i386: prepare shared kernel/sysenter.c

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

1 files changed, 0 insertions, 348 deletions

diff --git a/arch/i386/kernel/sysenter.c b/arch/i386/kernel/sysenter.c
deleted file mode 100644
index 4eb2e40..0000000
--- a/arch/i386/kernel/sysenter.c
+++ /dev/null
@@ -1,348 +0,0 @@
-/*
- * linux/arch/i386/kernel/sysenter.c
- *
- * (C) Copyright 2002 Linus Torvalds
- * Portions based on the vdso-randomization code from exec-shield:
- * Copyright(C) 2005-2006, Red Hat, Inc., Ingo Molnar
- *
- * This file contains the needed initializations to support sysenter.
- */
-
-#include <linux/init.h>
-#include <linux/smp.h>
-#include <linux/thread_info.h>
-#include <linux/sched.h>
-#include <linux/gfp.h>
-#include <linux/string.h>
-#include <linux/elf.h>
-#include <linux/mm.h>
-#include <linux/err.h>
-#include <linux/module.h>
-
-#include <asm/cpufeature.h>
-#include <asm/msr.h>
-#include <asm/pgtable.h>
-#include <asm/unistd.h>
-#include <asm/elf.h>
-#include <asm/tlbflush.h>
-
-enum {
-	VDSO_DISABLED = 0,
-	VDSO_ENABLED = 1,
-	VDSO_COMPAT = 2,
-};
-
-#ifdef CONFIG_COMPAT_VDSO
-#define VDSO_DEFAULT	VDSO_COMPAT
-#else
-#define VDSO_DEFAULT	VDSO_ENABLED
-#endif
-
-/*
- * Should the kernel map a VDSO page into processes and pass its
- * address down to glibc upon exec()?
- */
-unsigned int __read_mostly vdso_enabled = VDSO_DEFAULT;
-
-EXPORT_SYMBOL_GPL(vdso_enabled);
-
-static int __init vdso_setup(char *s)
-{
-	vdso_enabled = simple_strtoul(s, NULL, 0);
-
-	return 1;
-}
-
-__setup("vdso=", vdso_setup);
-
-extern asmlinkage void sysenter_entry(void);
-
-static __init void reloc_symtab(Elf32_Ehdr *ehdr,
-				unsigned offset, unsigned size)
-{
-	Elf32_Sym *sym = (void *)ehdr + offset;
-	unsigned nsym = size / sizeof(*sym);
-	unsigned i;
-
-	for(i = 0; i < nsym; i++, sym++) {
-		if (sym->st_shndx == SHN_UNDEF ||
-		    sym->st_shndx == SHN_ABS)
-			continue;  /* skip */
-
-		if (sym->st_shndx > SHN_LORESERVE) {
-			printk(KERN_INFO "VDSO: unexpected st_shndx %x\n",
-			       sym->st_shndx);
-			continue;
-		}
-
-		switch(ELF_ST_TYPE(sym->st_info)) {
-		case STT_OBJECT:
-		case STT_FUNC:
-		case STT_SECTION:
-		case STT_FILE:
-			sym->st_value += VDSO_HIGH_BASE;
-		}
-	}
-}
-
-static __init void reloc_dyn(Elf32_Ehdr *ehdr, unsigned offset)
-{
-	Elf32_Dyn *dyn = (void *)ehdr + offset;
-
-	for(; dyn->d_tag != DT_NULL; dyn++)
-		switch(dyn->d_tag) {
-		case DT_PLTGOT:
-		case DT_HASH:
-		case DT_STRTAB:
-		case DT_SYMTAB:
-		case DT_RELA:
-		case DT_INIT:
-		case DT_FINI:
-		case DT_REL:
-		case DT_DEBUG:
-		case DT_JMPREL:
-		case DT_VERSYM:
-		case DT_VERDEF:
-		case DT_VERNEED:
-		case DT_ADDRRNGLO ... DT_ADDRRNGHI:
-			/* definitely pointers needing relocation */
