[v6,0/8] crypto: x86: Fix indirect function call casts
mbox series

Message ID 20191122010334.12081-1-keescook@chromium.org
Headers show
Series
  • crypto: x86: Fix indirect function call casts
Related show

Message

Kees Cook Nov. 22, 2019, 1:03 a.m. UTC
v6:
- minimize need for various internal casts (ebiggers)
- clarify comments (ebiggers)
- switch all context pointers to const (ebiggers)
v5: https://lore.kernel.org/lkml/20191113182516.13545-1-keescook@chromium.org
v4: https://lore.kernel.org/lkml/20191111214552.36717-1-keescook@chromium.org
v3: https://lore.kernel.org/lkml/20190507161321.34611-1-keescook@chromium.org

Hi,

Now that Clang's CFI has been fixed to do the right thing with extern
asm functions, this patch series is much simplified. Repeating patch
1's commit log here:

    The crypto glue performed function prototype casting to make indirect
    calls to assembly routines. Instead of performing casts at the call
    sites (which trips Control Flow Integrity prototype checking), switch
    each prototype to a common standard set of arguments which allows the
    incremental removal of the existing macros. In order to keep pointer
    math unchanged, internal casting between u128 pointers and u8 pointers
    is added.

With this series (and the Clang LTO+CFI series) I am able to boot x86
with all crytpo selftests enabled without tripping any CFI checks.

Thanks!

-Kees

Kees Cook (8):
  crypto: x86/glue_helper: Regularize function prototypes
  crypto: x86/serpent: Remove glue function macros usage
  crypto: x86/camellia: Remove glue function macro usage
  crypto: x86/twofish: Remove glue function macro usage
  crypto: x86/cast6: Remove glue function macro usage
  crypto: x86/aesni: Remove glue function macro usage
  crypto: x86/glue_helper: Remove function prototype cast helpers
  crypto, x86/sha: Eliminate casts on asm implementations

 arch/x86/crypto/aesni-intel_asm.S          |  8 +--
 arch/x86/crypto/aesni-intel_glue.c         | 45 ++++++-------
 arch/x86/crypto/camellia_aesni_avx2_glue.c | 74 ++++++++++-----------
 arch/x86/crypto/camellia_aesni_avx_glue.c  | 72 +++++++++------------
 arch/x86/crypto/camellia_glue.c            | 45 +++++++------
 arch/x86/crypto/cast6_avx_glue.c           | 68 +++++++++-----------
 arch/x86/crypto/glue_helper.c              | 23 ++++---
 arch/x86/crypto/serpent_avx2_glue.c        | 65 +++++++++----------
 arch/x86/crypto/serpent_avx_glue.c         | 63 +++++++++---------
 arch/x86/crypto/serpent_sse2_glue.c        | 30 +++++----
 arch/x86/crypto/sha1_ssse3_asm.S           | 10 ++-
 arch/x86/crypto/sha1_ssse3_glue.c          | 64 ++++++++----------
 arch/x86/crypto/sha256-ssse3-asm.S         |  4 +-
 arch/x86/crypto/sha256_ssse3_glue.c        | 34 +++++-----
 arch/x86/crypto/sha512-ssse3-asm.S         |  4 +-
 arch/x86/crypto/sha512_ssse3_glue.c        | 31 +++++----
 arch/x86/crypto/twofish_avx_glue.c         | 75 ++++++++++------------
 arch/x86/crypto/twofish_glue_3way.c        | 37 ++++++-----
 arch/x86/include/asm/crypto/camellia.h     | 63 +++++++++---------
 arch/x86/include/asm/crypto/glue_helper.h  | 18 ++----
 arch/x86/include/asm/crypto/serpent-avx.h  | 20 +++---
 arch/x86/include/asm/crypto/serpent-sse2.h | 28 ++++----
 arch/x86/include/asm/crypto/twofish.h      | 19 +++---
 crypto/cast6_generic.c                     | 18 +++---
 crypto/serpent_generic.c                   |  6 +-
 include/crypto/cast6.h                     |  4 +-
 include/crypto/serpent.h                   |  4 +-
 include/crypto/xts.h                       |  2 -
 28 files changed, 446 insertions(+), 488 deletions(-)

Comments

Eric Biggers Nov. 22, 2019, 2:21 a.m. UTC | #1
On Thu, Nov 21, 2019 at 05:03:26PM -0800, Kees Cook wrote:
> v6:
> - minimize need for various internal casts (ebiggers)
> - clarify comments (ebiggers)
> - switch all context pointers to const (ebiggers)
> v5: https://lore.kernel.org/lkml/20191113182516.13545-1-keescook@chromium.org
> v4: https://lore.kernel.org/lkml/20191111214552.36717-1-keescook@chromium.org
> v3: https://lore.kernel.org/lkml/20190507161321.34611-1-keescook@chromium.org
> 
> Hi,
> 
> Now that Clang's CFI has been fixed to do the right thing with extern
> asm functions, this patch series is much simplified. Repeating patch
> 1's commit log here:
> 
>     The crypto glue performed function prototype casting to make indirect
>     calls to assembly routines. Instead of performing casts at the call
>     sites (which trips Control Flow Integrity prototype checking), switch
>     each prototype to a common standard set of arguments which allows the
>     incremental removal of the existing macros. In order to keep pointer
>     math unchanged, internal casting between u128 pointers and u8 pointers
>     is added.
> 
> With this series (and the Clang LTO+CFI series) I am able to boot x86
> with all crytpo selftests enabled without tripping any CFI checks.
> 
> Thanks!
> 
> -Kees
> 
> Kees Cook (8):
>   crypto: x86/glue_helper: Regularize function prototypes
>   crypto: x86/serpent: Remove glue function macros usage
>   crypto: x86/camellia: Remove glue function macro usage
>   crypto: x86/twofish: Remove glue function macro usage
>   crypto: x86/cast6: Remove glue function macro usage
>   crypto: x86/aesni: Remove glue function macro usage
>   crypto: x86/glue_helper: Remove function prototype cast helpers
>   crypto, x86/sha: Eliminate casts on asm implementations

This patchset doesn't actually compile until patch 6/8, due to
-Werror=incompatible-pointer-types in the kernel's top-level Makefile.  It's
generally expected that every kernel commit compiles, and I'm not sure it's a
good idea to allow any exceptions.

The easiest solution would be to just squash the first 6 patches together into
one big patch.

Alternatively, 'ccflags-y := -Wno-error=incompatible-pointer-types' could be
added to arch/x86/crypto/Makefile in patch 1 and removed in patch 7.

- Eric