From b02b1396c5e9033203bf242c022092e432f91e37 Mon Sep 17 00:00:00 2001
From: Bastien Nocera <hadess@hadess.net>
Date: Mon, 23 Aug 2021 12:40:31 +0200
Subject: [PATCH] utils: Add "tainting" detection

Throw a warning if custom fan curves are used on Asus systems as those
could potentially be setup in such a way as to not match intended
workloads, eg. it could make the performance profile have very little
cooling and throttling in a way that would be expected of a "quiet"
platform_profile.

See https://patchwork.kernel.org/project/platform-driver-x86/patch/20210820095726.14131-2-luke@ljones.dev/#24397127
---
 src/ppd-utils.c | 35 +++++++++++++++++++++++++++++++++++
 src/ppd-utils.h |  3 +++
 2 files changed, 38 insertions(+)

diff --git a/src/ppd-utils.c b/src/ppd-utils.c
index 553a1e0..ac8c7d9 100644
--- a/src/ppd-utils.c
+++ b/src/ppd-utils.c
@@ -115,3 +115,38 @@ ppd_utils_find_device (const char   *subsystem,
 
   return ret;
 }
+
+/* Custom fan curves used in asus-wmi module */
+#define ENABLED_FAN_CURVE_PROFILES "/sys/devices/platform/asus-nb-wmi/enabled_fan_curve_profiles"
+
+gboolean
+ppd_utils_can_taint (void)
+{
+  g_autofree char *fan_curves_file = NULL;
+  gboolean ret;
+
+  fan_curves_file = ppd_utils_get_sysfs_path (ENABLED_FAN_CURVE_PROFILES);
+  ret = g_file_test (fan_curves_file, G_FILE_TEST_IS_REGULAR);
+  g_debug ("%s %s: %s taint", ret ? "Detected" : "Didn't detect",
+           ENABLED_FAN_CURVE_PROFILES, ret ? "can" : "cannot");
+  return ret;
+}
+
+gboolean
+ppd_utils_try_taint (void)
+{
+  g_autofree char *fan_curves_file = NULL;
+  g_autofree char *contents = NULL;
+  g_autoptr(GError) error = NULL;
+
+  fan_curves_file = ppd_utils_get_sysfs_path (ENABLED_FAN_CURVE_PROFILES);
+  if (g_file_get_contents (fan_curves_file, &contents, NULL, &error)) {
+    if (g_strcmp0 (g_strchomp (contents), "") != 0) {
+      g_warning ("Custom fan curves are in use, please revert to defaults before reporting any problems");
+      return TRUE;
+    }
+  } else {
+    g_debug ("Failed to open %s: %s", ENABLED_FAN_CURVE_PROFILES, error->message);
+  }
+  return FALSE;
+}
diff --git a/src/ppd-utils.h b/src/ppd-utils.h
index 9b12e5b..3e32fc3 100644
--- a/src/ppd-utils.h
+++ b/src/ppd-utils.h
@@ -26,3 +26,6 @@ GFileMonitor *ppd_utils_monitor_sysfs_attr (GUdevDevice  *device,
 GUdevDevice *ppd_utils_find_device (const char   *subsystem,
                                     GCompareFunc  func,
                                     gpointer      user_data);
+
+gboolean ppd_utils_can_taint (void);
+gboolean ppd_utils_try_taint (void);