Merge branch 'busybox' into merge

28 files changed, 434 insertions, 238 deletions

diff --git a/util-linux/acpid.c b/util-linux/acpid.c
index d473e24fc..00613f8e3 100644
--- a/util-linux/acpid.c
+++ b/util-linux/acpid.c
@@ -99,7 +99,7 @@ struct acpi_event {
         const char *desc;
 };
 
-static const struct acpi_event f_evt_tab[] = {
+static const struct acpi_event f_evt_tab[] ALIGN_PTR = {
         { "EV_KEY", 0x01, "KEY_POWER", 116, 1, "button/power PWRF 00000080" },
         { "EV_KEY", 0x01, "KEY_POWER", 116, 1, "button/power PWRB 00000080" },
         { "EV_SW", 0x05, "SW_LID", 0x00, 1, "button/lid LID0 00000080" },
@@ -110,7 +110,7 @@ struct acpi_action {
         const char *action;
 };
 
-static const struct acpi_action f_act_tab[] = {
+static const struct acpi_action f_act_tab[] ALIGN_PTR = {
         { "PWRF", "PWRF/00000080" },
         { "LID0", "LID/00000080" },
 };
diff --git a/util-linux/blockdev.c b/util-linux/blockdev.c
index e60bbe609..20a031377 100644
--- a/util-linux/blockdev.c
+++ b/util-linux/blockdev.c
@@ -60,7 +60,7 @@ static const char bdcmd_names[] ALIGN1 =
         "flushbufs" "\0"
         "rereadpt"  "\0"
 ;
-static const uint32_t bdcmd_ioctl[] = {
+static const uint32_t bdcmd_ioctl[] ALIGN4 = {
         BLKROSET,       //setro
         BLKROSET,       //setrw
         BLKROGET,       //getro
diff --git a/util-linux/chrt.c b/util-linux/chrt.c
index 4dd78dabf..a8701b55f 100644
--- a/util-linux/chrt.c
+++ b/util-linux/chrt.c
@@ -17,7 +17,7 @@
 //kbuild:lib-$(CONFIG_CHRT) += chrt.o
 
 //usage:#define chrt_trivial_usage
-//usage:       "-m | -p [PRIO] PID | [-rfobi] PRIO PROG [ARGS]"
+//usage:       "-m | -p [PRIO] PID | [-rfobi] PRIO PROG ARGS"
 //usage:#define chrt_full_usage "\n\n"
 //usage:       "Change scheduling priority and class for a process\n"
 //usage:     "\n        -m      Show min/max priorities"
@@ -39,6 +39,17 @@
 # define SCHED_IDLE 5
 #endif
 
+//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
+
 static const char *policy_name(int pol)
 {
         if (pol > 6)
@@ -85,6 +96,7 @@ int chrt_main(int argc UNUSED_PARAM, char **argv)
         char *priority = priority; /* for compiler */
         const char *current_new;
         int policy = SCHED_RR;
+        int ret;
 
         opt = getopt32(argv, "^"
                         "+" "mprfobi"
@@ -132,7 +144,15 @@ int chrt_main(int argc UNUSED_PARAM, char **argv)
         if (opt & OPT_p) {
                 int pol;
  print_rt_info:
+#if LIBC_IS_MUSL
+                /* musl libc returns ENOSYS for its sched_getscheduler library
+                 * function, because the sched_getscheduler Linux kernel system call
+                 * does not conform to Posix; so we use the system call directly
+                 */
+                pol = syscall(SYS_sched_getscheduler, pid);
+#else
                 pol = sched_getscheduler(pid);
+#endif
                 if (pol < 0)
                         bb_perror_msg_and_die("can't %cet pid %u's policy", 'g', (int)pid);
 #ifdef SCHED_RESET_ON_FORK
@@ -149,7 +169,12 @@ int chrt_main(int argc UNUSED_PARAM, char **argv)
                 printf("pid %u's %s scheduling policy: SCHED_%s\n",
                         pid, current_new, policy_name(pol)
                 );
-                if (sched_getparam(pid, &sp))
+#if LIBC_IS_MUSL
+                ret = syscall(SYS_sched_getparam, pid, &sp);
+#else
+                ret = sched_getparam(pid, &sp);
+#endif
+                if (ret)
                         bb_perror_msg_and_die("can't get pid %u's attributes", (int)pid);
                 printf("pid %u's %s scheduling priority: %d\n",
                         (int)pid, current_new, sp.sched_priority
@@ -168,7 +193,12 @@ int chrt_main(int argc UNUSED_PARAM, char **argv)
                 sched_get_priority_min(policy), sched_get_priority_max(policy)
         );
 
-        if (sched_setscheduler(pid, policy, &sp) < 0)
+#if LIBC_IS_MUSL
+        ret = syscall(SYS_sched_setscheduler, pid, policy, &sp);
+#else
+        ret = sched_setscheduler(pid, policy, &sp);
+#endif
+        if (ret)
                 bb_perror_msg_and_die("can't %cet pid %u's policy", 's', (int)pid);
 
         if (!argv[0]) /* "-p PRIO PID [...]" */
diff --git a/util-linux/fbset.c b/util-linux/fbset.c
index 0b9a9a6bc..cc5413b40 100644
--- a/util-linux/fbset.c
+++ b/util-linux/fbset.c
@@ -193,7 +193,7 @@ static const struct cmdoptions_t {
         const char name[9];
         const unsigned char param_count;
         const unsigned char code;
-} g_cmdoptions[] = {
+} g_cmdoptions[] ALIGN1 = {
         /*"12345678" + NUL */
 //TODO: convert to index_in_strings()
         { "fb"      , 1, CMD_FB       },
diff --git a/util-linux/fdisk.c b/util-linux/fdisk.c
index 0fb2e3e17..c50ceead1 100644
--- a/util-linux/fdisk.c
+++ b/util-linux/fdisk.c
@@ -185,8 +185,11 @@ struct hd_geometry {
 
 #define HDIO_GETGEO     0x0301  /* get device geometry */
 
-/* TODO: #if ENABLE_FEATURE_FDISK_WRITABLE */
+/* TODO: just #if ENABLE_FEATURE_FDISK_WRITABLE */
 /* (currently fdisk_sun/sgi.c do not have proper WRITABLE #ifs) */
+#if ENABLE_FEATURE_FDISK_WRITABLE \
+ || ENABLE_FEATURE_SGI_LABEL \
+ || ENABLE_FEATURE_SUN_LABEL
 static const char msg_building_new_label[] ALIGN1 =
 "Building a new %s. Changes will remain in memory only,\n"
 "until you decide to write them. After that the previous content\n"
@@ -194,7 +197,7 @@ static const char msg_building_new_label[] ALIGN1 =
 
 static const char msg_part_already_defined[] ALIGN1 =
 "Partition %u is already defined, delete it before re-adding\n";
-/* #endif */
+#endif
 
 
 struct partition {
@@ -303,7 +306,7 @@ static sector_t get_nr_sects(const struct partition *p);
 
