mirror of
https://github.com/torvalds/linux.git
synced 2024-11-17 09:31:50 +00:00
645a387ecb
The size of the reserved memory for a 32 bit vdso must be the size of the 32 bit vDSO in pages + HPET page + VVAR page. One page is not enough for this. Grrrr.... silly copy and paste bug, was right in previous patch. Signed-off-by: Stefani Seibold <stefani@seibold.net> Cc: Andy Lutomirski <luto@amacapital.net> Link: http://lkml.kernel.org/r/1395592694-20571-1-git-send-email-stefani@seibold.net Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
297 lines
6.2 KiB
C
297 lines
6.2 KiB
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 <linux/slab.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>
|
|
#include <asm/vdso.h>
|
|
#include <asm/proto.h>
|
|
#include <asm/fixmap.h>
|
|
#include <asm/hpet.h>
|
|
#include <asm/vvar.h>
|
|
|
|
#ifdef CONFIG_COMPAT_VDSO
|
|
#define VDSO_DEFAULT 0
|
|
#else
|
|
#define VDSO_DEFAULT 1
|
|
#endif
|
|
|
|
#ifdef CONFIG_X86_64
|
|
#define vdso_enabled sysctl_vsyscall32
|
|
#define arch_setup_additional_pages syscall32_setup_pages
|
|
#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;
|
|
|
|
static int __init vdso_setup(char *s)
|
|
{
|
|
vdso_enabled = simple_strtoul(s, NULL, 0);
|
|
|
|
if (vdso_enabled > 1)
|
|
pr_warn("vdso32 values other than 0 and 1 are no longer allowed; vdso disabled\n");
|
|
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
* For consistency, the argument vdso32=[012] affects the 32-bit vDSO
|
|
* behavior on both 64-bit and 32-bit kernels.
|
|
* On 32-bit kernels, vdso=[012] means the same thing.
|
|
*/
|
|
__setup("vdso32=", vdso_setup);
|
|
|
|
#ifdef CONFIG_X86_32
|
|
__setup_param("vdso=", vdso32_setup, vdso_setup, 0);
|
|
|
|
EXPORT_SYMBOL_GPL(vdso_enabled);
|
|
#endif
|
|
|
|
static struct page **vdso32_pages;
|
|
static unsigned vdso32_size;
|
|
|
|
#ifdef CONFIG_X86_64
|
|
|
|
#define vdso32_sysenter() (boot_cpu_has(X86_FEATURE_SYSENTER32))
|
|
#define vdso32_syscall() (boot_cpu_has(X86_FEATURE_SYSCALL32))
|
|
|
|
/* May not be __init: called during resume */
|
|
void syscall32_cpu_init(void)
|
|
{
|
|
/* Load these always in case some future AMD CPU supports
|
|
SYSENTER from compat mode too. */
|
|
wrmsrl_safe(MSR_IA32_SYSENTER_CS, (u64)__KERNEL_CS);
|
|
wrmsrl_safe(MSR_IA32_SYSENTER_ESP, 0ULL);
|
|
wrmsrl_safe(MSR_IA32_SYSENTER_EIP, (u64)ia32_sysenter_target);
|
|
|
|
wrmsrl(MSR_CSTAR, ia32_cstar_target);
|
|
}
|
|
|
|
#else /* CONFIG_X86_32 */
|
|
|
|
#define vdso32_sysenter() (boot_cpu_has(X86_FEATURE_SEP))
|
|
#define vdso32_syscall() (0)
|
|
|
|
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.sp1 = sizeof(struct tss_struct) + (unsigned long) tss;
|
|
wrmsr(MSR_IA32_SYSENTER_CS, __KERNEL_CS, 0);
|
|
wrmsr(MSR_IA32_SYSENTER_ESP, tss->x86_tss.sp1, 0);
|
|
wrmsr(MSR_IA32_SYSENTER_EIP, (unsigned long) ia32_sysenter_target, 0);
|
|
put_cpu();
|
|
}
|
|
|
|
#endif /* CONFIG_X86_64 */
|
|
|
|
int __init sysenter_setup(void)
|
|
{
|
|
char *vdso32_start, *vdso32_end;
|
|
int npages, i;
|
|
|
|
#ifdef CONFIG_COMPAT
|
|
if (vdso32_syscall()) {
|
|
vdso32_start = vdso32_syscall_start;
|
|
vdso32_end = vdso32_syscall_end;
|
|
vdso32_pages = vdso32_syscall_pages;
|
|
} else
|
|
#endif
|
|
if (vdso32_sysenter()) {
|
|
vdso32_start = vdso32_sysenter_start;
|
|
vdso32_end = vdso32_sysenter_end;
|
|
vdso32_pages = vdso32_sysenter_pages;
|
|
} else {
|
|
vdso32_start = vdso32_int80_start;
|
|
vdso32_end = vdso32_int80_end;
|
|
vdso32_pages = vdso32_int80_pages;
|
|
}
|
|
|
|
npages = ((vdso32_end - vdso32_start) + PAGE_SIZE - 1) / PAGE_SIZE;
|
|
vdso32_size = npages << PAGE_SHIFT;
|
|
for (i = 0; i < npages; i++)
|
|
vdso32_pages[i] = virt_to_page(vdso32_start + i*PAGE_SIZE);
|
|
|
|
patch_vdso32(vdso32_start, vdso32_size);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/* 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;
|
|
|
|
#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,
|
|
NULL);
|
|
|
|
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;
|
|
}
|
|
|
|
#ifdef CONFIG_X86_64
|
|
|
|
subsys_initcall(sysenter_setup);
|
|
|
|
#ifdef CONFIG_SYSCTL
|
|
/* Register vsyscall32 into the ABI table */
|
|
#include <linux/sysctl.h>
|
|
|
|
static struct ctl_table abi_table2[] = {
|
|
{
|
|
.procname = "vsyscall32",
|
|
.data = &sysctl_vsyscall32,
|
|
.maxlen = sizeof(int),
|
|
.mode = 0644,
|
|
.proc_handler = proc_dointvec
|
|
},
|
|
{}
|
|
};
|
|
|
|
static struct ctl_table abi_root_table2[] = {
|
|
{
|
|
.procname = "abi",
|
|
.mode = 0555,
|
|
.child = abi_table2
|
|
},
|
|
{}
|
|
};
|
|
|
|
static __init int ia32_binfmt_init(void)
|
|
{
|
|
register_sysctl_table(abi_root_table2);
|
|
return 0;
|
|
}
|
|
__initcall(ia32_binfmt_init);
|
|
#endif
|
|
|
|
#else /* CONFIG_X86_32 */
|
|
|
|
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 mm_struct *mm)
|
|
{
|
|
return NULL;
|
|
}
|
|
|
|
int in_gate_area(struct mm_struct *mm, unsigned long addr)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
int in_gate_area_no_mm(unsigned long addr)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
#endif /* CONFIG_X86_64 */
|