Commit 3826121d authored by Sergey Fedorov's avatar Sergey Fedorov Committed by Peter Maydell
Browse files

target-arm: Implement checking of fired watchpoint 



ARM stops before access to a location covered by watchpoint. Also, QEMU
watchpoint fire is not necessarily an architectural watchpoint match.
Unfortunately, that is hardly possible to ignore a fired watchpoint in
debug exception handler. So move watchpoint check from debug exception
handler to the dedicated watchpoint checking callback.

Signed-off-by: default avatarSergey Fedorov <serge.fdrv@gmail.com>
Reviewed-by: default avatarPeter Maydell <peter.maydell@linaro.org>
Message-id: 1454256948-10485-3-git-send-email-serge.fdrv@gmail.com
Signed-off-by: default avatarPeter Maydell <peter.maydell@linaro.org>
parent 568496c0

target-arm/cpu.c

+1 −0
Original line number Diff line number Diff line
@@ -1483,6 +1483,7 @@ static void arm_cpu_class_init(ObjectClass *oc, void *data) 
    cc->gdb_arch_name = arm_gdb_arch_name;

    cc->gdb_stop_before_watchpoint = true;

    cc->debug_excp_handler = arm_debug_excp_handler;

    cc->debug_check_watchpoint = arm_debug_check_watchpoint;



    cc->disas_set_info = arm_disas_set_info;

target-arm/internals.h

+3 −0
Original line number Diff line number Diff line
@@ -409,6 +409,9 @@ void hw_breakpoint_update(ARMCPU *cpu, int n); 
 */

void hw_breakpoint_update_all(ARMCPU *cpu);



/* Callback function for checking if a watchpoint should trigger. */

bool arm_debug_check_watchpoint(CPUState *cs, CPUWatchpoint *wp);



/* Callback function for when a watchpoint or breakpoint triggers. */

void arm_debug_excp_handler(CPUState *cs);

target-arm/op_helper.c

+21 −14
Original line number Diff line number Diff line
@@ -976,6 +976,16 @@ void HELPER(check_breakpoints)(CPUARMState *env) 
    }

}



bool arm_debug_check_watchpoint(CPUState *cs, CPUWatchpoint *wp)

{

    /* Called by core code when a CPU watchpoint fires; need to check if this

     * is also an architectural watchpoint match.

     */

    ARMCPU *cpu = ARM_CPU(cs);



    return check_watchpoints(cpu);

}



void arm_debug_excp_handler(CPUState *cs)

{

    /* Called by core code when a watchpoint or breakpoint fires;
@@ -987,11 +997,11 @@ void arm_debug_excp_handler(CPUState *cs) 


    if (wp_hit) {

        if (wp_hit->flags & BP_CPU) {

            cs->watchpoint_hit = NULL;

            if (check_watchpoints(cpu)) {

            bool wnr = (wp_hit->flags & BP_WATCHPOINT_HIT_WRITE) != 0;

            bool same_el = arm_debug_target_el(env) == arm_current_el(env);



            cs->watchpoint_hit = NULL;



            if (extended_addresses_enabled(env)) {

                env->exception.fsr = (1 << 9) | 0x22;

            } else {
@@ -1001,9 +1011,6 @@ void arm_debug_excp_handler(CPUState *cs) 
            raise_exception(env, EXCP_DATA_ABORT,

                    syn_watchpoint(same_el, 0, wnr),

                    arm_debug_target_el(env));

            } else {

                cpu_resume_from_signal(cs, NULL);

            }

        }

    } else {

        uint64_t pc = is_a64(env) ? env->pc : env->regs[15];