 /* DOS partition types */
 
-static const char *const i386_sys_types[] = {
+static const char *const i386_sys_types[] ALIGN_PTR = {
         "\x00" "Empty",
         "\x01" "FAT12",
         "\x04" "FAT16 <32M",
@@ -2667,7 +2670,7 @@ reread_partition_table(int leave)
         /* Users with slow external USB disks on a 320MHz ARM system (year 2011)
          * report that sleep is needed, otherwise BLKRRPART may fail with -EIO:
          */
-        sleep(1);
+        sleep1();
         i = ioctl_or_perror(dev_fd, BLKRRPART, NULL,
                         "WARNING: rereading partition table "
                         "failed, kernel still uses old table");
diff --git a/util-linux/fdisk_osf.c b/util-linux/fdisk_osf.c
index 92180b2bc..765740ff1 100644
--- a/util-linux/fdisk_osf.c
+++ b/util-linux/fdisk_osf.c
@@ -144,7 +144,7 @@ struct xbsd_disklabel {
 #define BSD_DSTYPE_DOSPART(s)   ((s) & 3)       /* dos partition number */
 #define BSD_DSTYPE_GEOMETRY     0x10            /* drive params in label */
 
-static const char *const xbsd_dktypenames[] = {
+static const char *const xbsd_dktypenames[] ALIGN_PTR = {
         "unknown",
         "SMD",
         "MSCP",
@@ -190,7 +190,7 @@ static const char *const xbsd_dktypenames[] = {
 #define BSD_FS_MSDOS    8               /* MS-DOS file system */
 #endif
 
-static const char *const xbsd_fstypes[] = {
+static const char *const xbsd_fstypes[] ALIGN_PTR = {
         "\x00" "unused",            /* BSD_FS_UNUSED  */
         "\x01" "swap",              /* BSD_FS_SWAP    */
         "\x02" "Version 6",         /* BSD_FS_V6      */
diff --git a/util-linux/fdisk_sgi.c b/util-linux/fdisk_sgi.c
index c90c801e2..acb438ac0 100644
--- a/util-linux/fdisk_sgi.c
+++ b/util-linux/fdisk_sgi.c
@@ -174,7 +174,7 @@ isinfreelist(unsigned int b)
  * end of free blocks section
  */
 
-static const char *const sgi_sys_types[] = {
+static const char *const sgi_sys_types[] ALIGN_PTR = {
 /* SGI_VOLHDR   */      "\x00" "SGI volhdr"  ,
 /* 0x01         */      "\x01" "SGI trkrepl" ,
 /* 0x02         */      "\x02" "SGI secrepl" ,
diff --git a/util-linux/fdisk_sun.c b/util-linux/fdisk_sun.c
index 29d7c283a..427b9487b 100644
--- a/util-linux/fdisk_sun.c
+++ b/util-linux/fdisk_sun.c
@@ -61,7 +61,7 @@ guess_device_type(void)
         }
 }
 
-static const char *const sun_sys_types[] = {
+static const char *const sun_sys_types[] ALIGN_PTR = {
         "\x00" "Empty"       , /* 0            */
         "\x01" "Boot"        , /* 1            */
         "\x02" "SunOS root"  , /* 2            */
@@ -133,7 +133,7 @@ static const struct sun_predefined_drives {
         unsigned short ntrks;
         unsigned short nsect;
         unsigned short rspeed;
-} sun_drives[] = {
+} sun_drives[] ALIGN_PTR = {
         { "Quantum","ProDrive 80S",1,832,2,834,6,34,3662},
         { "Quantum","ProDrive 105S",1,974,2,1019,6,35,3662},
         { "CDC","Wren IV 94171-344",3,1545,2,1549,9,46,3600},
diff --git a/util-linux/fstrim.c b/util-linux/fstrim.c
index 8d29a6d54..6d673002f 100644
--- a/util-linux/fstrim.c
+++ b/util-linux/fstrim.c
@@ -20,18 +20,10 @@
 //usage:#define fstrim_trivial_usage
 //usage:       "[OPTIONS] MOUNTPOINT"
 //usage:#define fstrim_full_usage "\n\n"
-//usage:        IF_LONG_OPTS(
-//usage:       "        -o,--offset OFFSET      Offset in bytes to discard from"
-//usage:     "\n        -l,--length LEN         Bytes to discard"
-//usage:     "\n        -m,--minimum MIN        Minimum extent length"
-//usage:     "\n        -v,--verbose            Print number of discarded bytes"
-//usage:        )
-//usage:        IF_NOT_LONG_OPTS(
 //usage:       "        -o OFFSET       Offset in bytes to discard from"
 //usage:     "\n        -l LEN          Bytes to discard"
 //usage:     "\n        -m MIN          Minimum extent length"
 //usage:     "\n        -v              Print number of discarded bytes"
-//usage:        )
 
 #include "libbb.h"
 #include <linux/fs.h>
diff --git a/util-linux/hexdump.c b/util-linux/hexdump.c
index 2174c3008..57e7e8db7 100644
--- a/util-linux/hexdump.c
+++ b/util-linux/hexdump.c
@@ -28,7 +28,7 @@
 //kbuild:lib-$(CONFIG_HD) += hexdump.o
 
 //usage:#define hexdump_trivial_usage
-//usage:       "[-bcCdefnosvx] [FILE]..."
+//usage:       "[-bcdoxCv] [-e FMT] [-f FMT_FILE] [-n LEN] [-s OFS] [FILE]..."
 //usage:#define hexdump_full_usage "\n\n"
 //usage:       "Display FILEs (or stdin) in a user specified format\n"
 //usage:     "\n        -b              1-byte octal display"
diff --git a/util-linux/hexdump_xxd.c b/util-linux/hexdump_xxd.c
index d2f4b6ed8..29bbc6633 100644
--- a/util-linux/hexdump_xxd.c
+++ b/util-linux/hexdump_xxd.c
@@ -41,7 +41,7 @@
 //    -u          use upper case hex letters.
 
 //usage:#define xxd_trivial_usage
-//usage:       "[OPTIONS] [FILE]"
+//usage:       "[-pr] [-g N] [-c N] [-n LEN] [-s OFS] [FILE]"
 //usage:#define xxd_full_usage "\n\n"
 //usage:       "Hex dump FILE (or stdin)\n"
 //usage:     "\n        -g N            Bytes per group"
@@ -51,7 +51,6 @@
 //usage:     "\n        -l LENGTH       Show only first LENGTH bytes"
 //usage:     "\n        -s OFFSET       Skip OFFSET bytes"
 //usage:     "\n        -r              Reverse (with -p, assumes no offsets in input)"
-// TODO: implement -r (see hexdump -R)
 
 #include "libbb.h"
 #include "dump.h"
diff --git a/util-linux/hwclock.c b/util-linux/hwclock.c
index e85bca2b2..723b09589 100644
--- a/util-linux/hwclock.c
+++ b/util-linux/hwclock.c
@@ -36,6 +36,19 @@
 #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,
@@ -66,7 +79,7 @@ static time_t read_rtc(const char **pp_rtcname, struct timeval *sys_tv, int utc)
                 int before = tm_time.tm_sec;
                 while (1) {
                         rtc_read_tm(&tm_time, fd);
-                        gettimeofday(sys_tv, NULL);
+                        xgettimeofday(sys_tv);
                         if (before != (int)tm_time.tm_sec)
                                 break;
                 }
@@ -116,26 +129,72 @@ static void show_clock(const char **pp_rtcname, int utc)
 #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.
+ * (Unlike --hctosys, it does not read the RTC).
+ *
+ * util-linux's code has this comment:
+ *  RTC   | settimeofday calls
+ *  ------|-------------------------------------------------
+ *  Local | 1st) 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 */
+//It's tempting to call tzset() and use libc global "timezone" variable
+//...but it does NOT include DST shift (IOW: it's WRONG, usually by one hour,
+//if DST is in effect!) Thus this ridiculous dance:
+        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 */
+                xsettimeofday(hctosys);
+}
+
+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_simple_perror_msg_and_die("settimeofday");
+        return set_kernel_timezone_and_clock(utc, &tv);
 }
 
 static void from_sys_clock(const char **pp_rtcname, int utc)
@@ -146,7 +205,7 @@ static void from_sys_clock(const char **pp_rtcname, int utc)
         int rtc;
 
         rtc = rtc_xopen(pp_rtcname, O_WRONLY);
-        gettimeofday(&tv, NULL);
+        xgettimeofday(&tv);
         /* Prepare tm_time */
         if (sizeof(time_t) == sizeof(tv.tv_sec)) {
                 if (utc)
@@ -194,7 +253,7 @@ static void from_sys_clock(const char **pp_rtcname, int utc)
                 unsigned rem_usec;
                 time_t t;
 
