Re: git: 9cabef3d146e - main - ldd: use direct exec mode unconditionally

From: Konstantin Belousov <kostikbel_at_gmail.com>
Date: Fri, 21 Oct 2022 12:50:07 UTC
On Fri, Oct 21, 2022 at 02:18:04PM +0200, Kristof Provost wrote:
> On 6 Oct 2022, at 17:50, Konstantin Belousov wrote:
> > The branch main has been updated by kib:
> > 
> > URL: https://cgit.FreeBSD.org/src/commit/?id=9cabef3d146e9a844813b6bc8952d6cf2e9d45e5
> > 
> > commit 9cabef3d146e9a844813b6bc8952d6cf2e9d45e5
> > Author:     Konstantin Belousov <kib@FreeBSD.org>
> > AuthorDate: 2022-09-21 13:55:44 +0000
> > Commit:     Konstantin Belousov <kib@FreeBSD.org>
> > CommitDate: 2022-10-06 15:50:26 +0000
> > 
> >     ldd: use direct exec mode unconditionally
> > 
> >     Trying to exec malformed or unusual binary, for instance, a
> > non-FreeBSD
> >     ABI, or using a non-standard interpreter, might give unexpected
> > outcome.
> > 
> >     Reported by:    The UK's National Cyber Security Centre (NCSC)
> >     Reviewed by:    emaste, markj, philip
> >     Discussed with: jhb
> >     Sponsored by:   The FreeBSD Foundation
> >     admbug: 991
> >     PR:     127276, 175339, 231926
> >     MFC after:      1 week
> >     Differential revision:  https://reviews.freebsd.org/D36650
> > 
> This appears to break things for armv7 (running on aarch64).
> 
> This manifests while building pfsense (for 3100 / armv7), which we do on an
> aarch64 vm (to avoid having to deal with qemu, and because it’s faster).
> 
> During that build a couple ports fail to build, including databases/sqlite3.
> It fails running `/usr/bin/ldd -a "/wrkdirs/usr/ports/databases/sqlite3/work-default/stage/usr/local/bin/sqlite3" "/wrkdirs/usr/ports/databases/sqlite3/work-default/stage/usr/local/lib/libsqlite3.so”`,
> which produces:
> 
> 	ld-elf.so.1: /wrkdirs/usr/ports/databases/sqlite3/work-default/stage/usr/local/bin/sqlite3:
> mmap of entire address space failed: Cannot allocate memory
> 	/wrkdirs/usr/ports/databases/sqlite3/work-default/stage/usr/local/bin/sqlite3:
> exit status 1
> 
> That fails doing the `mapbase = mmap(base_addr, mapsize, PROT_NONE,
> base_flags, -1, 0);` call in rtld-elf’s map_object():217. That call does
> `mmap(0x10000, 0x1dc000, PROT_NONE, 0x6010, -1, 0) => 0xffffffff`.
> 
> With this patch reverted we can build successfully.

Can you manually invoke ldd on the binary under ktrace -i, and show me the
kdump output?

Thanks.