From 38303e8a2cfca62e9073014138a5e10f711459ee Mon Sep 17 00:00:00 2001 From: Richard Henderson Date: Wed, 12 Apr 2023 13:43:33 +0200 Subject: [PATCH] target/riscv: Reorg sum check in get_physical_address Implement this by adjusting prot, which reduces the set of checks required. This prevents exec to be set for U pages in MMUIdx_S_SUM. While it had been technically incorrect, it did not manifest as a bug, because we will never attempt to execute from MMUIdx_S_SUM. Signed-off-by: Richard Henderson Reviewed-by: Alistair Francis Reviewed-by: Weiwei Li Tested-by: Daniel Henrique Barboza Message-Id: <20230325105429.1142530-26-richard.henderson@linaro.org> Message-Id: <20230412114333.118895-26-richard.henderson@linaro.org> Signed-off-by: Alistair Francis --- target/riscv/cpu_helper.c | 22 +++++++++++----------- 1 file changed, 11 insertions(+), 11 deletions(-) diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c index 7849e18554..32a65f8007 100644 --- a/target/riscv/cpu_helper.c +++ b/target/riscv/cpu_helper.c @@ -786,7 +786,7 @@ static int get_physical_address(CPURISCVState *env, hwaddr *physical, *ret_prot = 0; hwaddr base; - int levels, ptidxbits, ptesize, vm, sum, widened; + int levels, ptidxbits, ptesize, vm, widened; if (first_stage == true) { if (use_background) { @@ -817,7 +817,7 @@ static int get_physical_address(CPURISCVState *env, hwaddr *physical, } widened = 2; } - sum = mmuidx_sum(mmu_idx); + switch (vm) { case VM_1_10_SV32: levels = 2; ptidxbits = 10; ptesize = 4; break; @@ -985,15 +985,15 @@ restart: prot |= PAGE_EXEC; } - if ((pte & PTE_U) && - ((mode != PRV_U) && (!sum || access_type == MMU_INST_FETCH))) { - /* - * User PTE flags when not U mode and mstatus.SUM is not set, - * or the access type is an instruction fetch. - */ - return TRANSLATE_FAIL; - } - if (!(pte & PTE_U) && (mode != PRV_S)) { + if (pte & PTE_U) { + if (mode != PRV_U) { + if (!mmuidx_sum(mmu_idx)) { + return TRANSLATE_FAIL; + } + /* SUM allows only read+write, not execute. */ + prot &= PAGE_READ | PAGE_WRITE; + } + } else if (mode != PRV_S) { /* Supervisor PTE flags when not S mode */ return TRANSLATE_FAIL; } -- 2.30.2