+   Copyright (C) 2005-2015 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
 
    The GNU C Library is free software; you can redistribute it and/or
@@ -15,16 +16,19 @@
    License along with the GNU C Library; if not, see
    <http://www.gnu.org/licenses/>.  */
 
+#ifndef _HURD_SYSVSHM_H
+#define _HURD_SYSVSHM_H
+
 #include <paths.h>
 #include <hurd.h>
 
 /* The area (from top to bottom) that is used for private keys.  These
    are all keys that have the second highest bit set.  */
-#define SHM_PRIV_KEY_START INT_MAX
-#define SHM_PRIV_KEY_END ((INT_MAX / 2) + 1)
+#define SHM_PRIV_KEY_START	INT_MAX
+#define SHM_PRIV_KEY_END	((INT_MAX / 2) + 1)
 
-#define SHM_PREFIX "shm-"
-#define SHM_DIR _PATH_DEV "shm/"
+#define SHM_PREFIX		"sysvshm-"
+#define SHM_DIR			_PATH_DEV "shm/"
 
 /* The maximum number of characters in a shared memory segment file name.
    32 is the max number of characters in a 128 bit number in hex.  */
@@ -41,6 +45,8 @@
 /* Adds a segment attachment.  */
 error_t __sysvshm_add (void *addr, size_t size);
 
-/* Removes a segment attachment.  Returns its size if found, or EINVAL
-   otherwise.  */
+/* Removes a segment attachment.  On success, returns 0 and sets *SIZE to its
+   size. Returns EINVAL if not found.  */
 error_t __sysvshm_remove (void *addr, size_t *size);
+
+#endif /* sysvshm.h */
diff --git a/sysdeps/mach/hurd/ftok.c b/sysdeps/mach/hurd/ftok.c
index 69e6bf58ff..a6aba15c86 100644
--- a/sysdeps/mach/hurd/ftok.c
+++ b/sysdeps/mach/hurd/ftok.c
@@ -1,6 +1,6 @@
-/* Copyright (C) 1995-2015 Free Software Foundation, Inc.
+/* SysV ftok for Hurd.
+   Copyright (C) 1995-2015 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
-   Contributed by Ulrich Drepper <drepper@gnu.ai.mit.edu>, August 1995.
 
    The GNU C Library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Lesser General Public
@@ -21,8 +21,9 @@
 
 
 /* In the Hurd, we use the second-to-most-significant bit as flag for
-   private keys.  We use a different order of the components so that
-   the biggest one---the inode number---is affected by this.  */
+   private keys.  We use an order of the components different from the generic
+   code in sysvipc/ftok.c so that the biggest one--the inode number--is
+   affected by this.  */
 
 key_t
 ftok (pathname, proj_id)
diff --git a/sysdeps/mach/hurd/shmat.c b/sysdeps/mach/hurd/shmat.c
index a8900e0a3f..6bc88705b8 100644
--- a/sysdeps/mach/hurd/shmat.c
+++ b/sysdeps/mach/hurd/shmat.c
@@ -1,4 +1,5 @@
-/* Copyright (C) 2005-2015 Free Software Foundation, Inc.
+/* SysV shmat for Hurd.
+   Copyright (C) 2005-2015 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
 
    The GNU C Library is free software; you can redistribute it and/or
@@ -53,7 +54,9 @@ __shmat (int shmid, const void *shmaddr, int shmflg)
   res = __fstat (fd, &statbuf);
   if (res < 0)
     {
+      err = errno;
       __close (fd);
+      errno = err;
       return (void *) -1;
     }
 
@@ -68,6 +71,7 @@ __shmat (int shmid, const void *shmaddr, int shmflg)
   if (err)
     {
       munmap (addr, statbuf.st_size);
+      errno = err;
       return (void *) -1;
     }
 
diff --git a/sysdeps/mach/hurd/shmctl.c b/sysdeps/mach/hurd/shmctl.c
index aee5e15a56..a991a0c8de 100644
--- a/sysdeps/mach/hurd/shmctl.c
+++ b/sysdeps/mach/hurd/shmctl.c
@@ -1,4 +1,5 @@
-/* Copyright (C) 2005-2015 Free Software Foundation, Inc.
+/* SysV shmctl for Hurd.
+   Copyright (C) 2005-2015 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
 
    The GNU C Library is free software; you can redistribute it and/or
@@ -26,7 +27,7 @@
 
 #include "sysvshm.h"
 
-/* Provide operations to control over shared memory segments.  */
+/* Provide operations to control shared memory segments.  */
 int
 __shmctl (int id, int cmd, struct shmid_ds *buf)
 {
diff --git a/sysdeps/mach/hurd/shmdt.c b/sysdeps/mach/hurd/shmdt.c
index 245fd55a89..988fab8ee6 100644
--- a/sysdeps/mach/hurd/shmdt.c
+++ b/sysdeps/mach/hurd/shmdt.c
@@ -1,4 +1,5 @@
-/* Copyright (C) 2005-2015 Free Software Foundation, Inc.
+/* SysV shmdt for Hurd.
+   Copyright (C) 2005-2015 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
 
    The GNU C Library is free software; you can redistribute it and/or
diff --git a/sysdeps/mach/hurd/shmget.c b/sysdeps/mach/hurd/shmget.c
index 9b580949b8..2065b41989 100644
--- a/sysdeps/mach/hurd/shmget.c
+++ b/sysdeps/mach/hurd/shmget.c
@@ -1,4 +1,5 @@
-/* Copyright (C) 2005-2015 Free Software Foundation, Inc.
+/* SysV shmget for Hurd.
+   Copyright (C) 2005-2015 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
 
    The GNU C Library is free software; you can redistribute it and/or
@@ -94,7 +95,7 @@ get_exclusive (int shmflags, size_t size, key_t *r_key, int *r_fd)
       key = SHM_PRIV_KEY_START;
 
       /* Try to link the shared memory segment into the filesystem
-	 (exclusively).  Private segments have negative keys.  */
+	 (exclusively).  */
       do
 	{
 	  sprintf (filename, SHM_NAMEPRI, key);