glibc/sysdeps/unix/sysv/linux/Makefile
Zack Weinberg 04da832e16 Linux/Alpha: don't use timeval32 system calls.
Linux/Alpha has two versions of several system call wrappers that take
or return data of type "struct timeval" (possibly nested inside a
larger structure).  The GLIBC_2.0 version is a compat symbol that
calls __NR_osf_foo or __NR_old_foo and uses a struct timeval with a
32-bit tv_sec field.  The GLIBC_2.1 version is used for current code,
calls __NR_foo, and uses a struct timeval with a 64-bit tv_sec field.

This patch changes all of the compat symbols of this type to be
wrappers around their GLIBC_2.1 counterparts; the compatibility system
calls will no longer be used.  It serves as a proposal for part of how
we do the transition to 64-bit time_t on systems that currently use
32-bit time_t:

 * The patched glibc will NOT use system calls that involve 32-bit
   time_t to implement its compatibility symbols.  This will make both
   our lives and the kernel maintainers' lives easier.  The primary
   argument I've seen against it is that the kernel could warn about
   uses of the old system calls, helping people find old binaries that
   need to be recompiled.  I think there are several other ways we
   could accomplish this, e.g. scripts to scan the filesystem for
   binaries with references to the old symbol versions, or issuing
   diagnostics ourselves.

 * The compat symbols do NOT report failure after the Y2038 deadline.
   An earlier revision of this patch had them return -1 and set errno
   to EOVERFLOW, but Adhemerval pointed out that many of them have
   already performed side effects at the point where we discover the
   overflow, so that would break more than it fixes.  Also, we don't
   want people to be _checking_ for EOVERFLOW from these functions; we
   want them to recompile with 64-bit time_t.  So it's not actually
   useful for them to report failure to the calling code.

 * What they do do, when they encounter overflow, is saturate the
   overflowed "struct timeval"(s): tv_sec is set to INT32_MAX and
   tv_nsec is set to 999999.  That means time stops advancing for
   programs with 32-bit time_t when they reach the deadline.  That's
   obviously going to break stuff, but I think wrapping around is
   probably going to break _more_ stuff.  I'd be interested to hear
   arguments against, if anyone has one.

The new header file tv32-compat.h is currently Alpha-specific but I
mean for it to be reused to aid in writing wrappers for all affected
architectures.  I only put it in sysdeps/unix/sysv/linux/alpha for now
because I haven't checked whether the various "foo32" structures it
defines agree with the ABI for ports other than Linux/Alpha.

Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
2019-10-30 17:03:42 -03:00

253 lines
8.4 KiB
Makefile

ifeq ($(subdir),csu)
sysdep_routines += errno-loc
endif
ifeq ($(subdir),assert)
CFLAGS-assert.c += -DFATAL_PREPARE_INCLUDE='<fatal-prepare.h>'
CFLAGS-assert-perr.c += -DFATAL_PREPARE_INCLUDE='<fatal-prepare.h>'
endif
ifeq ($(subdir),malloc)
CFLAGS-malloc.c += -DMORECORE_CLEARS=2
endif
ifeq ($(subdir),misc)
include $(firstword $(wildcard $(sysdirs:=/sysctl.mk)))
sysdep_routines += adjtimex clone umount umount2 readahead \
setfsuid setfsgid epoll_pwait signalfd \
eventfd eventfd_read eventfd_write prlimit \
personality epoll_wait tee vmsplice splice \
open_by_handle_at mlock2 pkey_mprotect pkey_set pkey_get
CFLAGS-gethostid.c = -fexceptions
CFLAGS-tee.c = -fexceptions -fasynchronous-unwind-tables
CFLAGS-vmsplice.c = -fexceptions -fasynchronous-unwind-tables
CFLAGS-splice.c = -fexceptions -fasynchronous-unwind-tables
CFLAGS-open_by_handle_at.c = -fexceptions -fasynchronous-unwind-tables
CFLAGS-sync_file_range.c = -fexceptions -fasynchronous-unwind-tables
CFLAGS-tst-writev.c += "-DARTIFICIAL_LIMIT=(0x80000000-sysconf(_SC_PAGESIZE))"
sysdep_headers += sys/mount.h sys/acct.h sys/sysctl.h \
sys/klog.h \
sys/user.h sys/prctl.h \
sys/kd.h sys/soundcard.h sys/vt.h \
sys/quota.h sys/fsuid.h \
scsi/sg.h scsi/scsi.h scsi/scsi_ioctl.h sys/pci.h \
sys/raw.h sys/personality.h sys/epoll.h \
bits/a.out.h sys/inotify.h sys/signalfd.h sys/eventfd.h \
sys/timerfd.h sys/fanotify.h bits/eventfd.h bits/inotify.h \
bits/signalfd.h bits/timerfd.h bits/epoll.h \
bits/socket_type.h bits/syscall.h bits/sysctl.h \
bits/mman-linux.h bits/mman-shared.h bits/ptrace-shared.h \
bits/siginfo-arch.h bits/siginfo-consts-arch.h \
bits/procfs.h bits/procfs-id.h bits/procfs-extra.h \
bits/procfs-prregset.h bits/mman-map-flags-generic.h \
bits/msq-pad.h bits/sem-pad.h bits/shmlba.h bits/shm-pad.h \
bits/termios-struct.h bits/termios-c_cc.h \
bits/termios-c_iflag.h bits/termios-c_oflag.h \
bits/termios-baud.h bits/termios-c_cflag.h \
bits/termios-c_lflag.h bits/termios-tcflow.h \
bits/termios-misc.h \
bits/ipc-perm.h
tests += tst-clone tst-clone2 tst-clone3 tst-fanotify tst-personality \
tst-quota tst-sync_file_range tst-sysconf-iov_max tst-ttyname \
test-errno-linux tst-memfd_create tst-mlock2 tst-pkey \
tst-rlimit-infinity tst-ofdlocks tst-gettid tst-gettid-kill \
tst-tgkill
tests-internal += tst-ofdlocks-compat tst-sigcontext-get_pc
CFLAGS-tst-sigcontext-get_pc.c = -fasynchronous-unwind-tables
# Generate the list of SYS_* macros for the system calls (__NR_*
# macros). The file syscall-names.list contains all possible system
# call names, and the generated header file produces SYS_* macros for
# the __NR_* macros which are actually defined.
generated += bits/syscall.h
$(objpfx)bits/syscall.h: \
../sysdeps/unix/sysv/linux/gen-syscall-h.awk \
../sysdeps/unix/sysv/linux/syscall-names.list
$(make-target-directory)
LC_ALL=C $(AWK) -f $^ > $@-tmp
$(move-if-change) $@-tmp $@
before-compile += $(objpfx)bits/syscall.h
# All macros defined by <sys/syscall.h>. Include <bits/syscall.h>
# explicitly because <sys/sycall.h> skips it if _LIBC is defined.
$(objpfx)tst-syscall-list-macros.list: \
$(objpfx)bits/syscall.h ../sysdeps/unix/sysv/linux/sys/syscall.h
printf '#include <linux/version.h>\n\
#include <sys/syscall.h>\n#include <bits/syscall.h>\n' | \
$(CC) -E -o $@-tmp $(CFLAGS) $(CPPFLAGS) -x c - -dM
$(move-if-change) $@-tmp $@
# __NR_* system call names. Used by the test below.
$(objpfx)tst-syscall-list-nr.list: \
../sysdeps/unix/sysv/linux/filter-nr-syscalls.awk \
$(objpfx)tst-syscall-list-macros.list
LC_ALL=C $(AWK) -f $^ > $@-tmp
$(move-if-change) $@-tmp $@
# SYS_* system call names. Used by the test below.
$(objpfx)tst-syscall-list-sys.list: $(objpfx)tst-syscall-list-macros.list
LC_ALL=C $(AWK) '/^#define SYS_/ { print substr($$2, 5) }' $< > $@-tmp
$(move-if-change) $@-tmp $@
tests-special += $(objpfx)tst-syscall-list.out
$(objpfx)tst-syscall-list.out: \
../sysdeps/unix/sysv/linux/tst-syscall-list.sh \
$(objpfx)tst-syscall-list-macros.list \
$(objpfx)tst-syscall-list-nr.list \
$(objpfx)tst-syscall-list-sys.list
$(BASH) $^ $(AWK) > $@; $(evaluate-test)
