execv() is a basic system interface. It should not be in libc/ but rather in sched/task. Its symboltable helper logic also belongs in the kernel but belings in binfmt/ with the other symbol table logic

7 files changed, 356 insertions, 14 deletions

diff --git a/nuttx/binfmt/Makefile b/nuttx/binfmt/Makefile
index 4e1f18ebc..c5cfe9736 100644
--- a/nuttx/binfmt/Makefile
+++ b/nuttx/binfmt/Makefile
@@ -1,7 +1,7 @@
 ############################################################################
 # nxflat/Makefile
 #
-#   Copyright (C) 2007-2009, 2012-2013 Gregory Nutt. All rights reserved.
+#   Copyright (C) 2007-2009, 2012-2014 Gregory Nutt. All rights reserved.
 #   Author: Gregory Nutt <gnutt@nuttx.org>
 #
 # Redistribution and use in source and binary forms, with or without
@@ -61,6 +61,10 @@ endif
 BINFMT_CSRCS += symtab_findbyname.c symtab_findbyvalue.c
 BINFMT_CSRCS += symtab_findorderedbyname.c symtab_findorderedbyvalue.c
 
+ifeq ($(CONFIG_LIBC_EXECFUNCS),y)
+BINFMT_CSRCS += binfmt_execsymtab.c
+endif
+
 # Add configured binary modules
 
 VPATH =
diff --git a/nuttx/binfmt/binfmt_execsymtab.c b/nuttx/binfmt/binfmt_execsymtab.c
new file mode 100644
index 000000000..63fa14adb
--- /dev/null
+++ b/nuttx/binfmt/binfmt_execsymtab.c
@@ -0,0 +1,156 @@
+/****************************************************************************
+ * binfmt/binfmt_execsymtab.c
+ *
+ *   Copyright (C) 2013 Gregory Nutt. All rights reserved.
+ *   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
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name NuttX nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <assert.h>
+
+#include <nuttx/arch.h>
+#include <nuttx/binfmt/symtab.h>
+
+#ifdef CONFIG_LIBC_EXECFUNCS
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+/* If CONFIG_LIBC_EXECFUNCS is defined in the configuration, then the
+ * following must also be defined:
+ */
+
+#ifdef CONFIG_EXECFUNCS_HAVE_SYMTAB
+  /* Symbol table used by exec[l|v] */
+
+#  ifndef CONFIG_EXECFUNCS_SYMTAB
+#    error "CONFIG_EXECFUNCS_SYMTAB must be defined"
+#  endif
+
+  /* Number of Symbols in the Table */
+
+#  ifndef CONFIG_EXECFUNCS_NSYMBOLS
+#    error "CONFIG_EXECFUNCS_NSYMBOLS must be defined"
+#  endif
+#endif
+
+/****************************************************************************
+ * Public Variables
+ ****************************************************************************/
+
+#ifdef CONFIG_EXECFUNCS_HAVE_SYMTAB
+extern const struct symtab_s CONFIG_EXECFUNCS_SYMTAB;
+#endif
+
+/****************************************************************************
+ * Private Data
+ ****************************************************************************/
+
+#ifdef CONFIG_EXECFUNCS_HAVE_SYMTAB
+static FAR const struct symtab_s *g_exec_symtab = &CONFIG_EXECFUNCS_SYMTAB;
+static int g_exec_nsymbols = CONFIG_EXECFUNCS_NSYMBOLS;
+#else
+static FAR const struct symtab_s *g_exec_symtab;
+static int g_exec_nsymbols;
+#endif
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: exec_getsymtab
+ *
+ * Description:
+ *   Get the current symbol table selection as an atomic operation.
+ *
+ * Input Parameters:
+ *   symtab - The location to store the symbol table.
+ *   nsymbols - The location to store the number of symbols in the symbol table.
+ *
+ * Returned Value:
+ *   None
+ *
+ ****************************************************************************/
+
+void exec_getsymtab(FAR const struct symtab_s **symtab, FAR int *nsymbols)
+{
+  irqstate_t flags;
+
+  DEBUGASSERT(symtab && nsymbols);
+
+  /* Disable interrupts very briefly so that both the symbol table and its
+   * size are returned as a single atomic operation.
+   */
+
+  flags     = irqsave();
+  *symtab   = g_exec_symtab;
+  *nsymbols = g_exec_nsymbols;
+  irqrestore(flags);
+}
+
+/****************************************************************************
+ * Name: exec_setsymtab
+ *
+ * Description:
+ *   Select a new symbol table selection as an atomic operation.
+ *
+ * Input Parameters:
+ *   symtab - The new symbol table.
+ *   nsymbols - The number of symbols in the symbol table.
+ *
+ * Returned Value:
+ *   None
+ *
+ ****************************************************************************/
+
+void exec_setsymtab(FAR const struct symtab_s *symtab, int nsymbols)
+{
+  irqstate_t flags;
+
+  DEBUGASSERT(symtab);
+
+  /* Disable interrupts very briefly so that both the symbol table and its
+   * size are set as a single atomic operation.
+   */
+
+  flags           = irqsave();
+  g_exec_symtab   = symtab;
+  g_exec_nsymbols = nsymbols;
+  irqrestore(flags);
+}
+
+#endif /* CONFIG_LIBC_EXECFUNCS */
\ No newline at end of file
diff --git a/nuttx/include/nuttx/binfmt/symtab.h b/nuttx/include/nuttx/binfmt/symtab.h
index 346c6099f..c6cdeffe4 100644
--- a/nuttx/include/nuttx/binfmt/symtab.h
+++ b/nuttx/include/nuttx/binfmt/symtab.h
@@ -77,12 +77,47 @@ struct symtab_s
 #undef EXTERN
 #if defined(__cplusplus)
 #define EXTERN extern "C"
-extern "C" {
+extern "C"
+{
 #else
 #define EXTERN extern
 #endif
 
