[PATCH v12 00/21] Compile-time stack metadata validation

[Josh Poimboeuf]

This is v12 of the compile-time stack metadata validation patch set,
along with proposed fixes for many of the warnings it found.  It's based
on the tip/master branch.

Biggest changes since v11:

- Moved the tool from scripts/ to tools/ so it can be a standalone
  program for use by non-kernel code bases.

- Renamed from "stackvalidate" to "stacktool" (for lack of a better
  name).  "stackvalidate" is too limiting because eventually it will do
  more than just validation -- it will also have the ability to modify
  the object file when CFI generation support gets added.

v11 can be found here:

  https://lkml.kernel.org/r/cover.1440423732.git.jpoimboe@xxxxxxxxxx

For more information about the motivation behind this patch set, and
more details about what it does, see the patch 4 changelog and
tools/stacktool/Documentation/stack-validation.txt.

Patch 1 fixes the formatting for the "make -C tools" help message.

Patches 2-6 add stacktool and some related macros.

Patches 7-21 are some proposed fixes for several of the warnings
reported by stacktool.  They've been compile-tested and boot-tested in a
VM, but I haven't attempted any meaningful testing for many of them.

v12:
- rename "stackvalidate" -> "stacktool"
- move from scripts/ to tools/:
  - makefile rework
  - make a copy of the x86 insn code (and warn if the code diverges)
  - use tools/include/linux/list.h
- move warning macros to a new warn.h file
- change wording: "stack validation" -> "stack metadata validation"

v11:
- attempt to answer the "why" question better in the documentation and
  commit message
- s/FP_SAVE/FRAME_BEGIN/ in documentation

v10:
- add scripts/mod to directory ignores
- remove circular dependencies for ignored objects which are built
  before stackvalidate
- fix CONFIG_MODVERSIONS incompatibility

v9:
- rename FRAME/ENDFRAME -> FRAME_BEGIN/FRAME_END
- fix jump table issue for when the original instruction is a jump
- drop paravirt thunk alignment patch
- add maintainers to CC for proposed warning fixes

v8:
- add proposed fixes for warnings
- fix all memory leaks
- process ignores earlier and add more ignore checks
- always assume POPCNT alternative is enabled
- drop hweight inline asm fix
- drop __schedule() ignore patch
- change .Ltemp_\@ to .Lstackvalidate_ignore_\@ in asm macro
- fix CONFIG_* checks in asm macros
- add C versions of ignore macros and frame macros
- change ";" to "\n" in C macros
- add ifdef CONFIG_STACK_VALIDATION checks in C ignore macros
- use numbered label in C ignore macro
- add missing break in switch case statement in arch-x86.c

v7:
- sibling call support
- document proposed solution for inline asm() frame pointer issues
- say "kernel entry/exit" instead of "context switch"
- clarify the checking of switch statement jump tables
- discard __stackvalidate_ignore_* sections in linker script
- use .Ltemp_\@ to get a unique label instead of static 3-digit number
- change STACKVALIDATE_IGNORE_FUNC variable to a static
- move STACKVALIDATE_IGNORE_INSN to arch-specific .h file

v6:
- rename asmvalidate -> stackvalidate (again)
- gcc-generated object file support
- recursive branch state analysis
- external jump support
- fixup/exception table support
- jump label support
- switch statement jump table support
- added documentation
- detection of "noreturn" dead end functions
- added a Kbuild mechanism for skipping files and dirs
- moved frame pointer macros to arch/x86/include/asm/frame.h
- moved ignore macros to include/linux/stackvalidate.h

v5:
- stackvalidate -> asmvalidate
- frame pointers only required for non-leaf functions
- check for the use of the FP_SAVE/RESTORE macros instead of manually
  analyzing code to detect frame pointer usage
- additional checks to ensure each function doesn't leave its boundaries
- make the macros simpler and more flexible
- support for analyzing ALTERNATIVE macros
- simplified the arch interfaces in scripts/asmvalidate/arch.h
- fixed some asmvalidate warnings
- rebased onto latest tip asm cleanups
- many more small changes

v4:
- Changed the default to CONFIG_STACK_VALIDATION=n, until all the asm
  code can get cleaned up.
- Fixed a stackvalidate error path exit code issue found by Michal
  Marek.

v3:
- Added a patch to make the push/pop CFI macros arch-independent, as
  suggested by H. Peter Anvin

v2:
- Fixed memory leaks reported by Petr Mladek

Cc: linux-kernel@xxxxxxxxxxxxxxx
Cc: live-patching@xxxxxxxxxxxxxxx
Cc: Michal Marek <mmarek@xxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Andy Lutomirski <luto@xxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Andi Kleen <andi@xxxxxxxxxxxxxx>
Cc: Pedro Alves <palves@xxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxx>
Cc: Bernd Petrovitsch <bernd@xxxxxxxxxxxxxxxxxxx>
Cc: "Chris J Arges" <chris.j.arges@xxxxxxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>

Josh Poimboeuf (21):
  tools: Fix formatting of the "make -C tools" help message
  x86/asm: Frame pointer macro cleanup
  x86/asm: Add C versions of frame pointer macros
  x86/stacktool: Compile-time stack metadata validation
  x86/stacktool: Add file and directory ignores
  x86/stacktool: Add ignore macros
  x86/xen: Add stack frame dependency to hypercall inline asm calls
  x86/paravirt: Add stack frame dependency to PVOP inline asm calls
  x86/paravirt: Create a stack frame in PV_CALLEE_SAVE_REGS_THUNK
  x86/amd: Set ELF function type for vide()
  x86/reboot: Add ljmp instructions to stacktool whitelist
  x86/xen: Add xen_cpuid() and xen_setup_gdt() to stacktool whitelists
  x86/asm/crypto: Create stack frames in aesni-intel_asm.S
  x86/asm/crypto: Move .Lbswap_mask data to .rodata section
  x86/asm/crypto: Move jump_table to .rodata section
  x86/asm/crypto: Create stack frames in clmul_ghash_mul/update()
  x86/asm/entry: Create stack frames in thunk functions
  x86/asm/acpi: Create a stack frame in do_suspend_lowlevel()
  x86/asm: Create stack frames in rwsem functions
  x86/asm/efi: Create a stack frame in efi_call()
  x86/asm/power: Create stack frames in hibernate_asm_64.S

