Fix some places in library where semaphore is not released on error conditions

git-svn-id: svn://svn.code.sf.net/p/nuttx/code/trunk@5071 42af7a65-404d-4744-a932-0658087f49c3

ChangeLog

@@ -3224,4 +3224,14 @@
 	* sched/os_bring.c, configs/*/defconfig, tools/mkconfig.c, and others:  Added
 	  configuration variable CONFIG_USER_ENTRYPOINT that may be used to change
 	  the default entry from user_start to some other symbol.  Contributed by
-	  Kate.
+	  Kate. NOTE: This change does introduce a minor backward incompatibility.
+	  For example, if your application uses NSH as its start-up program, then your
+	  code will not fail because it will be unable to find "user_start".  The fix
+	  for this link failure is to add the following to your configuration file:
+	  CONFIG_USER_ENTRYPOINT="nsh_main".
+	* libs/stdio/lib_libfread.c and lib_*flush*.c:  Correct a couple of
+	  error cases where the lib semaphore was not be released on error
+	  exits (thanks Ronen Vainish).  Also, improved some error reporting:
+	  the generic ERROR was being used instead of the specific errno
+	  value; the errno variable was not always set correctly.
+

lib/stdio/lib_fflush.c

@@ -2,7 +2,7 @@
  * lib/stdio/lib_fflush.c
  *
  *   Copyright (C) 2007-2009, 2011 Gregory Nutt. All rights reserved.
- *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -97,22 +97,36 @@
 
 int fflush(FAR FILE *stream)
 {
+  int ret;
+
   /* Is the stream argument NULL? */
 
   if (!stream)
     {
       /* Yes... then this is a request to flush all streams */
 
-      return lib_flushall(sched_getstreams());
+      ret = lib_flushall(sched_getstreams());
     }
-  else if (lib_fflush(stream, true) != 0)
+  else
     {
-      /* An error occurred during the flush AND/OR we were unable to flush all
+      ret = lib_fflush(stream, true);
-       * of the buffered write data.  Return EOF on failure.
+    }
+
+  /* Check the return value */
+
+  if (ret < 0)
+    {
+      /* An error occurred during the flush AND/OR we were unable to flush
+       * all of the buffered write data. Set the errno value.
        */
 
+      set_errno(-ret);
+
+      /* And return EOF on failure. */
+
       return EOF;
     }
+
   return OK;
 }
 

lib/stdio/lib_fgetc.c

@@ -2,7 +2,7 @@
  * lib/stdio/lib_fgetc.c
  *
  *   Copyright (C) 2007, 2008, 2011 Gregory Nutt. All rights reserved.
- *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions

lib/stdio/lib_fgetpos.c

@@ -2,7 +2,7 @@
  * lib/stdio/lib_fgetpos.c
  *
  *   Copyright (C) 2008-2009, 2011 Gregory Nutt. All rights reserved.
- *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions

lib/stdio/lib_fileno.c

@@ -2,7 +2,7 @@
  * lib/stdio/lib_fileno.c
  *
  *   Copyright (C) 2009, 2011 Gregory Nutt. All rights reserved.
- *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions

lib/stdio/lib_fread.c

@@ -2,7 +2,7 @@
  * lib/stdio/lib_fread.c
  *
  *   Copyright (C) 2007-2009, 2011 Gregory Nutt. All rights reserved.
- *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions

lib/stdio/lib_fseek.c

@@ -2,7 +2,7 @@
  * lib/stdio/lib_fseek.c
  *
  *   Copyright (C) 2007, 2008, 2011 Gregory Nutt. All rights reserved.
- *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions

lib/stdio/lib_fsetpos.c

@@ -2,7 +2,7 @@
  * lib/stdio/lib_fsetpos.c
  *
  *   Copyright (C) 2008, 2011 Gregory Nutt. All rights reserved.
- *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions

lib/stdio/lib_ftell.c

@@ -2,7 +2,7 @@
  * lib/stdio/lib_ftell.c
  *
  *   Copyright (C) 2008, 2011 Gregory Nutt. All rights reserved.
- *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions

lib/stdio/lib_fwrite.c

@@ -2,7 +2,7 @@
  * lib/stdio/lib_fwrite.c
  *
  *   Copyright (C) 2007-2009, 2011 Gregory Nutt. All rights reserved.
- *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions

lib/stdio/lib_libfflush.c

@@ -98,8 +98,8 @@
  *  bforce - flush must be complete.
  *
  * Return:
- *  ERROR on failure, otherwise the number of bytes remaining in the buffer.
+ *  A negated errno value on failure, otherwise the number of bytes remaining
- *  If bforce is set, then only the values ERROR and 0 will be returned.
+ *  in the buffer.
  *
  ****************************************************************************/
 
