target/riscv: fix counter-enable checks in ctr()

Access to a counter in U-mode is permitted only if the corresponding
bit is set in both mcounteren and scounteren.  The current code
ignores mcounteren and checks scounteren only for U-mode access.

Signed-off-by: Xi Wang <xi.wang@gmail.com>
Reviewed-by: Palmer Dabbelt <palmer@sifive.com>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
This commit is contained in:
Xi Wang 2019-01-26 15:02:56 -08:00 committed by Palmer Dabbelt
parent 7d04ac3895
commit ff9f31d9a0
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@ -56,9 +56,15 @@ static int fs(CPURISCVState *env, int csrno)
static int ctr(CPURISCVState *env, int csrno)
{
#if !defined(CONFIG_USER_ONLY)
target_ulong ctr_en = env->priv == PRV_U ? env->scounteren :
env->priv == PRV_S ? env->mcounteren : -1U;
if (!(ctr_en & (1 << (csrno & 31)))) {
uint32_t ctr_en = ~0u;
if (env->priv < PRV_M) {
ctr_en &= env->mcounteren;
}
if (env->priv < PRV_S) {
ctr_en &= env->scounteren;
}
if (!(ctr_en & (1u << (csrno & 31)))) {
return -1;
}
#endif