target-ppc, tcg: fix usermode segfault with pthread_create()

Programs run under qemu-ppc64 on an x86_64 host currently segfault
if they use pthread_create() due to the adjustment made to the NIP in
commit bd6fefe71c.

This patch changes cpu_loop() to set the NIP back to the
pre-incremented value before calling do_syscall(), which causes the
correct address to be used for the new thread and corrects the fault.

Signed-off-by: Sam Bobroff <sam.bobroff@au1.ibm.com>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
This commit is contained in:
Sam Bobroff 2017-02-07 14:21:39 +11:00 committed by David Gibson
parent c09cec683b
commit 2635531f20
1 changed files with 2 additions and 1 deletions

View File

@ -1712,10 +1712,12 @@ void cpu_loop(CPUPPCState *env)
* in syscalls.
*/
env->crf[0] &= ~0x1;
env->nip += 4;
ret = do_syscall(env, env->gpr[0], env->gpr[3], env->gpr[4],
env->gpr[5], env->gpr[6], env->gpr[7],
env->gpr[8], 0, 0);
if (ret == -TARGET_ERESTARTSYS) {
env->nip -= 4;
break;
}
if (ret == (target_ulong)(-TARGET_QEMU_ESIGRETURN)) {
@ -1723,7 +1725,6 @@ void cpu_loop(CPUPPCState *env)
Avoid corrupting register state. */
break;
}
env->nip += 4;
if (ret > (target_ulong)(-515)) {
env->crf[0] |= 0x1;
ret = -ret;