@@ -109,13 +109,13 @@ ssize_t lib_fflush(FAR FILE *stream, bool bforce)
   FAR const unsigned char *src;
   ssize_t bytes_written;
   ssize_t nbuffer;
+  int ret;
 
   /* Return EBADF if the file is not opened for writing */
 
   if (stream->fs_filedes < 0 || (stream->fs_oflags & O_WROK) == 0)
     {
-      set_errno(EBADF);
+      return -EBADF;
-      return ERROR;
     }
 
   /* Make sure that we have exclusive access to the stream */
@@ -132,8 +132,11 @@ ssize_t lib_fflush(FAR FILE *stream, bool bforce)
 
        if (stream->fs_bufread != stream->fs_bufstart)
         {
-          /* The buffer holds read data... just return zero */
+          /* The buffer holds read data... just return zero meaning "no bytes
+           * remaining in the buffer."
+           */
 
+          lib_give_semaphore(stream);
           return 0;
         }
 
@@ -151,8 +154,12 @@ ssize_t lib_fflush(FAR FILE *stream, bool bforce)
           bytes_written = write(stream->fs_filedes, src, nbuffer);
           if (bytes_written < 0)
             {
+              /* Write failed.  The cause of the failure is in 'errno'.
+               * returned the negated errno value.
+               */
+
               lib_give_semaphore(stream);
-              return ERROR;
+              return -get_errno();
             }
 
           /* Handle partial writes.  fflush() must either return with

lib/stdio/lib_libflushall.c

@@ -1,8 +1,8 @@
 /****************************************************************************
  * lib/stdio/lib_libflushall.c
  *
- *   Copyright (C) 2007-2009, 2011 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2007-2009, 2011-2012 Gregory Nutt. All rights reserved.
- *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -91,7 +91,7 @@
 int lib_flushall(FAR struct streamlist *list)
 {
   int lasterrno = OK;
-  int ret = OK;
+  int ret;
 
   /* Make sure that there are streams associated with this thread */
 
@@ -115,25 +115,23 @@ int lib_flushall(FAR struct streamlist *list)
              {
                /* Flush the writable FILE */
 
-               if (lib_fflush(stream, true) != 0)
+               ret = lib_fflush(stream, true);
+               if (ret < 0)
                  {
                    /* An error occurred during the flush AND/OR we were unable
-                    * to flush all of the buffered write data.  Return EOF on failure.
+                    * to flush all of the buffered write data.  Remember the
+                    * last errcode.
                     */
 
-                   lasterrno = get_errno();
+                   lasterrno = ret;
-                   ret = ERROR;
                  }
              }
          }
+
        stream_semgive(list);
     }
 
-  /* If any flush failed, return that last failed flush */
+  /* If any flush failed, return the errorcode of the last failed flush */
 
-  if (ret != OK)
+  return lasterrno;
-    {
-      set_errno(lasterrno);
-    }
-  return ret;
 }

lib/stdio/lib_libfread.c

@@ -1,8 +1,8 @@
 /****************************************************************************
  * lib/stdio/lib_libfread.c
  *
- *   Copyright (C) 2007-2009, 2011 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2007-2009, 2011-2012 Gregory Nutt. All rights reserved.
- *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -88,6 +88,7 @@ ssize_t lib_fread(FAR void *ptr, size_t count, FAR FILE *stream)
 {
   unsigned char *dest  = (unsigned char*)ptr;
   ssize_t        bytes_read;
+  int            ret;
 
   /* Make sure that reading from this stream is allowed */
 
@@ -127,9 +128,11 @@ ssize_t lib_fread(FAR void *ptr, size_t count, FAR FILE *stream)
        * buffered read/write access.
        */
 
