From: Heiko Carstens <heiko.carstens@de.ibm.com>
To: Dave Jones <davej@codemonkey.org.uk>
Cc: Dave Hansen <dave.hansen@linux.intel.com>,
linux-arch@vger.kernel.org, Dave Hansen <dave@sr71.net>,
mgorman@techsingularity.net, arnd@arndb.de,
linux-api@vger.kernel.org, linux-mm@kvack.org, luto@kernel.org,
akpm@linux-foundation.org, torvalds@linux-foundation.org
Subject: Re: pkeys: Remove easily triggered WARN
Date: Mon, 17 Oct 2016 09:16:48 +0200 [thread overview]
Message-ID: <20161017071648.GA3511@osiris> (raw)
In-Reply-To: <20161014182624.4yzw36n4hd7x56wi@codemonkey.org.uk>
On Fri, Oct 14, 2016 at 02:26:24PM -0400, Dave Jones wrote:
> This easy-to-trigger warning shows up instantly when running
> Trinity on a kernel with CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS disabled.
>
> At most this should have been a printk, but the -EINVAL alone should be more
> than adequate indicator that something isn't available.
>
> Signed-off-by: Dave Jones <davej@codemonkey.org.uk>
>
> diff --git a/include/linux/pkeys.h b/include/linux/pkeys.h
> index e4c08c1ff0c5..a1bacf1150b2 100644
> --- a/include/linux/pkeys.h
> +++ b/include/linux/pkeys.h
> @@ -25,7 +25,6 @@ static inline int mm_pkey_alloc(struct mm_struct *mm)
>
> static inline int mm_pkey_free(struct mm_struct *mm, int pkey)
> {
> - WARN_ONCE(1, "free of protection key when disabled");
> return -EINVAL;
> }
FWIW, are all architectures supposed to wire these new system calls up?
I decided to ignore these on s390 since we can't make any sane use of
them. However mips has them already wired up.
The only difference on s390 (and any other architecture without memory
protection keys with x86 like semantics) would be that pkey_alloc/pkey_free
will return -EINVAL instead of -ENOSYS and that we have a new mprotect
wrapper called pkey_mprotect, if being called with a pkey parameter of -1.
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next prev parent reply other threads:[~2016-10-17 7:16 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-10-14 18:26 pkeys: Remove easily triggered WARN Dave Jones
2016-10-14 19:16 ` Dave Hansen
2016-10-17 7:16 ` Heiko Carstens [this message]
2016-10-17 7:54 ` Heiko Carstens
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