From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-io1-xd2c.google.com (mail-io1-xd2c.google.com [IPv6:2607:f8b0:4864:20::d2c]) by sourceware.org (Postfix) with ESMTPS id D016C389681B for ; Mon, 10 Jan 2022 21:51:48 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org D016C389681B Received: by mail-io1-xd2c.google.com with SMTP id o7so19589850ioo.9 for ; Mon, 10 Jan 2022 13:51:48 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=bBSLgHdISEg2AEcHk8c7z/4KzwE3WsEiu1IgdfE9DZs=; b=47psHvl9pmUWz2VX4EpjLVl0yh225pfRON8B5QBH/X+NowF8ZmkPUZwnBXm9dtb22I fh4nTGAbt40g3paV1deasr5iO6t5Ub3gLmbUTsWuq04IBBMbOff9wTQBKuKhSZcrOkgB I6voujLcKZCwqqYdLTD62Q20MJVkrKo9g9CyJn1oA0D53QRovJkMDQh8r11DkP3u70IN PAuIUKdPc+yOmgfcsTTwtTgAACAPELpz18RWXiIfYya4NwOUhfa3d0VfkkTXAQWWAq0o /XjmPEDnSBWM/6N0GoLZyyW+VnYxIh4OmKPj2Upc+rfjAffoZ6kE8bBVzkEQ76qYYOPn 4j8w== X-Gm-Message-State: AOAM530+FCMpJVazzFIlUkcAvMuDq/NEkdxr0MnK3hYSRgbyQMO4MEWX AQotkhl9t9mj2B7LGoX6L4kX1QcRfh4kww== X-Google-Smtp-Source: ABdhPJx+6BSU0R+va0mh1iluvqTMBh+yZ6pdvjTJWD7ak0Xe2CVVrq0vbZyeveMutp5TZKMqcrB+OQ== X-Received: by 2002:a02:cd81:: with SMTP id l1mr941205jap.2.1641851508173; Mon, 10 Jan 2022 13:51:48 -0800 (PST) Received: from murgatroyd.Home (75-166-134-30.hlrn.qwest.net. [75.166.134.30]) by smtp.gmail.com with ESMTPSA id a1sm4820642iol.55.2022.01.10.13.51.47 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 10 Jan 2022 13:51:47 -0800 (PST) From: Tom Tromey To: gdb-patches@sourceware.org Cc: Tom Tromey Subject: [PATCH v2 2/3] Fix another crash with gdb parameters in Python Date: Mon, 10 Jan 2022 14:51:43 -0700 Message-Id: <20220110215144.1714909-3-tromey@adacore.com> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20220110215144.1714909-1-tromey@adacore.com> References: <20220110215144.1714909-1-tromey@adacore.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Spam-Status: No, score=-11.7 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, GIT_PATCH_0, RCVD_IN_DNSWL_NONE, SPF_HELO_NONE, SPF_PASS, TXREP autolearn=ham autolearn_force=no version=3.4.4 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on server2.sourceware.org X-BeenThere: gdb-patches@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gdb-patches mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 10 Jan 2022 21:51:50 -0000 While looking into the language-capturing issue, I found another way to crash gdb using parameters from Python: (gdb) python print(gdb.parameter('endian')) (This is related to PR python/12188, though this patch isn't going to fix what that bug is really about.) The problem here is that the global variable that underlies the "endian" parameter is initialized to NULL. However, that's not a valid value for an "enum" set/show parameter. My understanding is that, in gdb, an "enum" parameter's underlying variable must have a value that is "==" (not just strcmp-equal) to one of the values coming from the enum array. This invariant is relied on in various places. I started this patch by fixing the problem with "endian". Then I added some assertions to add_setshow_enum_cmd to try to catch other problems of the same type. This patch fixes all the problems that I found. I also looked at all the calls to add_setshow_enum_cmd to ensure that they were all included in the gdb I tested. I think they are: there are no calls in nat-* files, or in remote-sim.c; and I was trying a build with all targets, Python, and Guile enabled. Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=12188 --- gdb/arch-utils.c | 5 +++-- gdb/arm-tdep.c | 2 ++ gdb/charset.c | 9 +++++++++ gdb/cli/cli-decode.c | 10 ++++++++++ gdb/guile/scm-param.c | 4 ++-- gdb/language.c | 11 ++++++----- gdb/osabi.c | 4 +++- gdb/python/py-param.c | 4 ++-- gdb/testsuite/gdb.python/py-parameter.exp | 4 ++++ 9 files changed, 41 insertions(+), 12 deletions(-) diff --git a/gdb/arch-utils.c b/gdb/arch-utils.c index 38e3132668d..3ee978a0249 100644 --- a/gdb/arch-utils.c +++ b/gdb/arch-utils.c @@ -359,7 +359,7 @@ static const char *const endian_enum[] = endian_auto, NULL, }; -static const char *set_endian_string; +static const char *set_endian_string = endian_auto; enum bfd_endian selected_byte_order (void) @@ -757,7 +757,8 @@ initialize_current_architecture (void) list of architectures. */ { /* Append ``auto''. */ - arches.push_back ("auto"); + set_architecture_string = "auto"; + arches.push_back (set_architecture_string); arches.push_back (nullptr); set_show_commands architecture_cmds = add_setshow_enum_cmd ("architecture", class_support, diff --git a/gdb/arm-tdep.c b/gdb/arm-tdep.c index f6bd76a354d..f46913e8eaa 100644 --- a/gdb/arm-tdep.c +++ b/gdb/arm-tdep.c @@ -9802,6 +9802,8 @@ _initialize_arm_tdep () size_t offset = strlen ("reg-names-"); const char *style = disasm_options->name[i]; valid_disassembly_styles[j++] = &style[offset]; + if (strcmp (&style[offset], "std") == 0) + disassembly_style = &style[offset]; length = snprintf (rdptr, rest, "%s - %s\n", &style[offset], disasm_options->description[i]); rdptr += length; diff --git a/gdb/charset.c b/gdb/charset.c index 0b3ef26f1d6..e011793f746 100644 --- a/gdb/charset.c +++ b/gdb/charset.c @@ -1029,6 +1029,9 @@ _initialize_charset () #endif #endif + /* Recall that the first element is always "auto". */ + host_charset_name = charset_enum[0]; + gdb_assert (strcmp (host_charset_name, "auto") == 0); add_setshow_enum_cmd ("charset", class_support, charset_enum, &host_charset_name, _("\ Set the host and target character sets."), _("\ @@ -1057,6 +1060,9 @@ To see a list of the character sets GDB supports, type `set host-charset '. show_host_charset_name, &setlist, &showlist); + /* Recall that the first element is always "auto". */ + target_charset_name = charset_enum[0]; + gdb_assert (strcmp (target_charset_name, "auto") == 0); add_setshow_enum_cmd ("target-charset", class_support, charset_enum, &target_charset_name, _("\ Set the target character set."), _("\ @@ -1069,6 +1075,9 @@ To see a list of the character sets GDB supports, type `set target-charset' show_target_charset_name, &setlist, &showlist); + /* Recall that the first element is always "auto". */ + target_wide_charset_name = charset_enum[0]; + gdb_assert (strcmp (target_wide_charset_name, "auto") == 0); add_setshow_enum_cmd ("target-wide-charset", class_support, charset_enum, &target_wide_charset_name, _("\ diff --git a/gdb/cli/cli-decode.c b/gdb/cli/cli-decode.c index 7266fb36d0d..bf6404a5755 100644 --- a/gdb/cli/cli-decode.c +++ b/gdb/cli/cli-decode.c @@ -613,6 +613,16 @@ add_setshow_enum_cmd (const char *name, struct cmd_list_element **set_list, struct cmd_list_element **show_list) { + /* We require *VAR to be initialized before this call, and + furthermore it must be == to one of the values in ENUMLIST. */ + gdb_assert (var != nullptr && *var != nullptr); + for (int i = 0; ; ++i) + { + gdb_assert (enumlist[i] != nullptr); + if (*var == enumlist[i]) + break; + } + set_show_commands commands = add_setshow_cmd_full (name, theclass, var_enum, var, set_doc, show_doc, help_doc, diff --git a/gdb/guile/scm-param.c b/gdb/guile/scm-param.c index 125b0e4766b..a3af3c2251e 100644 --- a/gdb/guile/scm-param.c +++ b/gdb/guile/scm-param.c @@ -458,12 +458,12 @@ add_setshow_generic (enum var_types param_type, enum command_class cmd_class, break; case var_enum: + /* Initialize the value, just in case. */ + make_setting (self).set (self->enumeration[0]); commands = add_setshow_enum_cmd (cmd_name, cmd_class, self->enumeration, &self->value.cstringval, set_doc, show_doc, help_doc, set_func, show_func, set_list, show_list); - /* Initialize the value, just in case. */ - make_setting (self).set (self->enumeration[0]); break; default: diff --git a/gdb/language.c b/gdb/language.c index 0846b3e5eeb..f000142fc2d 100644 --- a/gdb/language.c +++ b/gdb/language.c @@ -476,7 +476,8 @@ add_set_language_command () /* Display "auto", "local" and "unknown" first, and then the rest, alpha sorted. */ const char **language_names_p = language_names; - *language_names_p++ = language_def (language_auto)->name (); + language = language_def (language_auto)->name (); + *language_names_p++ = language; *language_names_p++ = "local"; *language_names_p++ = language_def (language_unknown)->name (); const char **sort_begin = language_names_p; @@ -1150,6 +1151,8 @@ _initialize_language () add_alias_cmd ("c", setshow_check_cmds.show, no_class, 1, &showlist); add_alias_cmd ("ch", setshow_check_cmds.show, no_class, 1, &showlist); + range = type_or_range_names[3]; + gdb_assert (strcmp (range, "auto") == 0); add_setshow_enum_cmd ("range", class_support, type_or_range_names, &range, _("Set range checking (on/warn/off/auto)."), @@ -1158,6 +1161,8 @@ _initialize_language () show_range_command, &setchecklist, &showchecklist); + case_sensitive = case_sensitive_names[2]; + gdb_assert (strcmp (case_sensitive, "auto") == 0); add_setshow_enum_cmd ("case-sensitive", class_support, case_sensitive_names, &case_sensitive, _("\ Set case sensitivity in name search (on/off/auto)."), _("\ @@ -1174,10 +1179,6 @@ For Fortran the default is off; for other languages the default is on."), add_set_language_command (); - language = "auto"; - range = "auto"; - case_sensitive = "auto"; - /* Have the above take effect. */ set_language (language_auto); } diff --git a/gdb/osabi.c b/gdb/osabi.c index 40c86e782e7..d4a98061dbd 100644 --- a/gdb/osabi.c +++ b/gdb/osabi.c @@ -666,11 +666,13 @@ _initialize_gdb_osabi () generic_elf_osabi_sniffer); /* Register the "set osabi" command. */ + user_osabi_state = osabi_auto; + set_osabi_string = gdb_osabi_available_names[0]; + gdb_assert (strcmp (set_osabi_string, "auto") == 0); add_setshow_enum_cmd ("osabi", class_support, gdb_osabi_available_names, &set_osabi_string, _("Set OS ABI of target."), _("Show OS ABI of target."), NULL, set_osabi, show_osabi, &setlist, &showlist); - user_osabi_state = osabi_auto; } diff --git a/gdb/python/py-param.c b/gdb/python/py-param.c index 8559bc997ea..6ee14d42ab8 100644 --- a/gdb/python/py-param.c +++ b/gdb/python/py-param.c @@ -572,13 +572,13 @@ add_setshow_generic (int parmclass, enum command_class cmdclass, break; case var_enum: + /* Initialize the value, just in case. */ + self->value.cstringval = self->enumeration[0]; commands = add_setshow_enum_cmd (cmd_name.get (), cmdclass, self->enumeration, &self->value.cstringval, set_doc, show_doc, help_doc, get_set_value, get_show_value, set_list, show_list); - /* Initialize the value, just in case. */ - self->value.cstringval = self->enumeration[0]; break; default: diff --git a/gdb/testsuite/gdb.python/py-parameter.exp b/gdb/testsuite/gdb.python/py-parameter.exp index b025c2562f0..2de148c1b27 100644 --- a/gdb/testsuite/gdb.python/py-parameter.exp +++ b/gdb/testsuite/gdb.python/py-parameter.exp @@ -364,3 +364,7 @@ test_really_undocumented_parameter test_deprecated_api_parameter test_integer_parameter test_throwing_parameter + +# This caused a gdb crash. +gdb_test "python print(gdb.parameter('endian'))" "auto" \ + "print endian parameter" -- 2.31.1