glibc/malloc/Makefile
Florian Weimer 29d794863c malloc: Run fork handler as late as possible [BZ #19431]
Previously, a thread M invoking fork would acquire locks in this order:

  (M1) malloc arena locks (in the registered fork handler)
  (M2) libio list lock

A thread F invoking flush (NULL) would acquire locks in this order:

  (F1) libio list lock
  (F2) individual _IO_FILE locks

A thread G running getdelim would use this order:

  (G1) _IO_FILE lock
  (G2) malloc arena lock

After executing (M1), (F1), (G1), none of the threads can make progress.

This commit changes the fork lock order to:

  (M'1) libio list lock
  (M'2) malloc arena locks

It explicitly encodes the lock order in the implementations of fork,
and does not rely on the registration order, thus avoiding the deadlock.
2016-04-14 09:17:02 +02:00

168 lines
5.2 KiB
Makefile

# Copyright (C) 1991-2016 Free Software Foundation, Inc.
# This file is part of the GNU C Library.
# The GNU C Library is free software; you can redistribute it and/or
# modify it under the terms of the GNU Lesser General Public
# License as published by the Free Software Foundation; either
# version 2.1 of the License, or (at your option) any later version.
# The GNU C Library is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
# Lesser General Public License for more details.
# You should have received a copy of the GNU Lesser General Public
# License along with the GNU C Library; if not, see
# <http://www.gnu.org/licenses/>.
#
# Makefile for malloc routines
#
subdir := malloc
include ../Makeconfig
dist-headers := malloc.h
headers := $(dist-headers) obstack.h mcheck.h
tests := mallocbug tst-malloc tst-valloc tst-calloc tst-obstack \
tst-mallocstate tst-mcheck tst-mallocfork tst-trim1 \
tst-malloc-usable tst-realloc tst-posix_memalign \
tst-pvalloc tst-memalign tst-mallopt tst-scratch_buffer \
tst-malloc-backtrace tst-malloc-thread-exit \
tst-malloc-thread-fail tst-malloc-fork-deadlock
test-srcs = tst-mtrace
routines = malloc morecore mcheck mtrace obstack \
scratch_buffer_grow scratch_buffer_grow_preserve \
scratch_buffer_set_array_size
install-lib := libmcheck.a
non-lib.a := libmcheck.a
# Additional library.
extra-libs = libmemusage
extra-libs-others = $(extra-libs)
libmemusage-routines = memusage
libmemusage-inhibit-o = $(filter-out .os,$(object-suffixes))
$(objpfx)tst-malloc-backtrace: $(shared-thread-library)
$(objpfx)tst-malloc-thread-exit: $(shared-thread-library)
$(objpfx)tst-malloc-thread-fail: $(shared-thread-library)
$(objpfx)tst-malloc-fork-deadlock: $(shared-thread-library)
# These should be removed by `make clean'.
extra-objs = mcheck-init.o libmcheck.a
# Include the cleanup handler.
aux := set-freeres thread-freeres
# The Perl script to analyze the output of the mtrace functions.
ifneq ($(PERL),no)
install-bin-script = mtrace
generated += mtrace
# The Perl script will print addresses and to do this nicely we must know
# whether we are on a 32 or 64 bit machine.
ifneq ($(findstring wordsize-32,$(config-sysdirs)),)
address-width=10
else
address-width=18
endif
endif
# Unless we get a test for the availability of libgd which also works
# for cross-compiling we disable the memusagestat generation in this
# situation.
ifneq ($(cross-compiling),yes)
# If the gd library is available we build the `memusagestat' program.
ifneq ($(LIBGD),no)
others: $(objpfx)memusage
install-bin = memusagestat
install-bin-script += memusage
generated += memusagestat memusage
extra-objs += memusagestat.o
# The configure.ac check for libgd and its headers did not use $SYSINCLUDES.
# The directory specified by --with-headers usually contains only the basic
# kernel interface headers, not something like libgd. So the simplest thing
# is to presume that the standard system headers will be ok for this file.
$(objpfx)memusagestat.o: sysincludes = # nothing
endif
endif
# Another goal which can be used to override the configure decision.
.PHONY: do-memusagestat
do-memusagestat: $(objpfx)memusagestat
memusagestat-modules = memusagestat
cpp-srcs-left := $(memusagestat-modules)
lib := memusagestat
include $(patsubst %,$(..)cppflags-iterator.mk,$(cpp-srcs-left))
$(objpfx)memusagestat: $(memusagestat-modules:%=$(objpfx)%.o)
$(LINK.o) -o $@ $^ $(libgd-LDFLAGS) -lgd -lpng -lz -lm
ifeq ($(run-built-tests),yes)
ifeq (yes,$(build-shared))
ifneq ($(PERL),no)
tests-special += $(objpfx)tst-mtrace.out
endif
endif
endif
include ../Rules
CFLAGS-mcheck-init.c = $(PIC-ccflag)
CFLAGS-obstack.c = $(uses-callbacks)
$(objpfx)libmcheck.a: $(objpfx)mcheck-init.o
-rm -f $@
$(patsubst %/,cd % &&,$(objpfx)) \
$(LN_S) $(<F) $(@F)
lib: $(objpfx)libmcheck.a
ifeq ($(run-built-tests),yes)
ifeq (yes,$(build-shared))
ifneq ($(PERL),no)
$(objpfx)tst-mtrace.out: tst-mtrace.sh $(objpfx)tst-mtrace
$(SHELL) $< $(common-objpfx) '$(test-program-prefix-before-env)' \
'$(run-program-env)' '$(test-program-prefix-after-env)' ; \
$(evaluate-test)
endif
endif
endif
tst-mcheck-ENV = MALLOC_CHECK_=3
tst-malloc-usable-ENV = MALLOC_CHECK_=3
# Uncomment this for test releases. For public releases it is too expensive.
#CPPFLAGS-malloc.o += -DMALLOC_DEBUG=1
sLIBdir := $(shell echo $(slibdir) | sed 's,lib\(\|64\)$$,\\\\$$LIB,')
$(objpfx)mtrace: mtrace.pl
rm -f $@.new
sed -e 's|@PERL@|$(PERL)|' -e 's|@XXX@|$(address-width)|' \
-e 's|@VERSION@|$(version)|' \
-e 's|@PKGVERSION@|$(PKGVERSION)|' \
-e 's|@REPORT_BUGS_TO@|$(REPORT_BUGS_TO)|' $^ > $@.new \
&& rm -f $@ && mv $@.new $@ && chmod +x $@
$(objpfx)memusage: memusage.sh
rm -f $@.new
sed -e 's|@BASH@|$(BASH)|' -e 's|@VERSION@|$(version)|' \
-e 's|@SLIBDIR@|$(sLIBdir)|' -e 's|@BINDIR@|$(bindir)|' \
-e 's|@PKGVERSION@|$(PKGVERSION)|' \
-e 's|@REPORT_BUGS_TO@|$(REPORT_BUGS_TO)|' $^ > $@.new \
&& rm -f $@ && mv $@.new $@ && chmod +x $@
# The implementation uses `dlsym'
$(objpfx)libmemusage.so: $(libdl)
# Extra dependencies
$(foreach o,$(all-object-suffixes),$(objpfx)malloc$(o)): arena.c hooks.c