RE: [PATCH v2] x86/uaccess: Use pointer masking to limit uaccess speculation

2020-09-09 Thread David Laight
From: Josh Poimboeuf > Sent: 09 September 2020 13:47 > On Wed, Sep 09, 2020 at 08:20:07AM +, David Laight wrote: > > From: Josh Poimboeuf > > > Sent: 08 September 2020 18:43 > > > Hi x86 maintainers, > > ... > > > > --- a/arch/x86/lib/putuser.S > > > > +++ b/arch/x86/lib/putuser.S > > > > @@

Re: [PATCH v2] x86/uaccess: Use pointer masking to limit uaccess speculation

2020-09-09 Thread Josh Poimboeuf
On Wed, Sep 09, 2020 at 08:20:07AM +, David Laight wrote: > From: Josh Poimboeuf > > Sent: 08 September 2020 18:43 > > Hi x86 maintainers, > ... > > > --- a/arch/x86/lib/putuser.S > > > +++ b/arch/x86/lib/putuser.S > > > @@ -38,6 +38,8 @@ SYM_FUNC_START(__put_user_1) > > > ENTER > > > cmp

Re: [PATCH v2] x86/uaccess: Use pointer masking to limit uaccess speculation

2020-09-09 Thread Josh Poimboeuf
On Wed, Sep 09, 2020 at 07:46:51AM -0500, Josh Poimboeuf wrote: > On Wed, Sep 09, 2020 at 08:20:07AM +, David Laight wrote: > > From: Josh Poimboeuf > > > Sent: 08 September 2020 18:43 > > > Hi x86 maintainers, > > ... > > > > --- a/arch/x86/lib/putuser.S > > > > +++ b/arch/x86/lib/putuser.S

RE: [PATCH v2] x86/uaccess: Use pointer masking to limit uaccess speculation

2020-09-09 Thread David Laight
From: Josh Poimboeuf > Sent: 08 September 2020 18:43 > Hi x86 maintainers, ... > > --- a/arch/x86/lib/putuser.S > > +++ b/arch/x86/lib/putuser.S > > @@ -38,6 +38,8 @@ SYM_FUNC_START(__put_user_1) > > ENTER > > cmp TASK_addr_limit(%_ASM_BX),%_ASM_CX > > jae .Lbad_put_user > > + sbb

Re: [PATCH v2] x86/uaccess: Use pointer masking to limit uaccess speculation

2020-09-08 Thread Josh Poimboeuf
Hi x86 maintainers, Any objection to merging this patch? On Tue, Sep 01, 2020 at 10:30:19AM -0500, Josh Poimboeuf wrote: > The x86 uaccess code uses barrier_nospec() in various places to prevent > speculative dereferencing of user-controlled pointers (which might be > combined with further