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x86/mm: Remove kernel_unmap_pages_in_pgd() and efi_cleanup_page_tables()

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kernel_unmap_pages_in_pgd() is dangerous: if a PGD entry in
init_mm.pgd were to be cleared, callers would need to ensure that
the pgd entry hadn't been propagated to any other pgd.

Its only caller was efi_cleanup_page_tables(), and that, in turn,
was unused, so just delete both functions.  This leaves a couple of
other helpers unused, so delete them, too.

Signed-off-by: Andy Lutomirski <luto@kernel.org>
Reviewed-by: Matt Fleming <matt@codeblueprint.co.uk>
Acked-by: Borislav Petkov <bp@suse.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-efi@vger.kernel.org
Link: http://lkml.kernel.org/r/77ff20fdde3b75cd393be5559ad8218870520248.1468527351.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Andy Lutomirski
2016-07-14 13:22:51 -07:00
committed by Ingo Molnar
parent 360cb4d155
commit d92fc69cca
6 changed files with 0 additions and 41 deletions
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28
arch/x86/mm/pageattr.c
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@@ -746,18 +746,6 @@ static bool try_to_free_pmd_page(pmd_t *pmd)
return true;
}
static bool try_to_free_pud_page(pud_t *pud)
{
int i;
for (i = 0; i < PTRS_PER_PUD; i++)
if (!pud_none(pud[i]))
return false;
free_page((unsigned long)pud);
return true;
}
static bool unmap_pte_range(pmd_t *pmd, unsigned long start, unsigned long end)
{
pte_t *pte = pte_offset_kernel(pmd, start);
@@ -871,16 +859,6 @@ static void unmap_pud_range(pgd_t *pgd, unsigned long start, unsigned long end)
*/
}
static void unmap_pgd_range(pgd_t *root, unsigned long addr, unsigned long end)
{
pgd_t *pgd_entry = root + pgd_index(addr);
unmap_pud_range(pgd_entry, addr, end);
if (try_to_free_pud_page((pud_t *)pgd_page_vaddr(*pgd_entry)))
pgd_clear(pgd_entry);
}
static int alloc_pte_page(pmd_t *pmd)
{
pte_t *pte = (pte_t *)get_zeroed_page(GFP_KERNEL | __GFP_NOTRACK);
@@ -1994,12 +1972,6 @@ out:
return retval;
}
void kernel_unmap_pages_in_pgd(pgd_t *root, unsigned long address,
unsigned numpages)
{
unmap_pgd_range(root, address, address + (numpages << PAGE_SHIFT));
}
/*
* The testcases use internal knowledge of the implementation that shouldn't
* be exposed to the rest of the kernel. Include these directly here.