* Josh Poimboeuf <jpoim...@redhat.com> wrote:
> With the following commit:
>
> 51bad67ffbce ("x86/asm: Pad assembly functions with INT3 instructions")
>
> ... asm function alignments are padded with INT3, so it's no longer safe
> to fall through to an aligned function. Make sure we catch any such
> cases with objtool.
>
> Note this only adds checking for 64-bit, since objtool doesn't support
> x86-32.
>
> Suggested-by: Thomas Gleixner <t...@linutronix.de>
> Suggested-by: Linus Torvalds <torva...@linux-foundation.org>
> Signed-off-by: Josh Poimboeuf <jpoim...@redhat.com>
> ---
> arch/x86/kernel/head_64.S | 2 --
> tools/objtool/arch.h | 3 ++-
> tools/objtool/arch/x86/decode.c | 2 +-
> tools/objtool/check.c | 11 ++++++++++-
> 4 files changed, 13 insertions(+), 5 deletions(-)
Ok, this is cool, it addresses the robustness problem that INT3 padding
introduced
very nicely.
The concept of built-in kernel tooling working at the machine code level is
just
so powerful - we should have added our own KCC compiler 20 years ago.
Thanks,
Ingo
