From 2322c78f90f00ebbaf2ef2bcbea5376436eb4b57 Mon Sep 17 00:00:00 2001 From: Guo Ren Date: Thu, 26 Jan 2023 22:53:06 -0500 Subject: [PATCH] riscv: Fixup race condition on PG_dcache_clean in flush_icache_pte commit 950b879b7f0251317d26bae0687e72592d607532 upstream. In commit 588a513d3425 ("arm64: Fix race condition on PG_dcache_clean in __sync_icache_dcache()"), we found RISC-V has the same issue as the previous arm64. The previous implementation didn't guarantee the correct sequence of operations, which means flush_icache_all() hasn't been called when the PG_dcache_clean was set. That would cause a risk of page synchronization. Fixes: 08f051eda33b ("RISC-V: Flush I$ when making a dirty page executable") Signed-off-by: Guo Ren Signed-off-by: Guo Ren Reviewed-by: Andrew Jones Reviewed-by: Conor Dooley Link: https://lore.kernel.org/r/20230127035306.1819561-1-guoren@kernel.org Cc: stable@vger.kernel.org Signed-off-by: Palmer Dabbelt Signed-off-by: Greg Kroah-Hartman --- arch/riscv/mm/cacheflush.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/arch/riscv/mm/cacheflush.c b/arch/riscv/mm/cacheflush.c index 498c0a0814fe..62f8be2fdbb8 100644 --- a/arch/riscv/mm/cacheflush.c +++ b/arch/riscv/mm/cacheflush.c @@ -18,6 +18,8 @@ void flush_icache_pte(pte_t pte) { struct page *page = pte_page(pte); - if (!test_and_set_bit(PG_dcache_clean, &page->flags)) + if (!test_bit(PG_dcache_clean, &page->flags)) { flush_icache_all(); + set_bit(PG_dcache_clean, &page->flags); + } }