From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7092532E131; Fri, 17 Oct 2025 15:30:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760715038; cv=none; b=SGvpdm71WQqK6dAncjkLf8vowRfQKL6DFayoKrMiAqKRHQ1LFwZzzrOlRrT1XuKQSJmJMIBMeLXWlZAv+5jtYbTPYiBCqNGNi7TCtkbvArSD1wTX/ZL1bgTUT+acd1is7YpTBfTCA8p1DrF+CLSzg9CTgLqNM5dcB/TIpxeizjE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760715038; c=relaxed/simple; bh=Jh7MQRQfT+XQb56sQNF4fF6e2719ycv/OTkY5Dh65cw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=iRmHlSI1RNX3QWvwozgZ0N1jB4HxBgXhkPUkh9j32zOvYzppYHPVzEdkwHhzqsp5g1f1jZZDbEM9x++CCg6taP6xDVMZw6W+ewgsjPLtTeproRlXeLlKBKVYt0tHcK/LpcKkiY4vNcTvUcMn0jmEufTpnf4kqXxOLHkc1DzoKX0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=AT7jnbxz; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="AT7jnbxz" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E911CC4CEE7; Fri, 17 Oct 2025 15:30:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1760715038; bh=Jh7MQRQfT+XQb56sQNF4fF6e2719ycv/OTkY5Dh65cw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=AT7jnbxzDqvAJg0okMezxrLciXXZOYPxCDxgmexBVBS8LFxGbxkJt+2IRgad4x65E YuJoOQ6LEvJJvNvlmtsljlWzGiU1YY/dmpeBt1xA01Xtk+SjWekj7kEx6D66LhZ6YT sut84ZiFGZl/q+Nl+J31kMQlcV+n33+N9HGCqJss= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, kernel test robot , WANG Rui , Tiezhu Yang , Huacai Chen , Sasha Levin Subject: [PATCH 6.17 076/371] LoongArch: Add cflag -fno-isolate-erroneous-paths-dereference Date: Fri, 17 Oct 2025 16:50:51 +0200 Message-ID: <20251017145204.690121907@linuxfoundation.org> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20251017145201.780251198@linuxfoundation.org> References: <20251017145201.780251198@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.17-stable review patch. If anyone has any objections, please let me know. ------------------ From: Tiezhu Yang [ Upstream commit abb2a5572264b425e6dd9c213b735a82ab0ca68a ] Currently, when compiling with GCC, there is no "break 7" instruction for zero division due to using the option -mno-check-zero-division, but the compiler still generates "break 0" instruction for zero division. Here is a simple example: $ cat test.c int div(int a) { return a / 0; } $ gcc -O2 -S test.c -o test.s GCC generates "break 0" on LoongArch and "ud2" on x86, objtool decodes "ud2" as INSN_BUG for x86, so decode "break 0" as INSN_BUG can fix the objtool warnings for LoongArch, but this is not the intention. When decoding "break 0" as INSN_TRAP in the previous commit, the aim is to handle "break 0" as a trap. The generated "break 0" for zero division by GCC is not proper, it should generate a break instruction with proper bug type, so add the GCC option -fno-isolate-erroneous-paths-dereference to avoid generating the unexpected "break 0" instruction for now. Reported-by: kernel test robot Closes: https://lore.kernel.org/r/202509200413.7uihAxJ5-lkp@intel.com/ Fixes: baad7830ee9a ("objtool/LoongArch: Mark types based on break immediate code") Suggested-by: WANG Rui Signed-off-by: Tiezhu Yang Signed-off-by: Huacai Chen Signed-off-by: Sasha Levin --- arch/loongarch/Makefile | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/loongarch/Makefile b/arch/loongarch/Makefile index ae419e32f22e2..f2a585b4a9375 100644 --- a/arch/loongarch/Makefile +++ b/arch/loongarch/Makefile @@ -129,7 +129,7 @@ KBUILD_RUSTFLAGS_KERNEL += -Crelocation-model=pie LDFLAGS_vmlinux += -static -pie --no-dynamic-linker -z notext $(call ld-option, --apply-dynamic-relocs) endif -cflags-y += $(call cc-option, -mno-check-zero-division) +cflags-y += $(call cc-option, -mno-check-zero-division -fno-isolate-erroneous-paths-dereference) ifndef CONFIG_KASAN cflags-y += -fno-builtin-memcpy -fno-builtin-memmove -fno-builtin-memset -- 2.51.0