linux-kernel - Re: [PATCH 2/2] x86/boot/KASLR: Fix unused variable warning

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <ba5067ad-4fba-52c9-6872-c18bfeb947db@intel.com>
Date:   Tue, 3 Mar 2020 14:56:47 -0800
From:   Dave Hansen <dave.hansen@...el.com>
To:     Zhenzhong Duan <zhenzhong.duan@...il.com>,
        linux-kernel@...r.kernel.org
Cc:     x86@...nel.org, tglx@...utronix.de, mingo@...hat.com, bp@...en8.de,
        Borislav Petkov <bp@...e.de>, "H. Peter Anvin" <hpa@...or.com>,
        Dave Hansen <dave.hansen@...ux.intel.com>,
        "Rafael J. Wysocki" <rafael.j.wysocki@...el.com>
Subject: Re: [PATCH 2/2] x86/boot/KASLR: Fix unused variable warning

On 3/2/20 10:52 PM, Zhenzhong Duan wrote:
> Local variable 'i' is referenced only when CONFIG_MEMORY_HOTREMOVE and
> CONFIG_ACPI are defined, but definition of variable 'i' is out of guard.
> If any of the two macros is undefined, below warning triggers during
> build, fix it by moving 'i' in the guard.
> 
> arch/x86/boot/compressed/kaslr.c:698:6: warning: unused variable ‘i’ [-Wunused-variable]
...
> diff --git a/arch/x86/boot/compressed/kaslr.c b/arch/x86/boot/compressed/kaslr.c
> index d7408af55738..62bc46684581 100644
> --- a/arch/x86/boot/compressed/kaslr.c
> +++ b/arch/x86/boot/compressed/kaslr.c
> @@ -695,7 +695,6 @@ static bool process_mem_region(struct mem_vector *region,
>  			       unsigned long long minimum,
>  			       unsigned long long image_size)
>  {
> -	int i;
>  	/*
>  	 * If no immovable memory found, or MEMORY_HOTREMOVE disabled,
>  	 * use @region directly.
> @@ -711,6 +710,7 @@ static bool process_mem_region(struct mem_vector *region,
>  	}
>  
>  #if defined(CONFIG_MEMORY_HOTREMOVE) && defined(CONFIG_ACPI)
> +	int i;

Won't this just result in a different warning since it now it will
declare 'i' in the middle of the function once CONFIG_MEMORY_HOTREMOVE
and ACPI are enabled?