Subject: [PATCH 00/33] Compile-time stack metadata validation

From: Josh Poimboeuf <[email-masked]>
Date: Thu, 21 Jan 2016 16:49:04 -0600

This is v16 of the compile-time stack metadata validation patch set,
along with proposed fixes for most of the warnings it found.  It's based
on the tip/master branch.

v15 can be found here:

  https://lkml.kernel.org/r/[email-masked]

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

Patches 1-4 add stacktool and integrate it into the kernel build.

Patches 5-28 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.

Patches 29-33 add some directories, files, and functions to the
stacktool whitelist in order to silence false positive warnings.

v16:
- fix all allyesconfig warnings, except for staging
- get rid of STACKTOOL_IGNORE_INSN which is no longer needed
- remove several whitelists in favor of automatically whitelisting any
  function with a special instruction like ljmp, lret, or vmrun
- split up stacktool patch into 3 parts as suggested by Ingo
- update the global noreturn function list
- detect noreturn function fallthroughs
- skip weak functions in noreturn call detection logic
- add empty function check to noreturn logic
- allow non-section rela symbols for __ex_table sections
- support rare switch table case with jmpq *[addr](%rip)
- don't warn on frame pointer restore without save
- rearrange patch order a bit

v15:
- restructure code for a new cmdline interface "stacktool check" using
  the new subcommand framework in tools/lib/subcmd
- fix 32 bit build fail (put __sp at end) in paravirt_types.h patch 10
  which was reported by 0day

v14:
- make tools/include/linux/list.h self-sufficient
- create FRAME_OFFSET to allow 32-bit code to be able to access function
  arguments on the stack
- add FRAME_OFFSET usage in crypto patch 14/24: "Create stack frames in
  aesni-intel_asm.S"
- rename "index" -> "idx" to fix build with some compilers

v13:
- LDFLAGS order fix from Chris J Arges
- new warning fix patches from Chris J Arges
- "--frame-pointer" -> "--check-frame-pointer"

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: [email-masked]
Cc: [email-masked]
Cc: Michal Marek <[email-masked]>
Cc: Peter Zijlstra <[email-masked]>
Cc: Andy Lutomirski <[email-masked]>
Cc: Borislav Petkov <[email-masked]>
Cc: Linus Torvalds <torvalds-de/[email-masked]>
Cc: Andi Kleen <andi-Vw/[email-masked]>
Cc: Pedro Alves <[email-masked]>
Cc: Namhyung Kim <[email-masked]>
Cc: Bernd Petrovitsch <[email-masked]>
Cc: Chris J Arges <[email-masked]>
Cc: Andrew Morton <akpm-de/[email-masked]>
Cc: Jiri Slaby <[email-masked]>
Cc: Arnaldo Carvalho de Melo <[email-masked]>

Chris J Arges (1):
  x86/uaccess: Add stack frame output operand in get_user inline asm

Josh Poimboeuf (32):
  x86/stacktool: Compile-time stack metadata validation
  kbuild/stacktool: Add CONFIG_STACK_VALIDATION option
  x86/stacktool: Enable stacktool on x86_64
  x86/stacktool: Add STACKTOOL_IGNORE_FUNC macro
  x86/xen: Add stack frame dependency to hypercall inline asm calls
  x86/asm/xen: Set ELF function type for xen_adjust_exception_frame()
  x86/asm/xen: Create stack frames in xen-asm.S
  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/asm/crypto: Move .Lbswap_mask data to .rodata section
  x86/asm/crypto: Move jump_table to .rodata section
  x86/asm/crypto: Simplify stack usage in sha-mb functions
  x86/asm/crypto: Don't use rbp as a scratch register
  x86/asm/crypto: Create stack frames in crypto functions
  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
  x86/asm/bpf: Annotate callable functions
  x86/asm/bpf: Create stack frames in bpf_jit.S
  x86/kprobes: Get rid of kretprobe_trampoline_holder()
  x86/kvm: Set ELF function type for fastop functions
  x86/kvm: Add stack frame dependency to test_cc() inline asm
  watchdog/hpwdt: Create stack frame in asminline_call()
  x86/locking: Create stack frame in PV unlock
  x86/stacktool: Add directory and file whitelists
  x86/xen: Add xen_cpuid() to stacktool whitelist
  bpf: Add __bpf_prog_run() to stacktool whitelist
  sched: Add __schedule() to stacktool whitelist
  x86/kprobes: Add kretprobe_trampoline() to stacktool whitelist

