From: Jarkko Hietaniemi <jhi@iki.fi>
Date: Mon, 30 Jun 2003 08:36:38 +0000 (+0000)
Subject: The 'contiguous' test for argv[], envp[] was bogus
X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=commitdiff_plain;h=3cb9023dc910d8a9abbd8d44e501f6e492155eb5;p=p5sagit%2Fp5-mst-13.2.git

The 'contiguous' test for argv[], envp[] was bogus
since those need not be in memory end-to-end, e.g.
in Tru64 they are aligned by eight.  Loosen the test
so that 'contiguousness' is fulfilled if the elements
are within PTRSIZE alignment.  This makes Tru64 to pass
the join.t, too.

p4raw-id: //depot/perl@19889
---

diff --git a/ext/threads/t/join.t b/ext/threads/t/join.t
index f8b758e..0761a5f 100644
--- a/ext/threads/t/join.t
+++ b/ext/threads/t/join.t
@@ -91,7 +91,8 @@ ok(1,"");
     ok(1,"");
 }
 
-if ($^O eq 'linux') { # We parse ps output so this is OS-dependent.
+# We parse ps output so this is OS-dependent.
+if ($^O =~ /^(linux|dec_osf)$/) {
   # First modify $0 in a subthread.
   print "# mainthread: \$0 = $0\n";
   threads->new( sub {
@@ -100,7 +101,7 @@ if ($^O eq 'linux') { # We parse ps output so this is OS-dependent.
 		  print "# subthread: \$0 = $0\n" } )->join;
   print "# mainthread: \$0 = $0\n";
   print "# pid = $$\n";
-  if (open PS, "ps -f |") { # Note: must work in (all) Linux(es).
+  if (open PS, "ps -f |") { # Note: must work in (all) systems.
     my ($sawpid, $sawexe);
     while (<PS>) {
       chomp;
diff --git a/mg.c b/mg.c
index 8182376..1990b96 100644
--- a/mg.c
+++ b/mg.c
@@ -2372,13 +2372,7 @@ Perl_magic_set(pTHX_ SV *sv, MAGIC *mg)
 	     pstat(PSTAT_SETCMD, un, len, 0, 0);
 	}
 #endif
-	/* PL_origalen is set in perl_parse() to be the sum
-	 * of the contiguous argv[] elements plus the size of
-	 * the env in case that is contiguous with the argv[].
-	 *
-	 * This means that in the worst case the area we are able
-	 * to modify is limited to the size of the original argv[0].
-	 * --jhi */
+	/* PL_origalen is set in perl_parse(). */
 	s = SvPV_force(sv,len);
 	if (len >= (I32)PL_origalen) {
 	    /* Longer than original, will be truncated. */
@@ -2392,7 +2386,7 @@ Perl_magic_set(pTHX_ SV *sv, MAGIC *mg)
 	    memset(PL_origargv[0] + len + 1,
 		   /* Is the space counterintuitive?  Yes.
 		    * (You were expecting \0?)  
-		    * Does it work?  Seems to.  (In Linux at least.)
+		    * Does it work?  Seems to.  (In Linux 2.4.20 at least.)
 		    * --jhi */
 		   (int)' ',
 		   PL_origalen - len - 1);
diff --git a/perl.c b/perl.c
index 2f07f4c..ef3e205 100644
--- a/perl.c
+++ b/perl.c
@@ -934,35 +934,52 @@ setuid perl scripts securely.\n");
     PL_origargv = argv;
 
     {
-	 char *s = PL_origargv[0];
+	/* Set PL_origalen be the sum of the contiguous argv[]
+	 * elements plus the size of the env in case that it is
+	 * contiguous with the argv[].  This is used in mg.c:mg_set()
+	 * as the maximum modifiable length of $0.  In the worst case
+	 * the area we are able to modify is limited to the size of
+	 * the original argv[0].
+	 * --jhi */
+	 char *s;
 	 int i;
-
-	 s += strlen(s);
-	 /* See if all the arguments are contiguous in memory */
+	 int mask =
+	   ~(PTRSIZE == 4 ? 3 : PTRSIZE == 8 ? 7 : PTRSIZE == 16 ? 15 : 0);
+
+	 /* See if all the arguments are contiguous in memory.
+	  * Note that 'contiguous' is a loose term because some
+	  * platforms align the argv[] and the envp[].  We just check
+	  * that they are within aligned PTRSIZE bytes.  As long as no
+	  * system has something bizarre like the argv[] interleaved
+	  * with some other data, we are fine.  (Did I just evoke
+	  * Murphy's Law?) --jhi */
+	 s = PL_origargv[0];
+	 while (*s) s++;
 	 for (i = 1; i < PL_origargc; i++) {
-	      if (PL_origargv[i] == s + 1
-#ifdef OS2
-		  || PL_origargv[i] == s + 2
-#endif
-		   )
-	      {
-		   ++s;
-		   s += strlen(s);	/* this one is ok too */
+	      if (PL_origargv[i] >  s &&
+		  PL_origargv[i] <=
+		  INT2PTR(char *, PTR2UV(s + PTRSIZE) & mask)) {
+		   s = PL_origargv[i];
+		   while (*s) s++;
 	      }
 	      else
 		   break;
 	 }
-	 /* Can we grab env area too to be used as the area for $0
-	  * (in case we later modify it)? */
-	 if (PL_origenviron
-	     && (PL_origenviron[0] == s + 1))
-	 {
+	 /* Can we grab env area too to be used as the area for $0? */
+	 if (PL_origenviron &&
+	     PL_origenviron[0] >  s &&
+	     PL_origenviron[0] <=
+	     INT2PTR(char *, PTR2UV(s + PTRSIZE) & mask)) {
+	      s = PL_origenviron[0];
+	      while (*s) s++;
 	      my_setenv("NoNe  SuCh", Nullch);
-	      /* force copy of environment */
-	      for (i = 0; PL_origenviron[i]; i++)
-		   if (PL_origenviron[i] == s + 1) {
-			++s;
-			s += strlen(s);
+	      /* Force copy of environment. */
+	      for (i = 1; PL_origenviron[i]; i++)
+		   if (PL_origenviron[i] >  s &&
+		       PL_origenviron[i] <=
+		       INT2PTR(char *, PTR2UV(s + PTRSIZE) & mask)) {
+			s = PL_origenviron[i];
+			while (*s) s++;
 		   }
 		   else
 			break;