kldxref: Add arm support

2 files changed, 95 insertions, 0 deletions

diff --git a/usr.sbin/kldxref/Makefile b/usr.sbin/kldxref/Makefile
index 07451ba8f42b..7b392e020939 100644
--- a/usr.sbin/kldxref/Makefile
+++ b/usr.sbin/kldxref/Makefile
@@ -4,6 +4,7 @@ PROG=	kldxref
 MAN=	kldxref.8
 SRCS=	kldxref.c ef.c ef_obj.c elf.c
 SRCS+=	ef_aarch64.c \
+	ef_arm.c \
 	ef_amd64.c \
 	ef_i386.c \
 	ef_mips.c \
diff --git a/usr.sbin/kldxref/ef_arm.c b/usr.sbin/kldxref/ef_arm.c
new file mode 100644
index 000000000000..4b926839ee5d
--- /dev/null
+++ b/usr.sbin/kldxref/ef_arm.c
@@ -0,0 +1,94 @@
+/*-
+ * SPDX-License-Identifier: BSD-2-Clause
+ *
+ * Copyright (c) 2003 Jake Burkholder.
+ * Copyright 1996-1998 John D. Polstra.
+ * All rights reserved.
+ * Copyright (c) 2023 Jessica Clarke <jrtc27@FreeBSD.org>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <sys/endian.h>
+
+#include <err.h>
+#include <errno.h>
+#include <gelf.h>
+
+#include "ef.h"
+
+/*
+ * Apply relocations to the values we got from the file. `relbase' is the
+ * target relocation address of the section, and `dataoff' is the target
+ * relocation address of the data in `dest'.
+ */
+static int
+ef_arm_reloc(struct elf_file *ef, const void *reldata, Elf_Type reltype,
+    GElf_Addr relbase, GElf_Addr dataoff, size_t len, void *dest)
+{
+	char *where;
+	GElf_Addr addr, addend;
+	GElf_Size rtype, symidx;
+	const GElf_Rel *rel;
+	const GElf_Rela *rela;
+
+	switch (reltype) {
+	case ELF_T_REL:
+		rel = (const GElf_Rel *)reldata;
+		where = (char *)dest + relbase + rel->r_offset - dataoff;
+		addend = 0;
+		rtype = GELF_R_TYPE(rel->r_info);
+		symidx = GELF_R_SYM(rel->r_info);
+		break;
+	case ELF_T_RELA:
+		rela = (const GElf_Rela *)reldata;
+		where = (char *)dest + relbase + rela->r_offset - dataoff;
+		addend = rela->r_addend;
+		rtype = GELF_R_TYPE(rela->r_info);
+		symidx = GELF_R_SYM(rela->r_info);
+		break;
+	default:
+		return (EINVAL);
+	}
+
+	if (where < (char *)dest || where >= (char *)dest + len)
+		return (0);
+
+	if (reltype == ELF_T_REL)
+		addend = le32dec(where);
+
+	switch (rtype) {
+	case R_ARM_ABS32:	/* S + A */
+		addr = EF_SYMADDR(ef, symidx) + addend;
+		le32enc(where, addr);
+		break;
+	case R_ARM_RELATIVE:	/* B + A */
+		addr = addend + relbase;
+		le32enc(where, addr);
+		break;
+	default:
+		warnx("unhandled relocation type %d", (int)rtype);
+	}
+	return (0);
+}
+
+ELF_RELOC(ELFCLASS32, ELFDATA2LSB, EM_ARM, ef_arm_reloc);