-                gettimeofday(&tv, NULL);
+                xgettimeofday(&tv);
 
                 t = tv.tv_sec;
                 rem_usec = 1000000 - tv.tv_usec;
@@ -215,7 +274,7 @@ static void from_sys_clock(const char **pp_rtcname, int utc)
                 }
 
                 /* gmtime/localtime took some time, re-get cur time */
-                gettimeofday(&tv, NULL);
+                xgettimeofday(&tv);
 
                 if (tv.tv_sec < t /* we are still in old second */
                  || (tv.tv_sec == t && tv.tv_usec < adj) /* not too far into next second */
@@ -261,64 +320,53 @@ static void from_sys_clock(const char **pp_rtcname, int utc)
                 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_simple_perror_msg_and_die("settimeofday");
-        if (settimeofday(&tv, NULL))
-                bb_simple_perror_msg_and_die("settimeofday");
-}
+// hwclock from util-linux 2.36.1
+// hwclock [function] [option...]
+//Functions:
+// -r, --show           display the RTC time
+//     --get            display drift corrected RTC time
+//     --set            set the RTC according to --date
+// -s, --hctosys        set the system time from the RTC
+// -w, --systohc        set the RTC from the system time
+//     --systz          send timescale configurations to the kernel
+// -a, --adjust         adjust the RTC to account for systematic drift
+//     --predict        predict the drifted RTC time according to --date
+//Options:
+// -u, --utc            the RTC timescale is UTC
+// -l, --localtime      the RTC timescale is Local
+// -f, --rtc <file>     use an alternate file to /dev/rtc0
+//     --directisa      use the ISA bus instead of /dev/rtc0 access
+//     --date <time>    date/time input for --set and --predict
+//     --delay <sec>    delay used when set new RTC time
+//     --update-drift   update the RTC drift factor
+//     --noadjfile      do not use /etc/adjtime
+//     --adjfile <file> use an alternate file to /etc/adjtime
+//     --test           dry run; implies --verbose
+// -v, --verbose        display more details
 
 //usage:#define hwclock_trivial_usage
 //usage:        IF_LONG_OPTS(
-//usage:       "[-r|--show] [-s|--hctosys] [-w|--systohc] [--systz]"
-//usage:       " [--localtime] [-u|--utc]"
-//usage:       " [-f|--rtc FILE]"
+//usage:       "[-swul] [--systz] [-f DEV]"
 //usage:        )
 //usage:        IF_NOT_LONG_OPTS(
-//usage:       "[-r] [-s] [-w] [-t] [-l] [-u] [-f FILE]"
+//usage:       "[-swult] [-f DEV]"
 //usage:        )
 //usage:#define hwclock_full_usage "\n\n"
-//usage:       "Query and set hardware clock (RTC)\n"
-//usage:     "\n        -r      Show hardware clock time"
-//usage:     "\n        -s      Set system time from hardware clock"
-//usage:     "\n        -w      Set hardware clock from system time"
+//usage:       "Show or set hardware clock (RTC)\n"
+///////:     "\n        -r      Show RTC time"
+///////-r is default, don't bother showing it in help
+//usage:     "\n        -s      Set system time from RTC"
+//usage:     "\n        -w      Set RTC from system time"
 //usage:        IF_LONG_OPTS(
 //usage:     "\n        --systz Set in-kernel timezone, correct system time"
+//usage:     "\n                if RTC is kept in local time"
 //usage:        )
-//usage:     "\n                if hardware clock is in local time"
-//usage:     "\n        -u      Assume hardware clock is kept in UTC"
-//usage:        IF_LONG_OPTS(
-//usage:     "\n        --localtime     Assume hardware clock is kept in local time"
-//usage:        )
-//usage:     "\n        -f FILE Use specified device (e.g. /dev/rtc2)"
+//usage:     "\n        -f DEV  Use specified device (e.g. /dev/rtc2)"
+//usage:     "\n        -u      Assume RTC is kept in UTC"
+//usage:     "\n        -l      Assume RTC is kept in local time"
+//usage:     "\n                (if neither is given, read from "ADJTIME_PATH")"
 
-//TODO: get rid of incompatible -t and -l aliases to --systz and --localtime
+//TODO: get rid of incompatible -t alias to --systz?
 
 #define HWCLOCK_OPT_LOCALTIME   0x01
 #define HWCLOCK_OPT_UTC         0x02
@@ -334,10 +382,9 @@ int hwclock_main(int argc UNUSED_PARAM, char **argv)
         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 */
+                "localtime\0" No_argument "l"
                 "utc\0"       No_argument "u"
                 "show\0"      No_argument "r"
                 "hctosys\0"   No_argument "s"
@@ -346,17 +393,15 @@ int hwclock_main(int argc UNUSED_PARAM, char **argv)
                 "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",
+                "^""lurswtf:v" /* -v is accepted and ignored */
+                "\0"
+                "r--wst:w--rst:s--wrt:t--rsw:l--u:u--l",
                 hwclock_longopts,
                 &rtcname
         );
 
-        /* If -u or -l wasn't given check if we are using utc */
+        /* If -u or -l wasn't given, check if we are using utc */
         if (opt & (HWCLOCK_OPT_UTC | HWCLOCK_OPT_LOCALTIME))
                 utc = (opt & HWCLOCK_OPT_UTC);
         else
@@ -367,7 +412,7 @@ int hwclock_main(int argc UNUSED_PARAM, char **argv)
         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);
diff --git a/util-linux/ionice.c b/util-linux/ionice.c
index 40c04d5e0..c8fb1a777 100644
--- a/util-linux/ionice.c
+++ b/util-linux/ionice.c
@@ -18,11 +18,11 @@
 //kbuild:lib-$(CONFIG_IONICE) += ionice.o
 
 //usage:#define ionice_trivial_usage
-//usage:        "[-c 1-3] [-n 0-7] [-p PID] [PROG]"
+//usage:        "[-c 1-3] [-n 0-7] [-p PID] [PROG ARGS]"
 //usage:#define ionice_full_usage "\n\n"
 //usage:       "Change I/O priority and class\n"
-//usage:     "\n        -c      Class. 1:realtime 2:best-effort 3:idle"
-//usage:     "\n        -n      Priority"
+//usage:     "\n        -c N    Class. 1:realtime 2:best-effort 3:idle"
+//usage:     "\n        -n N    Priority"
 
 #include <sys/syscall.h>
 #include <asm/unistd.h>
@@ -61,7 +61,7 @@ int ionice_main(int argc UNUSED_PARAM, char **argv)
         /* Defaults */
         int ioclass = 0;
         int pri = 0;
-        int pid = 0; /* affect own porcess */
+        int pid = 0; /* affect own process */
         int opt;
         enum {
                 OPT_n = 1,
diff --git a/util-linux/mdev.c b/util-linux/mdev.c
index 59dbcf0cd..dbbcbc655 100644
--- a/util-linux/mdev.c
+++ b/util-linux/mdev.c
@@ -80,12 +80,14 @@
 //kbuild:lib-$(CONFIG_MDEV) += mdev.o
 
