| Message ID | 20140325192856.GW1817@tucnak.redhat.com |
|---|---|
| State | New |
| Headers | show |
On Tue, Mar 25, 2014 at 12:28 PM, Jakub Jelinek <jakub@redhat.com> wrote: > Hi! > > lto-plugin is another problematic directory in asan/ubsan bootstraps. > > Unlike fixincludes, it is bootstrapped, and like fixincludes it is also > linked against host libiberty. The problem for lto-plugin is that the > -static-libubsan -fsanitize=undefined -B/some/path/to/libsanitizer/ -B/some/path/to/libsanitizer/ubsan/.libs/ > switches are eaten by libtool, which throws them away on the floor. > > We apparently have libtool-ldflags which is used by other libraries > to filter some options so that libtool doesn't eat them, but even after > applying the lto-plugin/Makefile.am changes I got failures, because > while -fsanitize=undefined now made it through, the rest of the options > didn't. So, this patch also tweaks libtool-ldflags to handle some more > options. > lto-plugin is dlopened by ld. How does asan work in lto-plugin when ld isn't compiled with asan?
On Tue, Mar 25, 2014 at 12:44:58PM -0700, H.J. Lu wrote: > On Tue, Mar 25, 2014 at 12:28 PM, Jakub Jelinek <jakub@redhat.com> wrote: > > lto-plugin is another problematic directory in asan/ubsan bootstraps. > > > > Unlike fixincludes, it is bootstrapped, and like fixincludes it is also > > linked against host libiberty. The problem for lto-plugin is that the > > -static-libubsan -fsanitize=undefined -B/some/path/to/libsanitizer/ -B/some/path/to/libsanitizer/ubsan/.libs/ > > switches are eaten by libtool, which throws them away on the floor. > > > > We apparently have libtool-ldflags which is used by other libraries > > to filter some options so that libtool doesn't eat them, but even after > > applying the lto-plugin/Makefile.am changes I got failures, because > > while -fsanitize=undefined now made it through, the rest of the options > > didn't. So, this patch also tweaks libtool-ldflags to handle some more > > options. > > > > lto-plugin is dlopened by ld. How does asan work in lto-plugin > when ld isn't compiled with asan? It works fine for ubsan, and your fix is not the right thing to do, e.g. bootstrap-ubsan reveals some bugs in libiberty which would be otherwise unnoticed if you always filter away the sanitizing options from libiberty. So, I think my patch is the right thing to do for ubsan bootstraps, and for asan bootstraps we'll need something different (build libiberty twice, or build selected libiberty objects inside lto-plugin/ directory again, or something similar). You do want the libiberty parts in cc1, cc1plus, xgcc etc. instrumented. Jakub
On Tue, Mar 25, 2014 at 08:57:21PM +0100, Jakub Jelinek wrote: > It works fine for ubsan, and your fix is not the right thing to do, > e.g. bootstrap-ubsan reveals some bugs in libiberty which would be otherwise > unnoticed if you always filter away the sanitizing options from libiberty. > > So, I think my patch is the right thing to do for ubsan bootstraps, and for > asan bootstraps we'll need something different (build libiberty twice, or > build selected libiberty objects inside lto-plugin/ directory again, or > something similar). You do want the libiberty parts in cc1, cc1plus, xgcc > etc. instrumented. Seems libiberty builds (optionally) everything also into pic/ subdirectory, I think best would be if it in case it found -fsanitize=address in CFLAGS also built everything into noasan/ subdirectory with additional -fno-sanitize=address, and filter out -fsanitize=address just in lto-plugin Makefile and use noasan/libiberty.a preferrably over pic/libiberty.a over libiberty.a. I guess I can cook up a patch tomorrow for that, though probably won't have cycles to fully test that. Jakub
