mm: forbid splitting special mappings
Don't allow splitting of vm_special_mapping's. It affects vdso/vvar areas. Uprobes have only one page in xol_area so they aren't affected. Those restrictions were enforced by checks in .mremap() callbacks. Restrict resizing with generic .split() callback. Link: https://lkml.kernel.org/r/20201013013416.390574-7-dima@arista.com Signed-off-by: Dmitry Safonov <dima@arista.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Andy Lutomirski <luto@kernel.org> Cc: Brian Geffon <bgeffon@google.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Dan Carpenter <dan.carpenter@oracle.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Hugh Dickins <hughd@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: John Hubbard <jhubbard@nvidia.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Ralph Campbell <rcampbell@nvidia.com> Cc: Russell King <linux@armlinux.org.uk> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Родитель
73d5e06299
Коммит
871402e05b
|
@ -50,15 +50,6 @@ static const struct vm_special_mapping vdso_data_mapping = {
|
|||
static int vdso_mremap(const struct vm_special_mapping *sm,
|
||||
struct vm_area_struct *new_vma)
|
||||
{
|
||||
unsigned long new_size = new_vma->vm_end - new_vma->vm_start;
|
||||
unsigned long vdso_size;
|
||||
|
||||
/* without VVAR page */
|
||||
vdso_size = (vdso_total_pages - 1) << PAGE_SHIFT;
|
||||
|
||||
if (vdso_size != new_size)
|
||||
return -EINVAL;
|
||||
|
||||
current->mm->context.vdso = new_vma->vm_start;
|
||||
|
||||
return 0;
|
||||
|
|
|
@ -78,17 +78,9 @@ static union {
|
|||
} vdso_data_store __page_aligned_data;
|
||||
struct vdso_data *vdso_data = vdso_data_store.data;
|
||||
|
||||
static int __vdso_remap(enum vdso_abi abi,
|
||||
const struct vm_special_mapping *sm,
|
||||
struct vm_area_struct *new_vma)
|
||||
static int vdso_mremap(const struct vm_special_mapping *sm,
|
||||
struct vm_area_struct *new_vma)
|
||||
{
|
||||
unsigned long new_size = new_vma->vm_end - new_vma->vm_start;
|
||||
unsigned long vdso_size = vdso_info[abi].vdso_code_end -
|
||||
vdso_info[abi].vdso_code_start;
|
||||
|
||||
if (vdso_size != new_size)
|
||||
return -EINVAL;
|
||||
|
||||
current->mm->context.vdso = (void *)new_vma->vm_start;
|
||||
|
||||
return 0;
|
||||
|
@ -219,17 +211,6 @@ static vm_fault_t vvar_fault(const struct vm_special_mapping *sm,
|
|||
return vmf_insert_pfn(vma, vmf->address, pfn);
|
||||
}
|
||||
|
||||
static int vvar_mremap(const struct vm_special_mapping *sm,
|
||||
struct vm_area_struct *new_vma)
|
||||
{
|
||||
unsigned long new_size = new_vma->vm_end - new_vma->vm_start;
|
||||
|
||||
if (new_size != VVAR_NR_PAGES * PAGE_SIZE)
|
||||
return -EINVAL;
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
static int __setup_additional_pages(enum vdso_abi abi,
|
||||
struct mm_struct *mm,
|
||||
struct linux_binprm *bprm,
|
||||
|
@ -280,12 +261,6 @@ up_fail:
|
|||
/*
|
||||
* Create and map the vectors page for AArch32 tasks.
|
||||
*/
|
||||
static int aarch32_vdso_mremap(const struct vm_special_mapping *sm,
|
||||
struct vm_area_struct *new_vma)
|
||||
{
|
||||
return __vdso_remap(VDSO_ABI_AA32, sm, new_vma);
|
||||
}
|
||||
|
||||
enum aarch32_map {
|
||||
AA32_MAP_VECTORS, /* kuser helpers */
|
||||
AA32_MAP_SIGPAGE,
|
||||
|
@ -308,11 +283,10 @@ static struct vm_special_mapping aarch32_vdso_maps[] = {
|
|||
[AA32_MAP_VVAR] = {
|
||||
.name = "[vvar]",
|
||||
.fault = vvar_fault,
|
||||
.mremap = vvar_mremap,
|
||||
},
|
||||
[AA32_MAP_VDSO] = {
|
||||
.name = "[vdso]",
|
||||
.mremap = aarch32_vdso_mremap,
|
||||
.mremap = vdso_mremap,
|
||||
},
|
||||
};
|
||||
|
||||
|
@ -453,12 +427,6 @@ out:
|
|||
}
|
||||
#endif /* CONFIG_COMPAT */
|
||||
|
||||
static int vdso_mremap(const struct vm_special_mapping *sm,
|
||||
struct vm_area_struct *new_vma)
|
||||
{
|
||||
return __vdso_remap(VDSO_ABI_AA64, sm, new_vma);
|
||||
}
|
||||
|
||||
enum aarch64_map {
|
||||
AA64_MAP_VVAR,
