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author | Paul Eggert <eggert@cs.ucla.edu> | 2018-09-19 13:16:14 -0700 |
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committer | Paul Eggert <eggert@cs.ucla.edu> | 2018-09-19 17:09:08 -0700 |
commit | 8e6fd2bdb21efe2cc1ae7571ff8fb2599db6a05a (patch) | |
tree | 16623453ad42c7ad61408a410c312aae747cc4d6 /ChangeLog | |
parent | 83a552b0bb9fc2a5e80a0ab3723c0a80ce1db9f2 (diff) | |
download | glibc-8e6fd2bdb21efe2cc1ae7571ff8fb2599db6a05a.tar.gz glibc-8e6fd2bdb21efe2cc1ae7571ff8fb2599db6a05a.tar.xz glibc-8e6fd2bdb21efe2cc1ae7571ff8fb2599db6a05a.zip |
Merge mktime, timegm from upstream Gnulib
[BZ #23603][BZ #16346] This fixes some obscure problems with integer overflow. Although it looks scary, it is almost all a byte-for-byte copy from Gnulib, and the Gnulib code has been tested reasonably well. * include/intprops.h: New file, copied from Gnulib. * include/verify.h, time/mktime-internal.h: New tiny files, simplified from Gnulib. * time/mktime.c: Copy from Gnulib. This has the following changes: Do not include config.h if DEBUG_MKTIME is nonzero. Include stdbool.h, intprops.h, verify.h. Include string.h only if needed. Include stdlib.h on MS-Windows. Include mktime-internal.h. (DEBUG_MKTIME): Default to 0, and simplify later uses. (NEED_MKTIME_INTERNAL, NEED_MKTIME_WINDOWS) (NEED_MKTIME_WORKING): Give default values to pacify -Wundef, which glibc uses. Default NEED_MKTIME_WORKING to DEBUG_MKTIME, to simplify later conditionals; default the others to zero. Use these conditionals to express only the code needed on the current platform. In uses of these conditionals, explicitly spell out how _LIBC affects things, so it’s easier to review from a glibc viewpoint. (WRAPV): Remove; no longer needed now that we have systematic overflow checking. (my_tzset, __tzset) [!_LIBC]: New function and macro, to better compartmentalize tzset issues. Move system-dependent tzsettish code here from mktime. (verify): Remove; now done by verify.h. All uses changed. (long_int): Use a more-conservative definition, to avoid integer overflow. (SHR): Remove, replacing with ... (shr): New function, which means we needn’t worry about side effects in args, and conversion analysis is simpler. (TYPE_IS_INTEGER, TYPE_TWOS_COMPLEMENT, TYPE_SIGNED, TYPE_MINIMUM) (TYPE_MAXIMUM, TIME_T_MIN, TIME_T_MAX, TIME_T_MIDPOINT) (time_t_avg, time_t_add_ok): Remove. (mktime_min, mktime_max): New constants. (leapyear, isdst_differ): Use bool for booleans. (ydhms_diff, guess_time_tm, ranged_convert, __mktime_internal): Use long_int, not time_t, for mktime differences. (long_int_avg): New function, replacing time_t_avg. INT_ADD_WRAPV replaces time_t_add_ok. (guess_time_tm): 6th arg is now long_int, not time_t const *. All uses changed. (convert_time): New function. (ranged_convert): Use it. (__mktime_internal): Last arg now points to mktime_offset_t, not time_t. All uses changed. This is a no-op on glibc, where mktime_offset_t is always time_t. Use int, not time_t, for UTC offset guess. Directly check for integer overflow instead of using a heuristic that works only 99.9...% of the time. Access *OFFSET only once, to avoid an unlikely race if the compiler delays a load and if this cascades into a signed integer overflow. (mktime): Move tzsettish code to my_tzset, and move localtime_offset to within mktime so that it doesn’t need a separate ifdef. (main) [DEBUG_MKTIME]: Speed up by using localtime_r instead of localtime. * time/timegm.c: Copy from Gnulib. This has the following changes: Include mktime-internal.h. [!_LIBC]: Include config.h and time.h. Do not include timegm.h or time_r.h. Make __mktime_internal a macro, and include mktime-internal.h to get its declaration. (timegm): Temporary is now mktime_offset_t, not time_t. This affects only Gnulib.