 //usage:#define mdev_trivial_usage
-//usage:       "[-s]" IF_FEATURE_MDEV_DAEMON(" | [-df]")
+//usage:       "[-vS] " IF_FEATURE_MDEV_DAEMON("{ ") "[-s]" IF_FEATURE_MDEV_DAEMON(" | [-df] }")
 //usage:#define mdev_full_usage "\n\n"
-//usage:       "mdev -s is to be run during boot to scan /sys and populate /dev.\n"
+//usage:       "        -v      verbose\n"
+//usage:       "        -S      log to syslog too\n"
+//usage:       "        -s      scan /sys and populate /dev\n"
 //usage:        IF_FEATURE_MDEV_DAEMON(
-//usage:       "mdev -d[f]: daemon, listen on netlink.\n"
-//usage:       "        -f: stay in foreground.\n"
+//usage:       "        -d      daemon, listen on netlink\n"
+//usage:       "        -f      stay in foreground\n"
 //usage:        )
 //usage:       "\n"
 //usage:       "Bare mdev is a kernel hotplug helper. To activate it:\n"
@@ -113,6 +115,7 @@
 #include "common_bufsiz.h"
 #include "xregex.h"
 #include <linux/netlink.h>
+#include <syslog.h>
 
 /* "mdev -s" scans /sys/class/xxx, looking for directories which have dev
  * file (it is of the form "M:m\n"). Example: /sys/class/tty/tty0/dev
@@ -269,10 +272,6 @@
 # define dbg3s(msg) ((void)0)
 #endif
 
-
-#ifndef SO_RCVBUFFORCE
-#define SO_RCVBUFFORCE 33
-#endif
 static const char keywords[] ALIGN1 = "add\0remove\0"; // "change\0"
 enum { OP_add, OP_remove };
 
@@ -297,7 +296,7 @@ struct rule {
 
 struct globals {
         int root_major, root_minor;
-        smallint verbose;
+        int verbose;
         char *subsystem;
         char *subsys_env; /* for putenv("SUBSYSTEM=subsystem") */
 #if ENABLE_FEATURE_MDEV_CONF
@@ -921,7 +920,7 @@ static void load_firmware(const char *firmware, const char *sysfs_path)
                 loading_fd = open("loading", O_WRONLY);
                 if (loading_fd >= 0)
                         goto loading;
-                sleep(1);
+                sleep1();
         }
         goto out;
 
@@ -964,7 +963,7 @@ static void load_firmware(const char *firmware, const char *sysfs_path)
 static char *curtime(void)
 {
         struct timeval tv;
-        gettimeofday(&tv, NULL);
+        xgettimeofday(&tv);
         sprintf(
                 strftime_HHMMSS(G.timestr, sizeof(G.timestr), &tv.tv_sec),
                 ".%06u",
@@ -1152,15 +1151,50 @@ static void initial_scan(char *temp)
 
 #if ENABLE_FEATURE_MDEV_DAEMON
 
-/* uevent applet uses 16k buffer, and mmaps it before every read */
-# define BUFFER_SIZE (2 * 1024)
-# define RCVBUF (2 * 1024 * 1024)
+/*
+ * The kernel (as of v5.4) will pass up to 32 environment variables with a
+ * total of 2kiB on each event. On top of that the action string and device
+ * path are added. Using a 3kiB buffer for the event should suffice in any
+ * case.
+ *
+ * As far as the socket receive buffer size is concerned 2MiB proved to be too
+ * small (see [1]). Udevd seems to use a whooping 128MiB. The socket receive
+ * buffer size is just a resource limit. The buffers are allocated lazily so
+ * the memory is not wasted.
+ *
+ * [1] http://lists.busybox.net/pipermail/busybox/2019-December/087665.html
+ */
+# define USER_RCVBUF (3 * 1024)
+# define KERN_RCVBUF (128 * 1024 * 1024)
 # define MAX_ENV 32
 
+static int daemon_init(char *temp)
+{
+        int fd;
+
+        /* Subscribe for UEVENT kernel messages */
+        /* Without a sufficiently big RCVBUF, a ton of simultaneous events
+         * can trigger ENOBUFS on read, which is unrecoverable.
+         * Reproducer:
+         *      mdev -d
+         *      find /sys -name uevent -exec sh -c 'echo add >"{}"' ';'
+         */
+        fd = create_and_bind_to_netlink(NETLINK_KOBJECT_UEVENT, 1 << 0, KERN_RCVBUF);
+
+        /*
+         * Make inital scan after the uevent socket is alive and
+         * _before_ we fork away. Already open mdev.log because we work
+         * in daemon mode.
+         */
+        initial_scan(temp);
+
+        return fd;
+}
+
 static void daemon_loop(char *temp, int fd)
 {
         for (;;) {
-                char netbuf[BUFFER_SIZE];
+                char netbuf[USER_RCVBUF];
                 char *env[MAX_ENV];
                 char *s, *end;
                 ssize_t len;
@@ -1168,6 +1202,16 @@ static void daemon_loop(char *temp, int fd)
 
                 len = safe_read(fd, netbuf, sizeof(netbuf) - 1);
                 if (len < 0) {
+                        if (errno == ENOBUFS) {
+                                /*
+                                 * We ran out of socket receive buffer space.
+                                 * Start from scratch.
+                                 */
+                                dbg1s("uevent overrun, rescanning");
+                                close(fd);
+                                fd = daemon_init(temp);
+                                continue;
+                        }
                         bb_simple_perror_msg_and_die("read");
                 }
                 end = netbuf + len;
@@ -1196,8 +1240,9 @@ int mdev_main(int argc UNUSED_PARAM, char **argv)
 {
         enum {
                 MDEV_OPT_SCAN       = 1 << 0,
-                MDEV_OPT_DAEMON     = 1 << 1,
-                MDEV_OPT_FOREGROUND = 1 << 2,
+                MDEV_OPT_SYSLOG     = 1 << 1,
+                MDEV_OPT_DAEMON     = 1 << 2,
+                MDEV_OPT_FOREGROUND = 1 << 3,
         };
         int opt;
         RESERVE_CONFIG_BUFFER(temp, PATH_MAX + SCRATCH_SIZE);
@@ -1213,7 +1258,11 @@ int mdev_main(int argc UNUSED_PARAM, char **argv)
 
         xchdir("/dev");
 
-        opt = getopt32(argv, "s" IF_FEATURE_MDEV_DAEMON("df"));
+        opt = getopt32(argv, "^"
+                "sS" IF_FEATURE_MDEV_DAEMON("df") "v"
+                "\0"
+                "vv",
+                &G.verbose);
 
 #if ENABLE_FEATURE_MDEV_CONF
         G.filename = "/etc/mdev.conf";
@@ -1223,32 +1272,24 @@ int mdev_main(int argc UNUSED_PARAM, char **argv)
         }
 #endif
 
