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authorAlbert ARIBAUD (3ADEV) <albert.aribaud@3adev.fr>2018-10-24 14:43:06 +0200
committerAlbert ARIBAUD (3ADEV) <albert.aribaud@3adev.fr>2018-10-27 17:18:02 +0200
commit91ac988a6b8662cd1e13770cdc550c2609c42178 (patch)
treeafd50335d34eb1affa5c0a1c5a19db2e7c7a1ef0
parente5b8756dc2355c315247b710da8d50d48b7a9728 (diff)
downloadglibc-aaribaud/bugzilla/23789/v2.tar.gz
Ensure mktime sets errno on error (bug 23789)aaribaud/bugzilla/23789/v2
Posix mandates that mktime set errno to EOVERFLOW on error, that it, upon retuning -1, but the glibc mktime does not so far on 32-bit architectures. Fix this and add a test to prevent regressions. The test was run through 'make check' on i686-linux-gnu, then the fix was added and 'make check' run again. * time/mktime.c (mktime): Set errno to EOVERFLOW on error. * time/bug-mktime4.c: New file. * time/Makefile: Add bug-mktime4.
-rw-r--r--time/Makefile2
-rw-r--r--time/bug-mktime4.c28
-rw-r--r--time/mktime.c34
3 files changed, 59 insertions, 5 deletions
diff --git a/time/Makefile b/time/Makefile
index ec3e39dcea..743bd99f18 100644
--- a/time/Makefile
+++ b/time/Makefile
@@ -43,7 +43,7 @@ tests := test_time clocktest tst-posixtz tst-strptime tst_wcsftime \
tst-getdate tst-mktime tst-mktime2 tst-ftime_l tst-strftime \
tst-mktime3 tst-strptime2 bug-asctime bug-asctime_r bug-mktime1 \
tst-strptime3 bug-getdate1 tst-strptime-whitespace tst-ftime \
- tst-tzname tst-y2039
+ tst-tzname tst-y2039 bug-mktime4
include ../Rules
diff --git a/time/bug-mktime4.c b/time/bug-mktime4.c
new file mode 100644
index 0000000000..dd1e0c76bf
--- /dev/null
+++ b/time/bug-mktime4.c
@@ -0,0 +1,28 @@
+#include <time.h>
+#include <errno.h>
+#include <limits.h>
+#include <stdio.h>
+#include <string.h>
+
+static int
+do_test (void)
+{
+ struct tm tm = { .tm_year = INT_MIN, .tm_mon = INT_MIN, .tm_mday = INT_MIN,
+ .tm_hour = INT_MIN, .tm_min = INT_MIN, .tm_sec = INT_MIN };
+ errno = 0;
+ time_t tt = mktime (&tm);
+ if (tt != -1)
+ {
+ printf ("mktime() should have returned -1, returned %ld\n", (long int) tt);
+ return 1;
+ }
+ if (errno != EOVERFLOW)
+ {
+ printf ("mktime() returned -1, errno should be %d (EOVERFLOW) but is %d (%s)\n", EOVERFLOW, errno, strerror(errno));
+ return 1;
+ }
+ return 0;
+}
+
+#define TEST_FUNCTION do_test ()
+#include "../test-skeleton.c"
diff --git a/time/mktime.c b/time/mktime.c
index 00f0dec6b4..54478edab8 100644
--- a/time/mktime.c
+++ b/time/mktime.c
@@ -49,6 +49,7 @@
# define LEAP_SECONDS_POSSIBLE 1
#endif
+#include <errno.h>
#include <time.h>
#include <limits.h>
@@ -435,7 +436,10 @@ __mktime_internal (struct tm *tp,
useful than returning -1. */
goto offset_found;
else if (--remaining_probes == 0)
- return -1;
+ {
+ __set_errno (EOVERFLOW);
+ return -1;
+ }
/* We have a match. Check whether tm.tm_isdst has the requested
value, if any. */
@@ -507,7 +511,10 @@ __mktime_internal (struct tm *tp,
if (INT_ADD_WRAPV (t, sec_adjustment, &t)
|| ! (mktime_min <= t && t <= mktime_max)
|| ! convert_time (convert, t, &tm))
- return -1;
+ {
+ __set_errno (EOVERFLOW);
+ return -1;
+ }
}
*tp = tm;
@@ -522,18 +529,37 @@ __mktime_internal (struct tm *tp,
time_t
mktime (struct tm *tp)
{
+ time_t result;
+ /* When __mktime_internal() returns -1, we need to know it it has set
+ * errno (real error) or not (just returning valid time_t value -1),
+ * so we beed to clear errno before calling __mktime_internal().
+ * But we also need to preserve errno if __mktime_internal() does not
+ * modify it, so we need to back up its current value.
+ * Ditto for __tzset(). */
+ int errno_backup = errno;
+ errno = 0;
+
/* POSIX.1 8.1.1 requires that whenever mktime() is called, the
time zone names contained in the external variable 'tzname' shall
be set as if the tzset() function had been called. */
__tzset ();
+ if (errno != 0)
+ /* __tzset() did overwrite errno so let's not restore it. */
+ return -1;
# if defined _LIBC || NEED_MKTIME_WORKING
static mktime_offset_t localtime_offset;
- return __mktime_internal (tp, __localtime_r, &localtime_offset);
+ result = __mktime_internal (tp, __localtime_r, &localtime_offset);
# else
# undef mktime
- return mktime (tp);
+ result = mktime (tp);
# endif
+ if (result == -1 && errno ==0)
+ return result;
+ else if (errno != 0)
+ return -1;
+ __set_errno(errno_backup);
+ return result;
}
#endif /* _LIBC || NEED_MKTIME_WORKING || NEED_MKTIME_WINDOWS */