Re: [RFC PATCH v3] sparc64: Add support for Application Data Integrity (ADI)

[Khalid Aziz]

On 01/05/2017 02:37 AM, Jerome Marchand wrote:
> On 01/04/2017 11:46 PM, Khalid Aziz wrote:
> > ADI is a new feature supported on sparc M7 and newer processors to allow
> > hardware to catch rogue accesses to memory. ADI is supported for data
> > fetches only and not instruction fetches. An app can enable ADI on its
> > data pages, set version tags on them and use versioned addresses to
> > access the data pages. Upper bits of the address contain the version
> > tag. On M7 processors, upper four bits (bits 63-60) contain the version
> > tag. If a rogue app attempts to access ADI enabled data pages, its
> > access is blocked and processor generates an exception.
> >
> > This patch extends mprotect to enable ADI (TSTATE.mcde), enable/disable
> > MCD (Memory Corruption Detection) on selected memory ranges, enable
> > TTE.mcd in PTEs, return ADI parameters to userspace and save/restore ADI
> > version tags on page swap out/in.  It also adds handlers for all traps
> > related to MCD. ADI is not enabled by default for any task. A task must
> > explicitly enable ADI on a memory range and set version tag for ADI to
> > be effective for the task.
> >
> > Signed-off-by: Khalid Aziz <khalid.aziz@xxxxxxxxxx>
> > Cc: Khalid Aziz <khalid@xxxxxxxxxxxxxx>
> > ---
> > v2:
> > 	- Fixed a build error
> >
> > v3:
> > 	- Removed CONFIG_SPARC_ADI
> > 	- Replaced prctl commands with mprotect
> > 	- Added auxiliary vectors for ADI parameters
> > 	- Enabled ADI for swappable pages
> >
> >  Documentation/sparc/adi.txt             | 239 ++++++++++++++++++++++++++++++++
> >  arch/sparc/include/asm/adi.h            |   6 +
> >  arch/sparc/include/asm/adi_64.h         |  46 ++++++
> >  arch/sparc/include/asm/elf_64.h         |   8 ++
> >  arch/sparc/include/asm/hugetlb.h        |  13 ++
> >  arch/sparc/include/asm/hypervisor.h     |   2 +
> >  arch/sparc/include/asm/mman.h           |  40 +++++-
> >  arch/sparc/include/asm/mmu_64.h         |   2 +
> >  arch/sparc/include/asm/mmu_context_64.h |  32 +++++
> >  arch/sparc/include/asm/pgtable_64.h     |  97 ++++++++++++-
> >  arch/sparc/include/asm/ttable.h         |  10 ++
> >  arch/sparc/include/asm/uaccess_64.h     | 120 +++++++++++++++-
> >  arch/sparc/include/uapi/asm/asi.h       |   5 +
> >  arch/sparc/include/uapi/asm/auxvec.h    |   8 ++
> >  arch/sparc/include/uapi/asm/mman.h      |   2 +
> >  arch/sparc/include/uapi/asm/pstate.h    |  10 ++
> >  arch/sparc/kernel/Makefile              |   1 +
> >  arch/sparc/kernel/adi_64.c              |  93 +++++++++++++
> >  arch/sparc/kernel/entry.h               |   3 +
> >  arch/sparc/kernel/head_64.S             |   1 +
> >  arch/sparc/kernel/mdesc.c               |   4 +
> >  arch/sparc/kernel/process_64.c          |  21 +++
> >  arch/sparc/kernel/sun4v_mcd.S           |  16 +++
> >  arch/sparc/kernel/traps_64.c            | 142 ++++++++++++++++++-
> >  arch/sparc/kernel/ttable_64.S           |   6 +-
> >  arch/sparc/mm/gup.c                     |  37 +++++
> >  arch/sparc/mm/tlb.c                     |  28 ++++
> >  arch/x86/kernel/signal_compat.c         |   2 +-
> >  include/asm-generic/pgtable.h           |   5 +
> >  include/linux/mm.h                      |   2 +
> >  include/uapi/asm-generic/siginfo.h      |   5 +-
> >  mm/memory.c                             |   2 +-
> >  mm/rmap.c                               |   4 +-
>
> I haven't actually reviewed the code and looked at why you need
> set_swp_pte_at() function, but the code that add the generic version of
> this function need to be separated from the rest of the patch. Also,
> given the size of this patch, I suspect the rest also need to be broken
> into more patches.
>
> Jerome

Sure, I can do that. Code to add new signal codes can be one patch, 
generic changes to swap infrastructure can be another and I can look for 
logical breaks for the rest of the sparc specific code.

--
Khalid