From patchwork Wed Sep 6 13:44:44 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Malcolm X-Patchwork-Id: 137580 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:a59:ab0a:0:b0:3f2:4152:657d with SMTP id m10csp2320825vqo; Wed, 6 Sep 2023 06:46:49 -0700 (PDT) X-Google-Smtp-Source: AGHT+IHFJKS1KlrKuvzMT38sVrIAjUZ2G2qYU6GCFRDdcP+NigM1PBqVCaks40V9nAlfEpJuSYWe X-Received: by 2002:a17:906:d8:b0:9a1:ecb5:732e with SMTP id 24-20020a17090600d800b009a1ecb5732emr2245999eji.71.1694008009592; Wed, 06 Sep 2023 06:46:49 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1694008009; cv=none; d=google.com; s=arc-20160816; b=z0VOJXYNTFvRun5UCe5iweKO9Am8pdjkE8NxWc1XBoyzdGHmhcslNvPUyy0IR7giEL etwyW4vKfUIx6AUr5Jt+dDSr66wJRgH/3PGouB8GkF+FcEH3Mqmc9ky8AUJ/8vf+iy0M MowXnSapqwgYTEAzX34rs+5RekBC8PXT1eSpUWDQC6Cp6qcxNVi3tURLpcjvo2EezBWO rGubcMNUaAK04xHUuF+sl8AH6HZ0rrRdYaYvcW2yGZjdh4ju+q/rNJf574N8Zk9qVpcN PhpDPtl4bSWBa1cdKTdQkF6aPsBrFKyMWFN124bB5FurCPEX8HFlq6et9xpIoypJ1ouN NYBg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=sender:errors-to:reply-to:from:list-subscribe:list-help:list-post :list-archive:list-unsubscribe:list-id:precedence :content-transfer-encoding:mime-version:message-id:date:subject:to :dmarc-filter:delivered-to:dkim-signature:dkim-filter; bh=l/I7VpALFjA5XaZ8I92Tx0kxLh85ini22I0aTcuTVOU=; fh=hPrbWPhweUx4V0GV9uXJqbyAzg2ABmTz7kczrAQqMmM=; b=DI+ApynmukWb0hwXXOD9+zmPysnG63T/G1YmcrhUEsTMY2TA4d87LhLMBUt7M4/TMU MOGQNDBjZ/+5Mj6gaO063j2Eove4Hd2XicIDlkNjCqva3iVC5iwJ+Z1/hT3O1IfzCq3L v4Z/guSpRAvojiXPndSHJNCm/XylvpwYmFZiy42tzwQqTi/sYQ4rhBaZynd7bpb31/ty K/4KR+ykKEFsoWDNA9ENktMy7c6bCHN8YT3tLZX/cB11qokB7uDpYi1Qg6LulNWJl6cN TMAnAGKT9amINDPdNMr/6Ls+h/4dRV9m6w4RQmM0i1i3bZJAJSvz7usyy6IIhaGdk4MG JBnA== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@gcc.gnu.org header.s=default header.b=ZZcal0hm; spf=pass (google.com: domain of gcc-patches-bounces+ouuuleilei=gmail.com@gcc.gnu.org designates 8.43.85.97 as permitted sender) smtp.mailfrom="gcc-patches-bounces+ouuuleilei=gmail.com@gcc.gnu.org"; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=gnu.org Received: from server2.sourceware.org (ip-8-43-85-97.sourceware.org. [8.43.85.97]) by mx.google.com with ESMTPS id kf27-20020a17090776db00b00987d66e6d26si8935305ejc.250.2023.09.06.06.46.49 for (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 06 Sep 2023 06:46:49 -0700 (PDT) Received-SPF: pass (google.com: domain of gcc-patches-bounces+ouuuleilei=gmail.com@gcc.gnu.org designates 8.43.85.97 as permitted sender) client-ip=8.43.85.97; Authentication-Results: mx.google.com; dkim=pass header.i=@gcc.gnu.org header.s=default header.b=ZZcal0hm; spf=pass (google.com: domain of gcc-patches-bounces+ouuuleilei=gmail.com@gcc.gnu.org designates 8.43.85.97 as permitted sender) smtp.mailfrom="gcc-patches-bounces+ouuuleilei=gmail.com@gcc.gnu.org"; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=gnu.org Received: from server2.sourceware.org (localhost [IPv6:::1]) by sourceware.org (Postfix) with ESMTP id 666BB3856DF8 for ; Wed, 6 Sep 2023 13:46:27 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 666BB3856DF8 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org; s=default; t=1694007987; bh=l/I7VpALFjA5XaZ8I92Tx0kxLh85ini22I0aTcuTVOU=; h=To:Subject:Date:List-Id:List-Unsubscribe:List-Archive:List-Post: List-Help:List-Subscribe:From:Reply-To:From; b=ZZcal0hmJVx6dgL5ArTyx4f+ToCNnUU42nSwV9cWqFUW+0algkMHkpYMqQ2CYW8Nd 6Sk72K8p0dDOKls7fKliRg63saiUTRazp48G2Fl1NNPtrD3RaGlZ45FcIr07C2yCeW 5cfXEY1v6n0A0fNu8Nsr2/yNgoZhLiBmb2G4PF+E= X-Original-To: gcc-patches@gcc.gnu.org Delivered-To: gcc-patches@gcc.gnu.org Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by