0001-DEBUG-trace-firmware-loads-and-filp_open.patch

From eb32451cf180960441c68d699093aa6237631fb7 Mon Sep 17 00:00:00 2001
From: Samuel Dionne-Riel <samuel@dionne-riel.com>
Date: Thu, 18 Mar 2021 01:47:17 -0400
Subject: [PATCH] [DEBUG]: trace firmware loads and filp_open

The latter is useful to spy on kernel stealing files from the filesystem
without going through the firmware subsystem.
---
 drivers/base/firmware_class.c | 5 +++++
 fs/open.c                     | 1 +
 2 files changed, 6 insertions(+)

diff --git a/drivers/base/firmware_class.c b/drivers/base/firmware_class.c
index 364181591f77d..daea203b645f2 100644
--- a/drivers/base/firmware_class.c
+++ b/drivers/base/firmware_class.c
@@ -423,6 +423,9 @@ fw_get_filesystem_firmware(struct device *device, struct firmware_buf *buf)
 
 		len = snprintf(path, PATH_MAX, "%s/%s",
 			       fw_path[i], buf->fw_id);
+
+		printk("[TRACE] fw_get_filesystem_firmware(); // %s\n", path);
+
 		if (len >= PATH_MAX) {
 			rc = -ENAMETOOLONG;
 			break;
@@ -1228,6 +1231,8 @@ _request_firmware(const struct firmware **firmware_p, const char *name,
 		goto out;
 	}
 
+	printk("[TRACE] _request_firmware(); // %s\n", name);
+
 	ret = _request_firmware_prepare(&fw, name, device, buf, size,
 					opt_flags);
 	if (ret <= 0) /* error or already assigned */
diff --git a/fs/open.c b/fs/open.c
index 50d2b404c8a16..a83b190b6fdf7 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -1019,6 +1019,7 @@ struct file *file_open_name(struct filename *name, int flags, umode_t mode)
  */
 struct file *filp_open(const char *filename, int flags, umode_t mode)
 {
+	printk("[TRACE] filp_open(); // %s\n", filename);
 	struct filename *name = getname_kernel(filename);
 	struct file *file = ERR_CAST(name);
 	
-- 
2.29.2