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GET /api/patches/2194171/?format=api
{ "id": 2194171, "url": "http://patchwork.ozlabs.org/api/patches/2194171/?format=api", "web_url": "http://patchwork.ozlabs.org/project/gcc/patch/20260206233718.11975-1-code@fedang.net/", "project": { "id": 17, "url": "http://patchwork.ozlabs.org/api/projects/17/?format=api", "name": "GNU Compiler Collection", "link_name": "gcc", "list_id": "gcc-patches.gcc.gnu.org", "list_email": "gcc-patches@gcc.gnu.org", "web_url": null, "scm_url": null, "webscm_url": null, "list_archive_url": "", "list_archive_url_format": "", "commit_url_format": "" }, "msgid": "<20260206233718.11975-1-code@fedang.net>", "list_archive_url": null, "date": "2026-02-06T23:37:18", "name": "analyzer: Don't warn on null deref if target allows 0 address [PR123981]", "commit_ref": null, "pull_url": null, "state": "new", "archived": false, "hash": "6a3468391bc3238236d9e5e67306497c6d82136d", "submitter": { "id": 92598, "url": "http://patchwork.ozlabs.org/api/people/92598/?format=api", "name": "fedang", "email": "code@fedang.net" }, "delegate": null, "mbox": "http://patchwork.ozlabs.org/project/gcc/patch/20260206233718.11975-1-code@fedang.net/mbox/", "series": [ { "id": 491349, "url": "http://patchwork.ozlabs.org/api/series/491349/?format=api", "web_url": "http://patchwork.ozlabs.org/project/gcc/list/?series=491349", "date": "2026-02-06T23:37:18", "name": "analyzer: Don't warn on null deref if target allows 0 address [PR123981]", "version": 1, "mbox": "http://patchwork.ozlabs.org/series/491349/mbox/" } ], "comments": "http://patchwork.ozlabs.org/api/patches/2194171/comments/", "check": "pending", "checks": "http://patchwork.ozlabs.org/api/patches/2194171/checks/", "tags": {}, "related": [], "headers": { "Return-Path": "<gcc-patches-bounces~incoming=patchwork.ozlabs.org@gcc.gnu.org>", "X-Original-To": [ "incoming@patchwork.ozlabs.org", "gcc-patches@gcc.gnu.org" ], "Delivered-To": [ "patchwork-incoming@legolas.ozlabs.org", "gcc-patches@gcc.gnu.org" ], "Authentication-Results": [ "legolas.ozlabs.org;\n\tdkim=pass (2048-bit key;\n unprotected) header.d=fedang.net header.i=@fedang.net header.a=rsa-sha256\n header.s=mail header.b=QmT7ixZn;\n\tdkim-atps=neutral", "legolas.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=gcc.gnu.org\n (client-ip=38.145.34.32; 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Fri, 6 Feb 2026 23:38:40 +0000 (GMT)", "from mail.fedang.net (mail.fedang.net [194.164.169.34])\n by sourceware.org (Postfix) with ESMTPS id AE3934BA23E4\n for <gcc-patches@gcc.gnu.org>; Fri, 6 Feb 2026 23:38:13 +0000 (GMT)" ], "DKIM-Filter": [ "OpenDKIM Filter v2.11.0 sourceware.org 3BCB24B9DB76", "OpenDKIM Filter v2.11.0 sourceware.org