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From: Michael Ellerman <patch-notifications@ellerman.id.au>
To: Thiago Jung Bauermann <bauerman@linux.ibm.com>,
	linuxppc-dev@lists.ozlabs.org
Cc: Ram Pai <linuxram@us.ibm.com>,
	linux-kernel@vger.kernel.org,
	Thiago Jung Bauermann <bauerman@linux.ibm.com>
Subject: Re: powerpc/pkeys: Fix reading of ibm, processor-storage-keys property
Date: Fri, 21 Sep 2018 21:59:40 +1000 (AEST)	[thread overview]
Message-ID: <42GsbJ6bPwz9sC7@ozlabs.org> (raw)
In-Reply-To: <20180920043858.28773-1-bauerman@linux.ibm.com>

On Thu, 2018-09-20 at 04:38:58 UTC, Thiago Jung Bauermann wrote:
> scan_pkey_feature() uses of_property_read_u32_array() to read the
> ibm,processor-storage-keys property and calls be32_to_cpu() on the
> value it gets. The problem is that of_property_read_u32_array() already
> returns the value converted to the CPU byte order.
> 
> The value of pkeys_total ends up more or less sane because there's a min()
> call in pkey_initialize() which reduces pkeys_total to 32. So in practice
> the kernel ignores the fact that the hypervisor reserved one key for
> itself (the device tree advertises 31 keys in my test VM).
> 
> This is wrong, but the effect in practice is that when a process tries to
> allocate the 32nd key, it gets an -EINVAL error instead of -ENOSPC which
> would indicate that there aren't any keys available
> 
> Fixes: cf43d3b26452 ("powerpc: Enable pkey subsystem")
> Signed-off-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>

Applied to powerpc fixes, thanks.

https://git.kernel.org/powerpc/c/c716a25b9b70084e1144f77423f5ae

cheers

      parent reply	other threads:[~2018-09-21 11:59 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-09-20  4:38 [PATCH] powerpc/pkeys: Fix reading of ibm,processor-storage-keys property Thiago Jung Bauermann
2018-09-20 16:11 ` Ram Pai
2018-09-21 11:59 ` Michael Ellerman [this message]

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