 /****************************************************************************
+ * Name: exec_getsymtab
+ *
+ * Description:
+ *   Get the current symbol table selection as an atomic operation.
+ *
+ * Input Parameters:
+ *   symtab - The location to store the symbol table.
+ *   nsymbols - The location to store the number of symbols in the symbol table.
+ *
+ * Returned Value:
+ *   None
+ *
+ ****************************************************************************/
+
+void exec_getsymtab(FAR const struct symtab_s **symtab, FAR int *nsymbols);
+
+/****************************************************************************
+ * Name: exec_setsymtab
+ *
+ * Description:
+ *   Select a new symbol table selection as an atomic operation.
+ *
+ * Input Parameters:
+ *   symtab - The new symbol table.
+ *   nsymbols - The number of symbols in the symbol table.
+ *
+ * Returned Value:
+ *   None
+ *
+ ****************************************************************************/
+
+void exec_setsymtab(FAR const struct symtab_s *symtab, int nsymbols);
+
+/****************************************************************************
  * Name: symtab_findbyname
  *
  * Description:
@@ -96,7 +131,7 @@ extern "C" {
  *
  ****************************************************************************/
 
-EXTERN FAR const struct symtab_s *
+FAR const struct symtab_s *
 symtab_findbyname(FAR const struct symtab_s *symtab,
                   FAR const char *name, int nsyms);
 
@@ -113,7 +148,7 @@ symtab_findbyname(FAR const struct symtab_s *symtab,
  *
  ****************************************************************************/
 
-EXTERN FAR const struct symtab_s *
+FAR const struct symtab_s *
 symtab_findorderedbyname(FAR const struct symtab_s *symtab,
                          FAR const char *name, int nsyms);
 
@@ -132,7 +167,7 @@ symtab_findorderedbyname(FAR const struct symtab_s *symtab,
  *
  ****************************************************************************/
 
-EXTERN FAR const struct symtab_s *
+FAR const struct symtab_s *
 symtab_findbyvalue(FAR const struct symtab_s *symtab,
                    FAR void *value, int nsyms);
 
@@ -150,7 +185,7 @@ symtab_findbyvalue(FAR const struct symtab_s *symtab,
  *
  ****************************************************************************/
 
-EXTERN FAR const struct symtab_s *
+FAR const struct symtab_s *
 symtab_findorderedbyvalue(FAR const struct symtab_s *symtab,
                           FAR void *value, int nsyms);
 
diff --git a/nuttx/include/unistd.h b/nuttx/include/unistd.h
index 4dabdb35a..abaf7230c 100644
--- a/nuttx/include/unistd.h
+++ b/nuttx/include/unistd.h
@@ -173,12 +173,6 @@ int     rmdir(FAR const char *pathname);
 #ifdef CONFIG_LIBC_EXECFUNCS
 int     execl(FAR const char *path, ...);
 int     execv(FAR const char *path, FAR char *const argv[]);
-
-/* Non-standard functions to manage symbol tables */
-
-struct symtab_s; /* See include/nuttx/binfmt/symtab.h */
-void exec_getsymtab(FAR const struct symtab_s **symtab, FAR int *nsymbols);
-void exec_setsymtab(FAR const struct symtab_s *symtab, int nsymbols);
 #endif
 
 /* Other */
diff --git a/nuttx/libc/unistd/Make.defs b/nuttx/libc/unistd/Make.defs
index 69f371d8c..323e0a3b8 100644
--- a/nuttx/libc/unistd/Make.defs
+++ b/nuttx/libc/unistd/Make.defs
@@ -43,7 +43,7 @@ CSRCS += lib_chdir.c lib_getcwd.c
 endif
 
 ifeq ($(CONFIG_LIBC_EXECFUNCS),y)
-CSRCS += lib_execl.c lib_execv.c lib_execsymtab.c
+CSRCS += lib_execl.c
 endif
 endif
 
diff --git a/nuttx/sched/task/Make.defs b/nuttx/sched/task/Make.defs
index e393f9947..5d0b093da 100644
--- a/nuttx/sched/task/Make.defs
+++ b/nuttx/sched/task/Make.defs
@@ -51,7 +51,7 @@ endif
 
