[PATCH 1/7] linux-user/nios2: Fix clone child return

[Richard Henderson]

The child side of clone needs to set the secondary
syscall return value, r7, to indicate syscall success.

Advance the pc before do_syscall, so that the new thread
does not re-execute the clone syscall.

Signed-off-by: Richard Henderson <richard.hender...@linaro.org>
---
 linux-user/nios2/target_cpu.h | 1 +
 linux-user/nios2/cpu_loop.c   | 4 +---
 2 files changed, 2 insertions(+), 3 deletions(-)

diff --git a/linux-user/nios2/target_cpu.h b/linux-user/nios2/target_cpu.h
index 2d2008f002..830b4c0741 100644
--- a/linux-user/nios2/target_cpu.h
+++ b/linux-user/nios2/target_cpu.h
@@ -27,6 +27,7 @@ static inline void cpu_clone_regs_child(CPUNios2State *env, 
target_ulong newsp,
         env->regs[R_SP] = newsp;
     }
     env->regs[R_RET0] = 0;
+    env->regs[7] = 0;
 }
 
 static inline void cpu_clone_regs_parent(CPUNios2State *env, unsigned flags)
diff --git a/linux-user/nios2/cpu_loop.c b/linux-user/nios2/cpu_loop.c
index 1e93ef34e6..a3acaa92ca 100644
--- a/linux-user/nios2/cpu_loop.c
+++ b/linux-user/nios2/cpu_loop.c
@@ -42,8 +42,7 @@ void cpu_loop(CPUNios2State *env)
         case EXCP_TRAP:
             switch (env->error_code) {
             case 0:
-                qemu_log_mask(CPU_LOG_INT, "\nSyscall\n");
-
+                env->regs[R_PC] += 4;
                 ret = do_syscall(env, env->regs[2],
                                  env->regs[4], env->regs[5], env->regs[6],
                                  env->regs[7], env->regs[8], env->regs[9],
@@ -56,7 +55,6 @@ void cpu_loop(CPUNios2State *env)
                 env->regs[2] = abs(ret);
                 /* Return value is 0..4096 */
                 env->regs[7] = ret > 0xfffff000u;
-                env->regs[R_PC] += 4;
                 break;
 
             case 1:
-- 
2.25.1