Re: [PATCH] audit: remove unused macros

[Richard Guy Briggs]

On 2020-11-11 14:19, Alex Shi wrote:
> Thanks for comments!
> So here is the v2 according to your suggestion!
> 
> From 033425b6072ff4cee05d6bbffc97cd6a4c13166c Mon Sep 17 00:00:00 2001
> From: Alex Shi <alex.shi@xxxxxxxxxxxxxxxxx>
> Date: Fri, 6 Nov 2020 16:31:22 +0800
> Subject: [PATCH v2] kernel/audit: fix macros warning
> 
> 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]
> 
> AUDIT_UNINITIALIZED and AUDITSC_INVALID are still meaningful and could
> be used in code.

"and should be incorporated"

> Just remove AUDIT_AUX_IPCPERM.
> 
> Thanks comments from Richard Guy Briggs and Paul Moore.
> 
> Signed-off-by: Alex Shi <alex.shi@xxxxxxxxxxxxxxxxx>
> Cc: Paul Moore <paul@xxxxxxxxxxxxxx>
> Cc: Eric Paris <eparis@xxxxxxxxxx>
> Cc: linux-audit@xxxxxxxxxx
> Cc: linux-kernel@xxxxxxxxxxxxxxx
> ---
>  kernel/audit.c   |  2 +-
>  kernel/auditsc.c | 10 ++++------
>  2 files changed, 5 insertions(+), 7 deletions(-)
> 
> diff --git a/kernel/audit.c b/kernel/audit.c
> index ac0aeaa99937..e22f22bdc000 100644
> --- a/kernel/audit.c
> +++ b/kernel/audit.c
> @@ -67,7 +67,7 @@
>  #define AUDIT_DISABLED		-1
>  #define AUDIT_UNINITIALIZED	0
>  #define AUDIT_INITIALIZED	1
> -static int	audit_initialized;
> +static int	audit_initialized = AUDIT_UNINITIALIZED;
>  
>  u32		audit_enabled = AUDIT_OFF;
>  bool		audit_ever_enabled = !!AUDIT_OFF;
> diff --git a/kernel/auditsc.c b/kernel/auditsc.c
> index 183d79cc2e12..ea0ed81ddee0 100644
> --- a/kernel/auditsc.c
> +++ b/kernel/auditsc.c
> @@ -102,8 +102,6 @@ struct audit_aux_data {
>  	int			type;
>  };
>  
> -#define AUDIT_AUX_IPCPERM	0
> -
>  /* Number of target pids per aux struct. */
>  #define AUDIT_AUX_PIDS	16
>  
> @@ -552,11 +550,11 @@ static int audit_filter_rules(struct task_struct *tsk,
>  			break;
>  
>  		case AUDIT_EXIT:
> -			if (ctx && ctx->return_valid)
> +			if (ctx && ctx->return_valid != AUDITSC_INVALID)
>  				result = audit_comparator(ctx->return_code, f->op, f->val);
>  			break;
>  		case AUDIT_SUCCESS:
> -			if (ctx && ctx->return_valid) {
> +			if (ctx && ctx->return_valid != AUDITSC_INVALID) {
>  				if (f->val)
>  					result = audit_comparator(ctx->return_valid, f->op, AUDITSC_SUCCESS);
>  				else
> @@ -1488,7 +1486,7 @@ static void audit_log_exit(void)
>  			 context->arch, context->major);
>  	if (context->personality != PER_LINUX)
>  		audit_log_format(ab, " per=%lx", context->personality);
> -	if (context->return_valid)
> +	if (context->return_valid != AUDITSC_INVALID)
>  		audit_log_format(ab, " success=%s exit=%ld",
>  				 (context->return_valid==AUDITSC_SUCCESS)?"yes":"no",
>  				 context->return_code);
> @@ -1625,7 +1623,7 @@ void __audit_free(struct task_struct *tsk)
>  	 * need to log via audit_log_exit().
>  	 */
>  	if (tsk == current && !context->dummy && context->in_syscall) {
> -		context->return_valid = 0;
> +		context->return_valid = AUDITSC_INVALID;
>  		context->return_code = 0;
>  
>  		audit_filter_syscall(tsk, context,

This all looks good, but I don't see the initialization of
context->return_valid in audit_alloc_context() that was mentioned for
completeness.

> -- 
> 1.8.3.1
> 

- 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