 ifneq ($(CONFIG_BINFMT_DISABLE),y)
 ifeq ($(CONFIG_LIBC_EXECFUNCS),y)
-TSK_SRCS += task_posixspawn.c
+TSK_SRCS += task_execv.c task_posixspawn.c
 endif
 endif
 
diff --git a/nuttx/sched/task/task_execv.c b/nuttx/sched/task/task_execv.c
new file mode 100644
index 000000000..01d89f139
--- /dev/null
+++ b/nuttx/sched/task/task_execv.c
@@ -0,0 +1,153 @@
+/****************************************************************************
+ * sched/task/lib_execv.c
+ *
+ *   Copyright (C) 2013 Gregory Nutt. All rights reserved.
+ *   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
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ * 3. Neither the name NuttX nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+ * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ ****************************************************************************/
+
+/****************************************************************************
+ * Included Files
+ ****************************************************************************/
+
+#include <nuttx/config.h>
+
+#include <stdlib.h>
+#include <unistd.h>
+#include <errno.h>
+#include <debug.h>
+
+#include <nuttx/binfmt/binfmt.h>
+#include <nuttx/binfmt/symtab.h>
+
+#ifdef CONFIG_LIBC_EXECFUNCS
+
+/****************************************************************************
+ * Pre-processor Definitions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Private Variables
+ ****************************************************************************/
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: execv
+ *
+ * Description:
+ *   The standard 'exec' family of functions will replace the current process
+ *   image with a new process image. The new image will be constructed from a
+ *   regular, executable file called the new process image file. There will
+ *   be no return from a successful exec, because the calling process image
+ *   is overlaid by the new process image.
+ *
+ *   Simplified 'execl()' and 'execv()' functions are provided by NuttX for
+ *   compatibility.  NuttX is a tiny embedded RTOS that does not support
+ *   processes and hence the concept of overlaying a tasks process image with
+ *   a new process image does not make any sense.  In NuttX, these functions
+ *   are wrapper functions that:
+ *
+ *     1. Call the non-standard binfmt function 'exec', and then
+ *     2. exit(0).
+ *
+ *   Note the inefficiency when 'exec[l|v]()' is called in the normal, two-
+ *   step process:  (1) first call vfork() to create a new thread, then (2)
+ *   call 'exec[l|v]()' to replace the new thread with a program from the
+ *   file system.  Since the new thread will be terminated by the
+ *   'exec[l|v]()' call, it really served no purpose other than to support
+ *   Unix compatility.
+ *
+ *   The non-standard binfmt function 'exec()' needs to have (1) a symbol
+ *   table that provides the list of symbols exported by the base code, and
+ *   (2) the number of symbols in that table.  This information is currently
+ *   provided to 'exec()' from 'exec[l|v]()' via NuttX configuration settings:
+ *
+ *     CONFIG_LIBC_EXECFUNCS        : Enable exec[l|v] support
+ *     CONFIG_EXECFUNCS_HAVE_SYMTAB : Defined if there is a symbol table
+ *       CONFIG_EXECFUNCS_SYMTAB    : Symbol table used by exec[l|v]
+ *       CONFIG_EXECFUNCS_NSYMBOLS  : Number of symbols in the table
+ *
+ *   As a result of the above, the current implementations of 'execl()' and
+ *   'execv()' suffer from some incompatibilities that may or may not be
+ *   addressed in a future version of NuttX.  Other than just being an
+ *   inefficient use of MCU resource, the most serious of these is that
+ *   the exec'ed task will not have the same task ID as the vfork'ed
+ *   function.  So the parent function cannot know the ID of the exec'ed
+ *   task.
+ *
+ * Input Parameters:
+ *   path - The path to the program to be executed.  If CONFIG_BINFMT_EXEPATH
+ *     is defined in the configuration, then this may be a relative path
+ *     from the current working directory.  Otherwise, path must be the
+ *     absolute path to the program.
+ *   argv - A pointer to an array of string arguments.  The end of the
+ *     array is indicated with a NULL entry.
+ *
+ * Returned Value:
+ *   This function does not return on success.  On failure, it will return
+ *   -1 (ERROR) and will set the 'errno' value appropriately.
+ *
+ ****************************************************************************/
+
+int execv(FAR const char *path, FAR char * const argv[])
+{
+  FAR const struct symtab_s *symtab;
+  int nsymbols;
+  int ret;
+
+  /* Get the current symbol table selection */
+
+  exec_getsymtab(&symtab, &nsymbols);
+
+  /* Start the task */
+
+  ret = exec(path, (FAR char * const *)argv, symtab, nsymbols);
+  if (ret < 0)
+    {
+      sdbg("exec failed: %d\n", errno);
+      return ERROR;
+    }
+
+  /* Then exit */
+
+  exit(0);
+
+  /* We should not get here, but might be needed by some compilers.  Other,
+   * smarter compilers might complain that this code is unreachable.  You just
+   * can't win.
+   */
+
+  return ERROR;
+}
+
+#endif /* CONFIG_LIBC_EXECFUNCS */