From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 1363) id 7E2F33849AF3; Wed, 24 Apr 2024 14:39:58 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 7E2F33849AF3 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org; s=default; t=1713969598; bh=T5EScQ7jVWNnzYyNyLVyJhd3VVaxmUcWKMbQvs5S10c=; h=From:To:Subject:Date:From; b=wCuHZPP67Ft9HeiAvrvxoMH3C9416Oe5cjbijIXQiAGUHmqXw9BLtQxS0Zu99pjbu 3T5F0xaLe/XlCiRFFBdwx9Z2Ri4ibdBP4sZNoXt0Fld9wzNeI1N2eEY54pVJDmxNQO ZsOBajBVCCQoSY/TTH1ut/+XWhBG5ED6BbLLMmSY= 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 r11-11351] 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-11 X-Git-Oldrev: b4e1aee01a2fa617cf74ab04cf0ab574761aaaea X-Git-Newrev: 624c3bb9ff762f196852dc77233610d1cdf7d7be Message-Id: <20240424143958.7E2F33849AF3@sourceware.org> Date: Wed, 24 Apr 2024 14:39:58 +0000 (GMT) List-Id: https://gcc.gnu.org/g:624c3bb9ff762f196852dc77233610d1cdf7d7be commit r11-11351-g624c3bb9ff762f196852dc77233610d1cdf7d7be 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 gcc/ChangeLog: PR sanitizer/111736 * ubsan.c (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/testsuite/ChangeLog: * gcc.dg/ubsan/pr111736.c: New test. (cherry picked from commit ddd4a3ca87410886b039cc225907b4f6e650082e) Diff: --- gcc/testsuite/gcc.dg/ubsan/pr111736.c | 23 +++++++++++++++++++++++ gcc/ubsan.c | 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.c b/gcc/ubsan.c index 04e8c1552a7..2b12651b440 100644 --- a/gcc/ubsan.c +++ b/gcc/ubsan.c @@ -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;