On Fri, Oct 09, 2020 at 12:42:51PM -0700, ira.weiny@xxxxxxxxx wrote: > From: Fenghua Yu <fenghua.yu@xxxxxxxxx> > > Define a helper, update_pkey_val(), which will be used to support both > Protection Key User (PKU) and the new Protection Key for Supervisor > (PKS) in subsequent patches. > > Co-developed-by: Ira Weiny <ira.weiny@xxxxxxxxx> > Signed-off-by: Ira Weiny <ira.weiny@xxxxxxxxx> > Signed-off-by: Fenghua Yu <fenghua.yu@xxxxxxxxx> > --- > arch/x86/include/asm/pkeys.h | 2 ++ > arch/x86/kernel/fpu/xstate.c | 22 ++++------------------ > arch/x86/mm/pkeys.c | 21 +++++++++++++++++++++ > 3 files changed, 27 insertions(+), 18 deletions(-) This is not from Fenghua. https://lkml.kernel.org/r/20200717085442.GX10769@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx This is your patch based on the code I wrote. > diff --git a/arch/x86/mm/pkeys.c b/arch/x86/mm/pkeys.c > index f5efb4007e74..3cf8f775f36d 100644 > --- a/arch/x86/mm/pkeys.c > +++ b/arch/x86/mm/pkeys.c > @@ -208,3 +208,24 @@ static __init int setup_init_pkru(char *opt) > return 1; > } > __setup("init_pkru=", setup_init_pkru); > + > +/* > + * Update the pk_reg value and return it. > + * > + * Kernel users use the same flags as user space: > + * PKEY_DISABLE_ACCESS > + * PKEY_DISABLE_WRITE > + */ > +u32 update_pkey_val(u32 pk_reg, int pkey, unsigned int flags) > +{ > + int pkey_shift = pkey * PKR_BITS_PER_PKEY; > + > + pk_reg &= ~(((1 << PKR_BITS_PER_PKEY) - 1) << pkey_shift); > + > + if (flags & PKEY_DISABLE_ACCESS) > + pk_reg |= PKR_AD_BIT << pkey_shift; > + if (flags & PKEY_DISABLE_WRITE) > + pk_reg |= PKR_WD_BIT << pkey_shift; > + > + return pk_reg; > +} > -- > 2.28.0.rc0.12.gb6a658bd00c9 >
