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List:       kde-commits
Subject:    [kde-workspace/KDE/4.11] kdm/backend: fix resumption from console mode when monotonic clock is in us
From:       Oswald Buddenhagen <ossi () kde ! org>
Date:       2014-03-28 17:06:55
Message-ID: E1WTaF5-0000HO-BA () scm ! kde ! org
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Git commit 3b3f247f28b25e61a9d1820ea25f3c4a2b699a1d by Oswald Buddenhagen.
Committed on 28/03/2014 at 16:52.
Pushed by ossi into branch 'KDE/4.11'.

fix resumption from console mode when monotonic clock is in use

BUG: 312947
FIXED-IN: 4.11.8

M  +14   -3    kdm/backend/dm.c
M  +7    -3    kdm/backend/dm.h

http://commits.kde.org/kde-workspace/3b3f247f28b25e61a9d1820ea25f3c4a2b699a1d

diff --git a/kdm/backend/dm.c b/kdm/backend/dm.c
index e0f1366..77a2ef7 100644
--- a/kdm/backend/dm.c
+++ b/kdm/backend/dm.c
@@ -74,8 +74,11 @@ static int stopping;
 SdRec sdRec = { 0, 0, 0, TO_INF, TO_INF, 0, 0, 0 };
 
 time_t now;
-#ifndef nowMonotonic
+#if (_POSIX_MONOTONIC_CLOCK >= 0)
+time_t nowWallDelta;
+# ifndef nowMonotonic
 int nowMonotonic;
+# endif
 #endif
 
 #if KDM_LIBEXEC_STRIP != -1
@@ -339,6 +342,11 @@ updateNow(void)
         clock_gettime(CLOCK_MONOTONIC, &ts);
         /* Linux' monotonic clock starts at zero, but this is assumed to mean "long ago". */
         now = ts.tv_sec + 10000;
+        /* When we read wall clock dates (e.g. from UTMP), we need to map
+           them to the monotonic clock. Of course, such mapping defeats the
+           point of a monotonic clock in the first place, but we have little
+           choice. */
+        nowWallDelta = time(0) - now;
     } else
 #endif
         time(&now);
@@ -486,11 +494,14 @@ checkUtmp(void)
                 utp->hadSess = True;
                 utp->state = UtActive;
             }
+            nck = ut->ut_time - nowWallDelta;
+            if (nck > now)
+                nck = 0; /* Clock jumped. Time out immediately. */
 #ifdef HAVE_VTS
             /* tty with latest activity wins */
-            if (utp->time < ut->ut_time)
+            if (utp->time < nck)
 #endif
-                utp->time = ut->ut_time;
+                utp->time = nck;
         }
 #ifdef BSD_UTMP
         close(fd);
diff --git a/kdm/backend/dm.h b/kdm/backend/dm.h
index 64e106b..b2f8c61 100644
--- a/kdm/backend/dm.h
+++ b/kdm/backend/dm.h
@@ -406,12 +406,16 @@ int activateVT(int vt);
 #ifndef _POSIX_MONOTONIC_CLOCK
 # define _POSIX_MONOTONIC_CLOCK -1
 #endif
-#if (_POSIX_MONOTONIC_CLOCK > 0)
-# define nowMonotonic 1
-#elif (_POSIX_MONOTONIC_CLOCK < 0)
+#if (_POSIX_MONOTONIC_CLOCK < 0)
 # define nowMonotonic 0
+# define nowWallDelta 0
 #else
+# if (_POSIX_MONOTONIC_CLOCK > 0)
+#  define nowMonotonic 1
+# else
 extern int nowMonotonic;
+# endif
+extern time_t nowWallDelta;
 #endif
 void updateNow(void);
 
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