+        if (opt & MDEV_OPT_SYSLOG) {
+                openlog(applet_name, LOG_PID, LOG_DAEMON);
+                logmode |= LOGMODE_SYSLOG;
+        }
+
 #if ENABLE_FEATURE_MDEV_DAEMON
         if (opt & MDEV_OPT_DAEMON) {
-                /*
-                 * Daemon mode listening on uevent netlink socket.
-                 */
-                int fd;
-
-                /* Subscribe for UEVENT kernel messages */
-                /* Without a sufficiently big RCVBUF, a ton of simultaneous events
-                 * can trigger ENOBUFS on read, which is unrecoverable.
-                 * Reproducer:
-                 *      mdev -d
-                 *      find /sys -name uevent -exec sh -c 'echo add >"{}"' ';'
+                /* Daemon mode listening on uevent netlink socket. Fork away
+                 * after initial scan so that caller can be sure everything
+                 * is up-to-date when mdev process returns.
                  */
-                fd = create_and_bind_to_netlink(NETLINK_KOBJECT_UEVENT, 1 << 0, RCVBUF);
+                int fd = daemon_init(temp);
 
-                /*
-                 * Make inital scan after the uevent socket is alive and
-                 * _before_ we fork away.
-                 */
-                initial_scan(temp);
-
-                if (!(opt & MDEV_OPT_FOREGROUND))
+                if (!(opt & MDEV_OPT_FOREGROUND)) {
+                        /* there is no point in logging to /dev/null */
+                        logmode &= ~LOGMODE_STDIO;
                         bb_daemonize_or_rexec(0, argv);
-
-                open_mdev_log(NULL, getpid());
+                }
 
                 daemon_loop(temp, fd);
         }
diff --git a/util-linux/mkfs_ext2.c b/util-linux/mkfs_ext2.c
index 1f525d75b..fcf374b2d 100644
--- a/util-linux/mkfs_ext2.c
+++ b/util-linux/mkfs_ext2.c
@@ -131,7 +131,7 @@ static void allocate(uint8_t *bitmap, uint32_t blocksize, uint32_t start, uint32
 static uint32_t has_super(uint32_t x)
 {
         // 0, 1 and powers of 3, 5, 7 up to 2^32 limit
-        static const uint32_t supers[] = {
+        static const uint32_t supers[] ALIGN4 = {
                 0, 1, 3, 5, 7, 9, 25, 27, 49, 81, 125, 243, 343, 625, 729,
                 2187, 2401, 3125, 6561, 15625, 16807, 19683, 59049, 78125,
                 117649, 177147, 390625, 531441, 823543, 1594323, 1953125,
diff --git a/util-linux/mkswap.c b/util-linux/mkswap.c
index 9e51a1dcc..8fe5d0293 100644
--- a/util-linux/mkswap.c
+++ b/util-linux/mkswap.c
@@ -128,7 +128,7 @@ int mkswap_main(int argc UNUSED_PARAM, char **argv)
 
         /* Figure out how big the device is */
         len = get_volume_size_in_bytes(fd, argv[1], 1024, /*extend:*/ 1);
-        pagesize = getpagesize();
+        pagesize = bb_getpagesize();
         len -= pagesize;
 
         /* Announce our intentions */
diff --git a/util-linux/mount.c b/util-linux/mount.c
index fc5161d7f..831dab9e2 100644
--- a/util-linux/mount.c
+++ b/util-linux/mount.c
@@ -182,14 +182,16 @@
 //usage:       "Returns 0 for success, number of failed mounts for -a, or errno for one mount."
 
 #include <mntent.h>
+#if ENABLE_FEATURE_SYSLOG
 #include <syslog.h>
+#endif
 #include <sys/mount.h>
 // Grab more as needed from util-linux's mount/mount_constants.h
 #ifndef MS_DIRSYNC
 # define MS_DIRSYNC     (1 << 7) // Directory modifications are synchronous
 #endif
-#ifndef MS_UNION
-# define MS_UNION       (1 << 8)
+#ifndef MS_NOSYMFOLLOW
+# define MS_NOSYMFOLLOW (1 << 8)
 #endif
 #ifndef MS_BIND
 # define MS_BIND        (1 << 12)
@@ -216,12 +218,16 @@
 #ifndef MS_SHARED
 # define MS_SHARED      (1 << 20)
 #endif
+
 #ifndef MS_RELATIME
 # define MS_RELATIME    (1 << 21)
 #endif
 #ifndef MS_STRICTATIME
 # define MS_STRICTATIME (1 << 24)
 #endif
+#ifndef MS_LAZYTIME
+# define MS_LAZYTIME    (1 << 25)
+#endif
 
 /* Any ~MS_FOO value has this bit set: */
 #define BB_MS_INVERTED_VALUE (1u << 31)
@@ -323,7 +329,7 @@ enum {
 
 // Standard mount options (from -o options or --options),
 // with corresponding flags
-static const int32_t mount_options[] = {
+static const int32_t mount_options[] ALIGN4 = {
         // MS_FLAGS set a bit.  ~MS_FLAGS disable that bit.  0 flags are NOPs.
 
         IF_FEATURE_MOUNT_LOOP(
@@ -358,16 +364,19 @@ static const int32_t mount_options[] = {
                 /* "noatime"     */ MS_NOATIME,
                 /* "diratime"    */ ~MS_NODIRATIME,
                 /* "nodiratime"  */ MS_NODIRATIME,
-                /* "mand"        */ MS_MANDLOCK,
-                /* "nomand"      */ ~MS_MANDLOCK,
                 /* "relatime"    */ MS_RELATIME,
                 /* "norelatime"  */ ~MS_RELATIME,
                 /* "strictatime" */ MS_STRICTATIME,
-                /* "loud"        */ ~MS_SILENT,
-                /* "rbind"       */ MS_BIND|MS_RECURSIVE,
+                /* "nostrictatime"*/ ~MS_STRICTATIME,
+                /* "lazytime"    */ MS_LAZYTIME,
+                /* "nolazytime"  */ ~MS_LAZYTIME,
+                /* "nosymfollow" */ MS_NOSYMFOLLOW,
+                /* "mand"        */ MS_MANDLOCK,
+                /* "nomand"      */ ~MS_MANDLOCK,
+                /* "loud"        */ ~MS_SILENT,
 
                 // action flags
-                /* "union"       */ MS_UNION,
+                /* "rbind"       */ MS_BIND|MS_RECURSIVE,
                 /* "bind"        */ MS_BIND,
                 /* "move"        */ MS_MOVE,
                 /* "shared"      */ MS_SHARED,
@@ -404,29 +413,32 @@ static const char mount_option_str[] ALIGN1 =
         )
         IF_FEATURE_MOUNT_FLAGS(
                 // vfs flags
-                "nosuid\0"
-                "suid\0"
-                "dev\0"
-                "nodev\0"
-                "exec\0"
-                "noexec\0"
-                "sync\0"
-                "dirsync\0"
-                "async\0"
-                "atime\0"
-                "noatime\0"
-                "diratime\0"
-                "nodiratime\0"
-                "mand\0"
-                "nomand\0"
-                "relatime\0"
-                "norelatime\0"
-                "strictatime\0"
-                "loud\0"
-                "rbind\0"
+                "nosuid"       "\0"
+                "suid"         "\0"
+                "dev"          "\0"
+                "nodev"        "\0"
+                "exec"         "\0"
+                "noexec"       "\0"
+                "sync"         "\0"
+                "dirsync"      "\0"
+                "async"        "\0"
+                "atime"        "\0"
+                "noatime"      "\0"
+                "diratime"     "\0"
+                "nodiratime"   "\0"
+                "relatime"     "\0"
+                "norelatime"   "\0"
+                "strictatime"  "\0"
+                "nostrictatime""\0"
+                "lazytime"     "\0"
+                "nolazytime"   "\0"
+                "nosymfollow"  "\0"
+                "mand"         "\0"
+                "nomand"       "\0"
+                "loud"         "\0"
 
