glibc/sysdeps/unix/sysv/linux/Makefile
Zack Weinberg 329ea513b4 Avoid cancellable I/O primitives in ld.so.
Neither the <dlfcn.h> entry points, nor lazy symbol resolution, nor
initial shared library load-up, are cancellation points, so ld.so
should exclusively use I/O primitives that are not cancellable.  We
currently achieve this by having the cancellation hooks compile as
no-ops when IS_IN(rtld); this patch changes to using exclusively
_nocancel primitives in the source code instead, which makes the
intent clearer and significantly reduces the amount of code compiled
under IS_IN(rtld) as well as IS_IN(libc) -- in particular,
elf/Makefile no longer thinks we require a copy of unwind.c in
rtld-libc.a.  (The older mechanism is preserved as a backstop.)

The bulk of the change is splitting up the files that define the
_nocancel I/O functions, so they don't also define the variants that
*are* cancellation points; after which, the existing logic for picking
out the bits of libc that need to be recompiled as part of ld.so Just
Works.  I did this for all of the _nocancel functions, not just the
ones used by ld.so, for consistency.

fcntl was a little tricky because it's only a cancellation point for
certain opcodes (F_SETLKW(64), which can block), and the existing
__fcntl_nocancel wasn't applying the FCNTL_ADJUST_CMD hook, which
strikes me as asking for trouble, especially as the only nontrivial
definition of FCNTL_ADJUST_CMD (for powerpc64) changes F_*LK* opcodes.
To fix this, fcntl_common moves to fcntl_nocancel.c along with
__fcntl_nocancel, and changes its name to the extern (but hidden)
symbol __fcntl_nocancel_adjusted, so that regular fcntl can continue
calling it.  __fcntl_nocancel now applies FCNTL_ADJUST_CMD; so that
both both fcntl.c and fcntl_nocancel.c can see it, the only nontrivial
definition moves from sysdeps/u/s/l/powerpc/powerpc64/fcntl.c to
.../powerpc64/sysdep.h and becomes entirely a macro, instead of a macro
that calls an inline function.

The nptl version of libpthread also changes a little, because its
"compat-routines" formerly included files that defined all the
_nocancel functions it uses; instead of continuing to duplicate them,
I exported the relevant ones from libc.so as GLIBC_PRIVATE.  Since the
Linux fcntl.c calls a function defined by fcntl_nocancel.c, it can no
longer be used from libpthread.so; instead, introduce a custom
forwarder, pt-fcntl.c, and export __libc_fcntl from libc.so as
GLIBC_PRIVATE.  The nios2-linux ABI doesn't include a copy of vfork()
in libpthread, and it was handling that by manipulating
libpthread-routines in .../linux/nios2/Makefile; it is cleaner to do
what other such ports do, and have a pt-vfork.S that defines no symbols.

Right now, it appears that Hurd does not implement _nocancel I/O, so
sysdeps/generic/not-cancel.h will forward everything back to the
regular functions.  This changed the names of some of the functions
that sysdeps/mach/hurd/dl-sysdep.c needs to interpose.

	* elf/dl-load.c, elf/dl-misc.c, elf/dl-profile.c, elf/rtld.c
	* sysdeps/unix/sysv/linux/dl-sysdep.c
	Include not-cancel.h.  Use __close_nocancel instead of __close,
	__open64_nocancel instead of __open, __read_nocancel instead of
	__libc_read, and __write_nocancel instead of __libc_write.

	* csu/check_fds.c (check_one_fd)
	* sysdeps/posix/fdopendir.c (__fdopendir)
	* sysdeps/posix/opendir.c (__alloc_dir): Use __fcntl_nocancel
        instead of __fcntl and/or __libc_fcntl.

	* sysdeps/unix/sysv/linux/pthread_setname.c (pthread_setname_np)
	* sysdeps/unix/sysv/linux/pthread_getname.c (pthread_getname_np)
        * sysdeps/unix/sysv/linux/i386/smp.h (is_smp_system):
	Use __open64_nocancel instead of __open_nocancel.

	* sysdeps/unix/sysv/linux/not-cancel.h: Move all of the
	hidden_proto declarations to the end and issue them if either
	IS_IN(libc) or IS_IN(rtld).
	* sysdeps/unix/sysv/linux/Makefile [subdir=io] (sysdep_routines):
	Add close_nocancel, fcntl_nocancel, nanosleep_nocancel,
	open_nocancel, open64_nocancel, openat_nocancel, pause_nocancel,
	read_nocancel, waitpid_nocancel, write_nocancel.

        * io/Versions [GLIBC_PRIVATE]: Add __libc_fcntl,
        __fcntl_nocancel, __open64_nocancel, __write_nocancel.
        * posix/Versions: Add __nanosleep_nocancel, __pause_nocancel.

