/* Setup a VMA at program startup for the vsyscall page */
int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
{
struct mm_struct *mm = current->mm;
unsigned long addr;
int ret = 0;
bool compat;
#ifdef CONFIG_X86_X32_ABI
if (test_thread_flag(TIF_X32))
return x32_setup_additional_pages(bprm, uses_interp);
#endif
if (vdso_enabled == VDSO_DISABLED)
return 0;
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;
}
}
current->mm->context.vdso = (void *)addr;
if (compat_uses_vma || !compat) {
/*
* MAYWRITE to allow gdb to COW and set breakpoints
*/
ret = install_special_mapping(mm, addr, PAGE_SIZE,
VM_READ|VM_EXEC|
VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC,
vdso32_pages);
if (ret)
goto up_fail;
}
current_thread_info()->sysenter_return =
VDSO32_SYMBOL(addr, SYSENTER_RETURN);
up_fail:
if (ret)
current->mm->context.vdso = NULL;
up_write(&mm->mmap_sem);
return ret;
}
/* Setup a VMA at program startup for the vsyscall page */
int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
{
struct mm_struct *mm = current->mm;
unsigned long addr;
int ret = 0;
struct vm_area_struct *vma;
static struct page *no_pages[] = {NULL};
#ifdef CONFIG_X86_X32_ABI
if (test_thread_flag(TIF_X32))
return x32_setup_additional_pages(bprm, uses_interp);
#endif
if (vdso_enabled != 1) /* Other values all mean "disabled" */
return 0;
down_write(&mm->mmap_sem);
addr = get_unmapped_area(NULL, 0, vdso32_size + VDSO_OFFSET(VDSO_PREV_PAGES), 0, 0);
if (IS_ERR_VALUE(addr)) {
ret = addr;
goto up_fail;
}
addr += VDSO_OFFSET(VDSO_PREV_PAGES);
current->mm->context.vdso = (void *)addr;
/*
* MAYWRITE to allow gdb to COW and set breakpoints
*/
ret = install_special_mapping(mm,
addr,
vdso32_size,
VM_READ|VM_EXEC|
VM_MAYREAD|VM_MAYWRITE|VM_MAYEXEC,
vdso32_pages);
if (ret)
goto up_fail;
vma = _install_special_mapping(mm,
addr - VDSO_OFFSET(VDSO_PREV_PAGES),
VDSO_OFFSET(VDSO_PREV_PAGES),
VM_READ,
no_pages);
if (IS_ERR(vma)) {
ret = PTR_ERR(vma);
goto up_fail;
}
ret = remap_pfn_range(vma,
addr - VDSO_OFFSET(VDSO_VVAR_PAGE),
__pa_symbol(&__vvar_page) >> PAGE_SHIFT,
PAGE_SIZE,
PAGE_READONLY);
if (ret)
goto up_fail;
#ifdef CONFIG_HPET_TIMER
if (hpet_address) {
ret = io_remap_pfn_range(vma,
addr - VDSO_OFFSET(VDSO_HPET_PAGE),
hpet_address >> PAGE_SHIFT,
PAGE_SIZE,
pgprot_noncached(PAGE_READONLY));
if (ret)
goto up_fail;
}
#endif
current_thread_info()->sysenter_return =
VDSO32_SYMBOL(addr, SYSENTER_RETURN);
up_fail:
if (ret)
current->mm->context.vdso = NULL;
up_write(&mm->mmap_sem);
return ret;
}