Messages in this thread | | | Date | Thu, 20 Sep 2018 09:11:47 -0700 | From | Ram Pai <> | Subject | Re: [PATCH] powerpc/pkeys: Fix reading of ibm,processor-storage-keys property |
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On Thu, Sep 20, 2018 at 01:38:58AM -0300, 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
Thanks for the fix.
Reviewed-by: Ram Pai <linuxram@us.ibm.com>
> > Fixes: cf43d3b26452 ("powerpc: Enable pkey subsystem") > Signed-off-by: Thiago Jung Bauermann <bauerman@linux.ibm.com> > --- > arch/powerpc/mm/pkeys.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/powerpc/mm/pkeys.c b/arch/powerpc/mm/pkeys.c > index 333b1f80c435..b271b283c785 100644 > --- a/arch/powerpc/mm/pkeys.c > +++ b/arch/powerpc/mm/pkeys.c > @@ -45,7 +45,7 @@ static void scan_pkey_feature(void) > * Since any pkey can be used for data or execute, we will just treat > * all keys as equal and track them as one entity. > */ > - pkeys_total = be32_to_cpu(vals[0]); > + pkeys_total = vals[0]; > pkeys_devtree_defined = true; > }
-- Ram Pai
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