-      if (lib_wrflush(stream) != 0)
+      ret = lib_wrflush(stream);
+      if (ret < 0)
         {
-          return ERROR;
+          lib_give_semaphore(stream);
+          return ret;
         }
 
       /* Now get any other needed chars from the buffer or the file. */
@@ -176,15 +179,17 @@ ssize_t lib_fread(FAR void *ptr, size_t count, FAR FILE *stream)
                   bytes_read = read(stream->fs_filedes, dest, count);
                   if (bytes_read < 0)
                     {
-                      /* An error occurred on the read */
+                      /* An error occurred on the read.  The error code is
+                       * in the 'errno' variable.
+                       */
 
-                      goto err_out;
+                      goto errout_with_errno;
                     }
                   else if (bytes_read == 0)
                     {
                       /* We are at the end of the file */
 
-                      goto short_read;
+                      goto shortread;
                     }
                   else
                     {
@@ -198,7 +203,7 @@ ssize_t lib_fread(FAR void *ptr, size_t count, FAR FILE *stream)
                         {
                           /* No.  We must be at the end of file. */
 
-                          goto short_read;
+                          goto shortread;
                         }
                       else
                         {
@@ -219,15 +224,17 @@ ssize_t lib_fread(FAR void *ptr, size_t count, FAR FILE *stream)
                   bytes_read = read(stream->fs_filedes, stream->fs_bufread, buffer_available);
                   if (bytes_read < 0)
                     {
-                      /* An error occurred on the read */
+                      /* An error occurred on the read.  The error code is
+                       * in the 'errno' variable.
+                       */
 
-                      goto err_out;
+                      goto errout_with_errno;
                     }
                   else if (bytes_read == 0)
                     {
                       /* We are at the end of the file */
 
-                      goto short_read;
+                      goto shortread;
                     }
                   else
                     {
@@ -246,7 +253,11 @@ ssize_t lib_fread(FAR void *ptr, size_t count, FAR FILE *stream)
           bytes_read = read(stream->fs_filedes, dest, count);
           if (bytes_read < 0)
             {
-              goto err_out;
+              /* An error occurred on the read.  The error code is
+               * in the 'errno' variable.
+               */
+
+              goto errout_with_errno;
             }
           else if (bytes_read == 0)
             {
@@ -259,13 +270,21 @@ ssize_t lib_fread(FAR void *ptr, size_t count, FAR FILE *stream)
             }
         }
 #endif
+    /* Here after a successful (but perhaps short) read */
+
 #if CONFIG_STDIO_BUFFER_SIZE > 0
-    short_read:
+    shortread:
 #endif
       bytes_read = dest - (unsigned char*)ptr;
-    err_out:
-      lib_give_semaphore(stream);
     }
-  return bytes_read;
+
+  lib_give_semaphore(stream);
+  return bytes_read;  
+
+/* Error exits */
+
+errout_with_errno:
+  lib_give_semaphore(stream);
+  return -get_errno();  
 }
 

lib/stdio/lib_libsprintf.c

@@ -2,7 +2,7 @@
  * lib/stdio/lib_libsprintf.c
  *
  *   Copyright (C) 2007-2009, 2011 Gregory Nutt. All rights reserved.
- *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions

lib/stdio/lib_rdflush.c

@@ -2,7 +2,7 @@
  * lib/stdio/lib_rdflush.c
  *
  *   Copyright (C) 2008, 2011 Gregory Nutt. All rights reserved.
- *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions

lib/stdio/lib_snprintf.c

@@ -2,7 +2,7 @@
  * lib/stdio/lib_snprintf.c
  *
  *   Copyright (C) 2007-2009, 2011 Gregory Nutt. All rights reserved.
- *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions

lib/stdio/lib_sprintf.c

@@ -2,7 +2,7 @@
  * lib/stdio/lib_sprintf.c
  *
  *   Copyright (C) 2007-2009, 2011 Gregory Nutt. All rights reserved.
- *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions

lib/stdio/lib_sscanf.c

@@ -2,7 +2,7 @@
  * lib/stdio/lib_sscanf.c
  *
  *   Copyright (C) 2007, 2008, 2011 Gregory Nutt. All rights reserved.
- *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions

lib/stdio/lib_syslogstream.c

@@ -2,7 +2,7 @@
  * lib/stdio/lib_syslogstream.c
  *
  *   Copyright (C) 2012 Gregory Nutt. All rights reserved.
- *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions

lib/stdio/lib_ungetc.c

@@ -2,7 +2,7 @@
  * lib/stdio/lib_ungetc.c
  *
  *   Copyright (C) 2007, 2008, 2011 Gregory Nutt. All rights reserved.
- *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions

lib/stdio/lib_vfprintf.c

@@ -2,7 +2,7 @@
  * lib/stdio/lib_vfprintf.c
  *
  *   Copyright (C) 2007-2009, 2011 Gregory Nutt. All rights reserved.
- *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions

lib/stdio/lib_vprintf.c

@@ -2,7 +2,7 @@
  * lib/stdio/lib_vprintf.c
  *
  *   Copyright (C) 2007, 2008, 2011 Gregory Nutt. All rights reserved.
- *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions

lib/stdio/lib_vsnprintf.c

@@ -2,7 +2,7 @@
  * lib/stdio/lib_vsnprintf.c
  *
  *   Copyright (C) 2007-2009, 2011 Gregory Nutt. All rights reserved.
- *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions

lib/stdio/lib_vsprintf.c

@@ -2,7 +2,7 @@
  * lib/stdio/lib_vsprintf.c
  *
  *   Copyright (C) 2007-2009, 2011 Gregory Nutt. All rights reserved.
- *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions

lib/stdio/lib_wrflush.c

@@ -1,8 +1,8 @@
 /****************************************************************************
  * lib/stdio/lib_wrflush.c
  *
- *   Copyright (C) 2008-2009, 2011 Gregory Nutt. All rights reserved.
+ *   Copyright (C) 2008-2009, 2011-2012 Gregory Nutt. All rights reserved.
- *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ -88,29 +88,49 @@
 
 int lib_wrflush(FAR FILE *stream)
 {
+#if CONFIG_STDIO_BUFFER_SIZE > 0
+  int ret;
+
   /* Verify that we were passed a valid (i.e., non-NULL) stream */
 
-#if CONFIG_STDIO_BUFFER_SIZE > 0
+#ifdef CONFIG_DEBUG
-  if (stream)
+  if (!stream)
     {
-      /* Verify that the stream is opened for writing... lib_fflush will
+      return -EINVAL;
-       * return an error if it is called for a stream that is not opened for
+    }
-       * writing.
+#endif
+
+  /* Verify that the stream is opened for writing... lib_fflush will
+   * return an error if it is called for a stream that is not opened for
+   * writing.  Check that first so that this function will not fail in
+   * that case.
+   */
+
+  if ((stream->fs_oflags & O_WROK) == 0)
+    {
+      /* Report that the success was successful if we attempt to flush a
+       * read-only stream.
        */
 
-      if ((stream->fs_oflags & O_WROK) == 0 ||
+      return OK;
-          lib_fflush(stream, true) == 0)
-       {
-         /* Return success if there is no buffered write data -- i.e., that
-          * the stream is not opened for writing or, if it is, that all of
-          * the buffered write data was successfully flushed.
-          */
-
-         return OK;
-       }
     }
-  return ERROR;
+
+  /* Flush the stream.   Return success if there is no buffered write data
+   * -- i.e., that the stream is opened for writing and  that all of the
+   * buffered write data was successfully flushed by lib_fflush().
+   */
+
+  return lib_fflush(stream, true);
 #else
-  return stream ? OK : ERROR;
+  /* Verify that we were passed a valid (i.e., non-NULL) stream */
+
+#ifdef CONFIG_DEBUG
+  if (!stream)
+    {
+      return -EINVAL;
+    }
+#endif
+
+  return OK;
 #endif
 }

lib/stdio/lib_zeroinstream.c

@@ -2,7 +2,7 @@
  * lib/stdio/lib_zeroinstream.c
  *
  *   Copyright (C) 2009, 2011 Gregory Nutt. All rights reserved.
- *   Author: Gregory Nutt <spudmonkey@racsa.co.cr>
+ *   Author: Gregory Nutt <gnutt@nuttx.org>
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions