From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 1363) id 30E05384A880; Tue, 23 Apr 2024 17:09:21 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 30E05384A880 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org; s=default; t=1713892161; bh=zg2qbblyN1je41VQP79KpzHISKBk94ba+LeslY3x64s=; h=From:To:Subject:Date:From; b=cnnQILejJoMF8EtBXrr8mz9qu+K38i9fpZCpU3QRnfAI7PzDgJDXpwz3e1hM2BCqE JBo5RPKoAG/YPDiU/C+pagMp4MmLO0Dkwa0w5c93UvZZtb//f98RL5yKk8slIIpz8O Rai9cH/YQRBYq+cuHIZ+8GCHtOre/+z2sEeuWvbw= MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="utf-8" From: Uros Bizjak To: gcc-cvs@gcc.gnu.org Subject: [gcc r12-10389] ubsan: Don't -fsanitize=null instrument __seg_fs/gs pointers [PR111736] X-Act-Checkin: gcc X-Git-Author: Jakub Jelinek X-Git-Refname: refs/heads/releases/gcc-12 X-Git-Oldrev: e89b5ed62a5a06fb8918ffa1616f0f37c8d359c3 X-Git-Newrev: d6c62e4fb9a6d395599b7c78c831bace4bc7ff8f Message-Id: <20240423170921.30E05384A880@sourceware.org> Date: Tue, 23 Apr 2024 17:09:21 +0000 (GMT) List-Id: https://gcc.gnu.org/g:d6c62e4fb9a6d395599b7c78c831bace4bc7ff8f commit r12-10389-gd6c62e4fb9a6d395599b7c78c831bace4bc7ff8f Author: Jakub Jelinek Date: Fri Mar 22 09:23:44 2024 +0100 ubsan: Don't -fsanitize=null instrument __seg_fs/gs pointers [PR111736] On x86 and avr some address spaces allow 0 pointers (on avr actually even generic as, but libsanitizer isn't ported to it and I'm not convinced we should completely kill -fsanitize=null in that case). The following patch makes sure those aren't diagnosed for -fsanitize=null, though they are still sanitized for -fsanitize=alignment. 2024-03-22 Jakub Jelinek PR sanitizer/111736 * ubsan.cc (ubsan_expand_null_ifn, instrument_mem_ref): Avoid SANITIZE_NULL instrumentation for non-generic address spaces for which targetm.addr_space.zero_address_valid (as) is true. * gcc.dg/ubsan/pr111736.c: New test. (cherry picked from commit ddd4a3ca87410886b039cc225907b4f6e650082e) Diff: --- gcc/testsuite/gcc.dg/ubsan/pr111736.c | 23 +++++++++++++++++++++++ gcc/ubsan.cc | 19 +++++++++++++++++-- 2 files changed, 40 insertions(+), 2 deletions(-) diff --git a/gcc/testsuite/gcc.dg/ubsan/pr111736.c b/gcc/testsuite/gcc.dg/ubsan/pr111736.c new file mode 100644 index 00000000000..359b31828f0 --- /dev/null +++ b/gcc/testsuite/gcc.dg/ubsan/pr111736.c @@ -0,0 +1,23 @@ +/* PR sanitizer/111736 */ +/* { dg-do compile { target i?86-*-* x86_64-*-* } } */ +/* { dg-options "-fsanitize=null,alignment -fdump-tree-optimized -ffat-lto-objects" } */ +/* { dg-final { scan-tree-dump-times "__ubsan_handle_type_mismatch" 1 "optimized" } } */ +/* { dg-final { scan-tree-dump-not "p_\[0-9]*.D. \[=!]= 0" "optimized" } } */ + +#ifdef __x86_64__ +#define SEG __seg_fs +#else +#define SEG __seg_gs +#endif + +int +foo (int SEG *p, int *q) +{ + return *p; +} + +__attribute__((no_sanitize("alignment"))) int +bar (int SEG *p, int *q) +{ + return *p; +} diff --git a/gcc/ubsan.cc b/gcc/ubsan.cc index 0f5b372b195..4d8e7cd86c5 100644 --- a/gcc/ubsan.cc +++ b/gcc/ubsan.cc @@ -49,6 +49,7 @@ along with GCC; see the file COPYING3. If not see #include "tree-cfg.h" #include "gimple-fold.h" #include "varasm.h" +#include "target.h" /* Map from a tree to a VAR_DECL tree. */ @@ -784,6 +785,13 @@ ubsan_expand_null_ifn (gimple_stmt_iterator *gsip) } } check_null = sanitize_flags_p (SANITIZE_NULL); + if (check_null && POINTER_TYPE_P (TREE_TYPE (ptr))) + { + addr_space_t as = TYPE_ADDR_SPACE (TREE_TYPE (TREE_TYPE (ptr))); + if (!ADDR_SPACE_GENERIC_P (as) + && targetm.addr_space.zero_address_valid (as)) + check_null = false; + } if (check_align == NULL_TREE && !check_null) { @@ -1375,8 +1383,15 @@ instrument_mem_ref (tree mem, tree base, gimple_stmt_iterator *iter, if (align <= 1) align = 0; } - if (align == 0 && !sanitize_flags_p (SANITIZE_NULL)) - return; + if (align == 0) + { + if (!sanitize_flags_p (SANITIZE_NULL)) + return; + addr_space_t as = TYPE_ADDR_SPACE (TREE_TYPE (base)); + if (!ADDR_SPACE_GENERIC_P (as) + && targetm.addr_space.zero_address_valid (as)) + return; + } tree t = TREE_OPERAND (base, 0); if (!POINTER_TYPE_P (TREE_TYPE (t))) return;