1 files changed, 515 insertions, 0 deletions
diff --git a/sys/boot/common/load_elf_obj.c b/sys/boot/common/load_elf_obj.c
new file mode 100644
index 0000000..53b1317
--- /dev/null
+++ b/sys/boot/common/load_elf_obj.c
@@ -0,0 +1,515 @@
+/*-
+ * Copyright (c) 2004 Ian Dowse <iedowse@freebsd.org>
+ * Copyright (c) 1998 Michael Smith <msmith@freebsd.org>
+ * Copyright (c) 1998 Peter Wemm <peter@freebsd.org>
+ * All rights reserved.
+ *
+ * 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/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/param.h>
+#include <sys/exec.h>
+#include <sys/linker.h>
+#include <sys/module.h>
+#include <inttypes.h>
+#include <string.h>
+#include <machine/elf.h>
+#include <stand.h>
+#define FREEBSD_ELF
+#include <link.h>
+
+#include "bootstrap.h"
+
+#define COPYOUT(s,d,l)	archsw.arch_copyout((vm_offset_t)(s), d, l)
+
+#if defined(__i386__) && __ELF_WORD_SIZE == 64
+#undef ELF_TARG_CLASS
+#undef ELF_TARG_MACH
+#define ELF_TARG_CLASS  ELFCLASS64
+#define ELF_TARG_MACH   EM_X86_64
+#endif
+
+typedef struct elf_file {
+	Elf_Ehdr	hdr;
+	Elf_Shdr	*e_shdr;
+
+	int		symtabindex;	/* Index of symbol table */
+	int		shstrindex;	/* Index of section name string table */
+
+	int		fd;
+	vm_offset_t	off;
+} *elf_file_t;
+
+static int __elfN(obj_loadimage)(struct preloaded_file *mp, elf_file_t ef,
+    u_int64_t loadaddr);
+static int __elfN(obj_lookup_set)(struct preloaded_file *mp, elf_file_t ef,
+    const char *name, Elf_Addr *startp, Elf_Addr *stopp, int *countp);
+static int __elfN(obj_reloc_ptr)(struct preloaded_file *mp, elf_file_t ef,
+    Elf_Addr p, void *val, size_t len);
+static int __elfN(obj_parse_modmetadata)(struct preloaded_file *mp,
+    elf_file_t ef);
+static Elf_Addr __elfN(obj_symaddr)(struct elf_file *ef, Elf_Word symidx);
+
+const char	*__elfN(obj_kerneltype) = "elf kernel";
+const char	*__elfN(obj_moduletype) = "elf obj module";
+
+/*
+ * Attempt to load the file (file) as an ELF module.  It will be stored at
+ * (dest), and a pointer to a module structure describing the loaded object
+ * will be saved in (result).
+ */
+int
+__elfN(obj_loadfile)(char *filename, u_int64_t dest,
+    struct preloaded_file **result)
+{
+	struct preloaded_file *fp, *kfp;
+	struct elf_file	ef;
+	Elf_Ehdr *hdr;
+	int err;
+	ssize_t bytes_read;
+
+	fp = NULL;
+	bzero(&ef, sizeof(struct elf_file));
+
+	/*
+	 * Open the image, read and validate the ELF header
+	 */
+	if (filename == NULL)	/* can't handle nameless */
+		return(EFTYPE);
+	if ((ef.fd = open(filename, O_RDONLY)) == -1)
+		return(errno);
+
+	hdr = &ef.hdr;
+	bytes_read = read(ef.fd, hdr, sizeof(*hdr));
+	if (bytes_read != sizeof(*hdr)) {
+		err = EFTYPE;	/* could be EIO, but may be small file */
+		goto oerr;
+	}
+
+	/* Is it ELF? */
+	if (!IS_ELF(*hdr)) {
+		err = EFTYPE;
+		goto oerr;
+	}
+	if (hdr->e_ident[EI_CLASS] != ELF_TARG_CLASS ||	/* Layout ? */
+	    hdr->e_ident[EI_DATA] != ELF_TARG_DATA ||
+	    hdr->e_ident[EI_VERSION] != EV_CURRENT ||	/* Version ? */
+	    hdr->e_version != EV_CURRENT ||
+	    hdr->e_machine != ELF_TARG_MACH ||		/* Machine ? */
+	    hdr->e_type != ET_REL) {
+		err = EFTYPE;
+		goto oerr;
+	}
+
+	if (hdr->e_shnum * hdr->e_shentsize == 0 || hdr->e_shoff == 0 ||
+	    hdr->e_shentsize != sizeof(Elf_Shdr)) {
+		err = EFTYPE;
+		goto oerr;
+	}
+
+	kfp = file_findfile(NULL, NULL);
+	if (kfp == NULL) {
+		printf("elf" __XSTRING(__ELF_WORD_SIZE)
+		    "_obj_loadfile: can't load module before kernel\n");
+		err = EPERM;
+		goto oerr;
+	}
+	if (strcmp(__elfN(obj_kerneltype), kfp->f_type)) {
+		printf("elf" __XSTRING(__ELF_WORD_SIZE)
+		    "_obj_loadfile: can't load module with kernel type '%s'\n",
+		    kfp->f_type);
+		err = EPERM;
+		goto oerr;
+	}
+
+	/* Page-align the load address */
+	dest = roundup(dest, PAGE_SIZE);
+
+	/*
+	 * Ok, we think we should handle this.
+	 */
+	fp = file_alloc();
+	if (fp == NULL) {
+		printf("elf" __XSTRING(__ELF_WORD_SIZE)
+		    "_obj_loadfile: cannot allocate module info\n");
+		err = EPERM;
+		goto out;
+	}
+	fp->f_name = strdup(filename);
+	fp->f_type = strdup(__elfN(obj_moduletype));
+
+	printf("%s ", filename);
+
+	fp->f_size = __elfN(obj_loadimage)(fp, &ef, dest);
+	if (fp->f_size == 0 || fp->f_addr == 0)
+		goto ioerr;
+
+	/* save exec header as metadata */
+	file_addmetadata(fp, MODINFOMD_ELFHDR, sizeof(*hdr), hdr);
+
+	/* Load OK, return module pointer */
+	*result = (struct preloaded_file *)fp;
+	err = 0;
+	goto out;
+
+ioerr:
+	err = EIO;
+oerr:
+	file_discard(fp);
+out:
+	close(ef.fd);
+	if (ef.e_shdr != NULL)
+		free(ef.e_shdr);
+
+	return(err);
+}
+
+/*
+ * With the file (fd) open on the image, and (ehdr) containing
+ * the Elf header, load the image at (off)
+ */
+static int
+__elfN(obj_loadimage)(struct preloaded_file *fp, elf_file_t ef, u_int64_t off)
+{
+	Elf_Ehdr *hdr;
+	Elf_Shdr *shdr;
+	vm_offset_t firstaddr, lastaddr;
+	int i, nsym, res, ret, shdrbytes, symstrindex;
+
+	ret = 0;
+	firstaddr = lastaddr = (vm_offset_t)off;
+	hdr = &ef->hdr;
+	ef->off = (vm_offset_t)off;
+
+	/* Read in the section headers. */
+	shdrbytes = hdr->e_shnum * hdr->e_shentsize;
+	shdr = alloc_pread(ef->fd, (off_t)hdr->e_shoff, shdrbytes);
+	if (shdr == NULL) {
+		printf("\nelf" __XSTRING(__ELF_WORD_SIZE)
+		    "_obj_loadimage: read section headers failed\n");
+		goto out;
+	}
+	ef->e_shdr = shdr;
+
+	/*
+	 * Decide where to load everything, but don't read it yet.
+	 * We store the load address as a non-zero sh_addr value.
+	 * Start with the code/data and bss.
