[Bug 277863] Possible regression in mktime(3)
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=277863 --- Comment #13 from commit-h...@freebsd.org --- A commit in branch stable/13 references this bug: URL: https://cgit.FreeBSD.org/src/commit/?id=662dc74155ada993513a08190032710cf224e47f commit 662dc74155ada993513a08190032710cf224e47f Author: Dag-Erling Smørgrav AuthorDate: 2023-04-26 09:46:41 + Commit: Dag-Erling Smørgrav CommitDate: 2024-04-04 09:51:02 + tzcode: Clean up the ctime(3) manual page. MFC after: 3 weeks Sponsored by: Klara, Inc. Reviewed by:pauamma_gundo.com Differential Revision: https://reviews.freebsd.org/D39714 (cherry picked from commit 6f3c2f41b18b9a7a8feb3c50254a21db2d9908fd) libc: Improve description of mktime() / timegm(). * Mention that mktime() and timegm() set errno on failure. * Correctly determining whether mktime() / timegm() succeeded with arbitrary input (where -1 can be a valid result) is non-trivial. Document the recommended procedure. PR: 277863 MFC after: 1 week Reviewed by:pauamma_gundo.com, gbe Differential Revision: https://reviews.freebsd.org/D44503 (cherry picked from commit 7534109d13a6cdb22e78d9d4c0a0cd5efd323c45) lib/libc/stdtime/ctime.3 | 207 --- 1 file changed, 104 insertions(+), 103 deletions(-) -- You are receiving this mail because: You are the assignee for the bug.
[Bug 277863] Possible regression in mktime(3)
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=277863 --- Comment #12 from commit-h...@freebsd.org --- A commit in branch stable/14 references this bug: URL: https://cgit.FreeBSD.org/src/commit/?id=fdde01c5b44904e34ff3b003f446644de865fa21 commit fdde01c5b44904e34ff3b003f446644de865fa21 Author: Dag-Erling Smørgrav AuthorDate: 2024-03-27 10:03:37 + Commit: Dag-Erling Smørgrav CommitDate: 2024-04-04 09:41:41 + libc: Improve description of mktime() / timegm(). * Mention that mktime() and timegm() set errno on failure. * Correctly determining whether mktime() / timegm() succeeded with arbitrary input (where -1 can be a valid result) is non-trivial. Document the recommended procedure. PR: 277863 MFC after: 1 week Reviewed by:pauamma_gundo.com, gbe Differential Revision: https://reviews.freebsd.org/D44503 (cherry picked from commit 7534109d13a6cdb22e78d9d4c0a0cd5efd323c45) lib/libc/stdtime/ctime.3 | 18 -- 1 file changed, 16 insertions(+), 2 deletions(-) -- You are receiving this mail because: You are the assignee for the bug.
[Bug 277863] Possible regression in mktime(3)
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=277863 --- Comment #11 from commit-h...@freebsd.org --- A commit in branch main references this bug: URL: https://cgit.FreeBSD.org/src/commit/?id=7534109d13a6cdb22e78d9d4c0a0cd5efd323c45 commit 7534109d13a6cdb22e78d9d4c0a0cd5efd323c45 Author: Dag-Erling Smørgrav AuthorDate: 2024-03-27 10:03:37 + Commit: Dag-Erling Smørgrav CommitDate: 2024-03-27 10:03:37 + libc: Improve description of mktime() / timegm(). * Mention that mktime() and timegm() set errno on failure. * Correctly determining whether mktime() / timegm() succeeded with arbitrary input (where -1 can be a valid result) is non-trivial. Document the recommended procedure. PR: 277863 MFC after: 1 week Reviewed by:pauamma_gundo.com, gbe Differential Revision: https://reviews.freebsd.org/D44503 lib/libc/stdtime/ctime.3 | 18 -- 1 file changed, 16 insertions(+), 2 deletions(-) -- You are receiving this mail because: You are the assignee for the bug.
[Bug 277863] Possible regression in mktime(3)
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=277863 --- Comment #10 from Dag-Erling Smørgrav --- Dennis, see https://pubs.opengroup.org/onlinepubs/9699919799/functions/mktime.html -- You are receiving this mail because: You are the assignee for the bug.
[Bug 277863] Possible regression in mktime(3)
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=277863 --- Comment #9 from Dennis Clarke --- There is no mention of errno anywhere in the manpage CTIME(3). -- You are receiving this mail because: You are the assignee for the bug.
[Bug 277863] Possible regression in mktime(3)
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=277863
Dag-Erling Smørgrav changed:
What|Removed |Added
Status|New |Closed
Resolution|--- |Works As Intended
--- Comment #8 from Dag-Erling Smørgrav ---
Your code assumes that errno will be unchanged if mktime() succeeds. This is
incorrect. Here is a better test program:
#include
#include
#include
int
main(void)
{
struct tm tm = { .tm_mday = 1, .tm_year = 69, .tm_yday = -1 };
time_t t = mktime();
if (tm.tm_yday == -1) {
perror("mktime failed");
return 1;
}
printf("%04d-%02d-%02d %02d:%02d:%02d %s = %ld\n",
tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday,
tm.tm_hour, tm.tm_min, tm.tm_sec, tzname[0],
(long)t);
return 0;
}
If you want to argue that errno _should_ be zero if mktime() succeeds, I invite
you to make that argument to the tzcode maintainers
(https://www.iana.org/time-zones), the Austin Group
(https://www.austingroupbugs.net/), and the C standardization committee
(https://www.open-std.org/jtc1/sc22/wg14/), but please take the time to
familiarize yourself with prior work in this area (notably WG14 N3147) first.
