The console_write() semihosting function outputs guest data from a
buffer; it doesn't update that buffer.  It therefore doesn't need to
pass a length value to unlock_user(), but can pass 0, meaning "do not
copy any data back to the guest memory".

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
 semihosting/syscalls.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/semihosting/syscalls.c b/semihosting/syscalls.c
index 4847f66c023..508a0ad88c6 100644
--- a/semihosting/syscalls.c
+++ b/semihosting/syscalls.c
@@ -627,7 +627,7 @@ static void console_write(CPUState *cs, gdb_syscall_complete_cb complete,
     }
     ret = qemu_semihosting_console_write(ptr, len);
     complete(cs, ret ? ret : -1, ret ? 0 : EIO);
-    unlock_user(ptr, buf, ret);
+    unlock_user(ptr, buf, 0);
 }
 
 static void console_fstat(CPUState *cs, gdb_syscall_complete_cb complete,
-- 
2.25.1

On 7/19/22 17:41, Peter Maydell wrote:
> The console_write() semihosting function outputs guest data from a
> buffer; it doesn't update that buffer.  It therefore doesn't need to
> pass a length value to unlock_user(), but can pass 0, meaning "do not
> copy any data back to the guest memory".
> 
> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
> ---
>   semihosting/syscalls.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>


r~