Use ctime_r and localtime_r for threadsafety

To make these calls threadsafe. localtime_r is provided by gnulib if
necessary, and for ctime_r we can just use it because it is in a linux-
specific file.

gdb/ChangeLog:

2019-11-15  Christian Biesinger  <cbiesinger@google.com>

	* maint.c (scoped_command_stats::print_time): Use localtime_r
	instead of localtime (provided through gnulib if necessary).
	* nat/linux-osdata.c (time_from_time_t): Use ctime_r instead
	of ctime.

Change-Id: I329bbdc39d5b576f51859ba00f1617e024c30cbd

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index f31552b15f18610f506aa5f4aaa72d5674320134..f727aa4786c406ec5351a41ddf07472e0988237c 100644 (file)
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,10 @@
+2019-11-15  Christian Biesinger  <cbiesinger@google.com>
+
+       * maint.c (scoped_command_stats::print_time): Use localtime_r
+       instead of localtime (provided through gnulib if necessary).
+       * nat/linux-osdata.c (time_from_time_t): Use ctime_r instead
+       of ctime.
+
 2019-11-15  Christian Biesinger  <cbiesinger@google.com>
 
        * gdbsupport/common-defs.h: Include time.h before pathmax.h to

diff --git a/gdb/maint.c b/gdb/maint.c
index ec9f4abb26466936c76fc9bc0cef8a1091e616c9..a253584a1509af9d81c3bc315e916b64c28bb72d 100644 (file)
--- a/gdb/maint.c
+++ b/gdb/maint.c
@@ -1039,10 +1039,11 @@ scoped_command_stats::print_time (const char *msg)
   auto millis = ticks % 1000;
 
   std::time_t as_time = system_clock::to_time_t (now);
-  struct tm *tm = localtime (&as_time);
+  struct tm tm;
+  localtime_r (&as_time, &tm);
 
   char out[100];
-  strftime (out, sizeof (out), "%F %H:%M:%S", tm);
+  strftime (out, sizeof (out), "%F %H:%M:%S", &tm);
 
   printf_unfiltered ("%s.%03d - %s\n", out, (int) millis, msg);
 }

diff --git a/gdb/nat/linux-osdata.c b/gdb/nat/linux-osdata.c
index ca6acd39eb115992484fce0fa939d254f647a445..d82c062e6c234518f16b3d89aad7f34430860c5f 100644 (file)
--- a/gdb/nat/linux-osdata.c
+++ b/gdb/nat/linux-osdata.c
@@ -916,7 +916,11 @@ time_from_time_t (char *time, int maxlen, TIME_T seconds)
     {
       time_t t = (time_t) seconds;
 
-      strncpy (time, ctime (&t), maxlen);
+      /* Per the ctime_r manpage, this buffer needs to be at least 26
+         characters long.  */
+      char buf[30];
+      const char *time_str = ctime_r (&t, buf);
+      strncpy (time, time_str, maxlen);
       time[maxlen - 1] = '\0';
     }
 }