Re: [PATCH v3 1/3] audit: replace magic audit syscall class numbers with macros

From: Richard Guy Briggs
Date: Tue May 11 2021 - 14:50:32 EST


On 2021-05-10 21:23, Paul Moore wrote:
> On Fri, Apr 30, 2021 at 4:36 PM Richard Guy Briggs <rgb@xxxxxxxxxx> wrote:
> >
> > Replace audit syscall class magic numbers with macros.
> >
> > This required putting the macros into new header file
> > include/linux/auditscm.h since the syscall macros were included for both 64
> > bit and 32 bit in any compat code, causing redefinition warnings.
>
> The ifndef/define didn't protect against redeclaration? Huh. Maybe
> I'm not thinking about this correctly, or the arch specific code is
> doing something wonky ...

I had a chat with Arnd about it in IRC upstream and started digging
deeper and it got quite messy. As seen from the cover letter, audit.h
pulled in a chain of things which weren't entirely unreasonable given it
was compiling compat support in with native support by default. I
suppose I could have defined _ASM_X86_UNISTD_64_H to prevent it from
being added, but that would be ugly on a generated file, have caused a
failure elsewhere and would need to be done for each compat file. I
thought of defining CONFIG_X86_32 in arch/x86/ia32/audit.c but that
would cause other problems. This was the cleanest solution. Otherwise
I leave them as magic numbers like in V1.

> Regardless, assuming that it is necessary, I would prefer if we called
> it auditsc.h instead of auditscm.h; the latter makes me think of
> sockets and not syscalls.
>
> > Signed-off-by: Richard Guy Briggs <rgb@xxxxxxxxxx>
> > ---
> > MAINTAINERS | 1 +
> > arch/alpha/kernel/audit.c | 8 ++++----
> > arch/ia64/kernel/audit.c | 8 ++++----
> > arch/parisc/kernel/audit.c | 8 ++++----
> > arch/parisc/kernel/compat_audit.c | 9 +++++----
> > arch/powerpc/kernel/audit.c | 10 +++++-----
> > arch/powerpc/kernel/compat_audit.c | 11 ++++++-----
> > arch/s390/kernel/audit.c | 10 +++++-----
> > arch/s390/kernel/compat_audit.c | 11 ++++++-----
> > arch/sparc/kernel/audit.c | 10 +++++-----
> > arch/sparc/kernel/compat_audit.c | 11 ++++++-----
> > arch/x86/ia32/audit.c | 11 ++++++-----
> > arch/x86/kernel/audit_64.c | 8 ++++----
> > include/linux/audit.h | 1 +
> > include/linux/auditscm.h | 23 +++++++++++++++++++++++
> > kernel/auditsc.c | 12 ++++++------
> > lib/audit.c | 10 +++++-----
> > lib/compat_audit.c | 11 ++++++-----
> > 18 files changed, 102 insertions(+), 71 deletions(-)
> > create mode 100644 include/linux/auditscm.h
>
> ...
>
> > diff --git a/include/linux/auditscm.h b/include/linux/auditscm.h
> > new file mode 100644
> > index 000000000000..1c4f0ead5931
> > --- /dev/null
> > +++ b/include/linux/auditscm.h
> > @@ -0,0 +1,23 @@
> > +/* SPDX-License-Identifier: GPL-2.0-or-later */
> > +/* auditscm.h -- Auditing support syscall macros
> > + *
> > + * Copyright 2021 Red Hat Inc., Durham, North Carolina.
> > + * All Rights Reserved.
> > + *
> > + * Author: Richard Guy Briggs <rgb@xxxxxxxxxx>
> > + */
> > +#ifndef _LINUX_AUDITSCM_H_
> > +#define _LINUX_AUDITSCM_H_
> > +
> > +enum auditsc_class_t {
> > + AUDITSC_NATIVE = 0,
> > + AUDITSC_COMPAT,
> > + AUDITSC_OPEN,
> > + AUDITSC_OPENAT,
> > + AUDITSC_SOCKETCALL,
> > + AUDITSC_EXECVE,
> > +
> > + AUDITSC_NVALS /* count */
> > +};
> > +
> > +#endif
>
> --
> paul moore
> www.paul-moore.com
>

- RGB

--
Richard Guy Briggs <rgb@xxxxxxxxxx>
Sr. S/W Engineer, Kernel Security, Base Operating Systems
Remote, Ottawa, Red Hat Canada
IRC: rgb, SunRaycer
Voice: +1.647.777.2635, Internal: (81) 32635