From: Will Deacon <will@kernel.org>
To: Qian Cai <cai@lca.pw>
Cc: catalin.marinas@arm.com, andreyknvl@google.com,
linux-arm-kernel@lists.infradead.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] arm64/mm: fix variable 'tag' set but not used
Date: Thu, 1 Aug 2019 13:01:22 +0100 [thread overview]
Message-ID: <20190801120121.6cmtho3wd32nzfoz@willie-the-truck> (raw)
In-Reply-To: <1564605498-17629-1-git-send-email-cai@lca.pw>
On Wed, Jul 31, 2019 at 04:38:18PM -0400, Qian Cai wrote:
> When CONFIG_KASAN_SW_TAGS=n, set_tag() is compiled away. GCC throws a
> warning,
>
> mm/kasan/common.c: In function '__kasan_kmalloc':
> mm/kasan/common.c:464:5: warning: variable 'tag' set but not used
> [-Wunused-but-set-variable]
> u8 tag = 0xff;
> ^~~
>
> Fix it by making __tag_set() a static inline function.
>
> Signed-off-by: Qian Cai <cai@lca.pw>
> ---
> arch/arm64/include/asm/memory.h | 6 +++++-
> 1 file changed, 5 insertions(+), 1 deletion(-)
>
> diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h
> index b7ba75809751..9645b1340afe 100644
> --- a/arch/arm64/include/asm/memory.h
> +++ b/arch/arm64/include/asm/memory.h
> @@ -210,7 +210,11 @@ static inline unsigned long kaslr_offset(void)
> #define __tag_reset(addr) untagged_addr(addr)
> #define __tag_get(addr) (__u8)((u64)(addr) >> 56)
> #else
> -#define __tag_set(addr, tag) (addr)
> +static inline const void *__tag_set(const void *addr, u8 tag)
> +{
> + return addr;
> +}
Why doesn't this trigger a warning in page_to_virt(), which passes an
unsigned long for the address parameter?
Will
next prev parent reply other threads:[~2019-08-01 12:01 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-31 20:38 [PATCH] arm64/mm: fix variable 'tag' set but not used Qian Cai
2019-08-01 12:01 ` Will Deacon [this message]
2019-08-01 12:07 ` Qian Cai
2019-08-01 12:09 ` Qian Cai
2019-08-01 12:12 ` Will Deacon
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