Commit a9074977 authored by Peter Maydell's avatar Peter Maydell
Browse files

target/arm: Improve exception-taken logging 



Improve the exception-taken logging by logging in
v7m_exception_taken() the exception we're going to take
and whether it is secure/nonsecure.

This requires us to move logging at many callsites from after the
call to before it, so that the logging appears in a sensible order.

(This will make tail-chaining produce more useful logs; for the
current callers of v7m_exception_taken() we know which exception
we're going to take, so custom log messages at the callsite sufficed;
for tail-chaining only v7m_exception_taken() knows the exception
number that we're going to tail-chain to.)

Signed-off-by: default avatarPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: default avatarRichard Henderson <richard.henderson@linaro.org>
Reviewed-by: default avatarPhilippe Mathieu-Daudé <f4bug@amsat.org>
Message-id: 20180720145647.8810-2-peter.maydell@linaro.org
parent 3d0e3080

target/arm/helper.c

+11 −6
Original line number Diff line number Diff line
@@ -6840,6 +6840,8 @@ static void v7m_exception_taken(ARMCPU *cpu, uint32_t lr, bool dotailchain, 
    bool push_failed = false;



    armv7m_nvic_get_pending_irq_info(env->nvic, &exc, &targets_secure);

    qemu_log_mask(CPU_LOG_INT, "...taking pending %s exception %d\n",

                  targets_secure ? "secure" : "nonsecure", exc);



    if (arm_feature(env, ARM_FEATURE_V8)) {

        if (arm_feature(env, ARM_FEATURE_M_SECURITY) &&
@@ -6913,12 +6915,15 @@ static void v7m_exception_taken(ARMCPU *cpu, uint32_t lr, bool dotailchain, 
         * we might now want to take a different exception which

         * targets a different security state, so try again from the top.

         */

        qemu_log_mask(CPU_LOG_INT,

                      "...derived exception on callee-saves register stacking");

        v7m_exception_taken(cpu, lr, true, true);

        return;

    }



    if (!arm_v7m_load_vector(cpu, exc, targets_secure, &addr)) {

        /* Vector load failed: derived exception */

        qemu_log_mask(CPU_LOG_INT, "...derived exception on vector table load");

        v7m_exception_taken(cpu, lr, true, true);

        return;

    }
@@ -7129,9 +7134,9 @@ static void do_v7m_exception_exit(ARMCPU *cpu) 
    if (sfault) {

        env->v7m.sfsr |= R_V7M_SFSR_INVER_MASK;

        armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_SECURE, false);

        v7m_exception_taken(cpu, excret, true, false);

        qemu_log_mask(CPU_LOG_INT, "...taking SecureFault on existing "

                      "stackframe: failed EXC_RETURN.ES validity check\n");

        v7m_exception_taken(cpu, excret, true, false);

        return;

    }
@@ -7141,9 +7146,9 @@ static void do_v7m_exception_exit(ARMCPU *cpu) 
         */

        env->v7m.cfsr[env->v7m.secure] |= R_V7M_CFSR_INVPC_MASK;

        armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_USAGE, env->v7m.secure);

        v7m_exception_taken(cpu, excret, true, false);

        qemu_log_mask(CPU_LOG_INT, "...taking UsageFault on existing "

                      "stackframe: failed exception return integrity check\n");

        v7m_exception_taken(cpu, excret, true, false);

        return;

    }
@@ -7198,10 +7203,10 @@ static void do_v7m_exception_exit(ARMCPU *cpu) 
                /* Take a SecureFault on the current stack */

                env->v7m.sfsr |= R_V7M_SFSR_INVIS_MASK;

                armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_SECURE, false);

                v7m_exception_taken(cpu, excret, true, false);

                qemu_log_mask(CPU_LOG_INT, "...taking SecureFault on existing "

                              "stackframe: failed exception return integrity "

                              "signature check\n");

                v7m_exception_taken(cpu, excret, true, false);

                return;

            }
@@ -7234,6 +7239,7 @@ static void do_v7m_exception_exit(ARMCPU *cpu) 
            /* v7m_stack_read() pended a fault, so take it (as a tail

             * chained exception on the same stack frame)

             */

            qemu_log_mask(CPU_LOG_INT, "...derived exception on unstacking\n");

            v7m_exception_taken(cpu, excret, true, false);

            return;

        }
@@ -7270,10 +7276,10 @@ static void do_v7m_exception_exit(ARMCPU *cpu) 
                armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_USAGE,

                                        env->v7m.secure);

                env->v7m.cfsr[env->v7m.secure] |= R_V7M_CFSR_INVPC_MASK;

                v7m_exception_taken(cpu, excret, true, false);

                qemu_log_mask(CPU_LOG_INT, "...taking UsageFault on existing "

                              "stackframe: failed exception return integrity "

                              "check\n");

                v7m_exception_taken(cpu, excret, true, false);

                return;

            }

        }
@@ -7309,9 +7315,9 @@ static void do_v7m_exception_exit(ARMCPU *cpu) 
        armv7m_nvic_set_pending(env->nvic, ARMV7M_EXCP_USAGE, false);

        env->v7m.cfsr[env->v7m.secure] |= R_V7M_CFSR_INVPC_MASK;

        ignore_stackfaults = v7m_push_stack(cpu);

        v7m_exception_taken(cpu, excret, false, ignore_stackfaults);

        qemu_log_mask(CPU_LOG_INT, "...taking UsageFault on new stackframe: "

                      "failed exception return integrity check\n");

        v7m_exception_taken(cpu, excret, false, ignore_stackfaults);

        return;

    }
@@ -7727,7 +7733,6 @@ void arm_v7m_cpu_do_interrupt(CPUState *cs) 


    ignore_stackfaults = v7m_push_stack(cpu);

    v7m_exception_taken(cpu, lr, false, ignore_stackfaults);

    qemu_log_mask(CPU_LOG_INT, "... as %d\n", env->v7m.exception);

}



/* Function used to synchronize QEMU's AArch64 register set with AArch32