[PATCH]-19.07 busybox: backport hwclock fixes
Rosen Penev
rosenp at gmail.com
Sat Apr 10 00:43:31 BST 2021
Currently on devices with an RTC, sysfixtime uses busybox' hwclock to
set the RTC time. Unfortunately, g/settimeofday on musl completely
ignore the second parameter which forces users to use the syscall
directly.
Backport two patches to fix hwclock's support for timezones.
Signed-off-by: Rosen Penev <rosenp at gmail.com>
---
Note: this is already fixed in master and 21.02.
package/utils/busybox/Makefile | 2 +-
...ock-Fix-settimeofday-for-glibc-v2.31.patch | 53 +++++
...fix-musl-breakage-of-settimeofday-tz.patch | 195 ++++++++++++++++++
3 files changed, 249 insertions(+), 1 deletion(-)
create mode 100644 package/utils/busybox/patches/010-hwclock-Fix-settimeofday-for-glibc-v2.31.patch
create mode 100644 package/utils/busybox/patches/020-hwclock-fix-musl-breakage-of-settimeofday-tz.patch
diff --git a/package/utils/busybox/Makefile b/package/utils/busybox/Makefile
index 23dd5498a1..a12401ff30 100644
--- a/package/utils/busybox/Makefile
+++ b/package/utils/busybox/Makefile
@@ -9,7 +9,7 @@ include $(TOPDIR)/rules.mk
PKG_NAME:=busybox
PKG_VERSION:=1.30.1
-PKG_RELEASE:=6
+PKG_RELEASE:=7
PKG_FLAGS:=essential
PKG_SOURCE:=$(PKG_NAME)-$(PKG_VERSION).tar.bz2
diff --git a/package/utils/busybox/patches/010-hwclock-Fix-settimeofday-for-glibc-v2.31.patch b/package/utils/busybox/patches/010-hwclock-Fix-settimeofday-for-glibc-v2.31.patch
new file mode 100644
index 0000000000..c6dd897b78
--- /dev/null
+++ b/package/utils/busybox/patches/010-hwclock-Fix-settimeofday-for-glibc-v2.31.patch
@@ -0,0 +1,53 @@
+From 38b8f0a91a786f42531b1e27746060377fbdcaba Mon Sep 17 00:00:00 2001
+From: Eddie James <eajames at linux.ibm.com>
+Date: Mon, 10 Aug 2020 09:59:02 -0500
+Subject: [PATCH 1/2] hwclock: Fix settimeofday for glibc v2.31+
+
+The glibc implementation changed for settimeofday, resulting in "invalid
+argument" error when attempting to set both timezone and time with a single
+call. Fix this by calling settimeofday twice
+
+Signed-off-by: Eddie James <eajames at linux.ibm.com>
+Signed-off-by: Denys Vlasenko <vda.linux at googlemail.com>
+---
+ util-linux/hwclock.c | 14 +++++++++++---
+ 1 file changed, 11 insertions(+), 3 deletions(-)
+
+--- a/util-linux/hwclock.c
++++ b/util-linux/hwclock.c
+@@ -122,16 +122,20 @@ static void to_sys_clock(const char **pp
+ struct timeval tv;
+ struct timezone tz;
+
+- tz.tz_minuteswest = timezone/60;
++ tz.tz_minuteswest = timezone / 60;
+ /* ^^^ used to also subtract 60*daylight, but it's wrong:
+ * daylight!=0 means "this timezone has some DST
+ * during the year", not "DST is in effect now".
