ANDROID: syscall_check: add vendor hook for open syscall

Through this vendor hook, we can get the timing to check
current running task for the validation of its credential
and open operation.

Bug: 191291287

Signed-off-by: Kuan-Ying Lee <Kuan-Ying.Lee@mediatek.com>
Change-Id: Ia644ceb02dbc230ee1d25cad3630c2c3f908e41a

drivers/android/vendor_hooks.c

@@ -348,3 +348,4 @@ EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_rproc_recovery);
 EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_ptype_head);
 EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_kfree_skb);
 EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_check_mmap_file);
+EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_check_file_open);

fs/open.c

@@ -34,6 +34,7 @@
 #include <linux/compat.h>
 
 #include "internal.h"
+#include <trace/hooks/syscall_check.h>
 
 int do_truncate(struct dentry *dentry, loff_t length, unsigned int time_attrs,
 	struct file *filp)
@@ -800,6 +801,7 @@ static int do_dentry_open(struct file *f,
 		error = -ENODEV;
 		goto cleanup_all;
 	}
+	trace_android_vh_check_file_open(f);
 
 	error = security_file_open(f);
 	if (error)

include/trace/hooks/syscall_check.h

@@ -17,6 +17,10 @@ DECLARE_HOOK(android_vh_check_mmap_file,
 		unsigned long flag, unsigned long ret),
 	TP_ARGS(file, prot, flag, ret));
 
+DECLARE_HOOK(android_vh_check_file_open,
+	TP_PROTO(const struct file *file),
+	TP_ARGS(file));
+
 #endif /* _TRACE_HOOK_SYSCALL_CHECK_H */
 /* This part must be outside protection */
 #include <trace/define_trace.h>