From fa3b38e72d633fd179dd03f9665f6d84f742cf0f Mon Sep 17 00:00:00 2001
From: Waldemar Kozaczuk <jwkozaczuk@gmail.com>
Date: Wed, 29 Jun 2022 17:33:38 -0400
Subject: [PATCH] add another C-wrapper: osv_run_app()

In preparation to support building and running ZFS images on
the kernel built with most symbols hidden, this patch adds new
C function - osv_run_app() - that wraps code to run an arbitrary app.
This will allow an application like mkfs.so to be changed to not have to depend
on C++ symbols like osv::run() from OSv kernel.

Refs #1186

Signed-off-by: Waldemar Kozaczuk <jwkozaczuk@gmail.com>
---
 core/osv_c_wrappers.cc                  | 9 +++++++++
 exported_symbols/osv_module_api.symbols | 1 +
 include/osv/osv_c_wrappers.h            | 5 +++++
 3 files changed, 15 insertions(+)

diff --git a/core/osv_c_wrappers.cc b/core/osv_c_wrappers.cc
index ef2dc1970a..6b03d17da4 100644
--- a/core/osv_c_wrappers.cc
+++ b/core/osv_c_wrappers.cc
@@ -143,6 +143,15 @@ void osv_current_app_on_termination_request(void (*handler)()) {
     osv::this_application::on_termination_request(handler);
 }
 
+extern "C" OSV_MODULE_API
+int osv_run_app(const char *app_path, const char *args[], int args_len) {
+    int ret;
+    std::vector<std::string> _args(args, args + args_len);
+    auto ok = run(app_path, _args, &ret);
+    assert(ok);
+    return ret;
+}
+
 extern bool verbose;
 extern "C" OSV_MODULE_API
 bool osv_debug_enabled() {
diff --git a/exported_symbols/osv_module_api.symbols b/exported_symbols/osv_module_api.symbols
index 2ba5050c55..d0e5e52fea 100644
--- a/exported_symbols/osv_module_api.symbols
+++ b/exported_symbols/osv_module_api.symbols
@@ -7,4 +7,5 @@ osv_get_all_app_threads
 osv_get_all_threads
 osv_hypervisor_name
 osv_processor_features
+osv_run_app
 osv_version
diff --git a/include/osv/osv_c_wrappers.h b/include/osv/osv_c_wrappers.h
index f891c8e977..0f66e5d2ff 100644
--- a/include/osv/osv_c_wrappers.h
+++ b/include/osv/osv_c_wrappers.h
@@ -127,6 +127,11 @@ bool osv_debug_enabled();
  */
 void osv_current_app_on_termination_request(void (*handler)());
 
+/*
+ * Start an app and wait until it terminates
+ */
+int osv_run_app(const char *app_path, const char *args[], int args_len);
+
 #ifdef __cplusplus
 }
 #endif