According to the RISC-V Privileged Manual: "The Sv32 page-based virtual-memory scheme described in sv32 supports 34-bit physical addresses for RV32, so the PMP scheme must support addresses wider than XLEN for RV32."
However, the current QEMU implementation uses `target_ulong` (which resolves to `uint32_t` on RV32) for PMP address variables. When shifting these addresses left (e.g., `this_addr << 2`), an integer overflow occurs, truncating the high bits of the 34-bit physical address. Fix this issue by changing the types of PMP address variables (`this_addr` and `prev_addr`) to `hwaddr`. This issue was discovered and reported by SpecHunter, an AI-driven architecture specification analysis tool. Link: https://github.com/yizishun/rv-isa-sec/blob/master/output/riscv-isa-manual/pr-2472/qemu.txt Signed-off-by: Zishun Yi <[email protected]> --- Changes in v2: - Changed the types of `this_addr` and `prev_addr` to `hwaddr` instead of using inline casting, by Daniel's suggestion. target/riscv/pmp.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/target/riscv/pmp.c b/target/riscv/pmp.c index 5391caa59c7d..a71091a316e0 100644 --- a/target/riscv/pmp.c +++ b/target/riscv/pmp.c @@ -227,8 +227,8 @@ static void pmp_decode_napot(hwaddr a, hwaddr *sa, hwaddr *ea) void pmp_update_rule_addr(CPURISCVState *env, uint32_t pmp_index) { uint8_t this_cfg = env->pmp_state.pmp[pmp_index].cfg_reg; - target_ulong this_addr = env->pmp_state.pmp[pmp_index].addr_reg; - target_ulong prev_addr = 0u; + hwaddr this_addr = env->pmp_state.pmp[pmp_index].addr_reg; + hwaddr prev_addr = 0u; hwaddr sa = 0u; hwaddr ea = 0u; int g = pmp_get_granularity_g(env); -- 2.51.2
