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[8.43.85.97]) by mx.google.com with ESMTPS id m10-20020a50998a000000b0043b52adbf6esi6381410edb.557.2022.07.22.16.56.19 for (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 22 Jul 2022 16:56:19 -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=jGA7Clg2; 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 D2FD83857C50 for ; Fri, 22 Jul 2022 23:56:18 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org D2FD83857C50 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org; s=default; t=1658534178; bh=YncR38Md/eOox/D8KZPrZNQBPz7ZL5lU3nKZt+tgqIc=; h=To:Subject:Date:List-Id:List-Unsubscribe:List-Archive:List-Post: List-Help:List-Subscribe:From:Reply-To:From; b=jGA7Clg2T39cG0kabhzBQvfu+QRaZhFA4kKkyKASA8RSXyVUHpIoEkMDJZL5hrB2r IfV/Uu372pqaLcSrXPuFMPlU7FjAk+N/KzxOjIOUqFztNsqD9vAAXl66pCz/bktbw9 kuDO3eEU5mHgdMdGzU35pk+cq/ozvZNdbVpsht3U= 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 [170.10.129.124]) by sourceware.org (Postfix) with ESMTPS id 6E624385800F for ; Fri, 22 Jul 2022 23:54:54 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.1 sourceware.org 6E624385800F Received: from mimecast-mx02.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-169-hYofD0i6O2ydB8jJnurQvA-1; Fri, 22 Jul 2022 19:54:52 -0400 X-MC-Unique: hYofD0i6O2ydB8jJnurQvA-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.rdu2.redhat.com [10.11.54.2]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 7FEEA1C05EAB for ; Fri, 22 Jul 2022 23:54:52 +0000 (UTC) Received: from t14s.localdomain.com (unknown [10.2.16.236]) by smtp.corp.redhat.com (Postfix) with ESMTP id 1CD6640D296B; Fri, 22 Jul 2022 23:54:52 +0000 (UTC) To: gcc-patches@gcc.gnu.org Subject: [committed] analyzer: fix state explosion on va_arg [PR106413] Date: Fri, 22 Jul 2022 19:54:50 -0400 Message-Id: <20220722235450.1705677-1-dmalcolm@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.11.54.2 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com X-Spam-Status: No, score=-12.8 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_LOW, 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: 2.1.29 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: "Li, Pan2 via Gcc-patches" Reply-To: David Malcolm Errors-To: gcc-patches-bounces+ouuuleilei=gmail.com@gcc.gnu.org Sender: "Gcc-patches" X-getmail-retrieved-from-mailbox: =?utf-8?q?INBOX?= X-GMAIL-THRID: =?utf-8?q?1739099136624773785?= X-GMAIL-MSGID: =?utf-8?q?1739099136624773785?= Fix state explosion on va_arg when the call to va_start is in the top-level function of the analysis. Successfully bootstrapped & regrtested on x86_64-pc-linux-gnu. Pushed to trunk as r13-1807-g6d5194a10dc103. gcc/analyzer/ChangeLog: PR analyzer/106413 * varargs.cc (region_model::impl_call_va_start): Avoid iterating through non-existant variadic arguments by initializing the impl_region to "UNKNOWN" if the va_start occurs in the top-level function to the analysis. gcc/testsuite/ChangeLog: PR analyzer/106413 * gcc.dg/analyzer/torture/stdarg-4.c: New test. Signed-off-by: David Malcolm --- gcc/analyzer/varargs.cc | 26 +- .../gcc.dg/analyzer/torture/stdarg-4.c | 329 ++++++++++++++++++ 2 files changed, 350 insertions(+), 5 deletions(-) create mode 100644 gcc/testsuite/gcc.dg/analyzer/torture/stdarg-4.c diff --git a/gcc/analyzer/varargs.cc b/gcc/analyzer/varargs.cc index c45585ce457..9400086b10e 100644 --- a/gcc/analyzer/varargs.cc +++ b/gcc/analyzer/varargs.cc @@ -667,11 +667,27 @@ region_model::impl_call_va_start (const call_details &cd) const svalue *ptr_to_impl_reg = m_mgr->get_ptr_svalue (NULL_TREE, impl_reg); set_value (out_reg, ptr_to_impl_reg, cd.get_ctxt ()); - /* "*(&IMPL_REGION) = VA_LIST_VAL (0);". */ - const region *init_var_arg_reg - = m_mgr->get_var_arg_region (get_current_frame (), 0); - const svalue *ap_sval = m_mgr->get_ptr_svalue (NULL_TREE, init_var_arg_reg); - set_value (impl_reg, ap_sval, cd.get_ctxt ()); + if (get_stack_depth () > 1) + { + /* The interprocedural case: the frame containing the va_start call + will have been populated with any variadic aruguments. + Initialize IMPL_REGION with a ptr to var_arg_region 0. */ + const region *init_var_arg_reg + = m_mgr->get_var_arg_region (get_current_frame (), 0); + const svalue *ap_sval + = m_mgr->get_ptr_svalue (NULL_TREE, init_var_arg_reg); + set_value (impl_reg, ap_sval, cd.get_ctxt ()); + } + else + { + /* The frame containing va_start is an entry-point to the analysis, + so there won't be any specific var_arg_regions populated within it. + Initialize IMPL_REGION as the UNKNOWN_SVALUE to avoid state + explosions on repeated calls to va_arg. */ + const svalue *unknown_sval + = m_mgr->get_or_create_unknown_svalue (NULL_TREE); + set_value (impl_reg, unknown_sval, cd.get_ctxt ()); + } } /* Handle the on_call_pre part of "__builtin_va_copy". */ diff --git a/gcc/testsuite/gcc.dg/analyzer/torture/stdarg-4.c b/gcc/testsuite/gcc.dg/analyzer/torture/stdarg-4.c new file mode 100644 index 00000000000..8275b0fa9ba --- /dev/null +++ b/gcc/testsuite/gcc.dg/analyzer/torture/stdarg-4.c @@ -0,0 +1,329 @@ +/* { dg-skip-if "" { *-*-* } { "-fno-fat-lto-objects" } { "" } } */ + +#include "../analyzer-decls.h" + +/* va_arg in loop, with no caller to function containing va_start. */ + +int test_1a (const char *fmt, ...) +{ + __builtin_va_list args; + int sum = 0; + char ch; + + __builtin_va_start(args, fmt); + + while (ch = *fmt++) + if (ch == '%') + sum += __builtin_va_arg(args, int); + + __builtin_va_end(args); + + return sum; +} + +/* va_arg in loop, with no caller to function containing va_start. */ + +static int test_1b_callee (const char *fmt, __builtin_va_list args) +{ + int sum = 0; + char ch; + + while (ch = *fmt++) + if (ch == '%') + sum += __builtin_va_arg(args, int); + + return sum; +} + +int test_1b_caller (const char *fmt, ...) +{ + __builtin_va_list args; + int sum = 0; + + __builtin_va_start(args, fmt); + + sum = test_1b_callee (fmt, args); + + __builtin_va_end(args); + + return sum; +} + +/* va_arg in loop, with a caller to the function containing va_start, + with specific args. */ + +static int +test_1c_inner (const char *fmt, __builtin_va_list args) +{ + int sum = 0; + char ch; + + while (ch = *fmt++) + if (ch == '%') + sum += __builtin_va_arg(args, int); + + return sum; +} + +static int +test_1c_middle (const char *fmt, ...) +{ + __builtin_va_list args; + int sum = 0; + + __builtin_va_start(args, fmt); + + sum = test_1c_inner (fmt, args); + + __builtin_va_end(args); + + return sum; +} + +void test_1c_outer (void) +{ + int sum = test_1c_middle ("%%", 42, 17); + + __analyzer_describe (0, sum); /* { dg-message "'\\(int\\)59'" } */ +} + +/* va_arg in loop, with no caller to function containing va_start. */ + +int test_2a (int count, ...) +{ + __builtin_va_list args; + int sum = 0; + char ch; + + __builtin_va_start(args, count); + + while (count-- > 0) + sum += __builtin_va_arg(args, int); + + __builtin_va_end(args); + + return sum; +} + +/* va_arg in loop, with no caller to function containing va_start. */ + +static int test_2b_callee (int count, __builtin_va_list args) +{ + int sum = 0; + + while (count-- > 0) + sum += __builtin_va_arg(args, int); + + return sum; +} + +int test_2b_caller (int count, ...) +{ + __builtin_va_list args; + int sum = 0; + + __builtin_va_start(args, count); + + sum = test_2b_callee (count, args); + + __builtin_va_end(args); + + return sum; +} + +/* va_arg in loop, with a caller to the