-			dyn->d_un.d_ptr += VDSO_HIGH_BASE;
-			break;
-
-		case DT_ENCODING ... OLD_DT_LOOS-1:
-		case DT_LOOS ... DT_HIOS-1:
-			/* Tags above DT_ENCODING are pointers if
-			   they're even */
-			if (dyn->d_tag >= DT_ENCODING &&
-			    (dyn->d_tag & 1) == 0)
-				dyn->d_un.d_ptr += VDSO_HIGH_BASE;
-			break;
-
-		case DT_VERDEFNUM:
-		case DT_VERNEEDNUM:
-		case DT_FLAGS_1:
-		case DT_RELACOUNT:
-		case DT_RELCOUNT:
-		case DT_VALRNGLO ... DT_VALRNGHI:
-			/* definitely not pointers */
-			break;
-
-		case OLD_DT_LOOS ... DT_LOOS-1:
-		case DT_HIOS ... DT_VALRNGLO-1:
-		default:
-			if (dyn->d_tag > DT_ENCODING)
-				printk(KERN_INFO "VDSO: unexpected DT_tag %x\n",
-				       dyn->d_tag);
-			break;
-		}
-}
-
-static __init void relocate_vdso(Elf32_Ehdr *ehdr)
-{
-	Elf32_Phdr *phdr;
-	Elf32_Shdr *shdr;
-	int i;
-
-	BUG_ON(memcmp(ehdr->e_ident, ELFMAG, 4) != 0 ||
-	       !elf_check_arch(ehdr) ||
-	       ehdr->e_type != ET_DYN);
-
-	ehdr->e_entry += VDSO_HIGH_BASE;
-
-	/* rebase phdrs */
-	phdr = (void *)ehdr + ehdr->e_phoff;
-	for (i = 0; i < ehdr->e_phnum; i++) {
-		phdr[i].p_vaddr += VDSO_HIGH_BASE;
-
-		/* relocate dynamic stuff */
-		if (phdr[i].p_type == PT_DYNAMIC)
-			reloc_dyn(ehdr, phdr[i].p_offset);
-	}
-
-	/* rebase sections */
-	shdr = (void *)ehdr + ehdr->e_shoff;
-	for(i = 0; i < ehdr->e_shnum; i++) {
-		if (!(shdr[i].sh_flags & SHF_ALLOC))
-			continue;
-
-		shdr[i].sh_addr += VDSO_HIGH_BASE;
-
-		if (shdr[i].sh_type == SHT_SYMTAB ||
-		    shdr[i].sh_type == SHT_DYNSYM)
-			reloc_symtab(ehdr, shdr[i].sh_offset,
-				     shdr[i].sh_size);
-	}
-}
-
-void enable_sep_cpu(void)
-{
-	int cpu = get_cpu();
-	struct tss_struct *tss = &per_cpu(init_tss, cpu);
-
-	if (!boot_cpu_has(X86_FEATURE_SEP)) {
-		put_cpu();
-		return;
-	}
-
-	tss->x86_tss.ss1 = __KERNEL_CS;
-	tss->x86_tss.esp1 = sizeof(struct tss_struct) + (unsigned long) tss;
-	wrmsr(MSR_IA32_SYSENTER_CS, __KERNEL_CS, 0);
-	wrmsr(MSR_IA32_SYSENTER_ESP, tss->x86_tss.esp1, 0);
-	wrmsr(MSR_IA32_SYSENTER_EIP, (unsigned long) sysenter_entry, 0);
-	put_cpu();	
-}
-
-static struct vm_area_struct gate_vma;
-
-static int __init gate_vma_init(void)
-{
-	gate_vma.vm_mm = NULL;
-	gate_vma.vm_start = FIXADDR_USER_START;
-	gate_vma.vm_end = FIXADDR_USER_END;
-	gate_vma.vm_flags = VM_READ | VM_MAYREAD | VM_EXEC | VM_MAYEXEC;
-	gate_vma.vm_page_prot = __P101;
-	/*
-	 * Make sure the vDSO gets into every core dump.
-	 * Dumping its contents makes post-mortem fully interpretable later
-	 * without matching up the same kernel and hardware config to see
-	 * what PC values meant.
-	 */
-	gate_vma.vm_flags |= VM_ALWAYSDUMP;
-	return 0;
-}
-
-/*
- * These symbols are defined by vsyscall.o to mark the bounds
- * of the ELF DSO images included therein.
