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authorUwe Kleine-König <u.kleine-koenig@pengutronix.de>2023-04-20 14:13:17 +0200
committerDenys Vlasenko <vda.linux@googlemail.com>2023-05-07 18:57:06 +0200
commit40fa8eb998e27529fcd59830eb163b43658f9e81 (patch)
tree2b9c9be2b1fcf5f947f25d06dc7dc4859ee4ed00
parent07f8b6feac2ff80793394b5b5acff5cd149d7fb2 (diff)
downloadbusybox-40fa8eb998e27529fcd59830eb163b43658f9e81.tar.gz
build system: Make it possible to build with 64bit time_t
On most 32bit architectures time_t (and a few other time related types) are a signed 32bit wide integer type. As a consequence they can only represent dates between Fri Dec 13 08:45:52 PM UTC 1901 (-0x80000000 seconds before Jan 1 1970) and Tue Jan 19 03:14:07 AM UTC 2038 (0x7fffffff seconds after Jan 1 1970). Given that some machines that are built today have an expected lifetime of >15 years, this needs to be extended. To to that, define the cpp symbol _TIME_BITS to 64 which results in some magic in glibc to make time_t (and the few other time related types) 64 bit wide. This new switch CONFIG_TIME64 is in the spirit of CONFIG_LFS and only expected to have the expected effect with glibc. On musl for examples time_t already defaults to 64bit wide types. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
-rw-r--r--Config.in10
-rw-r--r--Makefile.flags1
2 files changed, 11 insertions, 0 deletions
diff --git a/Config.in b/Config.in
index a98a8b15b..214eba546 100644
--- a/Config.in
+++ b/Config.in
@@ -108,6 +108,16 @@ config LFS
programs that can benefit from large file support include dd, gzip,
cp, mount, tar.
+config TIME64
+ bool "Support 64bit wide time types"
+ default y
+ depends on LFS
+ help
+ Make times later than 2038 representable for several libc syscalls
+ (stat, clk_gettime etc.). Note this switch is specific to glibc and has
+ no effect on platforms that already use 64bit wide time types (i.e. all
+ 64bit archs and some selected 32bit archs (currently riscv and x32)).
+
config PAM
bool "Support PAM (Pluggable Authentication Modules)"
default n
diff --git a/Makefile.flags b/Makefile.flags
index 1cec5ba20..e4cd658fd 100644
--- a/Makefile.flags
+++ b/Makefile.flags
@@ -15,6 +15,7 @@ CPPFLAGS += \
-include include/autoconf.h \
-D_GNU_SOURCE -DNDEBUG \
$(if $(CONFIG_LFS),-D_LARGEFILE_SOURCE -D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64) \
+ $(if $(CONFIG_TIME64),-D_TIME_BITS=64) \
-DBB_VER=$(squote)$(quote)$(BB_VER)$(quote)$(squote)
CFLAGS += $(call cc-option,-Wall,)