Mon Mar 4 17:35:09 1996 Roland McGrath <roland@charlie-brown.gnu.ai.mit.edu>

	* hurd/catch-signal.c (hurd_safe_memmove): New function.
	(hurd_safe_copyin, hurd_safe_copyout): New functions.
	* hurd/hurd/sigpreempt.h: Declare them.

4 files changed, 92 insertions, 114 deletions

diff --git a/hurd/catch-signal.c b/hurd/catch-signal.c
index 3e8ee6c7e2..c148193f71 100644
--- a/hurd/catch-signal.c
+++ b/hurd/catch-signal.c
@@ -85,3 +85,82 @@ hurd_safe_memset (void *dest, int byte, size_t nbytes)
 			    (vm_address_t) dest, (vm_address_t) dest + nbytes,
 			    &operate, SIG_ERR);
 }
+
+
+error_t
+hurd_safe_copyout (void *dest, const void *src, size_t nbytes)
+{
+  error_t operate (struct hurd_signal_preempter *preempter)
+    {
+      memcpy (dest, src, nbytes);
+      return 0;
+    }
+  return hurd_catch_signal (sigmask (SIGBUS) | sigmask (SIGSEGV),
+			    (vm_address_t) dest, (vm_address_t) dest + nbytes,
+			    &operate, SIG_ERR);
+}
+
+error_t
+hurd_safe_copyin (void *dest, const void *src, size_t nbytes)
+{
+  error_t operate (struct hurd_signal_preempter *preempter)
+    {
+      memcpy (dest, src, nbytes);
+      return 0;
+    }
+  return hurd_catch_signal (sigmask (SIGBUS) | sigmask (SIGSEGV),
+			    (vm_address_t) src, (vm_address_t) src + nbytes,
+			    &operate, SIG_ERR);
+}
+
+error_t
+hurd_safe_memmove (void *dest, const void *src, size_t nbytes)
+{
+  jmp_buf buf;
+  void throw (int signo, long int sigcode, struct sigcontext *scp)
+    { longjmp (buf, scp->sc_error ?: EGRATUITOUS); }
+
+  struct hurd_signal_preempter src_preempter =
+    {
+      sigmask (SIGBUS) | sigmask (SIGSEGV),
+      (vm_address_t) src, (vm_address_t) src + nbytes,
+      NULL, (sighandler_t) &throw,
+    };
+  struct hurd_signal_preempter dest_preempter =
+    {
+      sigmask (SIGBUS) | sigmask (SIGSEGV),
+      (vm_address_t) dest, (vm_address_t) dest + nbytes,
+      NULL, (sighandler_t) &throw,
+      &src_preempter
+    };
+
+  struct hurd_sigstate *const ss = _hurd_self_sigstate ();
+  error_t error;
+
+  /* This returns again with nonzero value when we preempt a signal.  */
+  error = setjmp (buf);
+
+  if (error == 0)
+    {
+      /* Install a signal preempter for the thread.  */
+      __spin_lock (&ss->lock);
+      src_preempter.next = ss->preempters;
+      ss->preempters = &dest_preempter;
+      __spin_unlock (&ss->lock);
+
+      /* Do the copy; it might fault.  */
+      memmove (dest, src, nbytes);
+    }
+
+  /* Either memmove completed happily and ERROR is still zero, or it hit
+     an expected signal and `throw' made setjmp return the signal error
+     code in ERROR.  Now we can remove the preempter and return.  */
+
+  __spin_lock (&ss->lock);
+  assert (ss->preempters == &dest_preempter);
+  ss->preempters = src_preempter.next;
+  __spin_unlock (&ss->lock);
+
+  return error;
+}
+
diff --git a/hurd/hurd/sigpreempt.h b/hurd/hurd/sigpreempt.h
index eed67b2e94..4042ea2448 100644
--- a/hurd/hurd/sigpreempt.h
+++ b/hurd/hurd/sigpreempt.h
@@ -83,8 +83,20 @@ error_t hurd_catch_signal (sigset_t sigset,
 
 /* Convenience functions using `hurd_catch_signal'.  */
 
-error_t hurd_safe_memmove (void *dest, const void *src, size_t nbytes);
+
+/* Like `memset', but catch faults in DEST.  */
 error_t hurd_safe_memset (void *dest, int byte, size_t nbytes);
 
