[Qemu-devel] [PATCH 10/11] [v2] linux-user: implement m68k atomic syscalls

[riku . voipio]

From: Riku Voipio <address@hidden>

With nptl enabled, atomic_cmpxchg_32 and atomic_barrier
system calls are needed. This patch enabled really dummy
versions of the system calls, modeled after the m68k
kernel code.

With this patch I am able to execute m68k binaries
with qemu linux-user (busybox compiled for coldfire).

[v2] que an segfault instead of returning a EFAULT
to keep in line with kernel code.

Cc: Laurent Vivier <address@hidden>
Signed-off-by: Riku Voipio <address@hidden>
---
 linux-user/strace.list |  6 ++++++
 linux-user/syscall.c   | 28 ++++++++++++++++++++++++++++
 2 files changed, 34 insertions(+)

diff --git a/linux-user/strace.list b/linux-user/strace.list
index 4f9c364..cf5841a 100644
--- a/linux-user/strace.list
+++ b/linux-user/strace.list
@@ -1521,3 +1521,9 @@
 #ifdef TARGET_NR_pipe2
 { TARGET_NR_pipe2, "pipe2", NULL, NULL, NULL },
 #endif
+#ifdef TARGET_NR_atomic_cmpxchg_32
+{ TARGET_NR_atomic_cmpxchg_32, "atomic_cmpxchg_32", NULL, NULL, NULL },
+#endif
+#ifdef TARGET_NR_atomic_barrier
+{ TARGET_NR_atomic_barrier, "atomic_barrier", NULL, NULL, NULL },
+#endif
diff --git a/linux-user/syscall.c b/linux-user/syscall.c
index aebe36d..b3822b3 100644
--- a/linux-user/syscall.c
+++ b/linux-user/syscall.c
@@ -9133,6 +9133,34 @@ abi_long do_syscall(void *cpu_env, int num, abi_long 
arg1,
         break;
     }
 #endif
+#ifdef TARGET_NR_atomic_cmpxchg_32
+    case TARGET_NR_atomic_cmpxchg_32:
+    {
+        /* should use start_exclusive from main.c */
+        abi_ulong mem_value;
+        if (get_user_u32(mem_value, arg6)) {
+            target_siginfo_t info;
+            info.si_signo = SIGSEGV;
+            info.si_errno = 0;
+            info.si_code = TARGET_SEGV_MAPERR;
+            info._sifields._sigfault._addr = arg6;
+            queue_signal((CPUArchState *)cpu_env, info.si_signo, &info);
+            ret = 0xdeadbeef;
+
+        }
+        if (mem_value == arg2)
+            put_user_u32(arg1, arg6);
+        ret = mem_value;
+        break;
+    }
+#endif
+#ifdef TARGET_NR_atomic_barrier
+    case TARGET_NR_atomic_barrier:
+    {
+        /* Like the kernel implementation and the qemu arm barrier, no-op 
this? */
+        break;
+    }
+#endif
     default:
     unimplemented:
         gemu_log("qemu: Unsupported syscall: %d\n", num);
-- 
1.8.1.2