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[src/netbsd-8]: src/bin/sh Pull up following revision(s) (requested by kre in...



details:   https://anonhg.NetBSD.org/src/rev/1dddbcb090cb
branches:  netbsd-8
changeset: 435116:1dddbcb090cb
user:      martin <martin%NetBSD.org@localhost>
date:      Fri Jul 13 14:29:15 2018 +0000

description:
Pull up following revision(s) (requested by kre in ticket #906):

        bin/sh/eval.c: revision 1.155
        bin/sh/mknodes.sh: revision 1.3
        bin/sh/nodes.c.pat: revision 1.14
        bin/sh/exec.h: revision 1.27
        bin/sh/exec.c: revision 1.52

Deal with ref after free found by ASAN when a function redefines
itself, or some other function which is still active.

This was a long known bug (fixed ages ago in the FreeBSD sh) which
hadn't been fixed as in practice, the situation that causes the
problem simply doesn't arise .. ASAN found it in the sh dotcmd
tests which do have this odd "feature" in the way they are written
(but where it never caused a problem, as the tests are so simple
that no mem is ever allocated between when the old version of the
function was deleted, and when it finished executing, so its code
all remained intact, despite having been freed.)

The fix is taken from the FreeBSD sh.

XXX -- pullup-8 (after a while to ensure no other problems arise).

diffstat:

 bin/sh/eval.c      |   13 +++--
 bin/sh/exec.c      |   14 +++---
 bin/sh/exec.h      |    5 +-
 bin/sh/mknodes.sh  |   22 +++++---
 bin/sh/nodes.c.pat |  121 +++++++++++++++++++++++++++++++++++++---------------
 5 files changed, 117 insertions(+), 58 deletions(-)

diffs (truncated from 412 to 300 lines):

diff -r b51df4ce2ff6 -r 1dddbcb090cb bin/sh/eval.c
--- a/bin/sh/eval.c     Fri Jul 13 14:26:47 2018 +0000
+++ b/bin/sh/eval.c     Fri Jul 13 14:29:15 2018 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: eval.c,v 1.140.2.2 2017/07/23 14:58:14 snj Exp $       */
+/*     $NetBSD: eval.c,v 1.140.2.3 2018/07/13 14:29:15 martin Exp $    */
 
 /*-
  * Copyright (c) 1993
@@ -37,7 +37,7 @@
 #if 0
 static char sccsid[] = "@(#)eval.c     8.9 (Berkeley) 6/8/95";
 #else
-__RCSID("$NetBSD: eval.c,v 1.140.2.2 2017/07/23 14:58:14 snj Exp $");
+__RCSID("$NetBSD: eval.c,v 1.140.2.3 2018/07/13 14:29:15 martin Exp $");
 #endif
 #endif /* not lint */
 
@@ -1067,6 +1067,7 @@
                INTOFF;
                savelocalvars = localvars;
                localvars = NULL;
+               reffunc(cmdentry.u.func);
                INTON;
                if (setjmp(jmploc.loc)) {
                        if (exception == EXSHELLPROC) {
@@ -1076,6 +1077,7 @@
                                freeparam(&shellparam);
                                shellparam = saveparam;
                        }
+                       unreffunc(cmdentry.u.func);
                        poplocalvars();
                        localvars = savelocalvars;
                        funclinebase = savefuncline;
@@ -1094,8 +1096,8 @@
 
                        VTRACE(DBG_EVAL,
                          ("function: node: %d '%s' # %d%s; funclinebase=%d\n",
-                           cmdentry.u.func->type,
-                           NODETYPENAME(cmdentry.u.func->type),
+                           getfuncnode(cmdentry.u.func)->type,
+                           NODETYPENAME(getfuncnode(cmdentry.u.func)->type),
                            cmdentry.lineno, cmdentry.lno_frel?" (=1)":"",
                            funclinebase));
                }
@@ -1103,9 +1105,10 @@
                /* stop shell blowing its stack */
                if (++funcnest > 1000)
                        error("too many nested function calls");
-               evaltree(cmdentry.u.func, flags & EV_TESTED);
+               evaltree(getfuncnode(cmdentry.u.func), flags & EV_TESTED);
                funcnest--;
                INTOFF;
+               unreffunc(cmdentry.u.func);
                poplocalvars();
                localvars = savelocalvars;
                funclinebase = savefuncline;
diff -r b51df4ce2ff6 -r 1dddbcb090cb bin/sh/exec.c
--- a/bin/sh/exec.c     Fri Jul 13 14:26:47 2018 +0000
+++ b/bin/sh/exec.c     Fri Jul 13 14:29:15 2018 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: exec.c,v 1.47.2.2 2017/07/23 14:58:14 snj Exp $        */
+/*     $NetBSD: exec.c,v 1.47.2.3 2018/07/13 14:29:15 martin Exp $     */
 
