"Aneesh Kumar K.V" <aneesh.ku...@linux.ibm.com> writes: > max_pkey now represents max key value that userspace can allocate. > > Signed-off-by: Aneesh Kumar K.V <aneesh.ku...@linux.ibm.com> > --- > arch/powerpc/include/asm/pkeys.h | 7 +++++-- > arch/powerpc/mm/book3s64/pkeys.c | 14 +++++++------- > 2 files changed, 12 insertions(+), 9 deletions(-) > > diff --git a/arch/powerpc/include/asm/pkeys.h > b/arch/powerpc/include/asm/pkeys.h > index 75d2a2c19c04..652bad7334f3 100644 > --- a/arch/powerpc/include/asm/pkeys.h > +++ b/arch/powerpc/include/asm/pkeys.h > @@ -12,7 +12,7 @@ > #include <asm/firmware.h> > > DECLARE_STATIC_KEY_FALSE(pkey_disabled); > -extern int pkeys_total; /* total pkeys as per device tree */ > +extern int max_pkey; > extern u32 initial_allocation_mask; /* bits set for the initially allocated > keys */ > extern u32 reserved_allocation_mask; /* bits set for reserved keys */ > > @@ -44,7 +44,10 @@ static inline int vma_pkey(struct vm_area_struct *vma) > return (vma->vm_flags & ARCH_VM_PKEY_FLAGS) >> VM_PKEY_SHIFT; > } > > -#define arch_max_pkey() pkeys_total > +static inline int arch_max_pkey(void) > +{ > + return max_pkey; > +}
If pkeys_total = 32 then max_pkey = 31. So we can't just substitute one for the other. ie. arch_max_pkey() must have been wrong, or it is wrong now. > diff --git a/arch/powerpc/mm/book3s64/pkeys.c > b/arch/powerpc/mm/book3s64/pkeys.c > index 87d882a9aaf2..a4d7287082a8 100644 > --- a/arch/powerpc/mm/book3s64/pkeys.c > +++ b/arch/powerpc/mm/book3s64/pkeys.c > @@ -14,7 +14,7 @@ > > DEFINE_STATIC_KEY_FALSE(pkey_disabled); > DEFINE_STATIC_KEY_FALSE(execute_pkey_disabled); > -int pkeys_total; /* Total pkeys as per device tree */ > +int max_pkey; /* Maximum key value supported */ > u32 initial_allocation_mask; /* Bits set for the initially allocated keys > */ > /* > * Keys marked in the reservation list cannot be allocated by userspace > @@ -84,7 +84,7 @@ static int scan_pkey_feature(void) > > static int pkey_initialize(void) > { > - int os_reserved, i; > + int pkeys_total, i; > > /* > * We define PKEY_DISABLE_EXECUTE in addition to the arch-neutral > @@ -122,12 +122,12 @@ static int pkey_initialize(void) > * The OS can manage only 8 pkeys due to its inability to represent them > * in the Linux 4K PTE. Mark all other keys reserved. > */ > - os_reserved = pkeys_total - 8; > + max_pkey = min(8, pkeys_total); Shouldn't it be 7 ? > #else > - os_reserved = 0; > + max_pkey = pkeys_total; > #endif > > - if (unlikely((pkeys_total - os_reserved) <= execute_only_key)) { > + if (unlikely(max_pkey <= execute_only_key)) { Isn't that an off-by-one now? This is one-off boot time code, there's no need to clutter it with unlikely. > /* > * Insufficient number of keys to support > * execute only key. Mark it unavailable. > @@ -174,10 +174,10 @@ static int pkey_initialize(void) > default_uamor &= ~(0x3ul << pkeyshift(1)); > > /* > - * Prevent the usage of OS reserved the keys. Update UAMOR > + * Prevent the usage of OS reserved keys. Update UAMOR > * for those keys. > */ > - for (i = (pkeys_total - os_reserved); i < pkeys_total; i++) { > + for (i = max_pkey; i < pkeys_total; i++) { Another off-by-one? Shouldn't we start from max_pkey + 1 ? > reserved_allocation_mask |= (0x1 << i); > default_uamor &= ~(0x3ul << pkeyshift(i)); > } cheers