Commit f213e72f authored by Peter Maydell's avatar Peter Maydell
Browse files

user-exec: Push resume-from-signal code out to handle_cpu_signal() 



Since the only caller of page_unprotect() which might cause it to
need to call cpu_resume_from_signal() is handle_cpu_signal() in
the user-mode code, push the longjump handling out to that function.

Since this is the only caller of cpu_resume_from_signal() which
passes a non-NULL puc argument, split the non-NULL handling into
a new cpu_exit_tb_from_sighandler() function. This allows us
to merge the softmmu and usermode implementations of the
cpu_resume_from_signal() function, which are now identical.

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: 1463494687-25947-3-git-send-email-peter.maydell@linaro.org
parent 75809229

cpu-exec-common.c

+1 −1
Original line number Diff line number Diff line
@@ -29,7 +29,6 @@ CPUState *tcg_current_cpu; 
/* exit the current TB from a signal handler. The host registers are

   restored in a state compatible with the CPU emulator

 */

#if defined(CONFIG_SOFTMMU)

void cpu_resume_from_signal(CPUState *cpu, void *puc)

{

    /* XXX: restore cpu registers saved in host registers */
@@ -38,6 +37,7 @@ void cpu_resume_from_signal(CPUState *cpu, void *puc) 
    siglongjmp(cpu->jmp_env, 1);

}



#if defined(CONFIG_SOFTMMU)

void cpu_reloading_memory_map(void)

{

    if (qemu_in_vcpu_thread()) {

translate-all.c

+8 −4
Original line number Diff line number Diff line
@@ -1955,7 +1955,7 @@ int page_check_range(target_ulong start, target_ulong len, int flags) 
            /* unprotect the page if it was put read-only because it

               contains translated code */

            if (!(p->flags & PAGE_WRITE)) {

                if (!page_unprotect(addr, 0, NULL)) {

                if (!page_unprotect(addr, 0)) {

                    return -1;

                }

            }
@@ -1965,8 +1965,12 @@ int page_check_range(target_ulong start, target_ulong len, int flags) 
}



/* called from signal handler: invalidate the code and unprotect the

   page. Return TRUE if the fault was successfully handled. */

int page_unprotect(target_ulong address, uintptr_t pc, void *puc)

 * page. Return 0 if the fault was not handled, 1 if it was handled,

 * and 2 if it was handled but the caller must cause the TB to be

 * immediately exited. (We can only return 2 if the 'pc' argument is

 * non-zero.)

 */

int page_unprotect(target_ulong address, uintptr_t pc)

{

    unsigned int prot;

    PageDesc *p;
@@ -1999,7 +2003,7 @@ int page_unprotect(target_ulong address, uintptr_t pc, void *puc) 
               the corresponding translated code. */

            if (tb_invalidate_phys_page(addr, pc)) {

                mmap_unlock();

                cpu_resume_from_signal(current_cpu, puc);

                return 2;

            }

#ifdef DEBUG_TB_CHECK

            tb_invalidate_check(addr);

translate-all.h

+1 −1
Original line number Diff line number Diff line
@@ -27,7 +27,7 @@ void tb_invalidate_phys_range(tb_page_addr_t start, tb_page_addr_t end); 
void tb_check_watchpoint(CPUState *cpu);



#ifdef CONFIG_USER_ONLY

int page_unprotect(target_ulong address, uintptr_t pc, void *puc);

int page_unprotect(target_ulong address, uintptr_t pc);

#endif



#endif /* TRANSLATE_ALL_H */

user-exec.c

+29 −12
Original line number Diff line number Diff line
@@ -55,7 +55,7 @@ static void exception_action(CPUState *cpu) 
/* exit the current TB from a signal handler. The host registers are

   restored in a state compatible with the CPU emulator

 */

void cpu_resume_from_signal(CPUState *cpu, void *puc)

static void cpu_exit_tb_from_sighandler(CPUState *cpu, void *puc)

{

#ifdef __linux__

    struct ucontext *uc = puc;
@@ -63,7 +63,6 @@ void cpu_resume_from_signal(CPUState *cpu, void *puc) 
    struct sigcontext *uc = puc;

#endif



    if (puc) {

    /* XXX: use siglongjmp ? */

#ifdef __linux__

#ifdef __ia64
@@ -74,9 +73,8 @@ void cpu_resume_from_signal(CPUState *cpu, void *puc) 
#elif defined(__OpenBSD__)

    sigprocmask(SIG_SETMASK, &uc->sc_mask, NULL);

#endif

    }

    cpu->exception_index = -1;

    siglongjmp(cpu->jmp_env, 1);



    cpu_resume_from_signal(cpu, NULL);

}



/* 'pc' is the host PC at which the exception was raised. 'address' is
@@ -96,9 +94,28 @@ static inline int handle_cpu_signal(uintptr_t pc, unsigned long address, 
           pc, address, is_write, *(unsigned long *)old_set);

#endif

    /* XXX: locking issue */

    if (is_write && h2g_valid(address)

        && page_unprotect(h2g(address), pc, puc)) {

    if (is_write && h2g_valid(address)) {

        switch (page_unprotect(h2g(address), pc)) {

        case 0:

            /* Fault not caused by a page marked unwritable to protect

             * cached translations, must be the guest binary's problem

             */

            break;

        case 1:

            /* Fault caused by protection of cached translation; TBs

             * invalidated, so resume execution

             */

            return 1;

        case 2:

            /* Fault caused by protection of cached translation, and the

             * currently executing TB was modified and must be exited

             * immediately.

             */

            cpu_exit_tb_from_sighandler(current_cpu, puc);

            g_assert_not_reached();

        default:

            g_assert_not_reached();

        }

    }



    /* Convert forcefully to guest address space, invalid addresses