From: Guo Ren guoren@linux.alibaba.com
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 guoren@linux.alibaba.com Signed-off-by: Guo Ren guoren@kernel.org Reviewed-by: Andrew Jones ajones@ventanamicro.com Reviewed-by: Conor Dooley conor.dooley@microchip.com Link: https://lore.kernel.org/r/20230127035306.1819561-1-guoren@kernel.org Cc: stable@vger.kernel.org Signed-off-by: Palmer Dabbelt palmer@rivosinc.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- arch/riscv/mm/cacheflush.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
--- 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); + } }