openpower-pels: time: use gmtime for all operations

The test cases in `bcd_time_test.cpp` could fail if the executing
host were not in UTC.  By default the BMC uses UTC but the development
systems are often in a user's local time zone.  Switch all time
operations to work off UTC by using gmtime/timegm instead of
localtime/mktime.

Signed-off-by: Patrick Williams <[email protected]>
Change-Id: I6230fd014f44123fe917a8e2b39e3b903d3a05e8

Author: williamspatrick

extensions/openpower-pels/bcd_time.cpp

@@ -43,17 +43,17 @@ BCDTime getBCDTime(std::chrono::time_point<std::chrono::system_clock>& time)
 
     using namespace std::chrono;
     time_t t = system_clock::to_time_t(time);
-    tm* localTime = localtime(&t);
-    assert(localTime != nullptr);
+    tm* gmTime = gmtime(&t);
+    assert(gmTime != nullptr);
 
-    int year = 1900 + localTime->tm_year;
+    int year = 1900 + gmTime->tm_year;
     bcd.yearMSB = toBCD(year / 100);
     bcd.yearLSB = toBCD(year % 100);
-    bcd.month = toBCD(localTime->tm_mon + 1);
-    bcd.day = toBCD(localTime->tm_mday);
-    bcd.hour = toBCD(localTime->tm_hour);
-    bcd.minutes = toBCD(localTime->tm_min);
-    bcd.seconds = toBCD(localTime->tm_sec);
+    bcd.month = toBCD(gmTime->tm_mon + 1);
+    bcd.day = toBCD(gmTime->tm_mday);
+    bcd.hour = toBCD(gmTime->tm_hour);
+    bcd.minutes = toBCD(gmTime->tm_min);
+    bcd.seconds = toBCD(gmTime->tm_sec);
 
     auto ms = duration_cast<milliseconds>(time.time_since_epoch()).count();
     int hundredths = (ms % 1000) / 10;

extensions/openpower-pels/journal.cpp

@@ -177,7 +177,7 @@ std::string Journal::getTimeStamp(sd_journal* journal) const
     time_t secs = usec / 1000000;
 
     // Convert seconds to tm struct required by strftime()
-    struct tm* timeStruct = localtime(&secs);
+    struct tm* timeStruct = gmtime(&secs);
     if (timeStruct == nullptr)
     {
         throw std::runtime_error{

test/openpower-pels/bcd_time_test.cpp

@@ -81,7 +81,7 @@ TEST(BCDTimeTest, ConvertTest)
     time_tm.tm_sec = 42;
     time_tm.tm_isdst = 0;
 
-    auto timepoint = std::chrono::system_clock::from_time_t(mktime(&time_tm));
+    auto timepoint = std::chrono::system_clock::from_time_t(timegm(&time_tm));
     auto timeInBCD = getBCDTime(timepoint);
 
     EXPECT_EQ(timeInBCD.yearMSB, 0x20);

test/openpower-pels/private_header_test.cpp

@@ -156,7 +156,7 @@ TEST_F(PrivateHeaderTest, ConstructionTest)
     time_tm.tm_isdst = 0;
 
     // Convert the above time into a uint64_t in ms since the epoch time
-    auto timepoint = std::chrono::system_clock::from_time_t(mktime(&time_tm));
+    auto timepoint = std::chrono::system_clock::from_time_t(timegm(&time_tm));
     auto timestamp = std::chrono::duration_cast<std::chrono::milliseconds>(
                          timepoint.time_since_epoch())
                          .count();