 MAINTAINERS                                        |   6 +
 Makefile                                           |   5 +-
 arch/Kconfig                                       |   6 +
 arch/x86/Kconfig                                   |   1 +
 arch/x86/boot/Makefile                             |   1 +
 arch/x86/boot/compressed/Makefile                  |   3 +-
 arch/x86/crypto/aesni-intel_asm.S                  |  75 +-
 arch/x86/crypto/camellia-aesni-avx-asm_64.S        |  15 +
 arch/x86/crypto/camellia-aesni-avx2-asm_64.S       |  15 +
 arch/x86/crypto/cast5-avx-x86_64-asm_64.S          |   9 +
 arch/x86/crypto/cast6-avx-x86_64-asm_64.S          |  13 +
 arch/x86/crypto/crc32c-pcl-intel-asm_64.S          |   8 +-
 arch/x86/crypto/ghash-clmulni-intel_asm.S          |   5 +
 arch/x86/crypto/serpent-avx-x86_64-asm_64.S        |  13 +
 arch/x86/crypto/serpent-avx2-asm_64.S              |  13 +
 arch/x86/crypto/sha-mb/sha1_mb_mgr_flush_avx2.S    |  35 +-
 arch/x86/crypto/sha-mb/sha1_mb_mgr_submit_avx2.S   |  36 +-
 arch/x86/crypto/twofish-avx-x86_64-asm_64.S        |  13 +
 arch/x86/entry/Makefile                            |   4 +
 arch/x86/entry/thunk_64.S                          |   4 +
 arch/x86/entry/vdso/Makefile                       |   5 +-
 arch/x86/include/asm/paravirt.h                    |   9 +-
 arch/x86/include/asm/paravirt_types.h              |  18 +-
 arch/x86/include/asm/qspinlock_paravirt.h          |   4 +
 arch/x86/include/asm/uaccess.h                     |   5 +-
 arch/x86/include/asm/xen/hypercall.h               |   5 +-
 arch/x86/kernel/Makefile                           |   5 +
 arch/x86/kernel/acpi/wakeup_64.S                   |   3 +
 arch/x86/kernel/cpu/amd.c                          |   5 +-
 arch/x86/kernel/kprobes/core.c                     |  59 +-
 arch/x86/kernel/vmlinux.lds.S                      |   5 +-
 arch/x86/kvm/emulate.c                             |  33 +-
 arch/x86/lib/rwsem.S                               |  11 +-
 arch/x86/net/bpf_jit.S                             |  48 +-
 arch/x86/platform/efi/Makefile                     |   2 +
 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                           |   3 +-
 arch/x86/xen/xen-asm.S                             |  10 +-
 arch/x86/xen/xen-asm_64.S                          |   1 +
 drivers/firmware/efi/libstub/Makefile              |   1 +
 drivers/watchdog/hpwdt.c                           |   8 +-
 include/linux/stacktool.h                          |  23 +
 kernel/bpf/core.c                                  |   2 +
 kernel/sched/core.c                                |   2 +
 lib/Kconfig.debug                                  |  12 +
 scripts/Makefile.build                             |  38 +-
 scripts/mod/Makefile                               |   2 +
 tools/Makefile                                     |  14 +-
 tools/stacktool/.gitignore                         |   2 +
 tools/stacktool/Build                              |  13 +
 tools/stacktool/Documentation/stack-validation.txt | 333 +++++++
 tools/stacktool/Makefile                           |  60 ++
 tools/stacktool/arch.h                             |  44 +
 tools/stacktool/arch/x86/Build                     |  12 +
 tools/stacktool/arch/x86/decode.c                  | 172 ++++
 .../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/builtin-check.c                    | 991 +++++++++++++++++++++
 tools/stacktool/builtin.h                          |  22 +
 tools/stacktool/elf.c                              | 403 +++++++++
 tools/stacktool/elf.h                              |  79 ++
 tools/stacktool/special.c                          | 193 ++++
 tools/stacktool/special.h                          |  42 +
 tools/stacktool/stacktool.c                        | 134 +++
 tools/stacktool/warn.h                             |  60 ++
 74 files changed, 5516 insertions(+), 189 deletions(-)
 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/builtin-check.c
 create mode 100644 tools/stacktool/builtin.h
 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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