+	 */
+	for (i = 0; i < hdr->e_shnum; i++)
+		shdr[i].sh_addr = 0;
+	for (i = 0; i < hdr->e_shnum; i++) {
+		switch (shdr[i].sh_type) {
+		case SHT_PROGBITS:
+		case SHT_NOBITS:
+			lastaddr = roundup(lastaddr, shdr[i].sh_addralign);
+			shdr[i].sh_addr = (Elf_Addr)lastaddr;
+			lastaddr += shdr[i].sh_size;
+			break;
+		}
+	}
+
+	/* Symbols. */
+	nsym = 0;
+	for (i = 0; i < hdr->e_shnum; i++) {
+		switch (shdr[i].sh_type) {
+		case SHT_SYMTAB:
+			nsym++;
+			ef->symtabindex = i;
+			shdr[i].sh_addr = (Elf_Addr)lastaddr;
+			lastaddr += shdr[i].sh_size;
+			break;
+		}
+	}
+	if (nsym != 1) {
+		printf("\nelf" __XSTRING(__ELF_WORD_SIZE)
+		    "_obj_loadimage: file has no valid symbol table\n");
+		goto out;
+	}
+	lastaddr = roundup(lastaddr, shdr[ef->symtabindex].sh_addralign);
+	shdr[ef->symtabindex].sh_addr = (Elf_Addr)lastaddr;
+	lastaddr += shdr[ef->symtabindex].sh_size;
+
+	symstrindex = shdr[ef->symtabindex].sh_link;
+	if (symstrindex < 0 || symstrindex >= hdr->e_shnum ||
+	    shdr[symstrindex].sh_type != SHT_STRTAB) {
+		printf("\nelf" __XSTRING(__ELF_WORD_SIZE)
+		    "_obj_loadimage: file has invalid symbol strings\n");
+		goto out;
+	}
+	lastaddr = roundup(lastaddr, shdr[symstrindex].sh_addralign);
+	shdr[symstrindex].sh_addr = (Elf_Addr)lastaddr;
+	lastaddr += shdr[symstrindex].sh_size;
+
+	/* Section names. */
+	if (hdr->e_shstrndx == 0 || hdr->e_shstrndx >= hdr->e_shnum ||
+	    shdr[hdr->e_shstrndx].sh_type != SHT_STRTAB) {
+		printf("\nelf" __XSTRING(__ELF_WORD_SIZE)
+		    "_obj_loadimage: file has no section names\n");
+		goto out;
+	}
+	ef->shstrindex = hdr->e_shstrndx;
+	lastaddr = roundup(lastaddr, shdr[ef->shstrindex].sh_addralign);
+	shdr[ef->shstrindex].sh_addr = (Elf_Addr)lastaddr;
+	lastaddr += shdr[ef->shstrindex].sh_size;
+
+	/* Relocation tables. */
+	for (i = 0; i < hdr->e_shnum; i++) {
+		switch (shdr[i].sh_type) {
+		case SHT_REL:
+		case SHT_RELA:
+			lastaddr = roundup(lastaddr, shdr[i].sh_addralign);
+			shdr[i].sh_addr = (Elf_Addr)lastaddr;
+			lastaddr += shdr[i].sh_size;
+			break;
+		}
+	}
+
+	/* Clear the whole area, including bss regions. */
+	kern_bzero(firstaddr, lastaddr - firstaddr);
+
+	/* Now read it all in. */
+	for (i = 0; i < hdr->e_shnum; i++) {
+		if (shdr[i].sh_addr == 0 || shdr[i].sh_type == SHT_NOBITS)
+			continue;
+		if (kern_pread(ef->fd, (vm_offset_t)shdr[i].sh_addr,
+		    shdr[i].sh_size, (off_t)shdr[i].sh_offset) != 0) {
+			printf("\nelf" __XSTRING(__ELF_WORD_SIZE)
+			    "_obj_loadimage: read failed\n");
+			goto out;
+		}
+	}
+
+	file_addmetadata(fp, MODINFOMD_SHDR, shdrbytes, shdr);
+
+	res = __elfN(obj_parse_modmetadata)(fp, ef);
+	if (res != 0)
+		goto out;
+
+	ret = lastaddr - firstaddr;
+	fp->f_addr = firstaddr;
+
+	printf("size 0x%lx at 0x%lx", (u_long)ret, (u_long)firstaddr);
+
+out:
+	printf("\n");
+	return ret;
+}
+
+#if defined(__i386__) && __ELF_WORD_SIZE == 64
+struct mod_metadata64 {
+	int		md_version;	/* structure version MDTV_* */
+	int		md_type;	/* type of entry MDT_* */
