[PATCH v11 00/20] Compile-time stack validation

[Josh Poimboeuf]

This is v11 of the compile-time stack validation patch set, along with
proposed fixes for many of the warnings it found.  It's based on the
tip/master branch.

The only real change since v10 is some improvements in patch 3 to the
documentation and changelog which attempt to better describe why stack
validation is needed.

v10 can be found here:

  https://lkml.kernel.org/r/cover.1439521412.git.jpoimboe@xxxxxxxxxx

For more information about the motivation behind this patch set, and
more details about what it does, please see the changelog in patch 3.
Patch 3 also has Documentation/stack-validation.txt which has further
details.

Patches 1-5 are the stackvalidate tool and some related macros.

Patches 6-20 are some proposed fixes for several of the warnings
reported by stackvalidate.  They've been compile-tested and boot tested
in a VM, but I haven't attempted any meaningful testing for many of
them.

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 (20):
  x86/asm: Frame pointer macro cleanup
  x86/asm: Add C versions of frame pointer macros
  x86/stackvalidate: Compile-time stack validation
  x86/stackvalidate: Add file and directory ignores
  x86/stackvalidate: 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 stackvalidate whitelist
  x86/xen: Add xen_cpuid() and xen_setup_gdt() to stackvalidate
    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

 Documentation/stack-validation.txt        | 338 +++++++++++
 MAINTAINERS                               |   8 +
 arch/Kconfig                              |   6 +
 arch/x86/Kconfig                          |   1 +
 arch/x86/Makefile                         |   6 +-
 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/stackvalidate.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/stackvalidate.h             |  28 +
 lib/Kconfig.debug                         |  11 +
 scripts/Makefile                          |   1 +
 scripts/Makefile.build                    |  37 +-
 scripts/mod/Makefile                      |   2 +
 scripts/stackvalidate/Makefile            |  24 +
 scripts/stackvalidate/arch-x86.c          | 160 +++++
 scripts/stackvalidate/arch.h              |  44 ++
 scripts/stackvalidate/elf.c               | 427 +++++++++++++
 scripts/stackvalidate/elf.h               |  92 +++
 scripts/stackvalidate/list.h              | 217 +++++++
 scripts/stackvalidate/special.c           | 199 ++++++
 scripts/stackvalidate/special.h           |  42 ++
 scripts/stackvalidate/stackvalidate.c     | 976 ++++++++++++++++++++++++++++++
 43 files changed, 2803 insertions(+), 48 deletions(-)
 create mode 100644 Documentation/stack-validation.txt
 create mode 100644 arch/x86/include/asm/stackvalidate.h
 create mode 100644 include/linux/stackvalidate.h
 create mode 100644 scripts/stackvalidate/Makefile
 create mode 100644 scripts/stackvalidate/arch-x86.c
 create mode 100644 scripts/stackvalidate/arch.h
 create mode 100644 scripts/stackvalidate/elf.c
 create mode 100644 scripts/stackvalidate/elf.h
 create mode 100644 scripts/stackvalidate/list.h
 create mode 100644 scripts/stackvalidate/special.c
 create mode 100644 scripts/stackvalidate/special.h
 create mode 100644 scripts/stackvalidate/stackvalidate.c

-- 
2.4.3

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