| Message ID | 1529508227-24331-1-git-send-email-will.deacon@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Wed, Jun 20, 2018 at 04:23:47PM +0100, Will Deacon wrote: > We inspect __kpti_forced early on as part of the cpufeature enable > callback which remaps the swapper page table using non-global entries. > > Ensure that __kpti_forced has been updated to reflect the kpti= > command-line option before we start using it. > > Reported-by: Wei Xu <xuwei5@hisilicon.com> > Signed-off-by: Will Deacon <will.deacon@arm.com> Does it need a fixes tag? Fixes: ea1e3de85e94 ("arm64: entry: Add fake CPU feature for unmapping the kernel at EL0")
On Wed, Jun 20, 2018 at 04:40:32PM +0100, Catalin Marinas wrote: > On Wed, Jun 20, 2018 at 04:23:47PM +0100, Will Deacon wrote: > > We inspect __kpti_forced early on as part of the cpufeature enable > > callback which remaps the swapper page table using non-global entries. > > > > Ensure that __kpti_forced has been updated to reflect the kpti= > > command-line option before we start using it. > > > > Reported-by: Wei Xu <xuwei5@hisilicon.com> > > Signed-off-by: Will Deacon <will.deacon@arm.com> > > Does it need a fixes tag? > > Fixes: ea1e3de85e94 ("arm64: entry: Add fake CPU feature for unmapping the kernel at EL0") Perhaps, but really this is just a performance optimisation for the kpti=off case where we don't actually need to put the nG mappings down. Will
Hi Will, On 2018/6/20 16:23, Will Deacon wrote: > We inspect __kpti_forced early on as part of the cpufeature enable > callback which remaps the swapper page table using non-global entries. > > Ensure that __kpti_forced has been updated to reflect the kpti= > command-line option before we start using it. > > Reported-by: Wei Xu <xuwei5@hisilicon.com> > Signed-off-by: Will Deacon <will.deacon@arm.com> > --- > arch/arm64/kernel/cpufeature.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c > index d2856b129097..112b071e793f 100644 > --- a/arch/arm64/kernel/cpufeature.c > +++ b/arch/arm64/kernel/cpufeature.c > @@ -937,7 +937,7 @@ static int __init parse_kpti(char *str) > __kpti_forced = enabled ? 1 : -1; > return 0; > } > -__setup("kpti=", parse_kpti); > +early_param("kpti=", parse_kpti); %s/kpti=/kpti Thanks! Best Regards, Wei > #endif /* CONFIG_UNMAP_KERNEL_AT_EL0 */ > > #ifdef CONFIG_ARM64_HW_AFDBM >
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c index d2856b129097..112b071e793f 100644 --- a/arch/arm64/kernel/cpufeature.c +++ b/arch/arm64/kernel/cpufeature.c @@ -937,7 +937,7 @@ static int __init parse_kpti(char *str) __kpti_forced = enabled ? 1 : -1; return 0; } -__setup("kpti=", parse_kpti); +early_param("kpti=", parse_kpti); #endif /* CONFIG_UNMAP_KERNEL_AT_EL0 */ #ifdef CONFIG_ARM64_HW_AFDBM
We inspect __kpti_forced early on as part of the cpufeature enable callback which remaps the swapper page table using non-global entries. Ensure that __kpti_forced has been updated to reflect the kpti= command-line option before we start using it. Reported-by: Wei Xu <xuwei5@hisilicon.com> Signed-off-by: Will Deacon <will.deacon@arm.com> --- arch/arm64/kernel/cpufeature.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)