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authorWill Deacon <will.deacon@arm.com>2018-06-22 16:23:45 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-07-03 11:23:08 +0200
commitfb6786ce77ac4d65351832412703b8793e122f12 (patch)
treecb0dc82448cc2d012e46d223ecb4fa88f2197fb1 /arch/arm64
parent12942d52f23d79df25814730f559c54150ab3e84 (diff)
arm64: mm: Ensure writes to swapper are ordered wrt subsequent cache maintenance
commit 71c8fc0c96abf8e53e74ed4d891d671e585f9076 upstream. When rewriting swapper using nG mappings, we must performance cache maintenance around each page table access in order to avoid coherency problems with the host's cacheable alias under KVM. To ensure correct ordering of the maintenance with respect to Device memory accesses made with the Stage-1 MMU disabled, DMBs need to be added between the maintenance and the corresponding memory access. This patch adds a missing DMB between writing a new page table entry and performing a clean+invalidate on the same line. Fixes: f992b4dfd58b ("arm64: kpti: Add ->enable callback to remap swapper using nG mappings") Cc: <stable@vger.kernel.org> # 4.16.x- Acked-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/arm64')
-rw-r--r--arch/arm64/mm/proc.S5
1 files changed, 3 insertions, 2 deletions
diff --git a/arch/arm64/mm/proc.S b/arch/arm64/mm/proc.S
index 66cce2138f95..18d96d349a8b 100644
--- a/arch/arm64/mm/proc.S
+++ b/arch/arm64/mm/proc.S
@@ -186,8 +186,9 @@ ENDPROC(idmap_cpu_replace_ttbr1)
.macro __idmap_kpti_put_pgtable_ent_ng, type
orr \type, \type, #PTE_NG // Same bit for blocks and pages
- str \type, [cur_\()\type\()p] // Update the entry and ensure it
- dc civac, cur_\()\type\()p // is visible to all CPUs.
+ str \type, [cur_\()\type\()p] // Update the entry and ensure
+ dmb sy // that it is visible to all
+ dc civac, cur_\()\type\()p // CPUs.
.endm
/*