+	u_int64_t	md_data;	/* specific data */
+	u_int64_t	md_cval;	/* common string label */
+};
+#endif
+
+int
+__elfN(obj_parse_modmetadata)(struct preloaded_file *fp, elf_file_t ef)
+{
+	struct mod_metadata md;
+#if defined(__i386__) && __ELF_WORD_SIZE == 64
+	struct mod_metadata64 md64;
+#endif
+	struct mod_depend *mdepend;
+	struct mod_version mver;
+	char *s;
+	int error, modcnt, minfolen;
+	Elf_Addr v, p, p_stop;
+
+	if (__elfN(obj_lookup_set)(fp, ef, "modmetadata_set", &p, &p_stop,
+	    &modcnt) != 0)
+		return ENOENT;
+
+	modcnt = 0;
+	while (p < p_stop) {
+		COPYOUT(p, &v, sizeof(v));
+		error = __elfN(obj_reloc_ptr)(fp, ef, p, &v, sizeof(v));
+		if (error != 0)
+			return (error);
+#if defined(__i386__) && __ELF_WORD_SIZE == 64
+		COPYOUT(v, &md64, sizeof(md64));
+		error = __elfN(obj_reloc_ptr)(fp, ef, v, &md64, sizeof(md64));
+		if (error != 0)
+			return (error);
+		md.md_version = md64.md_version;
+		md.md_type = md64.md_type;
+		md.md_cval = (const char *)(uintptr_t)md64.md_cval;
+		md.md_data = (void *)(uintptr_t)md64.md_data;
+#else
+		COPYOUT(v, &md, sizeof(md));
+		error = __elfN(obj_reloc_ptr)(fp, ef, v, &md, sizeof(md));
+		if (error != 0)
+			return (error);
+#endif
+		p += sizeof(Elf_Addr);
+		switch(md.md_type) {
+		case MDT_DEPEND:
+			s = strdupout((vm_offset_t)md.md_cval);
+			minfolen = sizeof(*mdepend) + strlen(s) + 1;
+			mdepend = malloc(minfolen);
+			if (mdepend == NULL)
+				return ENOMEM;
+			COPYOUT((vm_offset_t)md.md_data, mdepend,
+			    sizeof(*mdepend));
+			strcpy((char*)(mdepend + 1), s);
+			free(s);
+			file_addmetadata(fp, MODINFOMD_DEPLIST, minfolen,
+			    mdepend);
+			free(mdepend);
+			break;
+		case MDT_VERSION:
+			s = strdupout((vm_offset_t)md.md_cval);
+			COPYOUT((vm_offset_t)md.md_data, &mver, sizeof(mver));
+			file_addmodule(fp, s, mver.mv_version, NULL);
+			free(s);
+			modcnt++;
+			break;
+		case MDT_MODULE:
+			break;
+		default:
+			printf("unknown type %d\n", md.md_type);
+			break;
+		}
+	}
+	return 0;
+}
+
+static int
+__elfN(obj_lookup_set)(struct preloaded_file *fp, elf_file_t ef,
+    const char* name, Elf_Addr *startp, Elf_Addr *stopp, int *countp)
+{
+	Elf_Ehdr *hdr;
+	Elf_Shdr *shdr;
+	char *p;
+	vm_offset_t shstrtab;
+	int i;
+
+	hdr = &ef->hdr;
+	shdr = ef->e_shdr;
+	shstrtab = shdr[ef->shstrindex].sh_addr;
+
+	for (i = 0; i < hdr->e_shnum; i++) {
+		if (shdr[i].sh_type != SHT_PROGBITS)
+			continue;
+		if (shdr[i].sh_name == 0)
+			continue;
+		p = strdupout(shstrtab + shdr[i].sh_name);
+		if (strncmp(p, "set_", 4) == 0 && strcmp(p + 4, name) == 0) {
+			*startp = shdr[i].sh_addr;
+			*stopp = shdr[i].sh_addr +  shdr[i].sh_size;
+			*countp = (*stopp - *startp) / sizeof(Elf_Addr);
+			free(p);
+			return (0);
+		}
+		free(p);
+	}
+
+	return (ESRCH);
+}
+
+/*
+ * Apply any intra-module relocations to the value. p is the load address
+ * of the value and val/len is the value to be modified. This does NOT modify
+ * the image in-place, because this is done by kern_linker later on.