function containing va_start, + with specific args. */ + +static int test_2c_inner (int count, __builtin_va_list args) +{ + int sum = 0; + + while (count-- > 0) + sum += __builtin_va_arg(args, int); + + return sum; +} + +int test_2c_middle (int count, ...) +{ + __builtin_va_list args; + int sum = 0; + + __builtin_va_start(args, count); + + sum = test_2c_inner (count, args); + + __builtin_va_end(args); + + return sum; +} + +void test_2c_outer (void) +{ + int sum = test_2c_middle (2, 50, 42); + + __analyzer_describe (0, sum); /* { dg-message "'\\(int\\)92'" } */ +} + +/* va_arg in loop, with no caller to function containing va_start. */ + +int test_3a (int placeholder, ...) +{ + __builtin_va_list args; + int sum = 0; + int val; + + __builtin_va_start(args, placeholder); + + while (val = __builtin_va_arg(args, int)) + sum += val; + + __builtin_va_end(args); + + return sum; +} + +/* va_arg in loop, with no caller to function containing va_start. */ + +static int test_3b_callee (__builtin_va_list args) +{ + int sum = 0; + int val; + while (val = __builtin_va_arg(args, int)) + sum += val; + return sum; +} + +int test_3b_caller (int placeholder, ...) +{ + __builtin_va_list args; + int sum = 0; + + __builtin_va_start(args, placeholder); + + sum = test_3b_callee (args); + + __builtin_va_end(args); + + return sum; +} + +/* va_arg in loop, with a caller to the function containing va_start, + with specific args. */ + +static int test_3c_inner (__builtin_va_list args) +{ + int sum = 0; + int val; + while (val = __builtin_va_arg(args, int)) + sum += val; + return sum; +} + +int test_3c_middle (int placeholder, ...) +{ + __builtin_va_list args; + int sum = 0; + + __builtin_va_start(args, placeholder); + + sum = test_3c_inner (args); + + __builtin_va_end(args); + + return sum; +} + +void test_3c_outer (void) +{ + int sum = test_3c_middle (0, 5, 12, 0); + __analyzer_describe (0, sum); /* { dg-message "'\\(int\\)17'" } */ +} + +/* va_arg in loop, with no caller to function containing va_start, + with a va_copy. */ + +static int test_3d_callee (__builtin_va_list args) +{ + int sum = 0; + int val; + while (val = __builtin_va_arg(args, int)) + sum += val; + return sum; +} + +int test_3d_caller (int placeholder, ...) +{ + __builtin_va_list args1, args2; + int sum = 0; + + __builtin_va_start(args1, placeholder); + __builtin_va_copy (args2, args1); + + sum = test_3d_callee (args1); + __builtin_va_end(args1); + + sum += test_3d_callee (args2); + __builtin_va_end(args2); + + return sum; +} + +/* va_arg in loop, with a caller to the function containing va_start, + with specific args, with a va_copy. */ + +static int test_3e_inner (__builtin_va_list args) +{ + int sum = 0; + int val; + while (val = __builtin_va_arg(args, int)) + sum += val; + return sum; +} + +int test_3e_middle (int placeholder, ...) +{ + __builtin_va_list args1, args2; + int sum = 0; + + __builtin_va_start(args1, placeholder); + __builtin_va_copy (args2, args1); + + sum = test_3e_inner (args1); + __builtin_va_end(args1); + + sum += test_3e_inner (args2); + __builtin_va_end(args2); + + return sum; +} + +void test_3e_outer (void) +{ + int sum = test_3e_middle (0, 5, 6, 0); + __analyzer_describe (0, sum); /* { dg-message "'\\(int\\)22'" } */ +} + +/* va_arg in loop, with specific symbolic args. */ + +static int test_3f_callee (int placeholder, ...) +{ + __builtin_va_list args; + int sum = 0; + int val; + + __builtin_va_start(args, placeholder); + + while (val = __builtin_va_arg(args, int)) + sum += val; + + __builtin_va_end(args); + + return sum; +} + +void test_3f_caller (int x, int y, int z) +{ + int sum = test_3f_callee (0, x, y, z, 0); + __analyzer_describe (0, sum); /* { dg-message "'UNKNOWN\\(int\\)'" } */ +}