linux-user: Use `qemu_log' for strace

This change switches linux-user strace logging to use the newer `qemu_log`
logging subsystem rather than the older `gemu_log` (notice the "g")
logger. `qemu_log` has several advantages, namely that it allows logging
to a file, and provides a more unified interface for configuration
of logging (via the QEMU_LOG environment variable or options).

This change introduces a new log mask: `LOG_STRACE` which is used for
logging of user-mode strace messages.

Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Signed-off-by: Josh Kunz <jkz@google.com>
Message-Id: <20200204025416.111409-3-jkz@google.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>

1 files changed, 7 insertions, 6 deletions

diff --git a/linux-user/syscall.c b/linux-user/syscall.c
index 16d98c1ff5..274e10e0ee 100644
--- a/linux-user/syscall.c
+++ b/linux-user/syscall.c
@@ -12171,14 +12171,15 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1,
     record_syscall_start(cpu, num, arg1,
                          arg2, arg3, arg4, arg5, arg6, arg7, arg8);
 
-    if (unlikely(do_strace)) {
+    if (unlikely(qemu_loglevel_mask(LOG_STRACE))) {
         print_syscall(num, arg1, arg2, arg3, arg4, arg5, arg6);
-        ret = do_syscall1(cpu_env, num, arg1, arg2, arg3, arg4,
-                          arg5, arg6, arg7, arg8);
+    }
+
+    ret = do_syscall1(cpu_env, num, arg1, arg2, arg3, arg4,
+                      arg5, arg6, arg7, arg8);
+
+    if (unlikely(qemu_loglevel_mask(LOG_STRACE))) {
         print_syscall_ret(num, ret);
-    } else {
-        ret = do_syscall1(cpu_env, num, arg1, arg2, arg3, arg4,
-                          arg5, arg6, arg7, arg8);
     }
 
     record_syscall_return(cpu, num, ret);