Initial import

1 files changed, 298 insertions, 0 deletions

diff --git a/arch/mips/kernel/module.c b/arch/mips/kernel/module.c
new file mode 100644
index 000000000..1833f5171
--- /dev/null
+++ b/arch/mips/kernel/module.c
@@ -0,0 +1,298 @@
+/*
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ *  Copyright (C) 2001 Rusty Russell.
+ *  Copyright (C) 2003, 2004 Ralf Baechle (ralf@linux-mips.org)
+ *  Copyright (C) 2005 Thiemo Seufer
+ */
+
+#undef DEBUG
+
+#include <linux/moduleloader.h>
+#include <linux/elf.h>
+#include <linux/mm.h>
+#include <linux/numa.h>
+#include <linux/vmalloc.h>
+#include <linux/slab.h>
+#include <linux/fs.h>
+#include <linux/string.h>
+#include <linux/kernel.h>
+#include <linux/spinlock.h>
+#include <linux/jump_label.h>
+
+#include <asm/pgtable.h>	/* MODULE_START */
+
+struct mips_hi16 {
+	struct mips_hi16 *next;
+	Elf_Addr *addr;
+	Elf_Addr value;
+};
+
+static LIST_HEAD(dbe_list);
+static DEFINE_SPINLOCK(dbe_lock);
+
+#ifdef MODULE_START
+void *module_alloc(unsigned long size)
+{
+	return __vmalloc_node_range(size, 1, MODULE_START, MODULE_END,
+				GFP_KERNEL, PAGE_KERNEL, 0, NUMA_NO_NODE,
+				__builtin_return_address(0));
+}
+#endif
+
+int apply_r_mips_none(struct module *me, u32 *location, Elf_Addr v)
+{
+	return 0;
+}
+
+static int apply_r_mips_32_rel(struct module *me, u32 *location, Elf_Addr v)
+{
+	*location += v;
+
+	return 0;
+}
+
+static int apply_r_mips_26_rel(struct module *me, u32 *location, Elf_Addr v)
+{
+	if (v % 4) {
+		pr_err("module %s: dangerous R_MIPS_26 REL relocation\n",
+		       me->name);
+		return -ENOEXEC;
+	}
+
+	if ((v & 0xf0000000) != (((unsigned long)location + 4) & 0xf0000000)) {
+		printk(KERN_ERR
+		       "module %s: relocation overflow\n",
+		       me->name);
+		return -ENOEXEC;
+	}
+
+	*location = (*location & ~0x03ffffff) |
+		    ((*location + (v >> 2)) & 0x03ffffff);
+
+	return 0;
+}
+
+static int apply_r_mips_hi16_rel(struct module *me, u32 *location, Elf_Addr v)
+{
+	struct mips_hi16 *n;
+
+	/*
+	 * We cannot relocate this one now because we don't know the value of
+	 * the carry we need to add.  Save the information, and let LO16 do the
+	 * actual relocation.
+	 */
+	n = kmalloc(sizeof *n, GFP_KERNEL);
+	if (!n)
+		return -ENOMEM;
+
+	n->addr = (Elf_Addr *)location;
+	n->value = v;
+	n->next = me->arch.r_mips_hi16_list;
+	me->arch.r_mips_hi16_list = n;
+
+	return 0;
+}
+
+static void free_relocation_chain(struct mips_hi16 *l)
+{
+	struct mips_hi16 *next;
+
+	while (l) {
+		next = l->next;
+		kfree(l);
+		l = next;
+	}
+}
+
+static int apply_r_mips_lo16_rel(struct module *me, u32 *location, Elf_Addr v)
+{
+	unsigned long insnlo = *location;
+	struct mips_hi16 *l;
+	Elf_Addr val, vallo;
+
+	/* Sign extend the addend we extract from the lo insn.	*/
+	vallo = ((insnlo & 0xffff) ^ 0x8000) - 0x8000;
+
+	if (me->arch.r_mips_hi16_list != NULL) {
+		l = me->arch.r_mips_hi16_list;
+		while (l != NULL) {
+			struct mips_hi16 *next;
+			unsigned long insn;
+
+			/*
+			 * The value for the HI16 had best be the same.
+			 */
+			if (v != l->value)
+				goto out_danger;
+
+			/*
+			 * Do the HI16 relocation.  Note that we actually don't
+			 * need to know anything about the LO16 itself, except
+			 * where to find the low 16 bits of the addend needed
+			 * by the LO16.
+			 */
+			insn = *l->addr;
+			val = ((insn & 0xffff) << 16) + vallo;
+			val += v;
+
+			/*
+			 * Account for the sign extension that will happen in
+			 * the low bits.
+			 */
+			val = ((val >> 16) + ((val & 0x8000) != 0)) & 0xffff;
+
+			insn = (insn & ~0xffff) | val;
+			*l->addr = insn;
+
+			next = l->next;
+			kfree(l);
+			l = next;
+		}
+
+		me->arch.r_mips_hi16_list = NULL;
+	}
+
+	/*
+	 * Ok, we're done with the HI16 relocs.	 Now deal with the LO16.
