Modules: Add mod_setsymtab to set global symtol table once. Now we can remove symbol table parameters from the insmod call. This will make implementing an NSH insmod command much easier

sched/module/Make.defs

@@ -42,8 +42,8 @@ CSRCS += mod_insmod.c mod_rmmod.c
 # loadable module library
 
 CSRCS += mod_bind.c mod_init.c mod_iobuffer.c mod_load.c mod_read.c
-CSRCS += mod_registry.c mod_sections.c mod_symbols.c mod_uninit.c
-CSRCS += mod_unload.c mod_verify.c
+CSRCS += mod_registry.c mod_sections.c mod_symbols.c mod_symtab.c
+CSRCS += mod_uninit.c mod_unload.c mod_verify.c
 
 # procfs support
 

sched/module/mod_bind.c

@@ -98,8 +98,7 @@ static inline int mod_readrel(FAR struct mod_loadinfo_s *loadinfo,
  *
  ****************************************************************************/
 
-static int mod_relocate(FAR struct mod_loadinfo_s *loadinfo, int relidx,
-                        FAR const struct symtab_s *exports, int nexports)
+static int mod_relocate(FAR struct mod_loadinfo_s *loadinfo, int relidx)
 
 {
   FAR Elf32_Shdr *relsec = &loadinfo->shdr[relidx];
@@ -149,7 +148,7 @@ static int mod_relocate(FAR struct mod_loadinfo_s *loadinfo, int relidx,
 
       /* Get the value of the symbol (in sym.st_value) */
 
-      ret = mod_symvalue(loadinfo, &sym, exports, nexports);
+      ret = mod_symvalue(loadinfo, &sym);
       if (ret < 0)
         {
           /* The special error -ESRCH is returned only in one condition:  The
@@ -200,8 +199,7 @@ static int mod_relocate(FAR struct mod_loadinfo_s *loadinfo, int relidx,
   return OK;
 }
 
-static int mod_relocateadd(FAR struct mod_loadinfo_s *loadinfo, int relidx,
-                              FAR const struct symtab_s *exports, int nexports)
+static int mod_relocateadd(FAR struct mod_loadinfo_s *loadinfo, int relidx)
 {
   sdbg("Not implemented\n");
   return -ENOSYS;
@@ -216,7 +214,7 @@ static int mod_relocateadd(FAR struct mod_loadinfo_s *loadinfo, int relidx,
  *
  * Description:
  *   Bind the imported symbol names in the loaded module described by
- *   'loadinfo' using the exported symbol values provided by 'symtab'.
+ *   'loadinfo' using the exported symbol values provided by mod_setsymtab().
  *
  * Returned Value:
  *   0 (OK) is returned on success and a negated errno is returned on
@@ -224,8 +222,7 @@ static int mod_relocateadd(FAR struct mod_loadinfo_s *loadinfo, int relidx,
  *
  ****************************************************************************/
 
-int mod_bind(FAR struct mod_loadinfo_s *loadinfo,
-             FAR const struct symtab_s *exports, int nexports)
+int mod_bind(FAR struct mod_loadinfo_s *loadinfo)
 {
   int ret;
   int i;
@@ -274,11 +271,11 @@ int mod_bind(FAR struct mod_loadinfo_s *loadinfo,
 
       if (loadinfo->shdr[i].sh_type == SHT_REL)
         {
-          ret = mod_relocate(loadinfo, i, exports, nexports);
+          ret = mod_relocate(loadinfo, i);
         }
       else if (loadinfo->shdr[i].sh_type == SHT_RELA)
         {
-          ret = mod_relocateadd(loadinfo, i, exports, nexports);
+          ret = mod_relocateadd(loadinfo, i);
         }
 
       if (ret < 0)

sched/module/mod_insmod.c

@@ -166,13 +166,16 @@ static void mod_dumpinitializer(mod_initializer_t initializer,
  *   Verify that the file is an ELF module binary and, if so, load the
  *   module into kernel memory and initialize it for use.
  *
+ *   NOTE: mod_setsymtab had to have been called in board-specific OS logic
+ *   prior to calling this function from application logic (perhaps via
+ *   boardctl(BOARDIOC_OS_SYMTAB).  Otherwise, insmod will be unable to
+ *   resolve symbols in the OS module.
+ *
  * Input Parameters:
  *
  *   filename   - Full path to the module binary to be loaded
  *   modulename - The name that can be used to refer to the module after
  *     it has been loaded.
- *   exports    - Table of exported symbols
- *   nexports   - The number of symbols in exports[]
  *
  * Returned Value:
  *   Zero (OK) on success.  On any failure, -1 (ERROR) is returned the
@@ -180,8 +183,7 @@ static void mod_dumpinitializer(mod_initializer_t initializer,
  *
  ****************************************************************************/
 
-int insmod(FAR const char *filename, FAR const char *modulename,
-           FAR const struct symtab_s *exports, int nexports)
+int insmod(FAR const char *filename, FAR const char *modulename)
 {
   struct mod_loadinfo_s loadinfo;
   FAR struct module_s *modp;
@@ -237,9 +239,9 @@ int insmod(FAR const char *filename, FAR const char *modulename,
       goto errout_with_registry_entry;
     }
 
-  /* Bind the program to the exported symbol table */
+  /* Bind the program to the kernel symbol table */
 
