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From: "jakub at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
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Subject: [Bug sanitizer/105714] [12/13 Regression] ASan in gcc trunk missed a
 buffer-overflow at -Os since r12-5138-ge82c382971664d6f
Date: Tue, 24 May 2022 09:27:50 +0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D105714

--- Comment #3 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
The problem is we have:
  <bb 6> [local count: 354334800]:
  # h_21 =3D PHI <h_15(6), 0(5)>
  *c.3_5 =3D *d.2_4;
  h_15 =3D h_21 + 1;
  if (h_15 !=3D 3)
    goto <bb 6>; [75.00%]
  else
    goto <bb 7>; [25.00%]

  <bb 7> [local count: 118111600]:
  *c.3_5 =3D MEM[(struct a *)&b + 12B];
  _13 =3D c.3_5->x;
  return _13;
We instrument in the *c.3_5 =3D *d.2_4 both the load and store, but then
when considering instrumentation of *c.3_5 =3D MEM[(struct a *)&b + 12B];
has_stmt_been_instrumented_p returns true because *c.3_5 has been indeed
instrumented in a dominating bb.  But the rhs hasn't been...=