tree ab0c4bca0040ad0a59879bc0953f1babee4279d3
parent a7e47f26039c26312a4144c3001b4e9fa886bd45
author Josh Poimboeuf <jpoimboe@redhat.com> 1563413807 -0500
committer Thomas Gleixner <tglx@linutronix.de> 1563476467 +0200

objtool: Track original function across branches

If 'insn->func' is NULL, objtool skips some important checks, including
sibling call validation.  So if some .fixup code does an invalid sibling
call, objtool ignores it.

Treat all code branches (including alts) as part of the original
function by keeping track of the original func value from
validate_functions().

This improves the usefulness of some clang function fallthrough
warnings, and exposes some additional kernel bugs in the process.

Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/505df630f33c9717e1ccde6e4b64c5303135c25f.1563413318.git.jpoimboe@redhat.com