InputDevice: warn if a potential IDC file can't be opened

When probing for IDC files, we expect to get "File not found" errors,
but any other error could indicate a deeper problem (such as the
permissions issue that appears to be behind b/365593937). In that case,
it would be useful to have a warning log even if DEBUG_PROBE isn't set.

Test: remove the read permissions for everyone on an IDC file, then
      watch logcat for the InputDevice tag while connecting the
      corresponding device
Bug: 365593937
Flag: EXEMPT logging change
Change-Id: I022ec383f0c0b22a66524341530c055a69e05f0b

1 files changed, 8 insertions, 0 deletions

diff --git a/libs/input/InputDevice.cpp b/libs/input/InputDevice.cpp
index 962ce09b46..c9030312f9 100644
--- a/libs/input/InputDevice.cpp
+++ b/libs/input/InputDevice.cpp
@@ -122,6 +122,10 @@ std::string getInputDeviceConfigurationFilePathByName(
             LOG_IF(INFO, DEBUG_PROBE)
                     << "Found system-provided input device configuration file at " << path;
             return path;
+        } else if (errno != ENOENT) {
+            LOG(WARNING) << "Couldn't find a system-provided input device configuration file at "
+                         << path << " due to error " << errno << " (" << strerror(errno)
+                         << "); there may be an IDC file there that cannot be loaded.";
         } else {
             LOG_IF(ERROR, DEBUG_PROBE)
                     << "Didn't find system-provided input device configuration file at " << path
@@ -142,6 +146,10 @@ std::string getInputDeviceConfigurationFilePathByName(
         LOG_IF(INFO, DEBUG_PROBE) << "Found system user input device configuration file at "
                                   << path;
         return path;
+    } else if (errno != ENOENT) {
+        LOG(WARNING) << "Couldn't find a system user input device configuration file at " << path
+                     << " due to error " << errno << " (" << strerror(errno)
+                     << "); there may be an IDC file there that cannot be loaded.";
     } else {
         LOG_IF(ERROR, DEBUG_PROBE) << "Didn't find system user input device configuration file at "
                                    << path << ": " << strerror(errno);