- */
-extern const char vsyscall_int80_start, vsyscall_int80_end;
-extern const char vsyscall_sysenter_start, vsyscall_sysenter_end;
-static struct page *syscall_pages[1];
-
-static void map_compat_vdso(int map)
-{
-	static int vdso_mapped;
-
-	if (map == vdso_mapped)
-		return;
-
-	vdso_mapped = map;
-
-	__set_fixmap(FIX_VDSO, page_to_pfn(syscall_pages[0]) << PAGE_SHIFT,
-		     map ? PAGE_READONLY_EXEC : PAGE_NONE);
-
-	/* flush stray tlbs */
-	flush_tlb_all();
-}
-
-int __init sysenter_setup(void)
-{
-	void *syscall_page = (void *)get_zeroed_page(GFP_ATOMIC);
-	const void *vsyscall;
-	size_t vsyscall_len;
-
-	syscall_pages[0] = virt_to_page(syscall_page);
-
-	gate_vma_init();
-
-	printk("Compat vDSO mapped to %08lx.\n", __fix_to_virt(FIX_VDSO));
-
-	if (!boot_cpu_has(X86_FEATURE_SEP)) {
-		vsyscall = &vsyscall_int80_start;
-		vsyscall_len = &vsyscall_int80_end - &vsyscall_int80_start;
-	} else {
-		vsyscall = &vsyscall_sysenter_start;
-		vsyscall_len = &vsyscall_sysenter_end - &vsyscall_sysenter_start;
-	}
-
-	memcpy(syscall_page, vsyscall, vsyscall_len);
-	relocate_vdso(syscall_page);
-
-	return 0;
-}
-
-/* Defined in vsyscall-sysenter.S */
-extern void SYSENTER_RETURN;
-
-/* Setup a VMA at program startup for the vsyscall page */
-int arch_setup_additional_pages(struct linux_binprm *bprm, int exstack)
-{
-	struct mm_struct *mm = current->mm;
-	unsigned long addr;
-	int ret = 0;
-	bool compat;
-
-	down_write(&mm->mmap_sem);
-
-	/* Test compat mode once here, in case someone
-	   changes it via sysctl */
-	compat = (vdso_enabled == VDSO_COMPAT);
-
-	map_compat_vdso(compat);
-
-	if (compat)
-		addr = VDSO_HIGH_BASE;
-	else {
-		addr = get_unmapped_area(NULL, 0, PAGE_SIZE, 0, 0);
-		if (IS_ERR_VALUE(addr)) {
-			ret = addr;
-			goto up_fail;
-		}
-
-		/*
-		 * MAYWRITE to allow gdb to COW and set breakpoints
-		 *
-		 * Make sure the vDSO gets into every core dump.
-		 * Dumping its contents makes post-mortem fully
-		 * interpretable later without matching up the same
-		 * kernel and hardware config to see what PC values
-		 * meant.
-		 */
-		ret = install_special_mapping(mm, addr, PAGE_SIZE,
-					      VM_READ|VM_EXEC|
-					      VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC|
-					      VM_ALWAYSDUMP,
-					      syscall_pages);
-
-		if (ret)
-			goto up_fail;
-	}
-
-	current->mm->context.vdso = (void *)addr;
-	current_thread_info()->sysenter_return =
-		(void *)VDSO_SYM(&SYSENTER_RETURN);
-
-  up_fail:
-	up_write(&mm->mmap_sem);
-
-	return ret;
-}
-
-const char *arch_vma_name(struct vm_area_struct *vma)
-{
-	if (vma->vm_mm && vma->vm_start == (long)vma->vm_mm->context.vdso)
-		return "[vdso]";
-	return NULL;
-}
-
-struct vm_area_struct *get_gate_vma(struct task_struct *tsk)
-{
-	struct mm_struct *mm = tsk->mm;
-
-	/* Check to see if this task was created in compat vdso mode */
-	if (mm && mm->context.vdso == (void *)VDSO_HIGH_BASE)
-		return &gate_vma;
-	return NULL;
-}
-
-int in_gate_area(struct task_struct *task, unsigned long addr)
-{
-	const struct vm_area_struct *vma = get_gate_vma(task);
-
-	return vma && addr >= vma->vm_start && addr < vma->vm_end;
-}
-
-int in_gate_area_no_task(unsigned long addr)
-{
-	return 0;
-}