svn commit: r346651 - head/usr.sbin/kldxref

[John Baldwin]

Author: jhb
Date: Wed Apr 24 23:35:10 2019
New Revision: 346651
URL: https://svnweb.freebsd.org/changeset/base/346651

Log:
  Parse MIPS relocations to unbreak kldxref on MIPS.
  
  Parse the R_MIPS_32 and R_MIPS_64 relocations.  Both Elf_Rel and
  Elf_Rela relocations are handled since O32 MIPS uses Elf_Rel while N64
  uses Elf_Rela.  Note that R_MIPS_32 is only handled for 32-bit mips
  and R_MIPS_64 for 64-bit.  N32 is untested.
  
  Reviewed by:	imp
  Sponsored by:	DARPA
  Differential Revision:	https://reviews.freebsd.org/D19870

Added:
  head/usr.sbin/kldxref/ef_mips.c   (contents, props changed)

Added: head/usr.sbin/kldxref/ef_mips.c
==============================================================================
--- /dev/null	00:00:00 1970	(empty, because file is newly added)
+++ head/usr.sbin/kldxref/ef_mips.c	Wed Apr 24 23:35:10 2019	(r346651)
@@ -0,0 +1,99 @@
+/*-
+ * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
+ *
+ * Copyright (c) 2019 John Baldwin <jhb at FreeBSD.org>
+ *
+ * This software was developed by SRI International and the University of
+ * Cambridge Computer Laboratory (Department of Computer Science and
+ * Technology) under DARPA contract HR0011-18-C-0016 ("ECATS"), as part of the
+ * DARPA SSITH research programme.
+ *
+ * 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.
+ *
+ * $FreeBSD$
+ */
+
+#include <sys/types.h>
+#include <machine/elf.h>
+
+#include <err.h>
+#include <errno.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'.
+ */
+int
+ef_reloc(struct elf_file *ef, const void *reldata, int reltype, Elf_Off relbase,
+    Elf_Off dataoff, size_t len, void *dest)
+{
+	Elf_Addr *where, val;
+	const Elf_Rel *rel;
+	const Elf_Rela *rela;
+	Elf_Addr addend, addr;
+	Elf_Size rtype, symidx;
+
+	switch (reltype) {
+	case EF_RELOC_REL:
+		rel = (const Elf_Rel *)reldata;
+		where = (Elf_Addr *)((char *)dest + relbase + rel->r_offset -
+		    dataoff);
+		addend = 0;
+		rtype = ELF_R_TYPE(rel->r_info);
+		symidx = ELF_R_SYM(rel->r_info);
+		break;
+	case EF_RELOC_RELA:
+		rela = (const Elf_Rela *)reldata;
+		where = (Elf_Addr *)((char *)dest + relbase + rela->r_offset -
+		    dataoff);
+		addend = rela->r_addend;
+		rtype = ELF_R_TYPE(rela->r_info);
+		symidx = ELF_R_SYM(rela->r_info);
+		break;
+	default:
+		return (EINVAL);
+	}
+
+	if ((char *)where < (char *)dest || (char *)where >= (char *)dest + len)
+		return (0);
+
+	if (reltype == EF_RELOC_REL)
+		addend = *where;
+
+	switch (rtype) {
+#ifdef __LP64__
+	case R_MIPS_64:		/* S + A */
+#else
+	case R_MIPS_32:		/* S + A */
+#endif
+		addr = EF_SYMADDR(ef, symidx);
+		val = addr + addend;
+		*where = val;
+		break;
+	default:
+		warnx("unhandled relocation type %d", (int)rtype);
+	}
+	return (0);
+}