From f8162068f18f2f264a0355938784f54089234211 Mon Sep 17 00:00:00 2001 From: Hesham Almatary Date: Thu, 30 May 2019 14:51:34 +0100 Subject: [PATCH] RISC-V: Fix a PMP bug where it succeeds even if PMP entry is off The current implementation returns 1 (PMP check success) if the address is in range even if the PMP entry is off. This is a bug. For example, if there is a PMP check in S-Mode which is in range, but its PMP entry is off, this will succeed, which it should not. The patch fixes this bug by only checking the PMP permissions if the address is in range and its corresponding PMP entry it not off. Otherwise, it will keep the ret = -1 which will be checked and handled correctly at the end of the function. Signed-off-by: Hesham Almatary Reviewed-by: Alistair Francis Signed-off-by: Palmer Dabbelt --- target/riscv/pmp.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/target/riscv/pmp.c b/target/riscv/pmp.c index 5944f4cb6607..958c7502a0e0 100644 --- a/target/riscv/pmp.c +++ b/target/riscv/pmp.c @@ -258,11 +258,12 @@ bool pmp_hart_has_privs(CPURISCVState *env, target_ulong addr, /* fully inside */ const uint8_t a_field = pmp_get_a_field(env->pmp_state.pmp[i].cfg_reg); - if ((s + e) == 2) { - if (PMP_AMATCH_OFF == a_field) { - return 1; - } + /* + * If the PMP entry is not off and the address is in range, do the priv + * check + */ + if (((s + e) == 2) && (PMP_AMATCH_OFF != a_field)) { allowed_privs = PMP_READ | PMP_WRITE | PMP_EXEC; if ((mode != PRV_M) || pmp_is_locked(env, i)) { allowed_privs &= env->pmp_state.pmp[i].cfg_reg;