diff options
| author | Steve Capper <steve.capper@arm.com> | 2016-06-07 17:58:06 +0100 |
|---|---|---|
| committer | Sasha Levin <sasha.levin@oracle.com> | 2016-07-11 11:15:55 -0400 |
| commit | cd46ef9b3315b165c3f3efc1bd90bf998a706421 (patch) | |
| tree | 1274525261c548978bb47e13206fe191c80d97c8 /arch/arm | |
| parent | 12088206279edcc09e07419a4f741059cd3b118a (diff) | |
ARM: 8579/1: mm: Fix definition of pmd_mknotpresent
[ Upstream commit 56530f5d2ddc9b9fade7ef8db9cb886e9dc689b5 ]
Currently pmd_mknotpresent will use a zero entry to respresent an
invalidated pmd.
Unfortunately this definition clashes with pmd_none, thus it is
possible for a race condition to occur if zap_pmd_range sees pmd_none
whilst __split_huge_pmd_locked is running too with pmdp_invalidate
just called.
This patch fixes the race condition by modifying pmd_mknotpresent to
create non-zero faulting entries (as is done in other architectures),
removing the ambiguity with pmd_none.
[catalin.marinas@arm.com: using L_PMD_SECT_VALID instead of PMD_TYPE_SECT]
Fixes: 8d9625070073 ("ARM: mm: Transparent huge page support for LPAE systems.")
Cc: <stable@vger.kernel.org> # 3.11+
Reported-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Cc: Russell King <linux@armlinux.org.uk>
Signed-off-by: Steve Capper <steve.capper@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Diffstat (limited to 'arch/arm')
| -rw-r--r-- | arch/arm/include/asm/pgtable-3level.h | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/arch/arm/include/asm/pgtable-3level.h b/arch/arm/include/asm/pgtable-3level.h index 7b4ba4d99ee2..b5ef8c7c6220 100644 --- a/arch/arm/include/asm/pgtable-3level.h +++ b/arch/arm/include/asm/pgtable-3level.h @@ -258,8 +258,11 @@ PMD_BIT_FUNC(mkyoung, |= PMD_SECT_AF); #define pfn_pmd(pfn,prot) (__pmd(((phys_addr_t)(pfn) << PAGE_SHIFT) | pgprot_val(prot))) #define mk_pmd(page,prot) pfn_pmd(page_to_pfn(page),prot) -/* represent a notpresent pmd by zero, this is used by pmdp_invalidate */ -#define pmd_mknotpresent(pmd) (__pmd(0)) +/* represent a notpresent pmd by faulting entry, this is used by pmdp_invalidate */ +static inline pmd_t pmd_mknotpresent(pmd_t pmd) +{ + return __pmd(pmd_val(pmd) & ~L_PMD_SECT_VALID); +} static inline pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot) { |