 /*-
  * Copyright (c) 1991, 1993
@@ -37,7 +37,7 @@
 #if 0
 static char sccsid[] = "@(#)exec.c     8.4 (Berkeley) 6/8/95";
 #else
-__RCSID("$NetBSD: exec.c,v 1.47.2.2 2017/07/23 14:58:14 snj Exp $");
+__RCSID("$NetBSD: exec.c,v 1.47.2.3 2018/07/13 14:29:15 martin Exp $");
 #endif
 #endif /* not lint */
 
@@ -481,8 +481,9 @@
                out1fmt("%s", cmdp->cmdname);
                if (verbose) {
                        struct procstat ps;
+
                        INTOFF;
-                       commandtext(&ps, cmdp->param.func);
+                       commandtext(&ps, getfuncnode(cmdp->param.func));
                        INTON;
                        out1str("() { ");
                        out1str(ps.cmd);
@@ -989,9 +990,8 @@
        INTOFF;
        cmdp = cmdlookup(name, 1);
        if (cmdp->cmdtype != CMDSPLBLTIN) {
-               if (cmdp->cmdtype == CMDFUNCTION) {
-                       freefunc(cmdp->param.func);
-               }
+               if (cmdp->cmdtype == CMDFUNCTION)
+                       unreffunc(cmdp->param.func);
                cmdp->cmdtype = entry->cmdtype;
                cmdp->lineno = entry->lineno;
                cmdp->fn_ln1 = entry->lno_frel;
@@ -1031,7 +1031,7 @@
 
        if ((cmdp = cmdlookup(name, 0)) != NULL &&
            cmdp->cmdtype == CMDFUNCTION) {
-               freefunc(cmdp->param.func);
+               unreffunc(cmdp->param.func);
                delete_cmd_entry();
        }
        return 0;
diff -r b51df4ce2ff6 -r 1dddbcb090cb bin/sh/exec.h
--- a/bin/sh/exec.h     Fri Jul 13 14:26:47 2018 +0000
+++ b/bin/sh/exec.h     Fri Jul 13 14:29:15 2018 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: exec.h,v 1.24.8.2 2017/07/23 14:58:14 snj Exp $        */
+/*     $NetBSD: exec.h,v 1.24.8.3 2018/07/13 14:29:15 martin Exp $     */
 
 /*-
  * Copyright (c) 1991, 1993
@@ -49,7 +49,7 @@
        union param {
                int index;
                int (*bltin)(int, char**);
-               union node *func;
+               struct funcdef *func;
        } u;
 };
 
@@ -72,6 +72,7 @@
 void changepath(const char *);
 void deletefuncs(void);
 void getcmdentry(char *, struct cmdentry *);
+union node;
 void defun(char *, union node *, int);
 int unsetfunc(char *);
 void hash_special_builtins(void);
diff -r b51df4ce2ff6 -r 1dddbcb090cb bin/sh/mknodes.sh
--- a/bin/sh/mknodes.sh Fri Jul 13 14:26:47 2018 +0000
+++ b/bin/sh/mknodes.sh Fri Jul 13 14:29:15 2018 +0000
@@ -1,5 +1,5 @@
 #! /bin/sh
-#      $NetBSD: mknodes.sh,v 1.2 2008/04/29 06:53:00 martin Exp $
+#      $NetBSD: mknodes.sh,v 1.2.56.1 2018/07/13 14:29:15 martin Exp $
 
 # Copyright (c) 2003 The NetBSD Foundation, Inc.
 # All rights reserved.
@@ -111,8 +111,12 @@
 echo "};"
 echo
 echo
-echo "union node *copyfunc(union node *);"
-echo "void freefunc(union node *);"
+echo 'struct funcdef;'
+echo 'struct funcdef *copyfunc(union node *);'
+echo 'union node *getfuncnode(struct funcdef *);'
+echo 'void reffunc(struct funcdef *);'
+echo 'void unreffunc(struct funcdef *);'
+echo 'void freefunc(struct funcdef *);'
 
