linux-user: Support for restarting system calls for Alpha targets

Update the Alpha main loop and sigreturn code:
 * on TARGET_ERESTARTSYS, wind guest PC backwards to repeat syscall insn
 * handle TARGET_QEMU_ESIGRETURN in the main loop as the indication
   that the main loop should not touch any guest CPU state

Signed-off-by: Timothy Edward Baldwin <T.E.Baldwin99@members.leeds.ac.uk>
Message-id: 1441497448-32489-13-git-send-email-T.E.Baldwin99@members.leeds.ac.uk
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
[PMM: tweak commit message; drop TARGET_USE_ERESTARTSYS define;
 PC is env->pc, not env->ir[IR_PV]]
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Riku Voipio <riku.voipio@linaro.org>
This commit is contained in:
Timothy E Baldwin 2016-05-12 18:47:36 +01:00 committed by Riku Voipio
parent ba41249678
commit 338c858c94
3 changed files with 8 additions and 4 deletions

View File

@ -27,6 +27,7 @@ static inline abi_ulong get_sp_from_cpustate(CPUAlphaState *state)
return state->ir[IR_SP];
}
/* From <asm/gentrap.h>. */
#define TARGET_GEN_INTOVF -1 /* integer overflow */
#define TARGET_GEN_INTDIV -2 /* integer division by zero */

View File

@ -3267,8 +3267,11 @@ void cpu_loop(CPUAlphaState *env)
env->ir[IR_A2], env->ir[IR_A3],
env->ir[IR_A4], env->ir[IR_A5],
0, 0);
if (trapnr == TARGET_NR_sigreturn
|| trapnr == TARGET_NR_rt_sigreturn) {
if (sysret == -TARGET_ERESTARTSYS) {
env->pc -= 4;
break;
}
if (sysret == -TARGET_QEMU_ESIGRETURN) {
break;
}
/* Syscall writes 0 to V0 to bypass error check, similar

View File

@ -5527,7 +5527,7 @@ long do_sigreturn(CPUAlphaState *env)
restore_sigcontext(env, sc);
unlock_user_struct(sc, sc_addr, 0);
return env->ir[IR_V0];
return -TARGET_QEMU_ESIGRETURN;
badframe:
force_sig(TARGET_SIGSEGV);
@ -5554,7 +5554,7 @@ long do_rt_sigreturn(CPUAlphaState *env)
}
unlock_user_struct(frame, frame_addr, 0);
return env->ir[IR_V0];
return -TARGET_QEMU_ESIGRETURN;
badframe: