From patchwork Sun Dec 3 09:49:34 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Masahiro Yamada X-Patchwork-Id: 13477225 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 C0E8528F5; Sun, 3 Dec 2023 09:50:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="VNv2/I0y" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 099D3C433CB; Sun, 3 Dec 2023 09:49:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1701597000; bh=3fREL+3pDb0+f3gpXJDWy/Z+fjSVV4sYVi1Ga8WtaHw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=VNv2/I0y1QaQgNoItB2fCs1RK2AgJtD5NdVHjX92RWhrLjqitS+cRVeZ2kXIsGx8o QER7zjLtrPvCDVpDGyc3FQjR1VGYW3GSPNVdnBPNTd/weX/xjWmn3qQ+K1pop+vvcg GFEsnbwuHQbnxVpzlV+Nq196TtY3G02V8Ierf2Za1v9CKfTZdcZyFKZPK5izOAbYYl ZOpkXYUBx5i1XQIVUb6TT7YK1VqGX0xTOhvmbj9cb/vYAtzzh/DiO1FD7tn+eXX70Q AtM5DljHuHWcL9uKAyXzFm49NNpivgg0zf9/3DC1s2cXsmpzfMak3IwicdamK9Zc7m G3A13S5DzjkPg== From: Masahiro Yamada To: linux-kbuild@vger.kernel.org Cc: Masahiro Yamada , Nathan Chancellor , Nick Desaulniers , Nicolas Schier , Tom Rix , linux-kernel@vger.kernel.org, llvm@lists.linux.dev Subject: [PATCH v2 4/4] modpost: remove unreachable code after fatal() Date: Sun, 3 Dec 2023 18:49:34 +0900 Message-Id: <20231203094934.1908270-4-masahiroy@kernel.org> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20231203094934.1908270-1-masahiroy@kernel.org> References: <20231203094934.1908270-1-masahiroy@kernel.org> Precedence: bulk X-Mailing-List: linux-kbuild@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Now compilers can recognize fatal() never returns. While GCC 4.5 dropped support for -Wunreachable-code, Clang is capable of detecting the unreachable code. $ make HOSTCC=clang HOSTCFLAGS=-Wunreachable-code-return [snip] HOSTCC scripts/mod/modpost.o scripts/mod/modpost.c:520:11: warning: 'return' will never be executed [-Wunreachable-code-return] return 0; ^ scripts/mod/modpost.c:477:10: warning: 'return' will never be executed [-Wunreachable-code-return] return 0; ^ 2 warnings generated. Signed-off-by: Masahiro Yamada Reviewed-by: Nathan Chancellor --- Changes in v2: - Change the patch order - Update the commit description and add warning example. scripts/mod/modpost.c | 9 +++------ 1 file changed, 3 insertions(+), 6 deletions(-) diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c index 3233946fa5f6..e2bc180cecc8 100644 --- a/scripts/mod/modpost.c +++ b/scripts/mod/modpost.c @@ -476,11 +476,9 @@ static int parse_elf(struct elf_info *info, const char *filename) fatal("%s: not relocatable object.", filename); /* Check if file offset is correct */ - if (hdr->e_shoff > info->size) { + if (hdr->e_shoff > info->size) fatal("section header offset=%lu in file '%s' is bigger than filesize=%zu\n", (unsigned long)hdr->e_shoff, filename, info->size); - return 0; - } if (hdr->e_shnum == SHN_UNDEF) { /* @@ -518,12 +516,11 @@ static int parse_elf(struct elf_info *info, const char *filename) const char *secname; int nobits = sechdrs[i].sh_type == SHT_NOBITS; - if (!nobits && sechdrs[i].sh_offset > info->size) { + if (!nobits && sechdrs[i].sh_offset > info->size) fatal("%s is truncated. sechdrs[i].sh_offset=%lu > sizeof(*hrd)=%zu\n", filename, (unsigned long)sechdrs[i].sh_offset, sizeof(*hdr)); - return 0; - } + secname = secstrings + sechdrs[i].sh_name; if (strcmp(secname, ".modinfo") == 0) { if (nobits)