 mv $objdir/nodes.h.tmp $objdir/nodes.h || exit 1
 
@@ -140,7 +144,7 @@
        '%CALCSIZE' )
                echo "      if (n == NULL)"
                echo "      return;"
-               echo "      funcblocksize += nodesize[n->type];"
+               echo "      res->bsize += nodesize[n->type];"
                echo "      switch (n->type) {"
                IFS=' '
                for struct in $struct_list; do
@@ -157,11 +161,11 @@
                                IFS=' '
                                set -- $line
                                name=$1
-                               cl=")"
+                               cl=", res)"
                                case $2 in
                                nodeptr ) fn=calcsize;;
                                nodelist ) fn=sizenodelist;;
-                               string ) fn="funcstringsize += strlen"
+                               string ) fn="res->ssize += strlen"
                                        cl=") + 1";;
                                * ) continue;;
                                esac
@@ -174,8 +178,8 @@
        '%COPY' )
                echo "      if (n == NULL)"
                echo "      return NULL;"
-               echo "      new = funcblock;"
-               echo "      funcblock = (char *) funcblock + nodesize[n->type];"
+               echo "      new = st->block;"
+               echo "      st->block = (char *) st->block + nodesize[n->type];"
                echo "      switch (n->type) {"
                IFS=' '
                for struct in $struct_list; do
@@ -200,7 +204,7 @@
                                * ) continue;;
                                esac
                                f="$struct.$name"
-                               echo "      new->$f = ${fn}n->$f${fn:+)};"
+                               echo "      new->$f = ${fn}n->$f${fn:+, st)};"
                        done
                        echo "      break;"
                done
diff -r b51df4ce2ff6 -r 1dddbcb090cb bin/sh/nodes.c.pat
--- a/bin/sh/nodes.c.pat        Fri Jul 13 14:26:47 2018 +0000
+++ b/bin/sh/nodes.c.pat        Fri Jul 13 14:29:15 2018 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: nodes.c.pat,v 1.13 2012/03/20 18:42:29 matt Exp $      */
+/*     $NetBSD: nodes.c.pat,v 1.13.26.1 2018/07/13 14:29:15 martin Exp $       */
 
 /*-
  * Copyright (c) 1991, 1993
@@ -35,6 +35,8 @@
  */
 
 #include <stdlib.h>
+#include <stddef.h>
+
 /*
  * Routine for dealing with parsed shell commands.
  */
@@ -46,43 +48,70 @@
 #include "mystring.h"
 
 
-int     funcblocksize;         /* size of structures in function */
-int     funcstringsize;                /* size of strings in node */
-pointer funcblock;             /* block to allocate function from */
-char   *funcstring;            /* block to allocate strings from */
+/* used to accumulate sizes of nodes */
+struct nodesize {
+       int bsize;              /* size of structures in function */
+       int ssize;              /* size of strings in node */
+};
+
+/* provides resources for node copies */
+struct nodecopystate {
+       pointer block;          /* block to allocate function from */
+       char *string;           /* block to allocate strings from */
+};
+
 
 %SIZES
 
 
-STATIC void calcsize(union node *);
-STATIC void sizenodelist(struct nodelist *);
-STATIC union node *copynode(union node *);
-STATIC struct nodelist *copynodelist(struct nodelist *);
-STATIC char *nodesavestr(char *);
 
+STATIC void calcsize(union node *, struct nodesize *);
+STATIC void sizenodelist(struct nodelist *, struct nodesize *);
+STATIC union node *copynode(union node *, struct nodecopystate *);
+STATIC struct nodelist *copynodelist(struct nodelist *, struct nodecopystate *);
+STATIC char *nodesavestr(char *, struct nodecopystate *);
+
+struct funcdef {
+       unsigned int refcount;
+       union node n;           /* must be last */
+};
 
 
 /*
  * Make a copy of a parse tree.
  */
 
-union node *
+struct funcdef *
 copyfunc(union node *n)
 {
+       struct nodesize sz;
+       struct nodecopystate st;
+       struct funcdef *fn;
+
        if (n == NULL)
                return NULL;
-       funcblocksize = 0;
-       funcstringsize = 0;
-       calcsize(n);
-       funcblock = ckmalloc(funcblocksize + funcstringsize);
-       funcstring = (char *) funcblock + funcblocksize;
-       return copynode(n);
+       sz.bsize = offsetof(struct funcdef, n);
+       sz.ssize = 0;
+       calcsize(n, &sz);
+       fn = ckmalloc(sz.bsize + sz.ssize);
+       fn->refcount = 1;
+       st.block = (char *)fn + offsetof(struct funcdef, n);
+       st.string = (char *)fn + sz.bsize;
+       copynode(n, &st);
+       return fn;
+}
+
+union node *
+getfuncnode(struct funcdef *fn)
+{
+       if (fn == NULL)
+               return NULL;
+       return &fn->n;
 }
 



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