Re: [PATCH] bfd: Define pagesize variables only for mmap

["H.J. Lu" <hjl.tools@gmail.com>]

On Mon, Apr 8, 2024 at 10:47 PM Alan Modra <amodra@gmail.com> wrote:
>
> On Mon, Apr 08, 2024 at 07:49:26PM -0700, H.J. Lu wrote:
> > On Mon, Apr 8, 2024 at 3:55 PM Alan Modra <amodra@gmail.com> wrote:
> > >
> > > On Mon, Apr 08, 2024 at 07:26:37AM -0700, H.J. Lu wrote:
> > > > On Sun, Apr 7, 2024 at 8:58 PM Simon Marchi <simon.marchi@polymtl.ca> wrote:
> > > > > Since this commit, when building for --host=x86_64-w64-mingw32, I get:
> > > > >
> > > > >
> > > > > make[4]: Entering directory '/home/simark/build/binutils-gdb-x86_64-w64-mingw32/bfd'
> > > > >   CC       libbfd.lo
> > > > > /home/simark/src/binutils-gdb/bfd/libbfd.c: In function ‘bfd_init_pagesize’:
> > > > > /home/simark/src/binutils-gdb/bfd/libbfd.c:1583:19: error: implicit declaration of function ‘getpagesize’ [-Werror=implicit-function-declaration]
> > > > >  1583 |   _bfd_pagesize = getpagesize ();
> > > > >       |                   ^~~~~~~~~~~
> > > > >
> > > > > Simon
> > > >
> > > > Please try this patch.
> > >
> > > You need to revert the change to lynx-core.c as well.
> >
> > The v2 patch is at
> >
> > https://sourceware.org/pipermail/binutils/2024-April/133466.html
> >
> > > Somewhat related, why does binutils/elfedit.c depend on HAVE_MMAP?
> >
> > It uses mmap to update the ELF program header directly.
> >
> > > I run into failures with asan builds (ie. -fsanitize=address,undefined
> > > in CFLAGS and CXXFLAGS passed to configure).
> > > elfedit: unrecognized option '--enable-x86-feature'
> >
> > I built binutils with GCC 13 using
> >
> > CC="gcc -fsanitize=address,undefined" CXX="g++
> > -fsanitize=address,undefined"
> > /export/gnu/import/git/gitlab/x86-binutils/configure \
> > --disable-werror --disable-gprofng \
> > \
> > --enable-plugins --disable-gdb --disable-gdbserver
> > --disable-libbacktrace --disable-libdecnumber --disable-readline
> > --disable-sim --enable-mark-plt --with-sysroot=/ --with-system-zlib \
> > --prefix=/usr/local \
> > --with-local-prefix=/usr/local
> >
> > elfedit works:
> >
> > [hjl@gnu-cfl-3 binutils]$ ./elfedit --enable-x86-feature ibt xx
> > [hjl@gnu-cfl-3 binutils]$
> >
> > > Apparently HAVE_MMAP configury fusses too much, see this comment:
> > > gnulib/import/m4/mmap-anon.m4:  # Check for mmap(). Don't use AC_FUNC_MMAP, because it checks too much: it
> >
> > It checks MAP_ANONYMOUS, not mmap:
> >
> >   # Check for mmap(). Don't use AC_FUNC_MMAP, because it checks too much: it
> >   # fails on HP-UX 11, because MAP_FIXED mappings do not work. But this is
> >   # irrelevant for anonymous mappings.
>
> Yes, it isn't that.  I fail to get HAVE_MMAP for the rather more
> mundane reason that the config test fails with:
> =================================================================
> ==231796==ERROR: LeakSanitizer: detected memory leaks
>
> Direct leak of 4096 byte(s) in 1 object(s) allocated from:
>     #0 0x7cdd3d0defdf in __interceptor_malloc ../../../../src/libsanitizer/asan/asan_malloc_linux.cpp:69
>     #1 0x5750c7f6d72b in main /home/alan/build/gas-san/all/bfd/conftest.c:239
>
> Direct leak of 4096 byte(s) in 1 object(s) allocated from:
>     #0 0x7cdd3d0defdf in __interceptor_malloc ../../../../src/libsanitizer/asan/asan_malloc_linux.cpp:69
>     #1 0x5750c7f6d2e1 in main /home/alan/build/gas-san/all/bfd/conftest.c:190
>
> SUMMARY: AddressSanitizer: 8192 byte(s) leaked in 2 allocation(s).
>
> This can be avoided by
> export ASAN_OPTIONS=detect_leaks=0
>

A patch set is posted at

https://sourceware.org/pipermail/binutils/2024-April/133484.html

--
H.J.