arm64: Do not issue IPIs for user executable ptes

commit 132fdc37 upstream.

Commit 3b8c9f1c ("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: 3b8c9f1c ("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>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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);
 	}
 }