diff options
Diffstat (limited to 'arch/i386/kernel/sysenter_32.c')
| -rw-r--r-- | arch/i386/kernel/sysenter_32.c | 348 |
1 files changed, 0 insertions, 348 deletions
diff --git a/arch/i386/kernel/sysenter_32.c b/arch/i386/kernel/sysenter_32.c deleted file mode 100644 index 4eb2e408764f..000000000000 --- a/arch/i386/kernel/sysenter_32.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; -} |