sourceware.org (Postfix) with ESMTPS id 8D3E83857C45 for ; Wed, 6 Sep 2023 13:44:47 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 8D3E83857C45 Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-624-vhwos7KvPpyEgeM4DDHOpw-1; Wed, 06 Sep 2023 09:44:45 -0400 X-MC-Unique: vhwos7KvPpyEgeM4DDHOpw-1 Received: from smtp.corp.redhat.com (int-mx09.intmail.prod.int.rdu2.redhat.com [10.11.54.9]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 8DF641825485 for ; Wed, 6 Sep 2023 13:44:45 +0000 (UTC) Received: from t14s.localdomain.com (unknown [10.22.34.57]) by smtp.corp.redhat.com (Postfix) with ESMTP id 44468493110; Wed, 6 Sep 2023 13:44:45 +0000 (UTC) To: gcc-patches@gcc.gnu.org Subject: [pushed] analyzer: implement kf_strstr [PR105899] Date: Wed, 6 Sep 2023 09:44:44 -0400 Message-Id: <20230906134444.682395-1-dmalcolm@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.9 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com X-Spam-Status: No, score=-11.4 required=5.0 tests=BAYES_00, DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, GIT_PATCH_0, RCVD_IN_DNSWL_NONE, RCVD_IN_MSPIKE_H4, RCVD_IN_MSPIKE_WL, SPF_HELO_NONE, SPF_NONE, TXREP autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org X-BeenThere: gcc-patches@gcc.gnu.org X-Mailman-Version: 2.1.30 Precedence: list List-Id: Gcc-patches mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-Patchwork-Original-From: David Malcolm via Gcc-patches From: David Malcolm Reply-To: David Malcolm Errors-To: gcc-patches-bounces+ouuuleilei=gmail.com@gcc.gnu.org Sender: "Gcc-patches" X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: 1776296142302793693 X-GMAIL-MSGID: 1776296142302793693 Successfully bootstrapped & regrtested on x86_64-pc-linux-gnu. Pushed to trunk as r14-3741-gf2d7a4001a3388. gcc/analyzer/ChangeLog: PR analyzer/105899 * kf.cc (class kf_strstr): New. (kf_strstr::impl_call_post): New. (register_known_functions): Register it. gcc/testsuite/ChangeLog: PR analyzer/105899 * c-c++-common/analyzer/strstr-1.c: New test. --- gcc/analyzer/kf.cc | 96 +++++++++++++++++++ .../c-c++-common/analyzer/strstr-1.c | 54 +++++++++++ 2 files changed, 150 insertions(+) create mode 100644 gcc/testsuite/c-c++-common/analyzer/strstr-1.c diff --git a/gcc/analyzer/kf.cc b/gcc/analyzer/kf.cc index 8a45c329c282..92959891fe44 100644 --- a/gcc/analyzer/kf.cc +++ b/gcc/analyzer/kf.cc @@ -1585,6 +1585,100 @@ public: } }; +/* Handler for "strstr" and "__builtin_strstr". + extern char *strstr (const char* str, const char* substr); + See e.g. https://en.cppreference.com/w/c/string/byte/strstr */ + +class kf_strstr : public builtin_known_function +{ +public: + bool matches_call_types_p (const call_details &cd) const final override + { + return (cd.num_args () == 2 + && cd.arg_is_pointer_p (0) + && cd.arg_is_pointer_p (1)); + } + enum built_in_function builtin_code () const final override + { + return BUILT_IN_STRSTR; + } + void impl_call_pre (const call_details &cd) const final override + { + cd.check_for_null_terminated_string_arg (0); + cd.check_for_null_terminated_string_arg (1); + } + void impl_call_post (const call_details &cd) const final override; +}; + +void +kf_strstr::impl_call_post (const call_details &cd) const +{ + class strstr_call_info : public call_info + { + public: + strstr_call_info (const call_details &cd, bool found) + : call_info (cd), m_found (found) + { + } + + label_text get_desc (bool can_colorize) const final override + { + if (m_found) + return make_label_text (can_colorize, + "when %qE returns non-NULL", + get_fndecl ()); + else + return make_label_text (can_colorize, + "when %qE returns