From 8492c4dd699e2a65a5a2e8fca3e0e530326c92b9 Mon Sep 17 00:00:00 2001 From: Florian Weimer Date: Tue, 7 Mar 2017 09:37:46 +0100 Subject: timezone: Remove TZNAME_MAX limit from sysconf [BZ #15576] glibc does not impose a limit, and POSIX does not allow a sysconf limit which changes during the lifetime of a process. --- ChangeLog | 18 ++++++++++++++++++ include/time.h | 8 -------- manual/conf.texi | 12 ++++-------- posix/sysconf.c | 2 +- sysdeps/posix/sysconf.c | 2 +- time/tzfile.c | 24 ------------------------ time/tzset.c | 41 ++++------------------------------------- 7 files changed, 28 insertions(+), 79 deletions(-) diff --git a/ChangeLog b/ChangeLog index 340ae0e..63b9a15 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,21 @@ +2017-03-07 Florian Weimer + + [BZ #15576] + Remove TZNAME_MAX limit from sysconf. + * include/time.h (__tzname_cur_max, __tzname_max): Remove + declaration. + * time/tzfile.c (__tzfile_read, __tzfile_default): Do not call + compute_tzname_max. + (compute_tzname_max): Remove. + * time/tzset.c (__tzname_cur_max, __tzname_max): Remove. + (update_vars): Do not update __tzname_cur_max. + (tzset_internal): Remove argument. + (__tzset): Adjust call to tzset_internal. + (__tz_convert): Likewise. + * posix/sysconf.c (__sysconf): Return -1 for _SC_TZNAME_MAX. + * sysdeps/posix/sysconf.c (__sysconf): Likewise. + * manual/conf.texi (Sysconf Definition): Update comment. + 2017-03-07 Siddhesh Poyarekar [BZ #21209] diff --git a/include/time.h b/include/time.h index 684ceb8..6badf0e 100644 --- a/include/time.h +++ b/include/time.h @@ -37,10 +37,6 @@ extern struct tm _tmbuf attribute_hidden; /* Defined in tzset.c. */ extern char *__tzstring (const char *string); -/* Defined in tzset.c. */ -extern size_t __tzname_cur_max attribute_hidden; - - extern int __use_tzfile attribute_hidden; extern void __tzfile_read (const char *file, size_t extra, @@ -82,10 +78,6 @@ extern void __tzset (void); /* Prototype for the internal function to get information based on TZ. */ extern struct tm *__tz_convert (const time_t *timer, int use_localtime, struct tm *tp); -/* Return the maximum length of a timezone name. - This is what `sysconf (_SC_TZNAME_MAX)' does. */ -extern long int __tzname_max (void); - extern int __nanosleep (const struct timespec *__requested_time, struct timespec *__remaining); libc_hidden_proto (__nanosleep) diff --git a/manual/conf.texi b/manual/conf.texi index 78b7a4d..1fe75c2 100644 --- a/manual/conf.texi +++ b/manual/conf.texi @@ -291,14 +291,10 @@ constants are declared in the header file @file{unistd.h}. @safety{@prelim{}@mtsafe{@mtsenv{}}@asunsafe{@asulock{} @ascuheap{}}@acunsafe{@aculock{} @acsmem{} @acsfd{}}} @c Some parts of the implementation open /proc and /sys files and dirs @c to collect system details, using fd and stream I/O depending on the -@c case. _SC_TZNAME_MAX calls __tzname_max, that (while holding a lock) -@c calls tzset_internal, that calls getenv if it's called the first -@c time; there are free and strdup calls in there too. The returned max -@c value may change over time for TZNAME_MAX, depending on selected -@c timezones; NPROCS, NPROCS_CONF, PHYS_PAGES, AVPHYS_PAGES, -@c NGROUPS_MAX, SIGQUEUE_MAX, depending on variable values read from -@c /proc at each call, and from rlimit-obtained values CHILD_MAX, -@c OPEN_MAX, ARG_MAX, SIGQUEUE_MAX. +@c case. The returned max value may change over time for NPROCS, +@c NPROCS_CONF, PHYS_PAGES, AVPHYS_PAGES, NGROUPS_MAX, SIGQUEUE_MAX, +@c depending on variable values read from /proc at each call, and from +@c rlimit-obtained values CHILD_MAX, OPEN_MAX, ARG_MAX, SIGQUEUE_MAX. This function is used to inquire about runtime system parameters. The @var{parameter} argument should be one of the @samp{_SC_} symbols listed below. diff --git a/posix/sysconf.c b/posix/sysconf.c index 0b73b6a..4e9ed97 100644 --- a/posix/sysconf.c +++ b/posix/sysconf.c @@ -37,7 +37,7 @@ __sysconf (int name) return -1; case _SC_TZNAME_MAX: - return MAX (__tzname_max (), _POSIX_TZNAME_MAX); + return -1; case _SC_CHARCLASS_NAME_MAX: #ifdef CHARCLASS_NAME_MAX diff --git a/sysdeps/posix/sysconf.c b/sysdeps/posix/sysconf.c index 19ed5b0..a95e1b3 100644 --- a/sysdeps/posix/sysconf.c +++ b/sysdeps/posix/sysconf.c @@ -93,7 +93,7 @@ __sysconf (int name) #endif case _SC_TZNAME_MAX: - return MAX (__tzname_max (), _POSIX_TZNAME_MAX); + return -1; case _SC_JOB_CONTROL: #if CONF_IS_DEFINED_SET (_POSIX_JOB_CONTROL) diff --git a/time/tzfile.c b/time/tzfile.c index 4987f1a..d412469 100644 --- a/time/tzfile.c +++ b/time/tzfile.c @@ -48,8 +48,6 @@ struct leap long int change; /* Seconds of correction to apply. */ }; -static void compute_tzname_max (size_t) internal_function; - static size_t num_transitions; libc_freeres_ptr (static time_t *transitions); static unsigned char *type_idxs; @@ -494,8 +492,6 @@ __tzfile_read (const char *file, size_t extra, char **extrap) if (__tzname[1] == NULL) __tzname[1] = __tzname[0]; - compute_tzname_max (chars); - if (num_transitions == 0) /* Use the first rule (which should also be the only one). */ rule_stdoff = rule_dstoff = types[0].offset; @@ -626,8 +622,6 @@ __tzfile_default (const char *std, const char *dst, /* Set the timezone. */ __timezone = -types[0].offset; - compute_tzname_max (stdlen + dstlen); - /* Invalidate the tzfile attribute cache to force rereading TZDEFRULES the next time it is used. */ tzfile_dev = 0; @@ -836,21 +830,3 @@ __tzfile_compute (time_t timer, int use_localtime, } } } - -static void -internal_function -compute_tzname_max (size_t chars) -{ - const char *p; - - p = zone_names; - do - { - const char *start = p; - while (*p != '\0') - ++p; - if ((size_t) (p - start) > __tzname_cur_max) - __tzname_cur_max = p - start; - } - while (++p < &zone_names[chars]); -} diff --git a/time/tzset.c b/time/tzset.c index 262bbe5..f0e5c95 100644 --- a/time/tzset.c +++ b/time/tzset.c @@ -68,8 +68,7 @@ static tz_rule tz_rules[2]; static void compute_change (tz_rule *rule, int year) __THROW internal_function; -static void tzset_internal (int always, int explicit) - __THROW internal_function; +static void tzset_internal (int always); /* List of buffers containing time zone strings. */ struct tzstring_l @@ -126,24 +125,7 @@ __tzstring (const char *s) { return __tzstring_len (s, strlen (s)); } - -/* Maximum length of a timezone name. tzset_internal keeps this up to date - (never decreasing it) when ! __use_tzfile. - tzfile.c keeps it up to date when __use_tzfile. */ -size_t __tzname_cur_max; - -long int -__tzname_max (void) -{ - __libc_lock_lock (tzset_lock); - - tzset_internal (0, 0); - - __libc_lock_unlock (tzset_lock); - return __tzname_cur_max; -} - static char *old_tz; static void @@ -154,14 +136,6 @@ update_vars (void) __timezone = -tz_rules[0].offset; __tzname[0] = (char *) tz_rules[0].name; __tzname[1] = (char *) tz_rules[1].name; - - /* Keep __tzname_cur_max up to date. */ - size_t len0 = strlen (__tzname[0]); - size_t len1 = strlen (__tzname[1]); - if (len0 > __tzname_cur_max) - __tzname_cur_max = len0; - if (len1 > __tzname_cur_max) - __tzname_cur_max = len1; } @@ -390,8 +364,7 @@ __tzset_parse_tz (const char *tz) /* Interpret the TZ envariable. */ static void -internal_function -tzset_internal (int always, int explicit) +tzset_internal (int always) { static int is_initialized; const char *tz; @@ -402,12 +375,6 @@ tzset_internal (int always, int explicit) /* Examine the TZ environment variable. */ tz = getenv ("TZ"); - if (tz == NULL && !explicit) - /* Use the site-wide default. This is a file name which means we - would not see changes to the file if we compare only the file - name for change. We want to notice file changes if tzset() has - been called explicitly. Leave TZ as NULL in this case. */ - tz = TZDEFAULT; if (tz && *tz == '\0') /* User specified the empty string; use UTC explicitly. */ tz = "Universal"; @@ -583,7 +550,7 @@ __tzset (void) { __libc_lock_lock (tzset_lock); - tzset_internal (1, 1); + tzset_internal (1); if (!__use_tzfile) { @@ -615,7 +582,7 @@ __tz_convert (const time_t *timer, int use_localtime, struct tm *tp) /* Update internal database according to current TZ setting. POSIX.1 8.3.7.2 says that localtime_r is not required to set tzname. This is a good idea since this allows at least a bit more parallelism. */ - tzset_internal (tp == &_tmbuf && use_localtime, 1); + tzset_internal (tp == &_tmbuf && use_localtime); if (__use_tzfile) __tzfile_compute (*timer, use_localtime, &leap_correction, -- cgit v1.1