From ec70ee2c604b82f9261513dbd3110ecdc9bc1f13 Mon Sep 17 00:00:00 2001
From: Siarhei Vishniakou <svv@google.com>
Date: Wed, 18 May 2022 09:42:52 -0700
Subject: Do not load keylayout if required kernel module is missing

Some key layouts require the presence of a specific kernel module. If
the kernel module is not present, the layout should not be loaded.

In this CL, we add an option to specify which kernel modules / configs
are needed inside the kl file.

Bug: 228005926
Test: atest libinput_tests
Change-Id: I0d2ab6298bd41df6dc56120bf0385e10da6c3bfe
Merged-In: I0d2ab6298bd41df6dc56120bf0385e10da6c3bfe
---
 libs/input/KeyLayoutMap.cpp | 82 ++++++++++++++++++++++++++++++++++++---------
 1 file changed, 66 insertions(+), 16 deletions(-)

(limited to 'libs/input/KeyLayoutMap.cpp')

diff --git a/libs/input/KeyLayoutMap.cpp b/libs/input/KeyLayoutMap.cpp
index 29df793a20..84a8ab42a1 100644
--- a/libs/input/KeyLayoutMap.cpp
+++ b/libs/input/KeyLayoutMap.cpp
@@ -27,6 +27,8 @@
 #include <utils/Errors.h>
 #include <utils/Timers.h>
 #include <utils/Tokenizer.h>
+#include <vintf/RuntimeInfo.h>
+#include <vintf/VintfObject.h>
 
 #include <cstdlib>
 #include <string_view>
@@ -73,6 +75,29 @@ static const std::unordered_map<std::string, InputDeviceSensorType> SENSOR_LIST
          {SENSOR_ENTRY(InputDeviceSensorType::GYROSCOPE_UNCALIBRATED)},
          {SENSOR_ENTRY(InputDeviceSensorType::SIGNIFICANT_MOTION)}};
 
+bool kernelConfigsArePresent(const std::set<std::string>& configs) {
+    std::shared_ptr<const android::vintf::RuntimeInfo> runtimeInfo =
+            android::vintf::VintfObject::GetInstance()->getRuntimeInfo(
+                    vintf::RuntimeInfo::FetchFlag::CONFIG_GZ);
+    LOG_ALWAYS_FATAL_IF(runtimeInfo == nullptr, "Kernel configs could not be fetched");
+
+    const std::map<std::string, std::string>& kernelConfigs = runtimeInfo->kernelConfigs();
+    for (const std::string& requiredConfig : configs) {
+        const auto configIt = kernelConfigs.find(requiredConfig);
+        if (configIt == kernelConfigs.end()) {
+            ALOGI("Required kernel config %s is not found", requiredConfig.c_str());
+            return false;
+        }
+        const std::string& option = configIt->second;
+        if (option != "y" && option != "m") {
+            ALOGI("Required kernel config %s has option %s", requiredConfig.c_str(),
+                  option.c_str());
+            return false;
+        }
+    }
+    return true;
+}
+
 // --- KeyLayoutMap ---
 
 KeyLayoutMap::KeyLayoutMap() {
@@ -83,32 +108,34 @@ KeyLayoutMap::~KeyLayoutMap() {
 
 base::Result<std::shared_ptr<KeyLayoutMap>> KeyLayoutMap::loadContents(const std::string& filename,
                                                                        const char* contents) {
-    Tokenizer* tokenizer;
-    status_t status = Tokenizer::fromContents(String8(filename.c_str()), contents, &tokenizer);
-    if (status) {
-        ALOGE("Error %d opening key layout map.", status);
-        return Errorf("Error {} opening key layout map file {}.", status, filename.c_str());
-    }
-    std::unique_ptr<Tokenizer> t(tokenizer);
-    auto ret = load(t.get());
-    if (ret.ok()) {
-        (*ret)->mLoadFileName = filename;
-    }
-    return ret;
+    return load(filename, contents);
 }
 
-base::Result<std::shared_ptr<KeyLayoutMap>> KeyLayoutMap::load(const std::string& filename) {
+base::Result<std::shared_ptr<KeyLayoutMap>> KeyLayoutMap::load(const std::string& filename,
+                                                               const char* contents) {
     Tokenizer* tokenizer;
-    status_t status = Tokenizer::open(String8(filename.c_str()), &tokenizer);
+    status_t status;
+    if (contents == nullptr) {
+        status = Tokenizer::open(String8(filename.c_str()), &tokenizer);
+    } else {
+        status = Tokenizer::fromContents(String8(filename.c_str()), contents, &tokenizer);
+    }
     if (status) {
         ALOGE("Error %d opening key layout map file %s.", status, filename.c_str());
         return Errorf("Error {} opening key layout map file {}.", status, filename.c_str());
     }
     std::unique_ptr<Tokenizer> t(tokenizer);
     auto ret = load(t.get());
-    if (ret.ok()) {
-        (*ret)->mLoadFileName = filename;
+    if (!ret.ok()) {
+        return ret;
+    }
+    const std::shared_ptr<KeyLayoutMap>& map = *ret;
+    LOG_ALWAYS_FATAL_IF(map == nullptr, "Returned map should not be null if there's no error");
+    if (!kernelConfigsArePresent(map->mRequiredKernelConfigs)) {
+        ALOGI("Not loading %s because the required kernel configs are not set", filename.c_str());
+        return Errorf("Missing kernel config");
     }
+    map->mLoadFileName = filename;
     return ret;
 }
 
@@ -268,6 +295,10 @@ status_t KeyLayoutMap::Parser::parse() {
                 mTokenizer->skipDelimiters(WHITESPACE);
                 status_t status = parseSensor();
                 if (status) return status;
+            } else if (keywordToken == "requires_kernel_config") {
+                mTokenizer->skipDelimiters(WHITESPACE);
+                status_t status = parseRequiredKernelConfig();
+                if (status) return status;
             } else {
                 ALOGE("%s: Expected keyword, got '%s'.", mTokenizer->getLocation().string(),
                         keywordToken.string());
@@ -569,4 +600,23 @@ status_t KeyLayoutMap::Parser::parseSensor() {
     map.emplace(code, sensor);
     return NO_ERROR;
 }
+
+// Parse the name of a required kernel config.
+// The layout won't be used if the specified kernel config is not present
+// Examples:
+// requires_kernel_config CONFIG_HID_PLAYSTATION
+status_t KeyLayoutMap::Parser::parseRequiredKernelConfig() {
+    String8 codeToken = mTokenizer->nextToken(WHITESPACE);
+    std::string configName = codeToken.string();
+
+    const auto result = mMap->mRequiredKernelConfigs.emplace(configName);
+    if (!result.second) {
+        ALOGE("%s: Duplicate entry for required kernel config %s.",
+              mTokenizer->getLocation().string(), configName.c_str());
+        return BAD_VALUE;
+    }
+
+    ALOGD_IF(DEBUG_PARSER, "Parsed required kernel config: name=%s", configName.c_str());
+    return NO_ERROR;
+}
 };
-- 
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