NULL", + get_fndecl ()); + } + + bool update_model (region_model *model, + const exploded_edge *, + region_model_context *ctxt) const final override + { + const call_details cd (get_call_details (model, ctxt)); + if (tree lhs_type = cd.get_lhs_type ()) + { + region_model_manager *mgr = model->get_manager (); + const svalue *result; + if (m_found) + { + const svalue *str_sval = cd.get_arg_svalue (0); + const region *str_reg + = model->deref_rvalue (str_sval, cd.get_arg_tree (0), + cd.get_ctxt ()); + /* We want str_sval + OFFSET for some unknown OFFSET. + Use a conjured_svalue to represent the offset, + using the str_reg as the id of the conjured_svalue. */ + const svalue *offset + = mgr->get_or_create_conjured_svalue (size_type_node, + cd.get_call_stmt (), + str_reg, + conjured_purge (model, + ctxt)); + result = mgr->get_or_create_binop (lhs_type, POINTER_PLUS_EXPR, + str_sval, offset); + } + else + result = mgr->get_or_create_int_cst (lhs_type, 0); + cd.maybe_set_lhs (result); + } + return true; + } + private: + bool m_found; + }; + + /* Body of kf_strstr::impl_call_post. */ + if (cd.get_ctxt ()) + { + cd.get_ctxt ()->bifurcate (make_unique (cd, false)); + cd.get_ctxt ()->bifurcate (make_unique (cd, true)); + cd.get_ctxt ()->terminate_path (); + } +} + class kf_ubsan_bounds : public internal_known_function { /* Empty. */ @@ -1806,6 +1900,8 @@ register_known_functions (known_function_manager &kfm) kfm.add ("__builtin_strndup", make_unique ()); kfm.add ("strlen", make_unique ()); kfm.add ("__builtin_strlen", make_unique ()); + kfm.add ("strstr", make_unique ()); + kfm.add ("__builtin_strstr", make_unique ()); register_atomic_builtins (kfm); register_varargs_builtins (kfm); diff --git a/gcc/testsuite/c-c++-common/analyzer/strstr-1.c b/gcc/testsuite/c-c++-common/analyzer/strstr-1.c new file mode 100644 index 000000000000..469e6a817d0d --- /dev/null +++ b/gcc/testsuite/c-c++-common/analyzer/strstr-1.c @@ -0,0 +1,54 @@ +/* See e.g. https://en.cppreference.com/w/c/string/byte/strstr */ + +/* { dg-additional-options "-fpermissive" { target c++ } } */ + +#include "../../gcc.dg/analyzer/analyzer-decls.h" + +extern char *strstr (const char* str, const char* substr); + +char * +test_passthrough (const char* str, const char* substr) +{ + return strstr (str, substr); +} + +char * +test_NULL_str (const char *substr) +{ + return strstr (NULL, substr); /* { dg-warning "use of NULL where non-null expected" } */ +} + +char * +test_unterminated_str (const char *substr) +{ + char str[3] = "abc"; /* { dg-warning "initializer-string for '\[^\n\]*' is too long" "" { target c++ } } */ + return strstr (str, substr); /* { dg-warning "stack-based buffer over-read" } */ + /* { dg-message "while looking for null terminator for argument 1" "note" { target *-*-* } .-1 } */ +} + +char * +test_uninitialized_str (const char *substr) +{ + char str[16]; + return strstr (str, substr); /* { dg-warning "use of uninitialized value 'str\\\[0\\\]'" } */ +} + +char * +test_NULL_substr (const char *str) +{ + return strstr (str, NULL); /* { dg-warning "use of NULL where non-null expected" } */ +} + +char * +test_unterminated_substr (const char *str) +{ + char substr[3] = "abc"; /* { dg-warning "initializer-string for '\[^\n\]*' is too long" "" { target c++ } } */ + return strstr (str, substr); /* { dg-warning "stack-based buffer over-read" } */ + /* { dg-message "while looking for null terminator for argument 2" "note" { target *-*-* } .-1 } */ +} + +char *test_uninitialized_substr (const char *str) +{ + char substr[16]; + return strstr (str, substr); /* { dg-warning "use of uninitialized value 'substr\\\[0\\\]'" } */ +}