bug#53484: 29.0.50; Removing libseccomp-dev 2.5.1-1~bpo10+1 allows emacs to compile

bug#53484: 29.0.50; Removing libseccomp-dev 2.5.1-1~bpo10+1 allows emacs to compile

[Mark A. Hershberger via Bug reports for GNU Emacs, the Swiss army knife of text editors]

I haven't compiled emacs in a while, but I decided to try it today and
it kept failing on some lines indicating a problem with seccomp.

After removing the debian package in the subject line, compilation was successful.

What am I missing without seccomp?

Some of the info from report-bug:

In GNU Emacs 29.0.50 (build 1, x86_64-pc-linux-gnu, GTK+ Version 3.24.5, cairo version 1.16.0)
 of 2022-01-23 built on silk
Repository revision: f4af1137e663f2644a30778a5466909cac26b4b3
Repository branch: master
Windowing system distributor 'The X.Org Foundation', version 11.0.12004000
System Description: Debian GNU/Linux 10 (buster)

Configured using:
 'configure --with-cairo --with-imagemagick --with-json
 --with-native-compilation --with-xinput2 --with-xwidgets
 --with-modules'

Configured features:
ACL CAIRO DBUS FREETYPE GIF GLIB GMP GNUTLS GPM GSETTINGS HARFBUZZ
IMAGEMAGICK JPEG JSON LCMS2 LIBOTF LIBSELINUX LIBSYSTEMD LIBXML2
M17N_FLT MODULES NATIVE_COMP NOTIFY INOTIFY PDUMPER PNG RSVG SECCOMP
SOUND SQLITE3 THREADS TIFF TOOLKIT_SCROLL_BARS WEBP X11 XDBE XIM XINPUT2
XPM XWIDGETS GTK3 ZLIB

Important settings:
  value of $LANG: en_US.UTF-8
  value of $XMODIFIERS: @im=ibus
  locale-coding-system: utf-8-unix

bug#53484: 29.0.50; Removing libseccomp-dev 2.5.1-1~bpo10+1 allows emacs to compile

[Philipp Stephani]

Am So., 23. Jan. 2022 um 21:26 Uhr schrieb Mark A. Hershberger via Bug
reports for GNU Emacs, the Swiss army knife of text editors
<bug-gnu-emacs@gnu.org>:
>
>
> I haven't compiled emacs in a while, but I decided to try it today and
> it kept failing on some lines indicating a problem with seccomp.
>
> After removing the debian package in the subject line, compilation was successful.
>
> What am I missing without seccomp?

I forgot to bump the minimum version after adding the latest batch of
syscalls. I've done that now (commit
c34d06e3d75bfbea2605e3ae292850175ce5c235, not yet merged to master);
could you please try again?

bug#53484: 29.0.50; Removing libseccomp-dev 2.5.1-1~bpo10+1 allows emacs to compile

[Mark A. Hershberger]

Philipp Stephani <p.stephani2@gmail.com> writes:

> I forgot to bump the minimum version after adding the latest batch of
> syscalls. I've done that now (commit
> c34d06e3d75bfbea2605e3ae292850175ce5c235, not yet merged to master);
> could you please try again?

That seems to have done the trick.  Compiling works for me after
re-installing libseccomp-dev and merging that commit with master.

Thanks!

bug#53484: 29.0.50; Removing libseccomp-dev 2.5.1-1~bpo10+1 allows emacs to compile

[Lars Ingebrigtsen]

"Mark A. Hershberger" <mah@everybody.org> writes:

> That seems to have done the trick.  Compiling works for me after
> re-installing libseccomp-dev and merging that commit with master.

Thanks for checking; I'm closing this bug report, then.  (The fix to
emacs-28 will be merged to master later.)

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no

bug#53484: 29.0.50; Removing libseccomp-dev 2.5.1-1~bpo10+1 allows emacs to compile

[Glenn Morris]

I note that the required version of libseccomp in emacs-28 (2.5.2) is
now greater than that found in eg rhel 8.5 (2.5.1). So there are some
platforms where libseccomp support was working in earlier emacs-28
pretests but is now absent.

bug#53484: 29.0.50; Removing libseccomp-dev 2.5.1-1~bpo10+1 allows emacs to compile

[Lars Ingebrigtsen]

Glenn Morris <rgm@gnu.org> writes:

> I note that the required version of libseccomp in emacs-28 (2.5.2) is
> now greater than that found in eg rhel 8.5 (2.5.1). So there are some
> platforms where libseccomp support was working in earlier emacs-28
> pretests but is now absent.

But were segfaulting, according to some reports, if I understand
correctly?

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no

bug#53484: 29.0.50; Removing libseccomp-dev 2.5.1-1~bpo10+1 allows emacs to compile

[Philipp Stephani]

> Am 24.01.2022 um 22:56 schrieb Glenn Morris <rgm@gnu.org>:
> 
> 
> I note that the required version of libseccomp in emacs-28 (2.5.2) is
> now greater than that found in eg rhel 8.5 (2.5.1). So there are some
> platforms where libseccomp support was working in earlier emacs-28
> pretests but is now absent.

Note that this only refers to the construction of the seccomp filter that we build for convenience.  The Emacs binary itself and the actual seccomp sandboxing mechanism doesn't depend on libseccomp.  Users that don't have libseccomp or an older version will still get the seccomp support, just not the specific filter file that we provide.