-  ret = mod_bind(&loadinfo, exports, nexports);
+  ret = mod_bind(&loadinfo);
   if (ret != 0)
     {
       sdbg("Failed to bind symbols program binary: %d\n", ret);

sched/module/mod_symbols.c

@@ -261,8 +261,7 @@ int mod_readsym(FAR struct mod_loadinfo_s *loadinfo, int index,
  *
  ****************************************************************************/
 
-int mod_symvalue(FAR struct mod_loadinfo_s *loadinfo, FAR Elf32_Sym *sym,
-                 FAR const struct symtab_s *exports, int nexports)
+int mod_symvalue(FAR struct mod_loadinfo_s *loadinfo, FAR Elf32_Sym *sym)
 {
   FAR const struct symtab_s *symbol;
   uintptr_t secbase;
@@ -306,9 +305,13 @@ int mod_symvalue(FAR struct mod_loadinfo_s *loadinfo, FAR Elf32_Sym *sym,
         /* Check if the base code exports a symbol of this name */
 
 #ifdef CONFIG_SYMTAB_ORDEREDBYNAME
-        symbol = symtab_findorderedbyname(exports, (FAR char *)loadinfo->iobuffer, nexports);
+        symbol = symtab_findorderedbyname(g_mod_symtab,
+                                          (FAR char *)loadinfo->iobuffer,
+                                          g_mod_nsymbols);
 #else
-        symbol = symtab_findbyname(exports, (FAR char *)loadinfo->iobuffer, nexports);
+        symbol = symtab_findbyname(g_mod_symtab,
+                                   (FAR char *)loadinfo->iobuffer,
+                                   g_mod_nsymbols);
 #endif
         if (!symbol)
           {

sched/module/mod_symtab.c

@@ -0,0 +1,110 @@
+/****************************************************************************
+ * sched/module/mod_symtab.c
+ *
+ *   Copyright (C) 2015 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/symtab.h>
+#include <nuttx/module.h>
+
+#include "module.h"
+
+/****************************************************************************
+ * Public Data
+ ****************************************************************************/
+
+FAR const struct symtab_s *g_mod_symtab;
+FAR int g_mod_nsymbols;
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: mod_getsymtab
+ *
+ * Description:
+ *   Get the current kernel 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 mod_getsymtab(FAR const struct symtab_s **symtab, FAR int *nsymbols)
+{
+  DEBUGASSERT(symtab != NULL && nsymbols != NULL);
+
+  /* Borrow the registry lock to assure atomic access */
+
+  mod_registry_lock();
+  *symtab   = g_mod_symtab;
+  *nsymbols = g_mod_nsymbols;
+  mod_registry_lock();
+}
+
+/****************************************************************************
+ * Name: mod_setsymtab
+ *
+ * Description:
+ *   Select a new kernel 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 mod_setsymtab(FAR const struct symtab_s *symtab, int nsymbols)
+{
+  /* Borrow the registry lock to assure atomic access */
+
+  mod_registry_lock();
+  g_mod_symtab   = symtab;
+  g_mod_nsymbols = nsymbols;
+  mod_registry_lock();
+}

sched/module/module.h

@@ -99,6 +99,13 @@ struct mod_loadinfo_s
   int               filfd;       /* Descriptor for the file being loaded */
 };
 
+/****************************************************************************
+ * Public Data
+ ****************************************************************************/
+
+FAR const struct symtab_s *g_mod_symtab;
+FAR int g_mod_nsymbols;
+
 /****************************************************************************
  * Public Function Prototypes
  ****************************************************************************/
@@ -154,7 +161,7 @@ int mod_load(FAR struct mod_loadinfo_s *loadinfo);
  *
  * Description:
  *   Bind the imported symbol names in the loaded module described by
- *   'loadinfo' using the exported symbol values provided by 'symtab'.
+ *   'loadinfo' using the exported symbol values provided by mod_setsymtab().
  *
  * Returned Value:
  *   0 (OK) is returned on success and a negated errno is returned on
@@ -162,9 +169,7 @@ int mod_load(FAR struct mod_loadinfo_s *loadinfo);
  *
  ****************************************************************************/
 
-struct symtab_s;
-int mod_bind(FAR struct mod_loadinfo_s *loadinfo,
-             FAR const struct symtab_s *exports, int nexports);
+int mod_bind(FAR struct mod_loadinfo_s *loadinfo);
 
 /****************************************************************************
  * Name: mod_unload
@@ -290,8 +295,6 @@ int mod_readsym(FAR struct mod_loadinfo_s *loadinfo, int index,
  * Input Parameters:
  *   loadinfo - Load state information
  *   sym      - Symbol table entry (value might be undefined)
- *   exports  - The symbol table to use for resolving undefined symbols.
- *   nexports - Number of symbols in the symbol table.
  *
  * Returned Value:
  *   0 (OK) is returned on success and a negated errno is returned on
@@ -305,8 +308,7 @@ int mod_readsym(FAR struct mod_loadinfo_s *loadinfo, int index,
  *
  ****************************************************************************/
 
-int mod_symvalue(FAR struct mod_loadinfo_s *loadinfo, FAR Elf32_Sym *sym,
-                 FAR const struct symtab_s *exports, int nexports);
+int mod_symvalue(FAR struct mod_loadinfo_s *loadinfo, FAR Elf32_Sym *sym);
 
 /****************************************************************************
  * Name: mod_freebuffers