[Qemu-devel] [PATCH] linux-user: make binfmt flag O require P

[Joakim Tjernlund <Joakim.Tjernlund@transmode.se>]

Qemu can autodetect if it is started from Linux binfmt loader
when binfmt flag O is on.
Use that and require binfmt flag P as well which will enable QEMU
to pass in correct argv0 to the application.

Signed-off-by: Joakim Tjernlund <Joakim.Tjernlund@transmode.se>
---
 linux-user/main.c | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/linux-user/main.c b/linux-user/main.c
index 71a33c7..9736768 100644
--- a/linux-user/main.c
+++ b/linux-user/main.c
@@ -3829,6 +3829,18 @@ int main(int argc, char **argv, char **envp)
     int ret;
     int execfd;
 
+    execfd = qemu_getauxval(AT_EXECFD);
+    if (execfd > 0 ) {
+        if (argc < 3) {
+            fprintf(stderr, "%s: Please use me through binfmt with P flag\n",
+                    argv[0]);
+            exit(1);
+        }
+        handle_arg_argv0(argv[2]); /* binfmt wrapper */
+        memmove(&argv[2], &argv[3], (argc-2)*sizeof(argv));
+        argc--;
+    }
+
     module_call_init(MODULE_INIT_QOM);
 
     if ((envlist = envlist_create()) == NULL) {
@@ -4003,7 +4015,6 @@ int main(int argc, char **argv, char **envp)
     cpu->opaque = ts;
     task_settid(ts);
 
-    execfd = qemu_getauxval(AT_EXECFD);
     if (execfd == 0) {
         execfd = open(filename, O_RDONLY);
         if (execfd < 0) {
-- 
1.8.5.5