+	 */
+	val = v + vallo;
+	insnlo = (insnlo & ~0xffff) | (val & 0xffff);
+	*location = insnlo;
+
+	return 0;
+
+out_danger:
+	free_relocation_chain(l);
+	me->arch.r_mips_hi16_list = NULL;
+
+	pr_err("module %s: dangerous R_MIPS_LO16 REL relocation\n", me->name);
+
+	return -ENOEXEC;
+}
+
+static int (*reloc_handlers_rel[]) (struct module *me, u32 *location,
+				Elf_Addr v) = {
+	[R_MIPS_NONE]		= apply_r_mips_none,
+	[R_MIPS_32]		= apply_r_mips_32_rel,
+	[R_MIPS_26]		= apply_r_mips_26_rel,
+	[R_MIPS_HI16]		= apply_r_mips_hi16_rel,
+	[R_MIPS_LO16]		= apply_r_mips_lo16_rel
+};
+
+int apply_relocate(Elf_Shdr *sechdrs, const char *strtab,
+		   unsigned int symindex, unsigned int relsec,
+		   struct module *me)
+{
+	Elf_Mips_Rel *rel = (void *) sechdrs[relsec].sh_addr;
+	Elf_Sym *sym;
+	u32 *location;
+	unsigned int i;
+	Elf_Addr v;
+	int res;
+
+	pr_debug("Applying relocate section %u to %u\n", relsec,
+	       sechdrs[relsec].sh_info);
+
+	me->arch.r_mips_hi16_list = NULL;
+	for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
+		/* This is where to make the change */
+		location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
+			+ rel[i].r_offset;
+		/* This is the symbol it is referring to */
+		sym = (Elf_Sym *)sechdrs[symindex].sh_addr
+			+ ELF_MIPS_R_SYM(rel[i]);
+		if (IS_ERR_VALUE(sym->st_value)) {
+			/* Ignore unresolved weak symbol */
+			if (ELF_ST_BIND(sym->st_info) == STB_WEAK)
+				continue;
+			printk(KERN_WARNING "%s: Unknown symbol %s\n",
+			       me->name, strtab + sym->st_name);
+			return -ENOENT;
+		}
+
+		v = sym->st_value;
+
+		res = reloc_handlers_rel[ELF_MIPS_R_TYPE(rel[i])](me, location, v);
+		if (res)
+			return res;
+	}
+
+	/*
+	 * Normally the hi16 list should be deallocated at this point.	A
+	 * malformed binary however could contain a series of R_MIPS_HI16
+	 * relocations not followed by a R_MIPS_LO16 relocation.  In that
+	 * case, free up the list and return an error.
+	 */
+	if (me->arch.r_mips_hi16_list) {
+		free_relocation_chain(me->arch.r_mips_hi16_list);
+		me->arch.r_mips_hi16_list = NULL;
+
+		return -ENOEXEC;
+	}
+
+	return 0;
+}
+
+/* Given an address, look for it in the module exception tables. */
+const struct exception_table_entry *search_module_dbetables(unsigned long addr)
+{
+	unsigned long flags;
+	const struct exception_table_entry *e = NULL;
+	struct mod_arch_specific *dbe;
+
+	spin_lock_irqsave(&dbe_lock, flags);
+	list_for_each_entry(dbe, &dbe_list, dbe_list) {
+		e = search_extable(dbe->dbe_start, dbe->dbe_end - 1, addr);
+		if (e)
+			break;
+	}
+	spin_unlock_irqrestore(&dbe_lock, flags);
+
+	/* Now, if we found one, we are running inside it now, hence
+	   we cannot unload the module, hence no refcnt needed. */
+	return e;
+}
+
+/* Put in dbe list if necessary. */
+int module_finalize(const Elf_Ehdr *hdr,
+		    const Elf_Shdr *sechdrs,
+		    struct module *me)
+{
+	const Elf_Shdr *s;
+	char *secstrings = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
+
+	/* Make jump label nops. */
+	jump_label_apply_nops(me);
+
+	INIT_LIST_HEAD(&me->arch.dbe_list);
+	for (s = sechdrs; s < sechdrs + hdr->e_shnum; s++) {
+		if (strcmp("__dbe_table", secstrings + s->sh_name) != 0)
+			continue;
+		me->arch.dbe_start = (void *)s->sh_addr;
+		me->arch.dbe_end = (void *)s->sh_addr + s->sh_size;
+		spin_lock_irq(&dbe_lock);
+		list_add(&me->arch.dbe_list, &dbe_list);
+		spin_unlock_irq(&dbe_lock);
+	}
+	return 0;
+}
+
+void module_arch_cleanup(struct module *mod)
+{
+	spin_lock_irq(&dbe_lock);
+	list_del(&mod->arch.dbe_list);
+	spin_unlock_irq(&dbe_lock);
+}