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[Bug 277863] Possible regression in mktime(3)
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=277863 Robert Clausecker changed: What|Removed |Added CC||d...@freebsd.org --- Comment #7 from Robert Clausecker --- CC des@, who did the last tzcode merge. This may need to be bisected (sigh..) -- You are receiving this mail because: You are the assignee for the bug.
[Bug 277863] Possible regression in mktime(3)
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=277863 Brennen Murphy changed: What|Removed |Added CC||brennenmu...@pm.me --- Comment #6 from Brennen Murphy --- (QEMU FreeBSD 14.0-RELEASE Test not actual hardware) Big Endian root@freebsd14_ppc64:~ # ./foo Unix time is: -31518000 root@freebsd14_ppc64:~ # Little Endian root@freebsd14_ppc64le:~ # ./foo foo: mktime failed: Value too large to be stored in data type root@freebsd14_ppc64le:~ # -- You are receiving this mail because: You are the assignee for the bug.
[Bug 277863] Possible regression in mktime(3)
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=277863 --- Comment #5 from John F. Carr --- I meant LONG_MIN and LONG_MAX. 64 bits signed, not 32 bits signed. -- You are receiving this mail because: You are the assignee for the bug.
[Bug 277863] Possible regression in mktime(3)
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=277863
John F. Carr changed:
What|Removed |Added
CC||j...@mit.edu
--- Comment #4 from John F. Carr ---
Stepping through mktime, I see a binary search in the range INT_MIN to INT_MAX
seconds that fails because time -4611686018427387904 seconds does not convert
cleanly to a 32 bit year number when using 32 bit intermediate variables. In
this code y = -109624180.
if (ckd_add(>tm_year, y, -TM_YEAR_BASE)) {
errno = EOVERFLOW;
return NULL;
}
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[Bug 277863] Possible regression in mktime(3)
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=277863 --- Comment #3 from Dennis Clarke --- Seems the breakage is somewhere between 13.1 and 13.2 : root@:~ # cc -g -O0 -o foo foo.c root@:~ # root@:~ # ./foo foo: mktime failed: Value too large to be stored in data type root@:~ # freebsd-version -ru 14.0-RELEASE-p5 13.2-RELEASE root@:~ # -- You are receiving this mail because: You are the assignee for the bug.
[Bug 277863] Possible regression in mktime(3)
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=277863 --- Comment #2 from Dennis Clarke --- We verified that it seems to work jusrt fine in a 13.0 and 13.1 jail : root@:~ # freebsd-version -ru 14.0-RELEASE-p5 13.1-RELEASE root@:~ # ./foo Unix time is: -31536000 root@:~ # -- You are receiving this mail because: You are the assignee for the bug.
[Bug 277863] Possible regression in mktime(3)
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=277863 Dennis Clarke changed: What|Removed |Added CC||dcla...@blastwave.org --- Comment #1 from Dennis Clarke --- I can confirm this is a bug even in 13.3-RELEASE : callisto$ callisto$ ./foo foo: mktime failed: Value too large to be stored in data type callisto$ uname -apKU FreeBSD callisto 13.3-RELEASE FreeBSD 13.3-RELEASE releng/13.3-n257428-80d2b634ddf0 GENERIC amd64 amd64 1303001 1303001 callisto$ Dennis Clarke -- You are receiving this mail because: You are the assignee for the bug.
[Bug 277863] Possible regression in mktime(3)
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=277863 Nico Sonack changed: What|Removed |Added URL||https://codeberg.org/schily ||tools/schilytools/issues/66 CC||f...@freebsd.org, ||nson...@outlook.com -- You are receiving this mail because: You are the assignee for the bug.
[Bug 277863] Possible regression in mktime(3)
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=277863
Bug ID: 277863
Summary: Possible regression in mktime(3)
Product: Base System
Version: 14.0-RELEASE
Hardware: Any
OS: Any
Status: New
Severity: Affects Many People
Priority: ---
Component: misc
Assignee: b...@freebsd.org
Reporter: nson...@outlook.com
Attachment #249371 text/plain
mime type:
Created attachment 249371
--> https://bugs.freebsd.org/bugzilla/attachment.cgi?id=249371=edit
Code that triggers the mktime bug
The following works on FreeBSD 13.0-RELEASE amd64 but fails on 14.0-RELEASE
amd64 (code included as an attachment):
#
# freebsd-version
13.0-RELEASE
#
# uname -m
amd64
#
# cat mktime_bug.c
#include
#include
#include
#include
#include
#include
#include
int
main(void)
{
struct tm time_buf = {
.tm_sec = 0,
.tm_min = 0,
.tm_hour = 0,
.tm_mday = 1,
.tm_mon = 0,
.tm_year = 69,
.tm_wday = 3,
.tm_yday = 0,
.tm_isdst = 0,
.tm_zone = "CET",
};
errno = 0;
time_t const unix_time = mktime(_buf);
if (errno)
err(EX_DATAERR, "mktime failed");
printf("Unix time is: %ld\n", unix_time);
return 0;
}
#
# cc -g -O0 -o mktime_bug mktime_bug.c
# ./mktime_bug
Unix time is: -31539600
#
Whereas on 14.0-RELEASE:
$ freebsd-version
14.0-RELEASE-p5
$
$ uname -m
amd64
$
$ cc -g -O0 -o mktime_bug mktime_bug.c
$ ./mktime_bug
mktime_bug: mktime failed: Value too large to be stored in data type
$
Note that the requested year is 1969 - the bug is possibly related to this
fact. This might be a regression due to a version bump of tzcode.
This bug was discovered due to a test failure in schilytools at
https://codeberg.org/schilytools/schilytools/issues/66.
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