Add Windows.PatchLevelKernel32 histogram.

Reports the PatchLevel of the current running Windows OS as
reported by a call to VerQueryValue() on kernel32.dll.

Also, add comments for missing functions in windows_version.h
and add Kernel32VersionNumber function on OSInfo for
determining Kernel32 version.

BUG=1130738

Change-Id: I70c652e6524e15382a511cfc12311d5ffffedb1f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2444452Reviewed-by: Alexei Svitkine <asvitkine@chromium.org>
Reviewed-by: Robert Liao <robliao@chromium.org>
Commit-Queue: Will Harris <wfh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#813824}

base/win/windows_version.cc

@@ -13,6 +13,7 @@
 #include "base/check_op.h"
 #include "base/file_version_info_win.h"
 #include "base/files/file_path.h"
+#include "base/logging.h"
 #include "base/no_destructor.h"
 #include "base/notreached.h"
 #include "base/strings/string_util.h"
@@ -199,6 +200,16 @@ Version OSInfo::Kernel32Version() const {
   return kernel32_version;
 }
 
+OSInfo::VersionNumber OSInfo::Kernel32VersionNumber() const {
+  DCHECK(Kernel32BaseVersion().components().size() == 4);
+  static const VersionNumber version = {
+      .major = Kernel32BaseVersion().components()[0],
+      .minor = Kernel32BaseVersion().components()[1],
+      .build = Kernel32BaseVersion().components()[2],
+      .patch = Kernel32BaseVersion().components()[3]};
+  return version;
+}
+
 // Retrieve a version from kernel32. This is useful because when running in
 // compatibility mode for a down-level version of the OS, the file version of
 // kernel32 will still be the "real" version.

base/win/windows_version.h

@@ -120,20 +120,42 @@ class BASE_EXPORT OSInfo {
   // process.  This doesn't touch member state, so you can bypass the singleton.
   static WOW64Status GetWOW64StatusForProcess(HANDLE process_handle);
 
+  // Returns the OS Version as returned from a call to GetVersionEx().
   const Version& version() const { return version_; }
+
+  // Returns detailed version info containing major, minor, build and patch.
+  const VersionNumber& version_number() const { return version_number_; }
+
+  // The Kernel32* set of functions return the OS version as determined by a
+  // call to VerQueryValue() on kernel32.dll. This avoids any running App Compat
+  // shims from manipulating the version reported.
   Version Kernel32Version() const;
+  VersionNumber Kernel32VersionNumber() const;
   base::Version Kernel32BaseVersion() const;
-  // The next two functions return arrays of values, [major, minor(, build)].
-  const VersionNumber& version_number() const { return version_number_; }
+
+  // Functions to determine Version Type (e.g. Enterprise/Home) and Service Pack
+  // value. See above for definitions of these values.
   const VersionType& version_type() const { return version_type_; }
   const ServicePack& service_pack() const { return service_pack_; }
   const std::string& service_pack_str() const { return service_pack_str_; }
+
+  // Returns the number of processors on the system.
   const int& processors() const { return processors_; }
+
+  // Returns the allocation granularity. See
+  // https://docs.microsoft.com/en-us/windows/win32/api/sysinfoapi/ns-sysinfoapi-system_info.
   const size_t& allocation_granularity() const {
     return allocation_granularity_;
   }
+
+  // Returns the WOW64 status of the running process. See above for definitions
+  // of the values.
   const WOW64Status& wow64_status() const { return wow64_status_; }
+
+  // Processor name as read from registry.
   std::string processor_model_name();
+
+  // Returns the "ReleaseId" (Windows 10 release number) from the registry.
   const std::string& release_id() const { return release_id_; }
 
  private:

chrome/browser/metrics/chrome_browser_main_extra_parts_metrics.cc

@@ -166,6 +166,14 @@ void RecordStartupMetrics() {
   DCHECK(patch_level) << "Windows version too high!";
   base::UmaHistogramSparse("Windows.PatchLevel", patch_level);
 
+  int kernel32_patch = os_info.Kernel32VersionNumber().patch;
+  int kernel32_build = os_info.Kernel32VersionNumber().build;
+  int kernel32_patch_level = 0;
+  if (kernel32_patch < 65536 && kernel32_build < 65536)
+    kernel32_patch_level = MAKELONG(kernel32_patch, kernel32_build);
+  DCHECK(kernel32_patch_level) << "Windows kernel32.dll version too high!";
+  base::UmaHistogramSparse("Windows.PatchLevelKernel32", kernel32_patch_level);
+
   base::UmaHistogramBoolean("Windows.HasHighResolutionTimeTicks",
                             base::TimeTicks::IsHighResolution());
 

tools/metrics/histograms/histograms_xml/windows/histograms.xml

@@ -154,7 +154,7 @@ reviews. Googlers can read more about this at go/gwsq-gerrit.
   <owner>wfh@chromium.org</owner>
   <owner>brucedawson@chromium.org</owner>
   <summary>
-    The Windows version (base::win::Version) as reported by VeryQueryValue() on
+    The Windows version (base::win::Version) as reported by VerQueryValue() on
     kernel32.dll. This is queried shortly after startup.
   </summary>
 </histogram>
@@ -222,11 +222,28 @@ reviews. Googlers can read more about this at go/gwsq-gerrit.
   <owner>brucedawson@chromium.org</owner>
   <summary>
     A 32-bit value formed from combining the minor and patch level of the
-    currently running Windows operating system. E.g. &quot;Windows 10 OS Version
-    1809 (Build 17763.503)&quot; would be 17763 (0x4563), combined with 503
-    (0x1F7) = 0x456301F7. If either minor or patch level exceeds the value that
-    can fit in a 16-bit unsigned integer, then this histogram will report 0.
-    Reported once, shortly after browser startup.
+    currently running Windows operating system as reported by GetVersionEx().
+    E.g. &quot;Windows 10 OS Version 1809 (Build 17763.503)&quot; would be 17763
+    (0x4563), combined with 503 (0x1F7) = 0x456301F7. If either minor or patch
+    level exceeds the value that can fit in a 16-bit unsigned integer, then this
+    histogram will report 0. Reported once, shortly after browser startup.
+  </summary>
+</histogram>
+
+<histogram name="Windows.PatchLevelKernel32" enum="WindowsPatchLevel"
+    expires_after="never">
+<!-- expires-never: Needed to measure Windows ecosystem. -->
+
+  <owner>wfh@chromium.org</owner>
+  <owner>brucedawson@chromium.org</owner>
+  <summary>
+    A 32-bit value formed from combining the minor and patch level of the
+    currently running Windows operating system as reported by VerQueryValue() of
+    kernel32.dll. E.g. &quot;Windows 10 OS Version 1809 (Build 17763.503)&quot;
+    would be 17763 (0x4563), combined with 503 (0x1F7) = 0x456301F7. If either
+    minor or patch level exceeds the value that can fit in a 16-bit unsigned
+    integer, then this histogram will report 0. Reported once, shortly after
+    browser startup.
   </summary>
 </histogram>