        * nptl/pt-fcntl.c: New file.
        * nptl/Makefile (pthread-compat-wrappers): Remove fcntl.
        (libpthread-routines): Add pt-fcntl.
        * include/fcntl.h (__fcntl_nocancel_adjusted): New function.
        (__libc_fcntl): Remove attribute_hidden.
	* sysdeps/unix/sysv/linux/fcntl.c (__libc_fcntl): Call
	__fcntl_nocancel_adjusted, not fcntl_common.
        (__fcntl_nocancel): Move to new file fcntl_nocancel.c.
	(fcntl_common): Rename to __fcntl_nocancel_adjusted; also move
	to fcntl_nocancel.c.
	* sysdeps/unix/sysv/linux/fcntl_nocancel.c: New file.
	* sysdeps/unix/sysv/linux/powerpc/powerpc64/fcntl.c: Remove file.
	* sysdeps/unix/sysv/linux/powerpc/powerpc64/sysdep.h:
	Define FCNTL_ADJUST_CMD here, as a self-contained macro.

	* sysdeps/unix/sysv/linux/close.c: Move __close_nocancel to...
	* sysdeps/unix/sysv/linux/close_nocancel.c: ...this new file.
	* sysdeps/unix/sysv/linux/nanosleep.c: Move __nanosleep_nocancel to...
	* sysdeps/unix/sysv/linux/nanosleep_nocancel.c: ...this new file.
	* sysdeps/unix/sysv/linux/open.c: Move __open_nocancel to...
	* sysdeps/unix/sysv/linux/open_nocancel.c: ...this new file.
	* sysdeps/unix/sysv/linux/open64.c: Move __open64_nocancel to...
	* sysdeps/unix/sysv/linux/open64_nocancel.c: ...this new file.
	* sysdeps/unix/sysv/linux/openat.c: Move __openat_nocancel to...
	* sysdeps/unix/sysv/linux/openat_nocancel.c: ...this new file.
	* sysdeps/unix/sysv/linux/openat64.c: Move __openat64_nocancel to...
	* sysdeps/unix/sysv/linux/openat64_nocancel.c: ...this new file.
	* sysdeps/unix/sysv/linux/pause.c: Move __pause_nocancel to...
	* sysdeps/unix/sysv/linux/pause_nocancel.c: ...this new file.
	* sysdeps/unix/sysv/linux/read.c: Move __read_nocancel to...
	* sysdeps/unix/sysv/linux/read_nocancel.c: ...this new file.
	* sysdeps/unix/sysv/linux/waitpid.c: Move __waitpid_nocancel to...
	* sysdeps/unix/sysv/linux/waitpid_nocancel.c: ...this new file.
	* sysdeps/unix/sysv/linux/write.c: Move __write_nocancel to...
	* sysdeps/unix/sysv/linux/write_nocancel.c: ...this new file.

        * sysdeps/unix/sysv/linux/nios2/Makefile: Don't override
        libpthread-routines.
        * sysdeps/unix/sysv/linux/nios2/pt-vfork.S: New file which
        defines nothing.

        * sysdeps/mach/hurd/dl-sysdep.c: Define __read instead of
        __libc_read, and __write instead of __libc_write.  Define
        __open64 in addition to __open.
2018-06-12 09:53:04 -04:00

208 lines
6.7 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 += 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
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
# 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)
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.sh \
$(objpfx)signal.o*
AWK=$(AWK) $(SHELL) ../sysdeps/unix/sysv/linux/tst-signal-numbers.sh \
$(CC) $(patsubst -DMODULE_NAME=%,-DMODULE_NAME=testsuite,$(CPPFLAGS)) \
< /dev/null > $@; $(evaluate-test)
endif
ifeq ($(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
sysdep_routines += cmsg_nxthdr
CFLAGS-recvmmsg.c = -fexceptions -fasynchronous-unwind-tables
CFLAGS-sendmmsg.c = -fexceptions -fasynchronous-unwind-tables
endif
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
tests += tst-affinity tst-affinity-pid
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 ($(subdir),dirent)
sysdep_routines += getdirentries getdirentries64
endif
ifeq ($(subdir),nis)
CFLAGS-ypclnt.c = -DUSE_BINDINGDIR=1
endif
ifeq ($(subdir),io)
sysdep_routines += xstatconv internal_statvfs internal_statvfs64 \
sync_file_range fallocate fallocate64 \
close_nocancel fcntl_nocancel nanosleep_nocancel \
open_nocancel open64_nocancel \
openat_nocancel openat64_nocancel \
pause_nocancel read_nocancel waitpid_nocancel write_nocancel
sysdep_headers += bits/fcntl-linux.h
tests += tst-fallocate tst-fallocate64
endif
ifeq ($(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