 MAINTAINERS                                        |   7 +
 Makefile                                           |   5 +-
 arch/Kconfig                                       |   6 +
 arch/x86/Kconfig                                   |   1 +
 arch/x86/boot/Makefile                             |   3 +-
 arch/x86/boot/compressed/Makefile                  |   3 +-
 arch/x86/crypto/aesni-intel_asm.S                  |  21 +
 arch/x86/crypto/crc32c-pcl-intel-asm_64.S          |   8 +-
 arch/x86/crypto/ghash-clmulni-intel_asm.S          |   5 +
 arch/x86/entry/thunk_64.S                          |   4 +
 arch/x86/entry/vdso/Makefile                       |   5 +-
 arch/x86/include/asm/frame.h                       |  51 +-
 arch/x86/include/asm/paravirt.h                    |   9 +-
 arch/x86/include/asm/paravirt_types.h              |  18 +-
 arch/x86/include/asm/stacktool.h                   |  45 +
 arch/x86/include/asm/xen/hypercall.h               |   5 +-
 arch/x86/kernel/acpi/wakeup_64.S                   |   3 +
 arch/x86/kernel/cpu/amd.c                          |   5 +-
 arch/x86/kernel/reboot.c                           |   7 +-
 arch/x86/kernel/vmlinux.lds.S                      |   5 +-
 arch/x86/lib/rwsem.S                               |  11 +-
 arch/x86/platform/efi/efi_stub_64.S                |   3 +
 arch/x86/power/hibernate_asm_64.S                  |   7 +
 arch/x86/purgatory/Makefile                        |   2 +
 arch/x86/realmode/Makefile                         |   4 +-
 arch/x86/realmode/rm/Makefile                      |   3 +-
 arch/x86/xen/enlighten.c                           |   4 +-
 drivers/firmware/efi/libstub/Makefile              |   1 +
 include/linux/stacktool.h                          |  29 +
 lib/Kconfig.debug                                  |  12 +
 scripts/Makefile.build                             |  37 +-
 scripts/mod/Makefile                               |   2 +
 tools/Makefile                                     |  43 +-
 tools/stacktool/.gitignore                         |   1 +
 tools/stacktool/Build                              |   4 +
 tools/stacktool/Documentation/stack-validation.txt | 336 +++++++
 tools/stacktool/Makefile                           |  51 ++
 tools/stacktool/arch.h                             |  44 +
 tools/stacktool/arch/x86/Build                     |  12 +
 tools/stacktool/arch/x86/decode.c                  | 163 ++++
 .../stacktool/arch/x86/insn/gen-insn-attr-x86.awk  | 387 ++++++++
 tools/stacktool/arch/x86/insn/inat.c               |  97 ++
 tools/stacktool/arch/x86/insn/inat.h               | 221 +++++
 tools/stacktool/arch/x86/insn/inat_types.h         |  29 +
 tools/stacktool/arch/x86/insn/insn.c               | 594 +++++++++++++
 tools/stacktool/arch/x86/insn/insn.h               | 201 +++++
 tools/stacktool/arch/x86/insn/x86-opcode-map.txt   | 984 +++++++++++++++++++++
 tools/stacktool/elf.c                              | 403 +++++++++
 tools/stacktool/elf.h                              |  79 ++
 tools/stacktool/special.c                          | 199 +++++
 tools/stacktool/special.h                          |  42 +
 tools/stacktool/stacktool.c                        | 980 ++++++++++++++++++++
 tools/stacktool/warn.h                             |  60 ++
 53 files changed, 5192 insertions(+), 69 deletions(-)
 create mode 100644 arch/x86/include/asm/stacktool.h
 create mode 100644 include/linux/stacktool.h
 create mode 100644 tools/stacktool/.gitignore
 create mode 100644 tools/stacktool/Build
 create mode 100644 tools/stacktool/Documentation/stack-validation.txt
 create mode 100644 tools/stacktool/Makefile
 create mode 100644 tools/stacktool/arch.h
 create mode 100644 tools/stacktool/arch/x86/Build
 create mode 100644 tools/stacktool/arch/x86/decode.c
 create mode 100644 tools/stacktool/arch/x86/insn/gen-insn-attr-x86.awk
 create mode 100644 tools/stacktool/arch/x86/insn/inat.c
 create mode 100644 tools/stacktool/arch/x86/insn/inat.h
 create mode 100644 tools/stacktool/arch/x86/insn/inat_types.h
 create mode 100644 tools/stacktool/arch/x86/insn/insn.c
 create mode 100644 tools/stacktool/arch/x86/insn/insn.h
 create mode 100644 tools/stacktool/arch/x86/insn/x86-opcode-map.txt
 create mode 100644 tools/stacktool/elf.c
 create mode 100644 tools/stacktool/elf.h
 create mode 100644 tools/stacktool/special.c
 create mode 100644 tools/stacktool/special.h
 create mode 100644 tools/stacktool/stacktool.c
 create mode 100644 tools/stacktool/warn.h

-- 
2.4.3

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