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| author |   Dmitry Safonov <dima@arista.com> | 2020-12-14 19:08:25 -0800 |
|---|---|---|
| committer |   Linus Torvalds <torvalds@linux-foundation.org> | 2020-12-15 12:13:41 -0800 |
| commit | 871402e05b24cb56bc69df47cff960d0e0d24267 (patch) | |
| tree | f8235ea5b089ed3c9def2e9c6ed2df51d205e8d3 /arch/x86/entry | |
| parent | mremap: check if it's possible to split original vma (diff) | |
| download | linux-dev-871402e05b24cb56bc69df47cff960d0e0d24267.tar.xz linux-dev-871402e05b24cb56bc69df47cff960d0e0d24267.zip | |
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>
Diffstat (limited to 'arch/x86/entry')
| -rw-r--r-- | arch/x86/entry/vdso/vma.c | 17 |
1 files changed, 0 insertions, 17 deletions
diff --git a/arch/x86/entry/vdso/vma.c b/arch/x86/entry/vdso/vma.c index 9185cb1d13b9..0c942b31825d 100644 --- a/arch/x86/entry/vdso/vma.c +++ b/arch/x86/entry/vdso/vma.c @@ -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, }; /* |