[RFC] Objtool toolchain proposal: -fannotate-{jump-table,noreturn}

Josh Poimboeuf jpoimboe at kernel.org
Tue Sep 13 17:12:05 PDT 2022


On Tue, Sep 13, 2022 at 03:51:44PM -0700, Indu Bhagat wrote:
> Curious to know what all features of objtool rely on the need to reverse
> engineer the control flow graph. Is it a larger set or it is only for ORC
> generation ?

Objtool features which rely on the CFG:

- Frame pointer rule validation (when using
  CONFIG_UNWINDER_FRAME_POINTER)

- ORC metadata generation

- Intel SMAP rule validation - ensures EFLAGS #AC is only set during
  usercopy

- "noinstr" rule validation - ensures no instrumentation/tracing
  functions are called in certain critical sections

-- 
Josh



More information about the linux-arm-kernel mailing list