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Date:   Tue, 10 Nov 2020 10:23:10 -0500
From:   Richard Guy Briggs <rgb@redhat.com>
To:     Alex Shi <alex.shi@linux.alibaba.com>
Cc:     paul@paul-moore.com, linux-audit@redhat.com,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH] audit: remove unused macros
Message-ID: <20201110152310.GB55411@madcap2.tricolour.ca>
References: <1604651482-9780-1-git-send-email-alex.shi@linux.alibaba.com>
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On 2020-11-06 16:31, Alex Shi wrote:
> Some unused macros could cause gcc warning:
> kernel/audit.c:68:0: warning: macro "AUDIT_UNINITIALIZED" is not used
> [-Wunused-macros]
> kernel/auditsc.c:104:0: warning: macro "AUDIT_AUX_IPCPERM" is not used
> [-Wunused-macros]
> kernel/auditsc.c:82:0: warning: macro "AUDITSC_INVALID" is not used
> [-Wunused-macros]
> 
> remove them to tame gcc.
> 
> Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
> Cc: Paul Moore <paul@paul-moore.com> 
> Cc: Eric Paris <eparis@redhat.com> 
> Cc: linux-audit@redhat.com 
> Cc: linux-kernel@vger.kernel.org 
> ---
>  kernel/audit.c   | 1 -
>  kernel/auditsc.c | 3 ---
>  2 files changed, 4 deletions(-)
> 
> diff --git a/kernel/audit.c b/kernel/audit.c
> index ac0aeaa99937..dfac1e0ca887 100644
> --- a/kernel/audit.c
> +++ b/kernel/audit.c
> @@ -65,7 +65,6 @@
>  /* No auditing will take place until audit_initialized == AUDIT_INITIALIZED.
>   * (Initialization happens after skb_init is called.) */
>  #define AUDIT_DISABLED		-1
> -#define AUDIT_UNINITIALIZED	0
>  #define AUDIT_INITIALIZED	1
>  static int	audit_initialized;

This one is part of a set, so it feels like it should stay, but the code
is structured in such a way that it is not necessary.

> diff --git a/kernel/auditsc.c b/kernel/auditsc.c
> index 183d79cc2e12..eeb4930d499f 100644
> --- a/kernel/auditsc.c
> +++ b/kernel/auditsc.c
> @@ -80,7 +80,6 @@
>  #include "audit.h"
>  
>  /* flags stating the success for a syscall */
> -#define AUDITSC_INVALID 0
>  #define AUDITSC_SUCCESS 1
>  #define AUDITSC_FAILURE 2

Same here, but this one should really be fixed by using
AUDITSC_INVALID as the value assigned to context->return_valid in
__audit_free() to avoid using magic numbers.  Similarly, the compared
values in audit_filter_rules() under the AUDIT_EXIT and AUDIT_SUCCESS
cases should be "ctx->return_valid != AUDITSC_INVALID" rather than just
"ctx->return_valid".  Same in audit_log_exit().

> @@ -102,8 +101,6 @@ struct audit_aux_data {
>  	int			type;
>  };
>  
> -#define AUDIT_AUX_IPCPERM	0
> -

Hmmm, this one looks like it was orphaned 15 years ago a couple of
months after it was introduced due to this commit:
c04049939f88 Steve Grubb <sgrubb@redhat.com> 2005-05-13
    ("AUDIT: Add message types to audit records")

Introduced here:
8e633c3fb2a2 David Woodhouse <dwmw2@shinybook.infradead.org> 2005-03-01 
    ("Audit IPC object owner/permission changes.")

I agree, remove it.

>  /* Number of target pids per aux struct. */
>  #define AUDIT_AUX_PIDS	16
>  
> -- 
> 1.8.3.1
> 
> --
> Linux-audit mailing list
> Linux-audit@redhat.com
> https://www.redhat.com/mailman/listinfo/linux-audit

- RGB

--
Richard Guy Briggs <rgb@redhat.com>
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