|
||||
AA64_MAP_VDSO,
|
||||
|
@ -468,7 +436,6 @@ static struct vm_special_mapping aarch64_vdso_maps[] __ro_after_init = {
|
|||
[AA64_MAP_VVAR] = {
|
||||
.name = "[vvar]",
|
||||
.fault = vvar_fault,
|
||||
.mremap = vvar_mremap,
|
||||
},
|
||||
[AA64_MAP_VDSO] = {
|
||||
.name = "[vdso]",
|
||||
|
|
|
@ -263,10 +263,6 @@ int main(int argc, char **argv)
|
|||
fprintf(out_file, " const struct vm_special_mapping *sm,\n");
|
||||
fprintf(out_file, " struct vm_area_struct *new_vma)\n");
|
||||
fprintf(out_file, "{\n");
|
||||
fprintf(out_file, " unsigned long new_size =\n");
|
||||
fprintf(out_file, " new_vma->vm_end - new_vma->vm_start;\n");
|
||||
fprintf(out_file, " if (vdso_image.size != new_size)\n");
|
||||
fprintf(out_file, " return -EINVAL;\n");
|
||||
fprintf(out_file, " current->mm->context.vdso =\n");
|
||||
fprintf(out_file, " (void *)(new_vma->vm_start);\n");
|
||||
fprintf(out_file, " return 0;\n");
|
||||
|
|
|
@ -61,17 +61,8 @@ static vm_fault_t vdso_fault(const struct vm_special_mapping *sm,
|
|||
static int vdso_mremap(const struct vm_special_mapping *sm,
|
||||
struct vm_area_struct *vma)
|
||||
{
|
||||
unsigned long vdso_pages;
|
||||
|
||||
vdso_pages = vdso64_pages;
|
||||
|
||||
if ((vdso_pages << PAGE_SHIFT) != vma->vm_end - vma->vm_start)
|
||||
return -EINVAL;
|
||||
|
||||
if (WARN_ON_ONCE(current->mm != vma->vm_mm))
|
||||
return -EFAULT;
|
||||
|
||||
current->mm->context.vdso_base = vma->vm_start;
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
|
|
|
@ -89,30 +89,14 @@ static void vdso_fix_landing(const struct vdso_image *image,
|
|||
static int vdso_mremap(const struct vm_special_mapping *sm,
|
||||
struct vm_area_struct *new_vma)
|
||||
{
|
||||
unsigned long new_size = new_vma->vm_end - new_vma->vm_start;
|
||||
const struct vdso_image *image = current->mm->context.vdso_image;
|
||||
|
||||
if (image->size != new_size)
|
||||
return -EINVAL;
|
||||
|
||||
vdso_fix_landing(image, new_vma);
|
||||
current->mm->context.vdso = (void __user *)new_vma->vm_start;
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
static int vvar_mremap(const struct vm_special_mapping *sm,
|
||||
struct vm_area_struct *new_vma)
|
||||
{
|
||||
const struct vdso_image *image = new_vma->vm_mm->context.vdso_image;
|
||||
unsigned long new_size = new_vma->vm_end - new_vma->vm_start;
|
||||
|
||||
if (new_size != -image->sym_vvar_start)
|
||||
return -EINVAL;
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
#ifdef CONFIG_TIME_NS
|
||||
static struct page *find_timens_vvar_page(struct vm_area_struct *vma)
|
||||
{
|
||||
|
@ -252,7 +236,6 @@ static const struct vm_special_mapping vdso_mapping = {
|
|||
static const struct vm_special_mapping vvar_mapping = {
|
||||
.name = "[vvar]",
|
||||
.fault = vvar_fault,
|
||||
.mremap = vvar_mremap,
|
||||
};
|
||||
|
||||
/*
|
||||
|
|
12
mm/mmap.c
12
mm/mmap.c
|
@ -3422,6 +3422,17 @@ static int special_mapping_mremap(struct vm_area_struct *new_vma,
|
|||
return 0;
|
||||
}
|
||||
|
||||
static int special_mapping_split(struct vm_area_struct *vma, unsigned long addr)
|
||||
{
|
||||
/*
|
||||
* Forbid splitting special mappings - kernel has expectations over
|
||||
* the number of pages in mapping. Together with VM_DONTEXPAND
|
||||
* the size of vma should stay the same over the special mapping's
|
||||
* lifetime.
|
||||
*/
|
||||
return -EINVAL;
|
||||
}
|
||||
|
||||
static const struct vm_operations_struct special_mapping_vmops = {
|
||||
.close = special_mapping_close,
|
||||
.fault = special_mapping_fault,
|
||||
|
@ -3429,6 +3440,7 @@ static const struct vm_operations_struct special_mapping_vmops = {
|
|||
.name = special_mapping_name,
|
||||
/* vDSO code relies that VVAR can't be accessed remotely */
|
||||
.access = NULL,
|
||||
.may_split = special_mapping_split,
|
||||
};
|
||||
|
||||
static const struct vm_operations_struct legacy_special_mapping_vmops = {
|
||||
|
|
Загрузка…
Ссылка в новой задаче