Commit 6b95ab42 authored Jul 16, 2019 by Anshuman Khandual Committed by Linus Torvalds Jul 16, 2019

mm/ioremap: check virtual address alignment while creating huge mappings



Virtual address alignment is essential in ensuring correct clearing for
all intermediate level pgtable entries and freeing associated pgtable
pages.  An unaligned address can end up randomly freeing pgtable page
that potentially still contains valid mappings.  Hence also check it's
alignment along with existing phys_addr check.

Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Toshi Kani <toshi.kani@hpe.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Chintan Pandya <cpandya@codeaurora.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

parent 5015a300

lib/ioremap.c

+9 −0

Original line number	Diff line number	Diff line
		@@ -86,6 +86,9 @@ static int ioremap_try_huge_pmd(pmd_t *pmd, unsigned long addr,
		if ((end - addr) != PMD_SIZE)
		return 0;

		if (!IS_ALIGNED(addr, PMD_SIZE))
		return 0;

		if (!IS_ALIGNED(phys_addr, PMD_SIZE))
		return 0;

		@@ -126,6 +129,9 @@ static int ioremap_try_huge_pud(pud_t *pud, unsigned long addr,
		if ((end - addr) != PUD_SIZE)
		return 0;

		if (!IS_ALIGNED(addr, PUD_SIZE))
		return 0;

		if (!IS_ALIGNED(phys_addr, PUD_SIZE))
		return 0;

		@@ -166,6 +172,9 @@ static int ioremap_try_huge_p4d(p4d_t *p4d, unsigned long addr,
		if ((end - addr) != P4D_SIZE)
		return 0;

		if (!IS_ALIGNED(addr, P4D_SIZE))
		return 0;

		if (!IS_ALIGNED(phys_addr, P4D_SIZE))
		return 0;

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