AE3934BA23E4" ], "DMARC-Filter": "OpenDMARC Filter v1.4.2 sourceware.org AE3934BA23E4", "ARC-Filter": "OpenARC Filter v1.0.0 sourceware.org AE3934BA23E4", "ARC-Seal": "i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1770421093; cv=none;\n b=qNjp5Mn1ZGH4+f10ZMMhO1sKhbEFvP3uS4FeXG9udx7zW5Ap+biWp5ZGJLyxU9LNnLi2wZZYjTqtA52GsuVps3l2u1mPhUdjxsfvPem1jsiJxxilkBsfyKo4lNpqJFf8ImbDdd+0F5VFQRrfBO098itxLWQxYDXBYqwExmDf1wY=", "ARC-Message-Signature": "i=1; a=rsa-sha256; d=sourceware.org; s=key;\n t=1770421093; c=relaxed/simple;\n bh=02y2JGF/dlYIH0EzPpb04maTDZQdsN2475o8AQAyGRg=;\n h=DKIM-Signature:From:To:Subject:Date:Message-ID:MIME-Version;\n b=VaQo0g+xfZ7lSuiA6ZQu1viHPJLlF3nsRGCfnsvJBqJypodvHQeO8JcKSJ4dp4KpojL9a0OPRhIoHdQ36IH3l15e1wDIlijjq4hR9kflX+o+OIPUFQ5KEVy+XX6sgIzq0LhpAOrhlGHr0s2oMagUl6HKMSPOf95MfIonyWe38gA=", "ARC-Authentication-Results": "i=1; server2.sourceware.org", "DKIM-Signature": "v=1; a=rsa-sha256; c=relaxed/simple; d=fedang.net; s=mail;\n t=1770421092; bh=02y2JGF/dlYIH0EzPpb04maTDZQdsN2475o8AQAyGRg=;\n h=From:To:Cc:Subject:Date:From;\n b=QmT7ixZnw1hnqIwDRhsiFf8sgB0Rv9ex/hFBgy4POMNBtg2qQcmUljVy+ljwr/QVY\n DazVvwbvro0dnQ/JZMkl3TXJpAFTDP2pTUwCJh375jtBn6raT/nZdSqZKcn0SfgY+k\n k/BZ/x0yAxSqmXHL+5PWvJU9XGDTOjbndTen+4ojE9JELiSlak1DId0Lq2ooRIvtMv\n H0uCYIhKy4pIoatJiFv77BbD7hqSCej8wN8HzXQvzIFvTK6J5bG3oAhZ8lNQgRAw+S\n z45xRsGaCzKCYm4xvjCMJQET11UyrhWNhsXd1NnooStL5Y/lTwwMFmlUbgZ4z+au4j\n dUBP9/tdrlUXA==", "From": "Federico Angelilli <code@fedang.net>", "To": "gcc-patches@gcc.gnu.org", "Cc": "David Malcolm <dmalcolm@redhat.com>, Federico Angelilli <code@fedang.net>", "Subject": "[PATCH] analyzer: Don't warn on null deref if target allows 0 address\n [PR123981]", "Date": "Sat, 7 Feb 2026 00:37:18 +0100", "Message-ID": "<20260206233718.11975-1-code@fedang.net>", "X-Mailer": "git-send-email 2.52.0", "MIME-Version": "1.0", "Content-Transfer-Encoding": "8bit", "X-BeenThere": "gcc-patches@gcc.gnu.org", "X-Mailman-Version": "2.1.30", "Precedence": "list", "List-Id": "Gcc-patches mailing list <gcc-patches.gcc.gnu.org>", "List-Unsubscribe": "<https://gcc.gnu.org/mailman/options/gcc-patches>,\n <mailto:gcc-patches-request@gcc.gnu.org?subject=unsubscribe>", "List-Archive": "<https://gcc.gnu.org/pipermail/gcc-patches/>", "List-Post": "<mailto:gcc-patches@gcc.gnu.org>", "List-Help": "<mailto:gcc-patches-request@gcc.gnu.org?subject=help>", "List-Subscribe": "<https://gcc.gnu.org/mailman/listinfo/gcc-patches>,\n <mailto:gcc-patches-request@gcc.gnu.org?subject=subscribe>", "Errors-To": "gcc-patches-bounces~incoming=patchwork.ozlabs.org@gcc.gnu.org" }, "content": "Previously the analyzer emitted a -Wanalyzer-null-dereference even when\nthe target pointer's address space allowed accesses at address 0.