# Separate object file for access to the constant from the UAPI header.
$(objpfx)tst-sysconf-iov_max: $(objpfx)tst-sysconf-iov_max-uapi.o
$(objpfx)tst-pkey: $(shared-thread-library)
tests-special += $(objpfx)tst-mman-consts.out
$(objpfx)tst-mman-consts.out: ../sysdeps/unix/sysv/linux/tst-mman-consts.py
PYTHONPATH=../scripts \
$(PYTHON) ../sysdeps/unix/sysv/linux/tst-mman-consts.py \
--cc="$(CC) $(patsubst -DMODULE_NAME=%, \
-DMODULE_NAME=testsuite, \
$(CPPFLAGS))" \
< /dev/null > $@ 2>&1; $(evaluate-test)
$(objpfx)tst-gettid: $(shared-thread-library)
$(objpfx)tst-gettid-kill: $(shared-thread-library)
$(objpfx)tst-tgkill: $(shared-thread-library)
endif # $(subdir) == misc
ifeq ($(subdir),time)
sysdep_headers += sys/timex.h bits/timex.h
sysdep_routines += ntp_gettime ntp_gettimex
endif
ifeq ($(subdir),signal)
tests-special += $(objpfx)tst-signal-numbers.out
# Depending on signal.o* is a hack. What we actually want is a dependency
# on signal.h and everything it includes. That's impractical to write
# in this context, but signal.c includes signal.h and not much else so it'll
# be conservatively correct.
$(objpfx)tst-signal-numbers.out: \
../sysdeps/unix/sysv/linux/tst-signal-numbers.py \
$(objpfx)signal.o*
PYTHONPATH=../scripts \
$(PYTHON) ../sysdeps/unix/sysv/linux/tst-signal-numbers.py \
--cc="$(CC) $(patsubst -DMODULE_NAME=%, \
-DMODULE_NAME=testsuite, \
$(CPPFLAGS))" \
< /dev/null > $@ 2>&1; $(evaluate-test)
endif
ifeq ($(subdir),socket)
sysdep_headers += net/if_ppp.h net/ppp-comp.h \
net/ppp_defs.h net/if_arp.h net/route.h net/ethernet.h \
net/if_slip.h net/if_packet.h net/if_shaper.h \
bits/socket-constants.h
sysdep_routines += cmsg_nxthdr
CFLAGS-recvmmsg.c = -fexceptions -fasynchronous-unwind-tables
CFLAGS-sendmmsg.c = -fexceptions -fasynchronous-unwind-tables
tests-special += $(objpfx)tst-socket-consts.out
$(objpfx)tst-socket-consts.out: ../sysdeps/unix/sysv/linux/tst-socket-consts.py
PYTHONPATH=../scripts \
$(PYTHON) ../sysdeps/unix/sysv/linux/tst-socket-consts.py \
--cc="$(CC) $(patsubst -DMODULE_NAME=%, \
-DMODULE_NAME=testsuite, \
$(CPPFLAGS)) -D_ISOMAC" \
< /dev/null > $@ 2>&1; $(evaluate-test)
endif # $(subdir) == socket
ifeq ($(subdir),sunrpc)
sysdep_headers += nfs/nfs.h
endif
ifeq ($(subdir),termios)
sysdep_headers += termio.h
endif
ifeq ($(subdir),posix)
sysdep_headers += bits/initspin.h
sysdep_routines += sched_getcpu oldglob getcpu
tests += tst-affinity tst-affinity-pid
tests-static := tst-affinity-static
tests += $(tests-static)
CFLAGS-fork.c = $(libio-mtsafe)
CFLAGS-getpid.o = -fomit-frame-pointer
CFLAGS-getpid.os = -fomit-frame-pointer
endif
ifeq ($(subdir),inet)
sysdep_headers += netinet/if_fddi.h netinet/if_tr.h \
netipx/ipx.h netash/ash.h netax25/ax25.h netatalk/at.h \
netrom/netrom.h netpacket/packet.h netrose/rose.h \
neteconet/ec.h netiucv/iucv.h
sysdep_routines += netlink_assert_response
endif
# Don't compile the ctype glue code, since there is no old non-GNU C library.
inhibit-glue = yes
ifeq ($(subdir),dirent)
sysdep_routines += getdirentries getdirentries64
tests += tst-getdents64
tests-internal += tst-readdir64-compat
endif
ifeq ($(subdir),nis)
CFLAGS-ypclnt.c = -DUSE_BINDINGDIR=1
endif
ifeq ($(subdir),io)
sysdep_routines += xstatconv internal_statvfs internal_statvfs64 \
sync_file_range fallocate fallocate64 \
close_nocancel fcntl_nocancel nanosleep_nocancel \
open_nocancel open64_nocancel \
openat_nocancel openat64_nocancel \
pause_nocancel read_nocancel pread64_nocancel \
waitpid_nocancel write_nocancel statx_cp
sysdep_headers += bits/fcntl-linux.h
tests += tst-fallocate tst-fallocate64
endif
ifeq ($(subdir),elf)
sysdep-rtld-routines += dl-brk dl-sbrk dl-getcwd dl-openat64 dl-opendir \
dl-fxstatat64
libof-lddlibc4 = lddlibc4
others += pldd
install-bin += pldd
$(objpfx)pldd: $(objpfx)xmalloc.o
endif
ifeq ($(subdir),rt)
CFLAGS-mq_send.c += -fexceptions
CFLAGS-mq_receive.c += -fexceptions
endif
ifeq ($(subdir),nscd)
sysdep-CFLAGS += -DHAVE_EPOLL -DHAVE_INOTIFY -DHAVE_NETLINK
CFLAGS-gai.c += -DNEED_NETLINK
endif
ifeq ($(subdir),nptl)
tests += tst-align-clone tst-getpid1 \
tst-thread-affinity-pthread tst-thread-affinity-pthread2 \
tst-thread-affinity-sched
tests-internal += tst-setgetname
endif