Messages in this thread | | | From | Lars Persson <> | Subject | [PATCH 0/2] New fix for icache coherency race | Date | Thu, 26 Feb 2015 14:16:01 +0100 |
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This patch set proposes an improved fix for the race condition that originally was fixed in commit 2a4a8b1e5d9d ("MIPS: Remove race window in page fault handling").
I have used the flush_icache_page API that is marked as deprecated in Documentation/cachetlb.txt. There are strong reasons to keep this API because it is not possible to implement an efficient and race-free lazy flushing using the other APIs.
You can refer to a discussion about the same issue in arch/arm where they chose to implement the solution in set_pte_at. In arch/mips we could not do this because we lack information about the executability of the mapping in set_pte_at() and thus we would have to flush all pages to be safe.
http://lists.infradead.org/pipermail/linux-arm-kernel/2010-November/030915.html
Lars Persson (2): Revert "MIPS: Remove race window in page fault handling" MIPS: Fix race condition in lazy cache flushing.
arch/mips/include/asm/cacheflush.h | 35 ++++++++++++++++++++--------------- arch/mips/include/asm/pgtable.h | 10 ++++++---- arch/mips/mm/cache.c | 27 ++++++++------------------- 3 files changed, 34 insertions(+), 38 deletions(-)
-- 1.7.10.4
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