                 // action flags
-                "union\0"
+                "rbind\0"
                 "bind\0"
                 "move\0"
                 "make-shared\0"
@@ -641,7 +653,7 @@ static unsigned long parse_mount_options(char *options, char **unrecognized)
 // Return a list of all block device backed filesystems
 static llist_t *get_block_backed_filesystems(void)
 {
-        static const char filesystems[2][sizeof("/proc/filesystems")] = {
+        static const char filesystems[2][sizeof("/proc/filesystems")] ALIGN1 = {
                 "/etc/filesystems",
                 "/proc/filesystems",
         };
@@ -2064,13 +2076,18 @@ static int singlemount(struct mntent *mp, int ignore_busy)
         }
 
         // Might this be an NFS filesystem?
-        if ((!mp->mnt_type || is_prefixed_with(mp->mnt_type, "nfs"))
-         && strchr(mp->mnt_fsname, ':') != NULL
+        if (!(vfsflags & (MS_BIND | MS_MOVE))
+         && (!mp->mnt_type || is_prefixed_with(mp->mnt_type, "nfs"))
         ) {
-                if (!mp->mnt_type)
-                        mp->mnt_type = (char*)"nfs";
-                rc = nfsmount(mp, vfsflags, filteropts);
-                goto report_error;
+                char *colon = strchr(mp->mnt_fsname, ':');
+                if (colon // looks like "hostname:..."
+                 && strchrnul(mp->mnt_fsname, '/') > colon // "hostname:" has no slashes
+                ) {
+                        if (!mp->mnt_type)
+                                mp->mnt_type = (char*)"nfs";
+                        rc = nfsmount(mp, vfsflags, filteropts);
+                        goto report_error;
+                }
         }
 
         // Look at the file.  (Not found isn't a failure for remount, or for
@@ -2110,7 +2127,7 @@ static int singlemount(struct mntent *mp, int ignore_busy)
                                         bb_simple_error_msg(bb_msg_perm_denied_are_you_root);
                                 else
                                         bb_simple_perror_msg("can't setup loop device");
-                                return errno;
+                                return loopfd; // was "return errno", but it can be 0 here
                         }
 
                 // Autodetect bind mounts
diff --git a/util-linux/nsenter.c b/util-linux/nsenter.c
index c48dcf885..e6339da2f 100644
--- a/util-linux/nsenter.c
+++ b/util-linux/nsenter.c
@@ -17,7 +17,7 @@
 //kbuild:lib-$(CONFIG_NSENTER) += nsenter.o
 
 //usage:#define nsenter_trivial_usage
-//usage:       "[OPTIONS] [PROG [ARGS]]"
+//usage:       "[OPTIONS] [PROG ARGS]"
 //usage:#define nsenter_full_usage "\n"
 //usage:     "\n        -t PID          Target process to get namespaces from"
 //usage:     "\n        -m[FILE]        Enter mount namespace"
@@ -103,8 +103,9 @@ static const struct namespace_descr ns_list[] = {
 };
 /*
  * Upstream nsenter doesn't support the short option for --preserve-credentials
+ * "+": stop on first non-option
  */
-static const char opt_str[] ALIGN1 = "U::i::u::n::p::m::""t:+S:+G:+r::w::F";
+static const char opt_str[] ALIGN1 = "+""U::i::u::n::p::m::""t:+S:+G:+r::w::F";
 
 #if ENABLE_LONG_OPTS
 static const char nsenter_longopts[] ALIGN1 =
diff --git a/util-linux/rdate.c b/util-linux/rdate.c
index bb1dc519a..9b80141c9 100644
--- a/util-linux/rdate.c
+++ b/util-linux/rdate.c
@@ -96,11 +96,10 @@ int rdate_main(int argc UNUSED_PARAM, char **argv)
                 if (time(NULL) == remote_time)
                         bb_simple_error_msg("current time matches remote time");
                 else {
-                        struct timespec ts;
+                        struct timeval ts;
                         ts.tv_sec = remote_time;
-                        ts.tv_nsec = 0;
-                        if (clock_settime(CLOCK_REALTIME, &ts) < 0)
-                                bb_simple_perror_msg_and_die("can't set time of day");
+                        ts.tv_usec = 0;
+                        xsettimeofday(&ts);
                 }
         }
 
diff --git a/util-linux/rtcwake.c b/util-linux/rtcwake.c
index 823e55662..eac16077d 100644
--- a/util-linux/rtcwake.c
+++ b/util-linux/rtcwake.c
@@ -36,24 +36,13 @@
 //usage:       "[-a | -l | -u] [-d DEV] [-m MODE] [-s SEC | -t TIME]"
 //usage:#define rtcwake_full_usage "\n\n"
 //usage:       "Enter a system sleep state until specified wakeup time\n"
-//usage:        IF_LONG_OPTS(
-//usage:     "\n        -a,--auto       Read clock mode from adjtime"
-//usage:     "\n        -l,--local      Clock is set to local time"
-//usage:     "\n        -u,--utc        Clock is set to UTC time"
-//usage:     "\n        -d,--device DEV Specify the RTC device"
-//usage:     "\n        -m,--mode MODE  Set sleep state (default: standby)"
-//usage:     "\n        -s,--seconds SEC Set timeout in SEC seconds from now"
-//usage:     "\n        -t,--time TIME  Set timeout to TIME seconds from epoch"
-//usage:        )
-//usage:        IF_NOT_LONG_OPTS(
-//usage:     "\n        -a      Read clock mode from adjtime"
+//usage:     "\n        -a      Read clock mode from "ADJTIME_PATH" (default)"
 //usage:     "\n        -l      Clock is set to local time"
 //usage:     "\n        -u      Clock is set to UTC time"
 //usage:     "\n        -d DEV  Specify the RTC device"
 //usage:     "\n        -m MODE Set sleep state (default: standby)"
 //usage:     "\n        -s SEC  Set timeout in SEC seconds from now"
 //usage:     "\n        -t TIME Set timeout to TIME seconds from epoch"
-//usage:        )
 
 #include "libbb.h"
 #include "rtc_.h"
diff --git a/util-linux/script.c b/util-linux/script.c
index 4eac5e94f..963435335 100644
--- a/util-linux/script.c
+++ b/util-linux/script.c
@@ -172,7 +172,7 @@ int script_main(int argc UNUSED_PARAM, char **argv)
                                                 struct timeval tv;
                                                 double newtime;
 
-                                                gettimeofday(&tv, NULL);
+                                                xgettimeofday(&tv);
                                                 newtime = tv.tv_sec + (double) tv.tv_usec / 1000000;
                                                 fprintf(timing_fp, "%f %u\n", newtime - oldtime, count);
                                                 oldtime = newtime;
diff --git a/util-linux/setpriv.c b/util-linux/setpriv.c
index 1e4b201ed..6904cf019 100644
--- a/util-linux/setpriv.c
+++ b/util-linux/setpriv.c
@@ -47,7 +47,7 @@
 //kbuild:lib-$(CONFIG_SETPRIV) += setpriv.o
 