+ */
+ tz.tz_dsttime = 0;
+
++ /* glibc v2.31+ returns an error if both args are non-NULL */
++ if (settimeofday(NULL, &tz))
++ bb_simple_perror_msg_and_die("settimeofday");
++
+ tv.tv_sec = read_rtc(pp_rtcname, NULL, utc);
+ tv.tv_usec = 0;
+- if (settimeofday(&tv, &tz))
++ if (settimeofday(&tv, NULL))
+ bb_perror_msg_and_die("settimeofday");
+ }
+
+@@ -283,7 +287,11 @@ static void set_system_clock_timezone(in
+ gettimeofday(&tv, NULL);
+ if (!utc)
+ tv.tv_sec += tz.tz_minuteswest * 60;
+- if (settimeofday(&tv, &tz))
++
++ /* glibc v2.31+ returns an error if both args are non-NULL */
++ if (settimeofday(NULL, &tz))
++ bb_perror_msg_and_die("settimeofday");
++ if (settimeofday(&tv, NULL))
+ bb_perror_msg_and_die("settimeofday");
+ }
+
diff --git a/package/utils/busybox/patches/020-hwclock-fix-musl-breakage-of-settimeofday-tz.patch b/package/utils/busybox/patches/020-hwclock-fix-musl-breakage-of-settimeofday-tz.patch
new file mode 100644
index 0000000000..88ab9f7b18
--- /dev/null
+++ b/package/utils/busybox/patches/020-hwclock-fix-musl-breakage-of-settimeofday-tz.patch
@@ -0,0 +1,195 @@
+From 54644059ef984727168c124858448ec66f4ecb5f Mon Sep 17 00:00:00 2001
+From: Denys Vlasenko <vda.linux at googlemail.com>
+Date: Wed, 16 Dec 2020 13:49:10 +0100
+Subject: [PATCH 2/2] hwclock: fix musl breakage of settimeofday(tz)
+
+function old new delta
+set_kernel_timezone_and_clock - 119 +119
+set_kernel_tz - 28 +28
+hwclock_main 480 301 -179
+------------------------------------------------------------------------------
+(add/remove: 2/0 grow/shrink: 0/1 up/down: 147/-179) Total: -32 bytes
+
+Signed-off-by: Denys Vlasenko <vda.linux at googlemail.com>
+---
+ util-linux/hwclock.c | 128 +++++++++++++++++++++++++------------------
+ 1 file changed, 75 insertions(+), 53 deletions(-)
+
+--- a/util-linux/hwclock.c
++++ b/util-linux/hwclock.c
+@@ -37,6 +37,19 @@
+ #include <sys/utsname.h>
+ #include "rtc_.h"
+
++
++//musl has no __MUSL__ or similar define to check for,
++//but its <sys/types.h> has these lines:
++// #define __NEED_fsblkcnt_t
++// #define __NEED_fsfilcnt_t
++#if defined(__linux__) && defined(__NEED_fsblkcnt_t) && defined(__NEED_fsfilcnt_t)
++# define LIBC_IS_MUSL 1
++# include <sys/syscall.h>
++#else
++# define LIBC_IS_MUSL 0
++#endif
++
++
+ /* diff code is disabled: it's not sys/hw clock diff, it's some useless
+ * "time between hwclock was started and we saw CMOS tick" quantity.
+ * It's useless since hwclock is started at a random moment,
+@@ -117,26 +130,73 @@ static void show_clock(const char **pp_r
+ #endif
+ }
+
+-static void to_sys_clock(const char **pp_rtcname, int utc)
++static void set_kernel_tz(const struct timezone *tz)
+ {
+- struct timeval tv;
+- struct timezone tz;
+-
+- tz.tz_minuteswest = timezone / 60;
+- /* ^^^ used to also subtract 60*daylight, but it's wrong:
+- * daylight!=0 means "this timezone has some DST
+- * during the year", not "DST is in effect now".
++#if LIBC_IS_MUSL
++ /* musl libc does not pass tz argument to syscall
++ * because "it's deprecated by POSIX, therefore it's fine
++ * if we gratuitously break stuff" :(
+ */
+- tz.tz_dsttime = 0;
+-
+- /* glibc v2.31+ returns an error if both args are non-NULL */
+- if (settimeofday(NULL, &tz))
++#if !defined(SYS_settimeofday) && defined(SYS_settimeofday_time32)
++# define SYS_settimeofday SYS_settimeofday_time32
++#endif
++ int ret = syscall(SYS_settimeofday, NULL, tz);
++#else
++ int ret = settimeofday(NULL, tz);
++#endif
++ if (ret)
+ bb_simple_perror_msg_and_die("settimeofday");
++}
++
++/*
++ * At system boot, kernel may set system time from RTC,
++ * but it knows nothing about timezones. If RTC is in local time,
++ * then system time is wrong - it is offset by timezone.
++ * --systz option corrects system time if RTC is in local time,
++ * and (always) sets in-kernel timezone.
++ *
++ * This is an alternate option to --hctosys that does not read the
++ * hardware clock.
++ *
++ * util-linux's code has this comment:
++ * RTC | settimeofday calls
++ * ------|-------------------------------------------------
++ * Local | 1) warps system time*, sets PCIL* and kernel tz
++ * UTC | 1st) locks warp_clock 2nd) sets kernel tz
++ * * only on first call after boot
++ * (PCIL is "persistent_clock_is_local" kernel internal flag,
++ * it makes kernel save RTC in local time, not UTC.)