\n\nThis patch uses the targetm.addr_space.zero_address_valid hook to\ncorrectly ignore such cases.\n\nTested on x86_64-pc-linux-gnu.\n\ngcc/analyzer/ChangeLog:\n\tPR analyzer/123981\n\n\t* sm-malloc.cc (malloc_state_machine::on_stmt): Check\n\tif zero access is valid for the pointer's address space.\n\ngcc/testsuite/ChangeLog:\n\tPR analyzer/123981\n\n\t* gcc.dg/analyzer/null-deref-pr123981-1.c: New test.\n\t* gcc.dg/analyzer/null-deref-pr123981-2.c: New test.\n\nSigned-off-by: Federico Angelilli <code@fedang.net>\n---\n gcc/analyzer/sm-malloc.cc | 5 +++++\n .../gcc.dg/analyzer/null-deref-pr123981-1.c | 12 ++++++++++++\n .../gcc.dg/analyzer/null-deref-pr123981-2.c | 8 ++++++++\n 3 files changed, 25 insertions(+)\n create mode 100644 gcc/testsuite/gcc.dg/analyzer/null-deref-pr123981-1.c\n create mode 100644 gcc/testsuite/gcc.dg/analyzer/null-deref-pr123981-2.c", "diff": "diff --git a/gcc/analyzer/sm-malloc.cc b/gcc/analyzer/sm-malloc.cc\nindex 6972a55d7fd..fb12b64d4be 100644\n--- a/gcc/analyzer/sm-malloc.cc\n+++ b/gcc/analyzer/sm-malloc.cc\n@@ -23,6 +23,7 @@ along with GCC; see the file COPYING3. If not see\n #include \"system.h\"\n #include \"coretypes.h\"\n #include \"make-unique.h\"\n+#include \"target.h\"\n #include \"tree.h\"\n #include \"function.h\"\n #include \"basic-block.h\"\n@@ -2267,6 +2268,10 @@ malloc_state_machine::on_stmt (sm_context &sm_ctxt,\n \t }\n \t else if (state == m_null)\n \t {\n+\t addr_space_t as = TYPE_ADDR_SPACE (TREE_TYPE (op));\n+\t if (targetm.addr_space.zero_address_valid (as))\n+\t\tcontinue;\n+\n \t tree diag_arg = sm_ctxt.get_diagnostic_tree (arg);\n \t sm_ctxt.warn (node, stmt, arg,\n \t\t\t make_unique<null_deref> (*this, diag_arg));\ndiff --git a/gcc/testsuite/gcc.dg/analyzer/null-deref-pr123981-1.c b/gcc/testsuite/gcc.dg/analyzer/null-deref-pr123981-1.c\nnew file mode 100644\nindex 00000000000..2df9d7813d6\n--- /dev/null\n+++ b/gcc/testsuite/gcc.dg/analyzer/null-deref-pr123981-1.c\n@@ -0,0 +1,12 @@\n+/* { dg-do compile { target x86_64-*-* } } */\n+/* { dg-additional-options \"-mfsgsbase\" } */\n+\n+#include <immintrin.h>\n+#define getgs() ((int __seg_gs *)0)\n+\n+int main()\n+{\n+ static int gsval = 42;\n+ _writegsbase_u64((unsigned long long)&gsval);\n+ return *getgs(); /* { dg-bogus \"-Wanalyzer-null-dereference\" } */\n+}\ndiff --git a/gcc/testsuite/gcc.dg/analyzer/null-deref-pr123981-2.c b/gcc/testsuite/gcc.dg/analyzer/null-deref-pr123981-2.c\nnew file mode 100644\nindex 00000000000..03a48349244\n--- /dev/null\n+++ b/gcc/testsuite/gcc.dg/analyzer/null-deref-pr123981-2.c\n@@ -0,0 +1,8 @@\n+/* { dg-do compile { target { i?86-*-* x86_64-*-* } } } */\n+\n+#define getfs() ((int __seg_fs *)0)\n+\n+int main()\n+{\n+ return *getfs(); /* { dg-bogus \"-Wanalyzer-null-dereference\" } */\n+}\n", "prefixes": [] }