#include <linux/gfp.h>
#include <linux/string.h>
#include <linux/elf.h>
+#include <linux/mm.h>
#include <linux/mman.h>
+#include <asm/a.out.h>
#include <asm/cpufeature.h>
#include <asm/msr.h>
#include <asm/pgtable.h>
#include <asm/unistd.h>
+#ifdef CONFIG_XEN
+#include <xen/interface/callback.h>
+#endif
+
extern asmlinkage void sysenter_entry(void);
-void enable_sep_cpu(void *info)
+void enable_sep_cpu(void)
{
+#ifndef CONFIG_X86_NO_TSS
int cpu = get_cpu();
struct tss_struct *tss = &per_cpu(init_tss, cpu);
+ if (!boot_cpu_has(X86_FEATURE_SEP)) {
+ put_cpu();
+ return;
+ }
+
tss->ss1 = __KERNEL_CS;
tss->esp1 = sizeof(struct tss_struct) + (unsigned long) tss;
wrmsr(MSR_IA32_SYSENTER_CS, __KERNEL_CS, 0);
wrmsr(MSR_IA32_SYSENTER_ESP, tss->esp1, 0);
wrmsr(MSR_IA32_SYSENTER_EIP, (unsigned long) sysenter_entry, 0);
put_cpu();
+#endif
}
/*
*/
extern const char vsyscall_int80_start, vsyscall_int80_end;
extern const char vsyscall_sysenter_start, vsyscall_sysenter_end;
+static struct page *sysenter_pages[2];
-struct page *sysenter_page;
-
-static int __init sysenter_setup(void)
+int __init sysenter_setup(void)
{
void *page = (void *)get_zeroed_page(GFP_ATOMIC);
- __set_fixmap(FIX_VSYSCALL, __pa(page), PAGE_KERNEL_RO);
- sysenter_page = virt_to_page(page);
+ sysenter_pages[0] = virt_to_page(page);
- if (!boot_cpu_has(X86_FEATURE_SEP)) {
+#ifdef CONFIG_XEN
+ if (boot_cpu_has(X86_FEATURE_SEP)) {
+ struct callback_register sysenter = {
+ .type = CALLBACKTYPE_sysenter,
+ .address = { __KERNEL_CS, (unsigned long)sysenter_entry },
+ };
+
+ if (HYPERVISOR_callback_op(CALLBACKOP_register, &sysenter) < 0)
+ clear_bit(X86_FEATURE_SEP, boot_cpu_data.x86_capability);
+ }
+#endif
+
+ if (boot_cpu_has(X86_FEATURE_SEP)) {
memcpy(page,
- &vsyscall_int80_start,
- &vsyscall_int80_end - &vsyscall_int80_start);
+ &vsyscall_sysenter_start,
+ &vsyscall_sysenter_end - &vsyscall_sysenter_start);
return 0;
}
memcpy(page,
- &vsyscall_sysenter_start,
- &vsyscall_sysenter_end - &vsyscall_sysenter_start);
-
- on_each_cpu(enable_sep_cpu, NULL, 1, 1);
+ &vsyscall_int80_start,
+ &vsyscall_int80_end - &vsyscall_int80_start);
return 0;
}
-__initcall(sysenter_setup);
-
extern void SYSENTER_RETURN_OFFSET;
-unsigned int vdso_enabled = 0;
+unsigned int vdso_enabled = 1;
-void map_vsyscall(void)
+/*
+ * This is called from binfmt_elf, we create the special vma for the
+ * vDSO and insert it into the mm struct tree.
+ */
+int arch_setup_additional_pages(struct linux_binprm *bprm,
+ int executable_stack, unsigned long start_code,
+ unsigned long interp_map_address)
{
struct thread_info *ti = current_thread_info();
- struct vm_area_struct *vma;
- unsigned long addr;
+ unsigned long addr = 0, len;
+ unsigned flags = MAP_PRIVATE;
+ int err;
- if (unlikely(!vdso_enabled)) {
- current->mm->context.vdso = NULL;
- return;
- }
+ current->mm->context.vdso = NULL;
+ if (unlikely(!vdso_enabled) || unlikely(!sysenter_pages[0]))
+ return 0;
/*
* Map the vDSO (it will be randomized):
*/
down_write(¤t->mm->mmap_sem);
- addr = do_mmap(NULL, 0, 4096, PROT_READ | PROT_EXEC, MAP_PRIVATE, 0);
- current->mm->context.vdso = (void *)addr;
- ti->sysenter_return = (void *)addr + (long)&SYSENTER_RETURN_OFFSET;
- if (addr != -1) {
- vma = find_vma(current->mm, addr);
- if (vma) {
- pgprot_val(vma->vm_page_prot) &= ~_PAGE_RW;
- get_page(sysenter_page);
- install_page(current->mm, vma, addr,
- sysenter_page, vma->vm_page_prot);
-
+ len = PAGE_SIZE > ELF_EXEC_PAGESIZE ? PAGE_SIZE : ELF_EXEC_PAGESIZE;
+ if (0==exec_shield) { /* off; %cs limit off */
+ addr = STACK_TOP; /* minimal interference with anybody */
+ flags = MAP_PRIVATE | MAP_FIXED;
+ }
+ else if ((3<<2) & exec_shield) { /* vdso just below .text */
+ addr = (((2<<2) & exec_shield) && interp_map_address) ?
+ interp_map_address : start_code;
+ /* 1MB for vm86; 64K for vm86 himem */
+ if ((0x110000 + len) <= addr) {
+ addr = (PAGE_MASK & addr) - len;
}
+ else { /* start_code is too low */
+ addr = 0;
+ }
+ }
+ addr = get_unmapped_area_prot(NULL, addr, len, 0,
+ flags, PROT_READ | PROT_EXEC);
+ if (unlikely(addr & ~PAGE_MASK)) {
+ up_write(¤t->mm->mmap_sem);
+ return addr;
+ }
+ err = install_special_mapping(current->mm, addr, len,
+ VM_DONTEXPAND | VM_READ | VM_EXEC |
+ VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC,
+ PAGE_READONLY_EXEC,
+ sysenter_pages);
+ if (likely(err == 0)) {
+ current->mm->context.vdso = (void *)addr;
+ ti->sysenter_return = &SYSENTER_RETURN_OFFSET + addr;
}
up_write(¤t->mm->mmap_sem);
+ return err;
}
-static int __init vdso_setup(char *str)
+#ifndef CONFIG_XEN
+int in_gate_area_no_task(unsigned long addr)
{
- vdso_enabled = simple_strtoul(str, NULL, 0);
- return 1;
+ return 0;
}
-__setup("vdso=", vdso_setup);
+int in_gate_area(struct task_struct *task, unsigned long addr)
+{
+ return 0;
+}
+
+struct vm_area_struct *get_gate_vma(struct task_struct *tsk)
+{
+ return NULL;
+}
+#endif
git://git.onelab.eu / linux-2.6.git / blobdiff