linux-kernel - [PATCH 1/2] modpost: drop executable ELF support

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-Id: <20220719165300.3000580-1-masahiroy@kernel.org>
Date:   Wed, 20 Jul 2022 01:52:59 +0900
From:   Masahiro Yamada <masahiroy@...nel.org>
To:     linux-kbuild@...r.kernel.org
Cc:     Masahiro Yamada <masahiroy@...nel.org>,
        Michal Marek <michal.lkml@...kovi.net>,
        Nick Desaulniers <ndesaulniers@...gle.com>,
        linux-kernel@...r.kernel.org
Subject: [PATCH 1/2] modpost: drop executable ELF support

Since commit 269a535ca931 ("modpost: generate vmlinux.symvers and
reuse it for the second modpost"), modpost only parses relocatable
files (ET_REL).

Signed-off-by: Masahiro Yamada <masahiroy@...nel.org>
---

 scripts/mod/modpost.c | 10 ++++------
 1 file changed, 4 insertions(+), 6 deletions(-)

diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
index 7735d095338c..6370f9accb8e 100644
--- a/scripts/mod/modpost.c
+++ b/scripts/mod/modpost.c
@@ -321,9 +321,6 @@ static void *sym_get_data_by_offset(const struct elf_info *info,
 {
 	Elf_Shdr *sechdr = &info->sechdrs[secindex];
 
-	if (info->hdr->e_type != ET_REL)
-		offset -= sechdr->sh_addr;
-
 	return (void *)info->hdr + sechdr->sh_offset + offset;
 }
 
@@ -477,6 +474,10 @@ static int parse_elf(struct elf_info *info, const char *filename)
 	sechdrs = (void *)hdr + hdr->e_shoff;
 	info->sechdrs = sechdrs;
 
+	/* modpost only works for relocatable objects */
+	if (hdr->e_type != ET_REL)
+		fatal("%s: not relocatable object.", filename);
+
 	/* Check if file offset is correct */
 	if (hdr->e_shoff > info->size) {
 		fatal("section header offset=%lu in file '%s' is bigger than filesize=%zu\n",
@@ -1633,9 +1634,6 @@ static int addend_386_rel(struct elf_info *elf, Elf_Shdr *sechdr, Elf_Rela *r)
 		break;
 	case R_386_PC32:
 		r->r_addend = TO_NATIVE(*location) + 4;
-		/* For CONFIG_RELOCATABLE=y */
-		if (elf->hdr->e_type == ET_EXEC)
-			r->r_addend += r->r_offset;
 		break;
 	}
 	return 0;
-- 
2.34.1