Commit 0c33682d authored by Peter Maydell's avatar Peter Maydell
Browse files

target-i386: Move user-mode exception actions out of user-exec.c 



The exception_action() function in user-exec.c is just a call to
cpu_loop_exit() for every target CPU except i386.  Since this
function is only called if the target's handle_mmu_fault() hook has
indicated an MMU fault, and that hook is only called from the
handle_cpu_signal() code path, we can simply move the x86-specific
setup into that hook, which allows us to remove the TARGET_I386
ifdef from user-exec.c.

Of the actions that were done by the call to raise_interrupt_err():
 * cpu_svm_check_intercept_param() is a no-op in user mode
 * check_exception() is a no-op since double faults are impossible
   for user-mode
 * assignments to cs->exception_index and env->error_code are no-ops
 * assigning to env->exception_next_eip is unnecessary because it
   is not used unless env->exception_is_int is true
 * cpu_loop_exit_restore() is equivalent to cpu_loop_exit() since
   pc is 0
which leaves just setting env_>exception_is_int as the action that
needs to be added to x86_cpu_handle_mmu_fault().

Signed-off-by: default avatarPeter Maydell <peter.maydell@linaro.org>
Reviewed-by: default avatarSergey Fedorov <sergey.fedorov@linaro.org>
Acked-by: default avatarEduardo Habkost <ehabkost@redhat.com>
Acked-by: default avatarRiku Voipio <riku.voipio@linaro.org>
Message-id: 1463494687-25947-7-git-send-email-peter.maydell@linaro.org
parent 33271823

target-i386/helper.c

+2 −0
Original line number Diff line number Diff line
@@ -701,6 +701,8 @@ int x86_cpu_handle_mmu_fault(CPUState *cs, vaddr addr, 
    env->error_code = (is_write << PG_ERROR_W_BIT);

    env->error_code |= PG_ERROR_U_MASK;

    cs->exception_index = EXCP0E_PAGE;

    env->exception_is_int = 0;

    env->exception_next_eip = -1;

    return 1;

}

user-exec.c

+1 −15
Original line number Diff line number Diff line
@@ -40,18 +40,6 @@ 


//#define DEBUG_SIGNAL



static void exception_action(CPUState *cpu)

{

#if defined(TARGET_I386)

    X86CPU *x86_cpu = X86_CPU(cpu);

    CPUX86State *env1 = &x86_cpu->env;



    raise_exception_err(env1, cpu->exception_index, env1->error_code);

#else

    cpu_loop_exit(cpu);

#endif

}



/* exit the current TB from a signal handler. The host registers are

   restored in a state compatible with the CPU emulator

 */
@@ -120,10 +108,8 @@ static inline int handle_cpu_signal(uintptr_t pc, unsigned long address, 
    /* now we have a real cpu fault */

    cpu_restore_state(cpu, pc);



    /* we restore the process signal mask as the sigreturn should

       do it (XXX: use sigsetjmp) */

    sigprocmask(SIG_SETMASK, old_set, NULL);

    exception_action(cpu);

    cpu_loop_exit(cpu);



    /* never comes here */

    return 1;