+ */
+static int
+__elfN(obj_reloc_ptr)(struct preloaded_file *mp, elf_file_t ef, Elf_Addr p,
+    void *val, size_t len)
+{
+	Elf_Ehdr *hdr;
+	Elf_Shdr *shdr;
+	Elf_Addr off = p;
+	Elf_Addr base;
+	Elf_Rela a, *abase;
+	Elf_Rel r, *rbase;
+	int error, i, j, nrel, nrela;
+
+	hdr = &ef->hdr;
+	shdr = ef->e_shdr;
+
+	for (i = 0; i < hdr->e_shnum; i++) {
+		if (shdr[i].sh_type != SHT_RELA && shdr[i].sh_type != SHT_REL)
+			continue;
+		base = shdr[shdr[i].sh_info].sh_addr;
+		if (base == 0 || shdr[i].sh_addr == 0)
+			continue;
+		if (off < base || off + len > base +
+		    shdr[shdr[i].sh_info].sh_size)
+			continue;
+
+		switch (shdr[i].sh_type) {
+		case SHT_RELA:
+			abase = (Elf_Rela *)(intptr_t)shdr[i].sh_addr;
+
+			nrela = shdr[i].sh_size / sizeof(Elf_Rela);
+			for (j = 0; j < nrela; j++) {
+				COPYOUT(abase + j, &a, sizeof(a));
+
+				error = __elfN(reloc)(ef, __elfN(obj_symaddr),
+				    &a, ELF_RELOC_RELA, base, off, val, len);
+				if (error != 0)
+					return (error);
+			}
+			break;
+		case SHT_REL:
+			rbase = (Elf_Rel *)(intptr_t)shdr[i].sh_addr;
+
+			nrel = shdr[i].sh_size / sizeof(Elf_Rel);
+			for (j = 0; j < nrel; j++) {
+				COPYOUT(rbase + j, &r, sizeof(r));
+
+				error = __elfN(reloc)(ef, __elfN(obj_symaddr),
+				    &r, ELF_RELOC_REL, base, off, val, len);
+				if (error != 0)
+					return (error);
+			}
+			break;
+		}
+	}
+	return (0);
+}
+
+/* Look up the address of a specified symbol. */
+static Elf_Addr
+__elfN(obj_symaddr)(struct elf_file *ef, Elf_Word symidx)
+{
+	Elf_Sym sym;
+	Elf_Addr base;
+	int symcnt;
+
+	symcnt = ef->e_shdr[ef->symtabindex].sh_size / sizeof(Elf_Sym);
+	if (symidx >= symcnt)
+		return (0);
+	COPYOUT(ef->e_shdr[ef->symtabindex].sh_addr + symidx * sizeof(Elf_Sym),
+	    &sym, sizeof(sym));
+	if (sym.st_shndx == SHN_UNDEF || sym.st_shndx >= ef->hdr.e_shnum)
+		return (0);
+	base = ef->e_shdr[sym.st_shndx].sh_addr;
+	if (base == 0)
+		return (0);
+	return (base + sym.st_value);
+}