++ */
++static void set_kernel_timezone_and_clock(int utc, const struct timeval *hctosys)
++{
++ time_t cur;
++ struct tm *broken;
++ struct timezone tz = { 0 };
++
++ /* if --utc, prevent kernel's warp_clock() with a dummy call */
++ if (utc)
++ set_kernel_tz(&tz);
++
++ /* Set kernel's timezone offset based on userspace one */
++ cur = time(NULL);
++ broken = localtime(&cur);
++ tz.tz_minuteswest = -broken->tm_gmtoff / 60;
++ /*tz.tz_dsttime = 0; already is */
++ set_kernel_tz(&tz); /* MIGHT warp_clock() if 1st call since boot */
++
++ if (hctosys) { /* it's --hctosys: set time too */
++ if (settimeofday(hctosys, NULL))
++ bb_simple_perror_msg_and_die("settimeofday");
++ }
++}
++
++static void to_sys_clock(const char **pp_rtcname, int utc)
++{
++ struct timeval tv;
+
+ tv.tv_sec = read_rtc(pp_rtcname, NULL, utc);
+ tv.tv_usec = 0;
+- if (settimeofday(&tv, NULL))
+- bb_perror_msg_and_die("settimeofday");
++ return set_kernel_timezone_and_clock(utc, &tv);
+ }
+
+ static void from_sys_clock(const char **pp_rtcname, int utc)
+@@ -262,39 +322,6 @@ static void from_sys_clock(const char **
+ close(rtc);
+ }
+
+-/*
+- * At system boot, kernel may set system time from RTC,
+- * but it knows nothing about timezones. If RTC is in local time,
+- * then system time is wrong - it is offset by timezone.
+- * This option corrects system time if RTC is in local time,
+- * and (always) sets in-kernel timezone.
+- *
+- * This is an alternate option to --hctosys that does not read the
+- * hardware clock.
+- */
+-static void set_system_clock_timezone(int utc)
+-{
+- struct timeval tv;
+- struct tm *broken;
+- struct timezone tz;
+-
+- gettimeofday(&tv, NULL);
+- broken = localtime(&tv.tv_sec);
+- tz.tz_minuteswest = timezone / 60;
+- if (broken->tm_isdst > 0)
+- tz.tz_minuteswest -= 60;
+- tz.tz_dsttime = 0;
+- gettimeofday(&tv, NULL);
+- if (!utc)
+- tv.tv_sec += tz.tz_minuteswest * 60;
+-
+- /* glibc v2.31+ returns an error if both args are non-NULL */
+- if (settimeofday(NULL, &tz))
+- bb_perror_msg_and_die("settimeofday");
+- if (settimeofday(&tv, NULL))
+- bb_perror_msg_and_die("settimeofday");
+-}
+-
+ //usage:#define hwclock_trivial_usage
+ //usage: IF_LONG_OPTS(
+ //usage: "[-r|--show] [-s|--hctosys] [-w|--systohc] [--systz]"
+@@ -335,7 +362,6 @@ int hwclock_main(int argc UNUSED_PARAM,
+ const char *rtcname = NULL;
+ unsigned opt;
+ int utc;
+-
+ #if ENABLE_LONG_OPTS
+ static const char hwclock_longopts[] ALIGN1 =
+ "localtime\0" No_argument "l" /* short opt is non-standard */
+@@ -347,10 +373,6 @@ int hwclock_main(int argc UNUSED_PARAM,
+ "rtc\0" Required_argument "f"
+ ;
+ #endif
+-
+- /* Initialize "timezone" (libc global variable) */
+- tzset();
+-
+ opt = getopt32long(argv,
+ "^lurswtf:" "\0" "r--wst:w--rst:s--wrt:t--rsw:l--u:u--l",
+ hwclock_longopts,
+@@ -368,7 +390,7 @@ int hwclock_main(int argc UNUSED_PARAM,
+ else if (opt & HWCLOCK_OPT_SYSTOHC)
+ from_sys_clock(&rtcname, utc);
+ else if (opt & HWCLOCK_OPT_SYSTZ)
+- set_system_clock_timezone(utc);
++ set_kernel_timezone_and_clock(utc, NULL);
+ else
+ /* default HWCLOCK_OPT_SHOW */
+ show_clock(&rtcname, utc);
--
2.30.2
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