Diffstat (limited to 'ChangeLog')
-rw-r--r-- | ChangeLog | 70 |
1 files changed, 70 insertions, 0 deletions
diff --git a/ChangeLog b/ChangeLog index 69ee9d08ca..a49dba34ea 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,73 @@ +2018-09-19 Paul Eggert <eggert@cs.ucla.edu> + + Merge mktime, timegm from upstream Gnulib + [BZ #23603][BZ #16346] + This fixes some obscure problems with integer overflow. + Although it looks scary, it is almost all a byte-for-byte copy + from Gnulib, and the Gnulib code has been tested reasonably well. + * include/intprops.h: New file, copied from Gnulib. + * include/verify.h, time/mktime-internal.h: + New tiny files, simplified from Gnulib. + * time/mktime.c: Copy from Gnulib. This has the following changes: + Do not include config.h if DEBUG_MKTIME is nonzero. + Include stdbool.h, intprops.h, verify.h. + Include string.h only if needed. + Include stdlib.h on MS-Windows. + Include mktime-internal.h. + (DEBUG_MKTIME): Default to 0, and simplify later uses. + (NEED_MKTIME_INTERNAL, NEED_MKTIME_WINDOWS) + (NEED_MKTIME_WORKING): Give default values to pacify -Wundef, + which glibc uses. Default NEED_MKTIME_WORKING to DEBUG_MKTIME, to + simplify later conditionals; default the others to zero. Use + these conditionals to express only the code needed on the current + platform. In uses of these conditionals, explicitly spell out how + _LIBC affects things, so it’s easier to review from a glibc + viewpoint. + (WRAPV): Remove; no longer needed now that we have + systematic overflow checking. + (my_tzset, __tzset) [!_LIBC]: New function and macro, to better + compartmentalize tzset issues. Move system-dependent tzsettish + code here from mktime. + (verify): Remove; now done by verify.h. All uses changed. + (long_int): Use a more-conservative definition, to avoid + integer overflow. + (SHR): Remove, replacing with ... + (shr): New function, which means we needn’t worry about side + effects in args, and conversion analysis is simpler. + (TYPE_IS_INTEGER, TYPE_TWOS_COMPLEMENT, TYPE_SIGNED, TYPE_MINIMUM) + (TYPE_MAXIMUM, TIME_T_MIN, TIME_T_MAX, TIME_T_MIDPOINT) + (time_t_avg, time_t_add_ok): Remove. + (mktime_min, mktime_max): New constants. + (leapyear, isdst_differ): Use bool for booleans. + (ydhms_diff, guess_time_tm, ranged_convert, __mktime_internal): + Use long_int, not time_t, for mktime differences. + (long_int_avg): New function, replacing time_t_avg. + INT_ADD_WRAPV replaces time_t_add_ok. + (guess_time_tm): 6th arg is now long_int, not time_t const *. + All uses changed. + (convert_time): New function. + (ranged_convert): Use it. + (__mktime_internal): Last arg now points to mktime_offset_t, not + time_t. All uses changed. This is a no-op on glibc, where + mktime_offset_t is always time_t. Use int, not time_t, for UTC + offset guess. Directly check for integer overflow instead of + using a heuristic that works only 99.9...% of the time. + Access *OFFSET only once, to avoid an unlikely race if the + compiler delays a load and if this cascades into a signed integer + overflow. + (mktime): Move tzsettish code to my_tzset, and move + localtime_offset to within mktime so that it doesn’t + need a separate ifdef. + (main) [DEBUG_MKTIME]: Speed up by using localtime_r + instead of localtime. + * time/timegm.c: Copy from Gnulib. This has the following changes: + Include mktime-internal.h. + [!_LIBC]: Include config.h and time.h. Do not include + timegm.h or time_r.h. Make __mktime_internal a macro, + and include mktime-internal.h to get its declaration. + (timegm): Temporary is now mktime_offset_t, not time_t. + This affects only Gnulib. + 2018-09-19 Wilco Dijkstra <wdijkstr@arm.com> [BZ #23637] |