--- libtool-ldflags.jj 2008-09-05 12:59:51.000000000 +0200 +++ libtool-ldflags 2014-03-25 15:43:36.726185093 +0100 @@ -2,7 +2,7 @@ # Script to translate LDFLAGS into a form suitable for use with libtool. -# Copyright (C) 2005 Free Software Foundation, Inc. +# Copyright (C) 2005-2014 Free Software Foundation, Inc. # # This file is free software; you can redistribute it and/or modify # it under the terms of the GNU General Public License as published by @@ -36,14 +36,15 @@ prev_arg= for arg do case $arg in - -f*|--*) + -f*|--*|-static-lib*|-shared-lib*|-B*) # Libtool does not ascribe any special meaning options # that begin with -f or with a double-dash. So, it will # think these options are linker options, and prefix them # with "-Wl,". Then, the compiler driver will ignore the # options. So, we prefix these options with -Xcompiler to # make clear to libtool that they are in fact compiler - # options. + # options. Similarly for e.g. -static-libstdc++, or + # -B/some/path. case $prev_arg in -Xpreprocessor|-Xcompiler|-Xlinker) # This option is already prefixed; don't prefix it again. --- lto-plugin/Makefile.am.jj 2014-03-17 20:01:54.000000000 +0100 +++ lto-plugin/Makefile.am 2014-03-25 15:46:26.832294118 +0100 @@ -18,6 +18,7 @@ in_gcc_libs = $(foreach lib, $(libexecsu # Can be removed when libiberty becomes a normal convenience library Wc=-Wc, +LTLDFLAGS = $(shell $(SHELL) $(top_srcdir)/../libtool-ldflags $(LDFLAGS)) liblto_plugin_la_SOURCES = lto-plugin.c liblto_plugin_la_LIBADD = \ @@ -28,6 +29,9 @@ liblto_plugin_la_LDFLAGS = $(AM_LDFLAGS) $(if $(wildcard ../libiberty/pic/libiberty.a),,-Wc,../libiberty/libiberty.a) liblto_plugin_la_DEPENDENCIES = $(if $(wildcard \ ../libiberty/pic/libiberty.a),../libiberty/pic/libiberty.a,) +liblto_plugin_la_LINK = $(LIBTOOL) --tag=CC $(AM_LIBTOOLFLAGS) \ + $(LIBTOOLFLAGS) --mode=link $(CCLD) $(AM_CFLAGS) $(CFLAGS) \ + $(liblto_plugin_la_LDFLAGS) $(LTLDFLAGS) -o $@ all-local: $(in_gcc_libs) --- lto-plugin/Makefile.in.jj 2014-03-17 20:01:54.000000000 +0100 +++ lto-plugin/Makefile.in 2014-03-25 15:47:10.059071353 +0100 @@ -84,9 +84,6 @@ am__installdirs = "$(DESTDIR)$(libexecsu LTLIBRARIES = $(libexecsub_LTLIBRARIES) am_liblto_plugin_la_OBJECTS = lto-plugin.lo liblto_plugin_la_OBJECTS = $(am_liblto_plugin_la_OBJECTS) -liblto_plugin_la_LINK = $(LIBTOOL) --tag=CC $(AM_LIBTOOLFLAGS) \ - $(LIBTOOLFLAGS) --mode=link $(CCLD) $(AM_CFLAGS) $(CFLAGS) \ - $(liblto_plugin_la_LDFLAGS) $(LDFLAGS) -o $@ DEFAULT_INCLUDES = -I.@am__isrc@ depcomp = am__depfiles_maybe = @@ -239,6 +236,7 @@ in_gcc_libs = $(foreach lib, $(libexecsu # Can be removed when libiberty becomes a normal convenience library Wc = -Wc, +LTLDFLAGS = $(shell $(SHELL) $(top_srcdir)/../libtool-ldflags $(LDFLAGS)) liblto_plugin_la_SOURCES = lto-plugin.c liblto_plugin_la_LIBADD = \ $(if $(wildcard ../libiberty/pic/libiberty.a),$(Wc)../libiberty/pic/libiberty.a,) @@ -251,6 +249,10 @@ liblto_plugin_la_LDFLAGS = $(AM_LDFLAGS) liblto_plugin_la_DEPENDENCIES = $(if $(wildcard \ ../libiberty/pic/libiberty.a),../libiberty/pic/libiberty.a,) +liblto_plugin_la_LINK = $(LIBTOOL) --tag=CC $(AM_LIBTOOLFLAGS) \ + $(LIBTOOLFLAGS) --mode=link $(CCLD) $(AM_CFLAGS) $(CFLAGS) \ + $(liblto_plugin_la_LDFLAGS) $(LTLDFLAGS) -o $@ + all: config.h $(MAKE) $(AM_MAKEFLAGS) all-am