[Qemu-devel] [PATCH v2 13/28] linux-user: Support for restarting system calls for UniCore32 targets

[Peter Maydell]

From: Timothy E Baldwin <address@hidden>

Update the UniCore32 main loop 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

(We don't support signals on this target so there is no sigreturn code
to update.)

Signed-off-by: Timothy Edward Baldwin <address@hidden>
Message-id: address@hidden
Reviewed-by: Peter Maydell <address@hidden>
[PMM: tweak commit message; drop TARGET_USE_ERESTARTSYS define]
Signed-off-by: Peter Maydell <address@hidden>
---
 linux-user/main.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/linux-user/main.c b/linux-user/main.c
index 94dc2d4..5e5efa9 100644
--- a/linux-user/main.c
+++ b/linux-user/main.c
@@ -1170,7 +1170,7 @@ void cpu_loop(CPUUniCore32State *env)
                             cpu_set_tls(env, env->regs[0]);
                             env->regs[0] = 0;
                     } else {
-                        env->regs[0] = do_syscall(env,
+                        abi_long ret = do_syscall(env,
                                                   n,
                                                   env->regs[0],
                                                   env->regs[1],
@@ -1179,6 +1179,11 @@ void cpu_loop(CPUUniCore32State *env)
                                                   env->regs[4],
                                                   env->regs[5],
                                                   0, 0);
+                        if (ret == -TARGET_ERESTARTSYS) {
+                            env->regs[31] -= 4;
+                        } else if (ret != -TARGET_QEMU_ESIGRETURN) {
+                            env->regs[0] = ret;
+                        }
                     }
                 } else {
                     goto error;
-- 
1.9.1