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

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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: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Sergey Fedorov <sergey.fedorov@linaro.org>
Acked-by: Eduardo Habkost <ehabkost@redhat.com>
Acked-by: Riku Voipio <riku.voipio@linaro.org>
Message-id: 1463494687-25947-7-git-send-email-peter.maydell@linaro.org
This commit is contained in:
Peter Maydell 2016-05-17 15:18:07 +01:00
parent 3327182332
commit 0c33682d5f
2 changed files with 3 additions and 15 deletions
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2
target-i386/helper.c
View file

@ -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;
}

16
user-exec.c
View file

@ -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;