[Valgrind-developers] valgrind/coregrind

[Nicholas N. <nj...@ca...>]

CVS commit by nethercote: 

Patch from Tom Hughes:

    Patch to provide a proper environment to the debugger

    Although this patch isn't strictly needed to allow alternative debuggers to
    be used, it is needed if you want to use an X based debugger such as ups
    (and presumably ddd) as VG_(system) has until now passed an empty
    enviroment when starting the debugger but that causes DISPLAY to be lost.

    This patch causes VG_(system) to pass a copy of the client environment
    instead, with the necessary mashing done to clean up the LD_xxx variables. 


  M +5 -0      vg_include.h   1.177
  M +62 -2     vg_mylibc.c   1.68
  M +8 -8      vg_syscalls.c   1.82


--- valgrind/coregrind/vg_include.h  #1.176:1.177
@@ -1088,4 +1088,5 @@ extern Int VG_(connect_via_socket)( UCha
 
 /* Environment manipulations */
+extern Char **VG_(env_clone) ( Char **oldenv );
 extern Char* VG_(env_getenv) ( Char **env, Char* varname );
 extern Char **VG_(env_setenv) ( Char ***envp, const Char* varname, const Char *val );
@@ -1414,4 +1415,8 @@ extern Bool VG_(sysinfo_page_exists);
 extern Addr VG_(sysinfo_page_addr);
 
+/* Walk through a colon separated list variable, removing entries
+   which match pattern. */
+extern void VG_(mash_colon_env)(Char *varp, const Char *pattern);
+
 /* Something of a function looking for a home ... start up debugger. */
 extern void VG_(start_debugger) ( Int tid );

--- valgrind/coregrind/vg_mylibc.c  #1.67:1.68
@@ -1344,4 +1344,30 @@ Bool VG_(getcwd_alloc) ( Char** out )
    ------------------------------------------------------------------ */
 
+/* clone the environment */
+Char **VG_(env_clone) ( Char **oldenv )
+{
+   Char **oldenvp;
+   Char **newenvp;
+   Char **newenv;
+   Int  envlen;
+
+   for (oldenvp = oldenv; oldenvp && *oldenvp; oldenvp++);
+
+   envlen = oldenvp - oldenv + 1;
+   
+   newenv = VG_(arena_malloc)(VG_AR_CORE, envlen * sizeof(Char **));
+
+   oldenvp = oldenv;
+   newenvp = newenv;
+   
+   while (oldenvp && *oldenvp) {
+      *newenvp++ = *oldenvp++;
+   }
+   
+   *newenvp = *oldenvp;
+
+   return newenv;
+}
+
 void  VG_(env_unsetenv) ( Char **env, const Char *varname )
 {
@@ -1497,5 +1523,4 @@ Int VG_(system) ( Char* cmd )
 {
    Int pid, res;
-   void* environ[1] = { NULL };
    if (cmd == NULL)
       return 1;
@@ -1505,5 +1530,38 @@ Int VG_(system) ( Char* cmd )
    if (pid == 0) {
       /* child */
+      static Char** envp = NULL;
       Char* argv[4];
+
+      if (envp == NULL) {
+         Int i;
+         Char* ld_preload_str = NULL;
+         Char* ld_library_path_str = NULL;
+         Char* buf;
+
+         envp = VG_(env_clone)(VG_(client_envp));
+         
+         for (i = 0; envp[i] != NULL; i++) {
+            if (VG_(strncmp)(envp[i], "LD_PRELOAD=", 11) == 0)
+               ld_preload_str = &envp[i][11];
+            if (VG_(strncmp)(envp[i], "LD_LIBRARY_PATH=", 16) == 0)
+               ld_library_path_str = &envp[i][16];
+         }
+
+         buf = VG_(arena_malloc)(VG_AR_CORE, VG_(strlen)(VG_(libdir)) + 20);
+
+         VG_(sprintf)(buf, "%s*/vg_inject.so", VG_(libdir));
+         VG_(mash_colon_env)(ld_preload_str, buf);
+
+         VG_(sprintf)(buf, "%s*/vgpreload_*.so", VG_(libdir));
+         VG_(mash_colon_env)(ld_preload_str, buf);
+
+         VG_(sprintf)(buf, "%s*", VG_(libdir));
+         VG_(mash_colon_env)(ld_library_path_str, buf);
+
+         VG_(env_unsetenv)(envp, VALGRINDCLO);
+
+         VG_(arena_free)(VG_AR_CORE, buf);
+      }
+
       argv[0] = "/bin/sh";
       argv[1] = "-c";
@@ -1510,6 +1568,8 @@ Int VG_(system) ( Char* cmd )
       argv[2] = cmd;
       argv[3] = 0;
+
       (void)VG_(do_syscall)(__NR_execve, 
-                            (UInt)"/bin/sh", (UInt)argv, (UInt)&environ);
+                            (UInt)"/bin/sh", (UInt)argv, (UInt)envp);
+
       /* If we're still alive here, execve failed. */
       return -1;

--- valgrind/coregrind/vg_syscalls.c  #1.81:1.82
@@ -164,5 +164,5 @@ static Bool valid_client_addr(Addr start
    delimited by ':' are considered to be '.' in a path.
 */
-static void mash_colon_env(Char *varp, const Char *remove_pattern)
+void VG_(mash_colon_env)(Char *varp, const Char *remove_pattern)
 {
    Char *const start = varp;
@@ -1870,11 +1870,11 @@ PRE(execve)
 
          VG_(sprintf)(buf, "%s*/vg_inject.so", VG_(libdir));
-         mash_colon_env(ld_preload_str, buf);
+         VG_(mash_colon_env)(ld_preload_str, buf);
 
          VG_(sprintf)(buf, "%s*/vgpreload_*.so", VG_(libdir));
-         mash_colon_env(ld_preload_str, buf);
+         VG_(mash_colon_env)(ld_preload_str, buf);
 
          VG_(sprintf)(buf, "%s*", VG_(libdir));
-         mash_colon_env(ld_library_path_str, buf);
+         VG_(mash_colon_env)(ld_library_path_str, buf);
 
          VG_(env_unsetenv)(envp, VALGRINDCLO);