Compile-time stack metadata validation

This is v19 of the compile-time stack metadata validation patch set.

It's based on tip:core/objtool.

v18 can be found here:

https://lkml.kernel.org/r/[email protected]

For more information about the motivation behind this patch set, and more details about what it does, see the patch 8 changelog and tools/objtool/Documentation/stack-validation.txt.

Patches 1-7 mark various directories, files, and functions as "non-standard" in preparation for objtool.

Patches 8-10 add objtool and integrate it into the kernel build.

v19:
- add support for CONFIG_GCOV_KERNEL, CONFIG_KASAN, CONFIG_UBSAN
- always inline context_switch() to prevent gcov inline changes
- add main() return value in objtool.c
- change warning output format to mimic gcc warnings

v18:
- include/linux/objtool.h -> include/linux/frame.h
- __objtool_ignore_func -> __func_stack_frame_non_standard
- reword commit messages and comments a bit
- reorder patches

v17:
- __ex_table fix
- rename stacktool -> objtool
- STACKTOOL_IGNORE_FUNCTION -> STACK_FRAME_NON_STANDARD
- 'STACKTOOL := n' -> 'OBJECT_FILES_NON_STANDARD := y'
- updated global_noreturns list

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

Josh Poimboeuf (10):
objtool: Mark non-standard files and directories
objtool: Add STACK_FRAME_NON_STANDARD macro
x86/xen: Mark xen_cpuid() stack frame as non-standard
bpf: Mark __bpf_prog_run() stack frame as non-standard
sched: Mark __schedule() stack frame as non-standard
sched: always inline context_switch()
x86/kprobes: Mark kretprobe_trampoline() stack frame as non-standard
objtool: Compile-time stack metadata validation
objtool: Add CONFIG_STACK_VALIDATION option
objtool: Enable stack metadata validation on x86_64

 MAINTAINERS                                       |    5 +
 Makefile                                          |    5 +-
 arch/Kconfig                                      |    6 +
 arch/x86/Kconfig                                  |    1 +
 arch/x86/boot/Makefile                            |    3 +-
 arch/x86/boot/compressed/Makefile                 |    3 +-
 arch/x86/entry/Makefile                           |    4 +
 arch/x86/entry/vdso/Makefile                      |    6 +-
 arch/x86/kernel/Makefile                          |   11 +-
 arch/x86/kernel/kprobes/core.c                    |    2 +
 arch/x86/kernel/vmlinux.lds.S                     |    5 +-
 arch/x86/platform/efi/Makefile                    |    2 +
 arch/x86/purgatory/Makefile                       |    2 +
 arch/x86/realmode/Makefile                        |    4 +-
 arch/x86/realmode/rm/Makefile                     |    3 +-
 arch/x86/xen/enlighten.c                          |    3 +-
 drivers/firmware/efi/libstub/Makefile             |    1 +
 include/linux/frame.h                             |   23 +
 kernel/bpf/core.c                                 |    2 +
 kernel/sched/core.c                               |    4 +-
 lib/Kconfig.debug                                 |   12 +
 scripts/Makefile.build                            |   39 +-
 scripts/mod/Makefile                              |    2 +
 tools/Makefile                                    |   14 +-
 tools/objtool/.gitignore                          |    2 +
 tools/objtool/Build                               |   13 +
 tools/objtool/Documentation/stack-validation.txt  |  342 +++++++
 tools/objtool/Makefile                            |   60 ++
 tools/objtool/arch.h                              |   44 +
 tools/objtool/arch/x86/Build                      |   12 +
 tools/objtool/arch/x86/decode.c                   |  172 ++++
 tools/objtool/arch/x86/insn/gen-insn-attr-x86.awk |  387 ++++++++
 tools/objtool/arch/x86/insn/inat.c                |   97 ++
 tools/objtool/arch/x86/insn/inat.h                |  221 +++++
 tools/objtool/arch/x86/insn/inat_types.h          |   29 +
 tools/objtool/arch/x86/insn/insn.c                |  594 ++++++++++++
 tools/objtool/arch/x86/insn/insn.h                |  201 ++++
 tools/objtool/arch/x86/insn/x86-opcode-map.txt    |  984 +++++++++++++++++++
 tools/objtool/builtin-check.c                     | 1072 +++++++++++++++++++++
 tools/objtool/builtin.h                           |   22 +
 tools/objtool/elf.c                               |  403 ++++++++
 tools/objtool/elf.h                               |   79 ++
 tools/objtool/objtool.c                           |  136 +++
 tools/objtool/special.c                           |  193 ++++
 tools/objtool/special.h                           |   42 +
 tools/objtool/warn.h                              |   60 ++
 46 files changed, 5304 insertions(+), 23 deletions(-)
 create mode 100644 include/linux/frame.h
 create mode 100644 tools/objtool/.gitignore
 create mode 100644 tools/objtool/Build
 create mode 100644 tools/objtool/Documentation/stack-validation.txt
 create mode 100644 tools/objtool/Makefile
 create mode 100644 tools/objtool/arch.h
 create mode 100644 tools/objtool/arch/x86/Build
 create mode 100644 tools/objtool/arch/x86/decode.c
 create mode 100644 tools/objtool/arch/x86/insn/gen-insn-attr-x86.awk
 create mode 100644 tools/objtool/arch/x86/insn/inat.c
 create mode 100644 tools/objtool/arch/x86/insn/inat.h
 create mode 100644 tools/objtool/arch/x86/insn/inat_types.h
 create mode 100644 tools/objtool/arch/x86/insn/insn.c
 create mode 100644 tools/objtool/arch/x86/insn/insn.h
 create mode 100644 tools/objtool/arch/x86/insn/x86-opcode-map.txt
 create mode 100644 tools/objtool/builtin-check.c
 create mode 100644 tools/objtool/builtin.h
 create mode 100644 tools/objtool/elf.c
 create mode 100644 tools/objtool/elf.h
 create mode 100644 tools/objtool/objtool.c
 create mode 100644 tools/objtool/special.c
 create mode 100644 tools/objtool/special.h
 create mode 100644 tools/objtool/warn.h

2.4.3