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

On Fri, Oct 21, 2022 at 02:54:59PM +0200, Kristof Provost wrote:
> On 21 Oct 2022, at 14:50, Konstantin Belousov wrote:
> > 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?
> > 
> I might be doing something wrong:
> 
> 	# ktrace -i /usr/obj/usr/src/arm.armv7/usr.bin/ldd/ldd -a "/wrkdirs/usr/ports/databases/sqlite3/work-default/stage/usr/local/bin/sqlite3"
> 	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
> 	# kdump -f ktrace.out
> 	    16 @      UNKNOWN(265)
> 	kdump: data too short
> 	#
> 
> Perhaps because this is running in a jail?
You need to run host-native kdump, because your kernel is arm64, I guess.

> 
> Here’s truss at least:
...