 //usage:#define setpriv_trivial_usage
-//usage:        "[OPTIONS] PROG [ARGS]"
+//usage:        "[OPTIONS] PROG ARGS"
 //usage:#define setpriv_full_usage "\n\n"
 //usage:       "Run PROG with different privilege settings\n"
 //usage:        IF_FEATURE_SETPRIV_DUMP(
diff --git a/util-linux/uevent.c b/util-linux/uevent.c
index 57d9328ef..db11746d0 100644
--- a/util-linux/uevent.c
+++ b/util-linux/uevent.c
@@ -15,7 +15,7 @@
 //kbuild:lib-$(CONFIG_UEVENT) += uevent.o
 
 //usage:#define uevent_trivial_usage
-//usage:       "[PROG [ARGS]]"
+//usage:       "[PROG ARGS]"
 //usage:#define uevent_full_usage "\n\n"
 //usage:       "uevent runs PROG for every netlink notification."
 //usage:   "\n""PROG's environment contains data passed from the kernel."
@@ -26,22 +26,26 @@
 #include "common_bufsiz.h"
 #include <linux/netlink.h>
 
-#define BUFFER_SIZE 16*1024
-
 #define env ((char **)bb_common_bufsiz1)
 #define INIT_G() do { setup_common_bufsiz(); } while (0)
 enum {
         MAX_ENV = COMMON_BUFSIZE / sizeof(char*) - 1,
-        /* sizeof(env[0]) instead of sizeof(char*)
-         * makes gcc-6.3.0 emit "strict-aliasing" warning.
-         */
+        // ^^^sizeof(env[0]) instead of sizeof(char*)
+        // makes gcc-6.3.0 emit "strict-aliasing" warning.
+
+        // socket receive buffer of 2MiB proved to be too small:
+        //  http://lists.busybox.net/pipermail/busybox/2019-December/087665.html
+        // udevd seems to use a whooping 128MiB.
+        // The socket receive buffer size is just a resource limit.
+        // The buffers are allocated lazily so the memory is not wasted.
+        KERN_RCVBUF = 128 * 1024 * 1024,
+
+        // Might be made smaller: the kernel v5.4 passes up to 32 environment
+        // variables with a total of 2kb on each event.
+        // On top of that the action string and device path are added.
+        USER_RCVBUF = 16 * 1024,
 };
 
-#ifndef SO_RCVBUFFORCE
-#define SO_RCVBUFFORCE 33
-#endif
-enum { RCVBUF = 2 * 1024 * 1024 };
-
 int uevent_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
 int uevent_main(int argc UNUSED_PARAM, char **argv)
 {
@@ -57,7 +61,8 @@ int uevent_main(int argc UNUSED_PARAM, char **argv)
         // Reproducer:
         //      uevent mdev &
         //      find /sys -name uevent -exec sh -c 'echo add >"{}"' ';'
-        fd = create_and_bind_to_netlink(NETLINK_KOBJECT_UEVENT, /*groups:*/ 1 << 0, RCVBUF);
+ reopen:
+        fd = create_and_bind_to_netlink(NETLINK_KOBJECT_UEVENT, /*groups:*/ 1 << 0, KERN_RCVBUF);
 
         for (;;) {
                 char *netbuf;
@@ -69,17 +74,20 @@ int uevent_main(int argc UNUSED_PARAM, char **argv)
                 // for a new uevent notification to come in.
                 // We use a fresh mmap so that buffer is not allocated
                 // until kernel actually starts filling it.
-                netbuf = mmap(NULL, BUFFER_SIZE,
-                                        PROT_READ | PROT_WRITE,
-                                        MAP_PRIVATE | MAP_ANON,
-                                        /* ignored: */ -1, 0);
-                if (netbuf == MAP_FAILED)
-                        bb_simple_perror_msg_and_die("mmap");
+                netbuf = xmmap_anon(USER_RCVBUF);
 
                 // Here we block, possibly for a very long time
-                len = safe_read(fd, netbuf, BUFFER_SIZE - 1);
-                if (len < 0)
+                len = safe_read(fd, netbuf, USER_RCVBUF - 1);
+                if (len < 0) {
+                        if (errno == ENOBUFS) {
+                                // Ran out of socket receive buffer
+                                bb_simple_error_msg("uevent overrun");
+                                close(fd);
+                                munmap(netbuf, USER_RCVBUF);
+                                goto reopen;
+                        }
                         bb_simple_perror_msg_and_die("read");
+                }
                 end = netbuf + len;
                 *end = '\0';
 
@@ -108,7 +116,7 @@ int uevent_main(int argc UNUSED_PARAM, char **argv)
                         while (env[idx])
                                 bb_unsetenv(env[idx++]);
                 }
-                munmap(netbuf, BUFFER_SIZE);
+                munmap(netbuf, USER_RCVBUF);
         }
 
         return 0; // not reached
diff --git a/util-linux/umount.c b/util-linux/umount.c
index 63a3bf504..23da32868 100644
--- a/util-linux/umount.c
+++ b/util-linux/umount.c
@@ -41,16 +41,16 @@
 //kbuild:lib-$(CONFIG_UMOUNT) += umount.o
 
 //usage:#define umount_trivial_usage
-//usage:       "[OPTIONS] FILESYSTEM|DIRECTORY"
+//usage:       "[-rlf"IF_FEATURE_MTAB_SUPPORT("m")IF_FEATURE_MOUNT_LOOP("d")IF_FEATURE_UMOUNT_ALL("a")"] [-t FSTYPE] FILESYSTEM|DIRECTORY"
 //usage:#define umount_full_usage "\n\n"
-//usage:       "Unmount file systems\n"
+//usage:       "Unmount filesystems\n"
 //usage:        IF_FEATURE_UMOUNT_ALL(
-//usage:     "\n        -a      Unmount all file systems" IF_FEATURE_MTAB_SUPPORT(" in /etc/mtab")
+//usage:     "\n        -a      Unmount all filesystems" IF_FEATURE_MTAB_SUPPORT(" in /etc/mtab")
 //usage:        )
 //usage:        IF_FEATURE_MTAB_SUPPORT(
 //usage:     "\n        -n      Don't erase /etc/mtab entries"
 //usage:        )
-//usage:     "\n        -r      Try to remount devices as read-only if mount is busy"
+//usage:     "\n        -r      Remount devices read-only if mount is busy"
 //usage:     "\n        -l      Lazy umount (detach filesystem)"
 //usage:     "\n        -f      Force umount (i.e., unreachable NFS server)"
 //usage:        IF_FEATURE_MOUNT_LOOP(
diff --git a/util-linux/unshare.c b/util-linux/unshare.c
index 2087413e8..68ccdd874 100644
--- a/util-linux/unshare.c
+++ b/util-linux/unshare.c
@@ -23,7 +23,7 @@
 //kbuild:lib-$(CONFIG_UNSHARE) += unshare.o
 
