Commit 3b8c9f1cdfc5 ("arm64: IPI each CPU after invalidating the I-cache for kernel mappings") was aimed at fixing the I-cache invalidation for kernel mappings. However, it inadvertently caused all cache maintenance for user mappings via set_pte_at() -> __sync_icache_dcache() -> sync_icache_aliases() to call kick_all_cpus_sync().

Reported-by: Shijith Thotton sthotton@marvell.com Tested-by: Shijith Thotton sthotton@marvell.com Reported-by: Wandun Chen chenwandun@huawei.com Fixes: 3b8c9f1cdfc5 ("arm64: IPI each CPU after invalidating the I-cache for kernel mappings") Cc: stable@vger.kernel.org # 4.19.x- Signed-off-by: Catalin Marinas catalin.marinas@arm.com ---

Hi Will,

You acked the previous inlined patch but I think that's a better option to revert the kernel behaviour w.r.t. user mapping to that prior to commit 3b8c9f1cdfc5.

If you plan a pull request for 5.0-rc4, please pick this up as well.

Thanks.

arch/arm64/mm/flush.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/mm/flush.c b/arch/arm64/mm/flush.c index 30695a868107..5c9073bace83 100644 --- a/arch/arm64/mm/flush.c +++ b/arch/arm64/mm/flush.c @@ -33,7 +33,11 @@ void sync_icache_aliases(void *kaddr, unsigned long len) __clean_dcache_area_pou(kaddr, len); __flush_icache_all(); } else { - flush_icache_range(addr, addr + len); + /* + * Don't issue kick_all_cpus_sync() after I-cache invalidation + * for user mappings. + */ + __flush_icache_range(addr, addr + len); } }