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| author | ShihPo Hung <shihpo.hung@sifive.com> | 2019-06-17 12:26:17 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-06-25 11:36:00 +0800 |
| commit | a96ac5cb8a56ad24c663dd67f8865df30f4f7b84 (patch) | |
| tree | 7533fede94058fe12778d5910f908b3ac2eba524 /arch/riscv | |
| parent | 5ad9a23e6daef31c23895c5a0d8f0bc1fb4f69f6 (diff) | |
| download | linux-stable-a96ac5cb8a56ad24c663dd67f8865df30f4f7b84.tar.gz linux-stable-a96ac5cb8a56ad24c663dd67f8865df30f4f7b84.tar.bz2 linux-stable-a96ac5cb8a56ad24c663dd67f8865df30f4f7b84.zip | |
riscv: mm: synchronize MMU after pte change
commit bf587caae305ae3b4393077fb22c98478ee55755 upstream.
Because RISC-V compliant implementations can cache invalid entries
in TLB, an SFENCE.VMA is necessary after changes to the page table.
This patch adds an SFENCE.vma for the vmalloc_fault path.
Signed-off-by: ShihPo Hung <shihpo.hung@sifive.com>
[paul.walmsley@sifive.com: reversed tab->whitespace conversion,
wrapped comment lines]
Signed-off-by: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Palmer Dabbelt <palmer@sifive.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: linux-riscv@lists.infradead.org
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/riscv')
| -rw-r--r-- | arch/riscv/mm/fault.c | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/arch/riscv/mm/fault.c b/arch/riscv/mm/fault.c index 88401d5125bc..523dbfbac03d 100644 --- a/arch/riscv/mm/fault.c +++ b/arch/riscv/mm/fault.c @@ -29,6 +29,7 @@ #include <asm/pgalloc.h> #include <asm/ptrace.h> +#include <asm/tlbflush.h> /* * This routine handles page faults. It determines the address and the @@ -281,6 +282,18 @@ vmalloc_fault: pte_k = pte_offset_kernel(pmd_k, addr); if (!pte_present(*pte_k)) goto no_context; + + /* + * The kernel assumes that TLBs don't cache invalid + * entries, but in RISC-V, SFENCE.VMA specifies an + * ordering constraint, not a cache flush; it is + * necessary even after writing invalid entries. + * Relying on flush_tlb_fix_spurious_fault would + * suffice, but the extra traps reduce + * performance. So, eagerly SFENCE.VMA. + */ + local_flush_tlb_page(addr); + return; } } |