From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 29406 invoked by alias); 11 Apr 2002 17:56:15 -0000 Mailing-List: contact gdb-patches-help@sources.redhat.com; run by ezmlm Precedence: bulk List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sources.redhat.com Received: (qmail 29356 invoked from network); 11 Apr 2002 17:56:13 -0000 Received: from unknown (HELO cygnus.com) (205.180.230.5) by sources.redhat.com with SMTP; 11 Apr 2002 17:56:13 -0000 Received: from theotherone.redhat-remotie.org (romulus.sfbay.redhat.com [172.16.27.251]) by runyon.cygnus.com (8.8.7-cygnus/8.8.7) with ESMTP id KAA11555; Thu, 11 Apr 2002 10:56:10 -0700 (PDT) Received: from localhost (localhost.fidalgo.net [127.0.0.1]) by theotherone.redhat-remotie.org (Postfix) with ESMTP id C782ABB255; Thu, 11 Apr 2002 10:55:26 -0700 (PDT) Date: Thu, 11 Apr 2002 10:56:00 -0000 From: Don Howard X-X-Sender: To: Cc: Daniel Jacobowitz , Andreas Schwab , Michael Snyder , Subject: Re: [RFA] Avoid recursivly defined user functions. In-Reply-To: Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-SW-Source: 2002-04/txt/msg00417.txt.bz2 On Tue, 9 Apr 2002, Don Howard wrote: > On Tue, 9 Apr 2002, Paul Hilfinger wrote: > > > > > > How about something even simpler - track user command depth at runtime? > > > Set an absurd limit, like 1024 deep, if we can handle that in a > > > normal-sized stack limit. Then complain if we hit it at runtime. > > > > I completely agree with this. After all, if you were willing to > > contemplate outlawing recursion altogether, you certainly won't LOSE > > anything by Daniel's approach, and you gain everything you wanted in > > the first place---to avoid crashing GDB. > > > > Paul > > > > > I like this approach, also. > 2002-04-11 Don Howard * cli/cli-cmds.c (init_cli_cmds): Add new user settable value: max_user_call_depth. (init_cmd_lists): Initialize the new value; * cli/cli-script.c (execute_user_command): Limit the call depth of user defined commands. This avoids a core-dump when user commands are infinitly recursive. Index: cli/cli-cmds.c =================================================================== RCS file: /cvs/src/src/gdb/cli/cli-cmds.c,v retrieving revision 1.18 diff -p -u -w -r1.18 cli-cmds.c --- cli/cli-cmds.c 28 Mar 2002 01:35:56 -0000 1.18 +++ cli/cli-cmds.c 11 Apr 2002 17:30:58 -0000 @@ -80,6 +80,9 @@ static void shell_escape (char *, int); void apropos_command (char *, int); +/* Limit the call depth of user-defined commands */ +int max_user_call_depth; + /* Define all cmd_list_elements. */ /* Chain containing all defined commands. */ @@ -606,6 +609,8 @@ show_debug (char *args, int from_tty) void init_cmd_lists (void) { + max_user_call_depth = 1024; + cmdlist = NULL; infolist = NULL; enablelist = NULL; @@ -823,4 +828,11 @@ With no arguments, run an inferior shell Argument is the name of the user defined command.\n\ With no argument, show definitions of all user defined commands.", &showlist); add_com ("apropos", class_support, apropos_command, "Search for commands matching a REGEXP"); + + add_show_from_set ( + add_set_cmd ("max_user_call_depth", no_class, var_integer, + (char *) &max_user_call_depth, + "Set the max call depth for user-defined commands.\n", + &setlist), + &showlist); } Index: cli/cli-script.c =================================================================== RCS file: /cvs/src/src/gdb/cli/cli-script.c,v retrieving revision 1.11 diff -p -u -w -r1.11 cli-script.c --- cli/cli-script.c 17 Mar 2002 19:53:39 -0000 1.11 +++ cli/cli-script.c 11 Apr 2002 17:30:59 -0000 @@ -247,6 +247,15 @@ execute_cmd_post_hook (struct cmd_list_e } /* Execute the command in CMD. */ +void +do_restore_user_call_depth (void * call_depth) +{ + int * depth = call_depth; + /* We will be returning_to_top_level() at this point, so we want to + reset our depth. */ + (*depth) = 0; +} + void execute_user_command (struct cmd_list_element *c, char *args) @@ -254,6 +263,8 @@ execute_user_command (struct cmd_list_el register struct command_line *cmdlines; struct cleanup *old_chain; enum command_control_type ret; + static int user_call_depth = 0; + extern int max_user_call_depth; old_chain = setup_user_args (args); @@ -262,6 +273,11 @@ execute_user_command (struct cmd_list_el /* Null command */ return; + if (user_call_depth++ > max_user_call_depth) + error ("Max user call depth exceeded -- command aborted\n"); + + old_chain = make_cleanup (do_restore_user_call_depth, &user_call_depth); + /* Set the instream to 0, indicating execution of a user-defined function. */ old_chain = make_cleanup (do_restore_instream_cleanup, instream); @@ -277,6 +293,8 @@ execute_user_command (struct cmd_list_el cmdlines = cmdlines->next; } do_cleanups (old_chain); + + user_call_depth--; } enum command_control_type -- dhoward@redhat.com gdb engineering