+/* Like `memcpy', but catch faults in SRC.  */
+error_t hurd_safe_copyin (void *dest, const void *src, size_t nbytes);
+
+/* Like `memcpy', but catch faults in DEST.  */
+error_t hurd_safe_copyout (void *dest, const void *src, size_t nbytes);
+
+/* Like `memmove', but catch faults in SRC or DEST.
+   If only one region is expected to fault, it is more efficient
+   to use `hurd_safe_copyin' or `hurd_safe_copyout' as appropriate.  */
+error_t hurd_safe_memmove (void *dest, const void *src, size_t nbytes);
+
 
 #endif	/* hurd/sigpreempt.h */
diff --git a/sysdeps/unix/bsd/dirstream.h b/sysdeps/unix/bsd/dirstream.h
deleted file mode 100644
index d46c59ec58..0000000000
--- a/sysdeps/unix/bsd/dirstream.h
+++ /dev/null
@@ -1,43 +0,0 @@
-/* Copyright (C) 1993, 1994, 1995 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
-modify it under the terms of the GNU Library General Public License as
-published by the Free Software Foundation; either version 2 of the
-License, or (at your option) any later version.
-
-The GNU C Library is distributed in the hope that it will be useful,
-but WITHOUT ANY WARRANTY; without even the implied warranty of
-MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-Library General Public License for more details.
-
-You should have received a copy of the GNU Library General Public
-License along with the GNU C Library; see the file COPYING.LIB.  If
-not, write to the Free Software Foundation, Inc., 675 Mass Ave,
-Cambridge, MA 02139, USA.  */
-
-#ifndef	_DIRSTREAM_H
-
-#define	_DIRSTREAM_H	1
-
-#define __need_size_t
-#include <stddef.h>
-#include <gnu/types.h>		/* For __off_t.  */
-
-/* Directory stream type.
-
-   The BSD directory format is the same as `struct dirent', so `readdir'
-   returns a pointer into the buffer we read directory data into.  */
-
-struct __dirstream
-  {
-    int __fd;			/* File descriptor.  */
-
-    char *__data;		/* Directory block.  */
-    size_t __allocation;	/* Space allocated for the block.  */
-    size_t __offset;		/* Current offset into the block.  */
-    size_t __size;		/* Total valid data in the block.  */
-    __off_t __pos;		/* Position in directory of this block.  */
-  };
-
-#endif	/* dirstream.h */
diff --git a/sysdeps/unix/bsd/readdir.c b/sysdeps/unix/bsd/readdir.c
deleted file mode 100644
index e3d020cd46..0000000000
--- a/sysdeps/unix/bsd/readdir.c
+++ /dev/null
@@ -1,70 +0,0 @@
-/* Copyright (C) 1991, 1992, 1993, 1994, 1995 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
-modify it under the terms of the GNU Library General Public License as
-published by the Free Software Foundation; either version 2 of the
-License, or (at your option) any later version.
-
-The GNU C Library is distributed in the hope that it will be useful,
-but WITHOUT ANY WARRANTY; without even the implied warranty of
-MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
-Library General Public License for more details.
-
-You should have received a copy of the GNU Library General Public
-License along with the GNU C Library; see the file COPYING.LIB.  If
-not, write to the Free Software Foundation, Inc., 675 Mass Ave,
-Cambridge, MA 02139, USA.  */
-
-#include <ansidecl.h>
-#include <errno.h>
-#include <limits.h>
-#include <stddef.h>
-#include <string.h>
-#include <dirent.h>
-#include <unistd.h>
-#include <sys/types.h>
-#include "direct.h"
-#include "dirstream.h"
-
-/* Read a directory entry from DIRP.  */
-struct dirent *
-DEFUN(readdir, (dirp), DIR *dirp)
-{
-  struct dirent *dp;
-
-  if (dirp == NULL || dirp->__data == NULL)
-    {
-      errno = EINVAL;
-      return NULL;
-    }
-
-  do
-    {
-      if (dirp->__offset >= dirp->__size)
-	{
-	  /* We've emptied out our buffer.  Refill it.  */
-
-	  ssize_t bytes = __getdirentries (dirp->__fd, dirp->__data,
-					   dirp->__allocation, &dirp->__pos);
-	  if (bytes <= 0)
-	    return NULL;
-	  dirp->__size = (size_t) bytes;
-
-	  /* Reset the offset into the buffer.  */
-	  dirp->__offset = 0;
-	}
-
-      dp = (struct dirent *) &dirp->__data[dirp->__offset];
-      dirp->__offset += dp->d_reclen;
-
-#ifndef HAVE_D_TYPE
-      dp->d_namlen = ((struct direct *) dp)->d_namlen;
-      dp->d_type = DT_UNKNOWN;
-#endif
-
-      /* Loop to ignore deleted files.  */
-    } while (dp->d_fileno == 0);
-
-  return dp;
-}