 //usage:#define unshare_trivial_usage
-//usage:       "[OPTIONS] [PROG [ARGS]]"
+//usage:       "[OPTIONS] [PROG ARGS]"
 //usage:#define unshare_full_usage "\n"
 //usage:     "\n        -m,--mount[=FILE]       Unshare mount namespace"
 //usage:     "\n        -u,--uts[=FILE]         Unshare UTS namespace (hostname etc.)"
@@ -31,8 +31,8 @@
 //usage:     "\n        -n,--net[=FILE]         Unshare network namespace"
 //usage:     "\n        -p,--pid[=FILE]         Unshare PID namespace"
 //usage:     "\n        -U,--user[=FILE]        Unshare user namespace"
-//usage:     "\n        -f,--fork               Fork before execing PROG"
-//usage:     "\n        -r,--map-root-user      Map current user to root (implies -U)"
+//usage:     "\n        -f                      Fork before execing PROG"
+//usage:     "\n        -r                      Map current user to root (implies -U)"
 //usage:     "\n        --mount-proc[=DIR]      Mount /proc filesystem first (implies -m)"
 //usage:     "\n        --propagation slave|shared|private|unchanged"
 //usage:     "\n                                Modify mount propagation in mount namespace"
diff --git a/util-linux/volume_id/erofs.c b/util-linux/volume_id/erofs.c
new file mode 100644
index 000000000..a163a353d
--- /dev/null
+++ b/util-linux/volume_id/erofs.c
@@ -0,0 +1,67 @@
+/*
+ * volume_id - reads filesystem label and uuid
+ *
+ * Copyright (C) 2020 Norbert Lange <nolange79@gmail.com>
+ *
+ * Licensed under GPLv2, see file LICENSE in this source tree.
+ */
+//config:config FEATURE_VOLUMEID_EROFS
+//config:       bool "erofs filesystem"
+//config:       default y
+//config:       depends on VOLUMEID
+//config:       help
+//config:       Erofs is a compressed readonly filesystem for Linux.
+
+//kbuild:lib-$(CONFIG_FEATURE_VOLUMEID_EROFS) += erofs.o
+
+#include "volume_id_internal.h"
+
+#define EROFS_SUPER_MAGIC_V1    0xE0F5E1E2
+#define EROFS_SUPER_OFFSET      1024
+#define EROFS_FEATURE_COMPAT_SB_CHKSUM          0x00000001
+
+/* 128-byte erofs on-disk super block */
+struct erofs_super_block {
+        uint32_t magic;           /* file system magic number */
+        uint32_t checksum;        /* crc32c(super_block) */
+        uint32_t feature_compat;
+        uint8_t blkszbits;         /* support block_size == PAGE_SIZE only */
+        uint8_t reserved;
+
+        uint16_t root_nid;      /* nid of root directory */
+        uint64_t inos;            /* total valid ino # (== f_files - f_favail) */
+
+        uint64_t build_time;      /* inode v1 time derivation */
+        uint32_t build_time_nsec;       /* inode v1 time derivation in nano scale */
+        uint32_t blocks;          /* used for statfs */
+        uint32_t meta_blkaddr;  /* start block address of metadata area */
+        uint32_t xattr_blkaddr; /* start block address of shared xattr area */
+        uint8_t uuid[16];          /* 128-bit uuid for volume */
+        uint8_t volume_name[16];   /* volume name */
+        uint32_t feature_incompat;
+        uint8_t reserved2[44];
+} PACKED;
+
+int FAST_FUNC volume_id_probe_erofs(struct volume_id *id /*,uint64_t off*/)
+{
+        struct erofs_super_block *sb;
+
+        BUILD_BUG_ON(sizeof(struct erofs_super_block) != 128);
+
+        dbg("erofs: probing at offset 0x%llx", EROFS_SUPER_OFFSET);
+        sb = volume_id_get_buffer(id, EROFS_SUPER_OFFSET, sizeof(*sb));
+        if (!sb)
+                return -1;
+
+        if (sb->magic != cpu_to_le32(EROFS_SUPER_MAGIC_V1))
+                return -1;
+
+        IF_FEATURE_BLKID_TYPE(id->type = "erofs");
+
+        volume_id_set_label_string(id, sb->volume_name,
+                MIN(sizeof(sb->volume_name), VOLUME_ID_LABEL_SIZE));
+
+        volume_id_set_uuid(id, sb->uuid, UUID_DCE);
+
+        return 0;
+}
diff --git a/util-linux/volume_id/volume_id.c b/util-linux/volume_id/volume_id.c
index c3f07a741..8ceb61bde 100644
--- a/util-linux/volume_id/volume_id.c
+++ b/util-linux/volume_id/volume_id.c
@@ -49,7 +49,7 @@
 typedef int FAST_FUNC (*raid_probe_fptr)(struct volume_id *id, /*uint64_t off,*/ uint64_t size);
 typedef int FAST_FUNC (*probe_fptr)(struct volume_id *id /*, uint64_t off*/);
 
-static const raid_probe_fptr raid1[] = {
+static const raid_probe_fptr raid1[] ALIGN_PTR = {
 #if ENABLE_FEATURE_VOLUMEID_LINUXRAID
         volume_id_probe_linux_raid,
 #endif
@@ -76,7 +76,7 @@ static const raid_probe_fptr raid1[] = {
 #endif
 };
 
-static const probe_fptr raid2[] = {
+static const probe_fptr raid2[] ALIGN_PTR = {
 #if ENABLE_FEATURE_VOLUMEID_LVM
         volume_id_probe_lvm1,
         volume_id_probe_lvm2,
@@ -90,7 +90,7 @@ static const probe_fptr raid2[] = {
 };
 
 /* signature in the first block, only small buffer needed */
-static const probe_fptr fs1[] = {
+static const probe_fptr fs1[] ALIGN_PTR = {
 #if ENABLE_FEATURE_VOLUMEID_FAT
         volume_id_probe_vfat,
 #endif
@@ -106,6 +106,9 @@ static const probe_fptr fs1[] = {
 #if ENABLE_FEATURE_VOLUMEID_SQUASHFS
         volume_id_probe_squashfs,
 #endif
+#if ENABLE_FEATURE_VOLUMEID_EROFS
+        volume_id_probe_erofs,
+#endif
 #if ENABLE_FEATURE_VOLUMEID_XFS
         volume_id_probe_xfs,
 #endif
@@ -115,7 +118,7 @@ static const probe_fptr fs1[] = {
 };
 
 /* fill buffer with maximum */
-static const probe_fptr fs2[] = {
+static const probe_fptr fs2[] ALIGN_PTR = {
 #if ENABLE_FEATURE_VOLUMEID_LINUXSWAP
         volume_id_probe_linux_swap,
 #endif
diff --git a/util-linux/volume_id/volume_id_internal.h b/util-linux/volume_id/volume_id_internal.h
index ada18339d..b1e44481f 100644
--- a/util-linux/volume_id/volume_id_internal.h
+++ b/util-linux/volume_id/volume_id_internal.h
@@ -66,6 +66,9 @@ struct volume_id {
         uint8_t         *sbbuf;
         uint8_t         *seekbuf;
         uint64_t        seekbuf_off;
+#if ENABLE_FEATURE_BLKID_TYPE
+        const char      *type;
+#endif
 #ifdef UNUSED_PARTITION_CODE
         struct volume_id_partition *partitions;
         size_t          partition_count;
@@ -80,9 +83,6 @@ struct volume_id {
 //      char            type_version[VOLUME_ID_FORMAT_SIZE];
 //      smallint        usage_id;
 //      const char      *usage;
-#if ENABLE_FEATURE_BLKID_TYPE
-        const char      *type;
-#endif
 };
 
 struct volume_id* FAST_FUNC volume_id_open_node(int fd);
@@ -215,6 +215,8 @@ int FAST_FUNC volume_id_probe_romfs(struct volume_id *id /*,uint64_t off*/);
 
 int FAST_FUNC volume_id_probe_squashfs(struct volume_id *id /*,uint64_t off*/);
 
+int FAST_FUNC volume_id_probe_erofs(struct volume_id *id /*,uint64_t off*/);
+
 int FAST_FUNC volume_id_probe_sysv(struct volume_id *id /*,uint64_t off*/);
 
 int FAST_FUNC volume_id_probe_udf(struct volume_id *id /*,uint64_t off*/);