Commit 1169d3aa authored by Peter Maydell's avatar Peter Maydell
Browse files

target/arm: Handle SPSEL and current stack being out of sync in MSP/PSP reads 



For v8M it is possible for the CONTROL.SPSEL bit value and the
current stack to be out of sync. This means we need to update
the checks used in reads and writes of the PSP and MSP special
registers to use v7m_using_psp() rather than directly checking
the SPSEL bit in the control register.

Signed-off-by: default avatarPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: default avatarRichard Henderson <richard.henderson@linaro.org>
Message-id: 1512153879-5291-2-git-send-email-peter.maydell@linaro.org
Reviewed-by: default avatarPhilippe Mathieu-Daudé <f4bug@amsat.org>
parent ba2aecab

target/arm/helper.c

+4 −6
Original line number Diff line number Diff line
@@ -9953,11 +9953,9 @@ uint32_t HELPER(v7m_mrs)(CPUARMState *env, uint32_t reg) 


    switch (reg) {

    case 8: /* MSP */

        return (env->v7m.control[env->v7m.secure] & R_V7M_CONTROL_SPSEL_MASK) ?

            env->v7m.other_sp : env->regs[13];

        return v7m_using_psp(env) ? env->v7m.other_sp : env->regs[13];

    case 9: /* PSP */

        return (env->v7m.control[env->v7m.secure] & R_V7M_CONTROL_SPSEL_MASK) ?

            env->regs[13] : env->v7m.other_sp;

        return v7m_using_psp(env) ? env->regs[13] : env->v7m.other_sp;

    case 16: /* PRIMASK */

        return env->v7m.primask[env->v7m.secure];

    case 17: /* BASEPRI */
@@ -10059,14 +10057,14 @@ void HELPER(v7m_msr)(CPUARMState *env, uint32_t maskreg, uint32_t val) 
        }

        break;

    case 8: /* MSP */

        if (env->v7m.control[env->v7m.secure] & R_V7M_CONTROL_SPSEL_MASK) {

        if (v7m_using_psp(env)) {

            env->v7m.other_sp = val;

        } else {

            env->regs[13] = val;

        }

        break;

    case 9: /* PSP */

        if (env->v7m.control[env->v7m.secure] & R_V7M_CONTROL_SPSEL_MASK) {

        if (v7m_using_psp(env)) {

            env->regs[13] = val;

        } else {

            env->v7m.other_sp = val;