x86_64: prepare shared kernel/module.c

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 185 insertions, 0 deletions

diff --git a/arch/x86_64/kernel/module_64.c b/arch/x86_64/kernel/module_64.c
new file mode 100644
index 000000000000..a888e67f5874
--- /dev/null
+++ b/arch/x86_64/kernel/module_64.c
@@ -0,0 +1,185 @@
+/*  Kernel module help for x86-64
+    Copyright (C) 2001 Rusty Russell.
+    Copyright (C) 2002,2003 Andi Kleen, SuSE Labs.
+
+    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
+*/
+#include <linux/moduleloader.h>
+#include <linux/elf.h>
+#include <linux/vmalloc.h>
+#include <linux/fs.h>
+#include <linux/string.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/bug.h>
+
+#include <asm/system.h>
+#include <asm/page.h>
+#include <asm/pgtable.h>
+
+#define DEBUGP(fmt...) 
+
+#ifndef CONFIG_UML
+void module_free(struct module *mod, void *module_region)
+{
+        vfree(module_region);
+        /* FIXME: If module_region == mod->init_region, trim exception
+           table entries. */
+}
+
+void *module_alloc(unsigned long size)
+{
+        struct vm_struct *area;
+
+        if (!size)
+                return NULL;
+        size = PAGE_ALIGN(size);
+        if (size > MODULES_LEN)
+                return NULL;
+
+        area = __get_vm_area(size, VM_ALLOC, MODULES_VADDR, MODULES_END);
+        if (!area)
+                return NULL;
+
+        return __vmalloc_area(area, GFP_KERNEL, PAGE_KERNEL_EXEC);
+}
+#endif
+
+/* We don't need anything special. */
+int module_frob_arch_sections(Elf_Ehdr *hdr,
+                              Elf_Shdr *sechdrs,
+                              char *secstrings,
+                              struct module *mod)
+{
+        return 0;
+}
+
+int apply_relocate_add(Elf64_Shdr *sechdrs,
+                   const char *strtab,
+                   unsigned int symindex,
+                   unsigned int relsec,
+                   struct module *me)
+{
+        unsigned int i;
+        Elf64_Rela *rel = (void *)sechdrs[relsec].sh_addr;
+        Elf64_Sym *sym;
+        void *loc;
+        u64 val; 
+
+        DEBUGP("Applying relocate section %u to %u\n", relsec,
+               sechdrs[relsec].sh_info);
+        for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
+                /* This is where to make the change */
+                loc = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
+                        + rel[i].r_offset;
+
+                /* This is the symbol it is referring to.  Note that all
+                   undefined symbols have been resolved.  */
+                sym = (Elf64_Sym *)sechdrs[symindex].sh_addr
+                        + ELF64_R_SYM(rel[i].r_info);
+
+                DEBUGP("type %d st_value %Lx r_addend %Lx loc %Lx\n",
+                       (int)ELF64_R_TYPE(rel[i].r_info), 
+                       sym->st_value, rel[i].r_addend, (u64)loc);
+
+                val = sym->st_value + rel[i].r_addend; 
+
+                switch (ELF64_R_TYPE(rel[i].r_info)) {
+                case R_X86_64_NONE:
+                        break;
+                case R_X86_64_64:
+                        *(u64 *)loc = val;
+                        break;
+                case R_X86_64_32:
+                        *(u32 *)loc = val;
+                        if (val != *(u32 *)loc)
+                                goto overflow;
+                        break;
+                case R_X86_64_32S:
+                        *(s32 *)loc = val;
+                        if ((s64)val != *(s32 *)loc)
+                                goto overflow;
+                        break;
+                case R_X86_64_PC32: 
+                        val -= (u64)loc;
+                        *(u32 *)loc = val;
+#if 0
+                        if ((s64)val != *(s32 *)loc)
+                                goto overflow; 
+#endif
+                        break;
+                default:
+                        printk(KERN_ERR "module %s: Unknown rela relocation: %Lu\n",
+                               me->name, ELF64_R_TYPE(rel[i].r_info));
+                        return -ENOEXEC;
+                }
+        }
+        return 0;
+
+overflow:
+        printk(KERN_ERR "overflow in relocation type %d val %Lx\n", 
+               (int)ELF64_R_TYPE(rel[i].r_info), val);
+        printk(KERN_ERR "`%s' likely not compiled with -mcmodel=kernel\n",
+               me->name);
+        return -ENOEXEC;
+}
+
+int apply_relocate(Elf_Shdr *sechdrs,
+                   const char *strtab,
+                   unsigned int symindex,
+                   unsigned int relsec,
+                   struct module *me)
+{
+        printk("non add relocation not supported\n");
+        return -ENOSYS;
+} 
+
+int module_finalize(const Elf_Ehdr *hdr,
+                    const Elf_Shdr *sechdrs,
+                    struct module *me)
+{
+        const Elf_Shdr *s, *text = NULL, *alt = NULL, *locks = NULL;
+        char *secstrings = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
+
+        for (s = sechdrs; s < sechdrs + hdr->e_shnum; s++) {
+                if (!strcmp(".text", secstrings + s->sh_name))
+                        text = s;
+                if (!strcmp(".altinstructions", secstrings + s->sh_name))
+                        alt = s;
+                if (!strcmp(".smp_locks", secstrings + s->sh_name))
+                        locks= s;
+        }
+
+        if (alt) {
+                /* patch .altinstructions */
+                void *aseg = (void *)alt->sh_addr;
+                apply_alternatives(aseg, aseg + alt->sh_size);
+        }
+        if (locks && text) {
+                void *lseg = (void *)locks->sh_addr;
+                void *tseg = (void *)text->sh_addr;
+                alternatives_smp_module_add(me, me->name,
+                                            lseg, lseg + locks->sh_size,
+                                            tseg, tseg + text->sh_size);
+        }
+
+        return module_bug_finalize(hdr, sechdrs, me);
+}
+
+void module_arch_cleanup(struct module *mod)
+{
+        alternatives_smp_module_del(mod);
+        module_bug_cleanup(mod);
+}