[v7,00/12] x86: PIE support to extend KASLR randomization

Message

Thomas Garnier May 20, 2019, 11:19 p.m. UTC

Splitting the previous serie in two. This part contains assembly code
changes required for PIE but without any direct dependencies with the
rest of the patchset.

Changes:
 - patch v7 (assembly):
   - Split patchset and reorder changes.
 - patch v6:
   - Rebase on latest changes in jump tables and crypto.
   - Fix wording on couple commits.
   - Revisit checkpatch warnings.
   - Moving to @chromium.org.
 - patch v5:
   - Adapt new crypto modules for PIE.
   - Improve per-cpu commit message.
   - Fix xen 32-bit build error with .quad.
   - Remove extra code for ftrace.
 - patch v4:
   - Simplify early boot by removing global variables.
   - Modify the mcount location script for __mcount_loc intead of the address
     read in the ftrace implementation.
   - Edit commit description to explain better where the kernel can be located.
   - Streamlined the testing done on each patch proposal. Always testing
     hibernation, suspend, ftrace and kprobe to ensure no regressions.
 - patch v3:
   - Update on message to describe longer term PIE goal.
   - Minor change on ftrace if condition.
   - Changed code using xchgq.
 - patch v2:
   - Adapt patch to work post KPTI and compiler changes
   - Redo all performance testing with latest configs and compilers
   - Simplify mov macro on PIE (MOVABS now)
   - Reduce GOT footprint
 - patch v1:
   - Simplify ftrace implementation.
   - Use gcc mstack-protector-guard-reg=%gs with PIE when possible.
 - rfc v3:
   - Use --emit-relocs instead of -pie to reduce dynamic relocation space on
     mapped memory. It also simplifies the relocation process.
   - Move the start the module section next to the kernel. Remove the need for
     -mcmodel=large on modules. Extends module space from 1 to 2G maximum.
   - Support for XEN PVH as 32-bit relocations can be ignored with
     --emit-relocs.
   - Support for GOT relocations previously done automatically with -pie.
   - Remove need for dynamic PLT in modules.
   - Support dymamic GOT for modules.
 - rfc v2:
   - Add support for global stack cookie while compiler default to fs without
     mcmodel=kernel
   - Change patch 7 to correctly jump out of the identity mapping on kexec load
     preserve.

These patches make some of the changes necessary to build the kernel as
Position Independent Executable (PIE) on x86_64. Another patchset will
add the PIE option and larger architecture changes.

The patches:
 - 1-2, 4-12: Change in assembly code to be PIE compliant.
 - 3: Add a new _ASM_MOVABS macro to fetch a symbol address generically.

diffstat:
 crypto/aegis128-aesni-asm.S         |    6 +-
 crypto/aegis128l-aesni-asm.S        |    8 +--
 crypto/aegis256-aesni-asm.S         |    6 +-
 crypto/aes-x86_64-asm_64.S          |   45 ++++++++++------
 crypto/aesni-intel_asm.S            |    8 +--
 crypto/camellia-aesni-avx-asm_64.S  |   42 +++++++--------
 crypto/camellia-aesni-avx2-asm_64.S |   44 ++++++++--------
 crypto/camellia-x86_64-asm_64.S     |    8 +--
 crypto/cast5-avx-x86_64-asm_64.S    |   50 ++++++++++--------
 crypto/cast6-avx-x86_64-asm_64.S    |   44 +++++++++-------
 crypto/des3_ede-asm_64.S            |   96 ++++++++++++++++++++++++------------
 crypto/ghash-clmulni-intel_asm.S    |    4 -
 crypto/glue_helper-asm-avx.S        |    4 -
 crypto/glue_helper-asm-avx2.S       |    6 +-
 crypto/morus1280-avx2-asm.S         |    4 -
 crypto/morus1280-sse2-asm.S         |    8 +--
 crypto/morus640-sse2-asm.S          |    6 +-
 crypto/sha256-avx2-asm.S            |   23 +++++---
 entry/entry_64.S                    |   16 ++++--
 include/asm/alternative.h           |    6 +-
 include/asm/asm.h                   |    1 
 include/asm/jump_label.h            |    8 +--
 include/asm/paravirt_types.h        |   12 +++-
 include/asm/pm-trace.h              |    2 
 include/asm/processor.h             |    6 +-
 kernel/acpi/wakeup_64.S             |   31 ++++++-----
 kernel/head_64.S                    |   16 +++---
 kernel/relocate_kernel_64.S         |    2 
 power/hibernate_asm_64.S            |    4 -
 29 files changed, 299 insertions(+), 217 deletions(-)

Patchset is based on next-20190515.

Comments

Kees Cook June 10, 2019, 9:32 p.m. UTC | #1

On Mon, May 20, 2019 at 04:19:25PM -0700, Thomas Garnier wrote:
> Splitting the previous serie in two. This part contains assembly code
> changes required for PIE but without any direct dependencies with the
> rest of the patchset.

Thanks for doing this! It should be easier to land the "little" fixes so
there's less to review for the big PIE changes down the road.