Messages in this thread | | | From | Geert Uytterhoeven <> | Date | Mon, 11 Mar 2019 11:52:09 +0100 | Subject | Re: [PATCH 2/2] lib: Introduce test_stackinit module |
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Hi Kees,
On Tue, Feb 12, 2019 at 7:08 PM Kees Cook <keescook@chromium.org> wrote: > Adds test for stack initialization coverage. We have several build options > that control the level of stack variable initialization. This test lets us > visualize which options cover which cases, and provide tests for some of > the pathological padding conditions the compiler will sometimes fail to > initialize.
With current upstream, using gcc Ubuntu 8.2.0-1ubuntu2~18.04, I get on m68k:
test_stackinit: u8_zero: stack fill missed target!? test_stackinit: u8_zero: fill 1 wide test_stackinit: u8_zero: target offset by 20 test_stackinit: u16_zero: stack fill missed target!? test_stackinit: u16_zero: fill 2 wide test_stackinit: u16_zero: target offset by 20 test_stackinit: u32_zero: stack fill missed target!? test_stackinit: u32_zero: fill 4 wide test_stackinit: u32_zero: target offset by 20 test_stackinit: u64_zero: stack fill missed target!? test_stackinit: u64_zero: fill 8 wide test_stackinit: u64_zero: target offset by 20 test_stackinit: char_array_zero: stack fill missed target!? test_stackinit: char_array_zero: fill 16 wide test_stackinit: char_array_zero: target offset by -12 test_stackinit: small_hole_zero: stack fill missed target!? test_stackinit: small_hole_zero: fill 14 wide test_stackinit: small_hole_zero: target offset by -12 test_stackinit: big_hole_zero ok test_stackinit: trailing_hole_zero: stack fill missed target!? test_stackinit: trailing_hole_zero: fill 14 wide test_stackinit: trailing_hole_zero: target offset by -12 test_stackinit: packed_zero: stack fill missed target!? test_stackinit: packed_zero: fill 16 wide test_stackinit: packed_zero: target offset by -12 test_stackinit: small_hole_dynamic_partial: stack fill missed target!? test_stackinit: small_hole_dynamic_partial: fill 14 wide test_stackinit: small_hole_dynamic_partial: target offset by -12 test_stackinit: big_hole_dynamic_partial ok test_stackinit: trailing_hole_dynamic_partial: stack fill missed target!? test_stackinit: trailing_hole_dynamic_partial: fill 14 wide test_stackinit: trailing_hole_dynamic_partial: target offset by -12 test_stackinit: packed_dynamic_partial: stack fill missed target!? test_stackinit: packed_dynamic_partial: fill 16 wide test_stackinit: packed_dynamic_partial: target offset by -12 test_stackinit: small_hole_static_partial: stack fill missed target!? test_stackinit: small_hole_static_partial: fill 14 wide test_stackinit: small_hole_static_partial: target offset by -12 test_stackinit: big_hole_static_partial ok test_stackinit: trailing_hole_static_partial: stack fill missed target!? test_stackinit: trailing_hole_static_partial: fill 14 wide test_stackinit: trailing_hole_static_partial: target offset by -12 test_stackinit: packed_static_partial: stack fill missed target!? test_stackinit: packed_static_partial: fill 16 wide test_stackinit: packed_static_partial: target offset by -12 test_stackinit: small_hole_static_all: stack fill missed target!? test_stackinit: small_hole_static_all: fill 14 wide test_stackinit: small_hole_static_all: target offset by -12 test_stackinit: big_hole_static_all FAIL (uninit bytes: 61) test_stackinit: trailing_hole_static_all: stack fill missed target!? test_stackinit: trailing_hole_static_all: fill 14 wide test_stackinit: trailing_hole_static_all: target offset by -12 test_stackinit: packed_static_all: stack fill missed target!? test_stackinit: packed_static_all: fill 16 wide test_stackinit: packed_static_all: target offset by -12 test_stackinit: small_hole_dynamic_all: stack fill missed target!? test_stackinit: small_hole_dynamic_all: fill 14 wide test_stackinit: small_hole_dynamic_all: target offset by -12 test_stackinit: big_hole_dynamic_all FAIL (uninit bytes: 61) test_stackinit: trailing_hole_dynamic_all: stack fill missed target!? test_stackinit: trailing_hole_dynamic_all: fill 14 wide test_stackinit: trailing_hole_dynamic_all: target offset by -12 test_stackinit: packed_dynamic_all: stack fill missed target!? test_stackinit: packed_dynamic_all: fill 16 wide test_stackinit: packed_dynamic_all: target offset by -12 test_stackinit: small_hole_runtime_partial: stack fill missed target!? test_stackinit: small_hole_runtime_partial: fill 14 wide test_stackinit: small_hole_runtime_partial: target offset by -12 test_stackinit: big_hole_runtime_partial FAIL (uninit bytes: 127) test_stackinit: trailing_hole_runtime_partial: stack fill missed target!? test_stackinit: trailing_hole_runtime_partial: fill 14 wide test_stackinit: trailing_hole_runtime_partial: target offset by -12 test_stackinit: packed_runtime_partial: stack fill missed target!? test_stackinit: packed_runtime_partial: fill 16 wide test_stackinit: packed_runtime_partial: target offset by -12 test_stackinit: small_hole_runtime_all: stack fill missed target!? test_stackinit: small_hole_runtime_all: fill 14 wide test_stackinit: small_hole_runtime_all: target offset by -12 test_stackinit: big_hole_runtime_all FAIL (uninit bytes: 61) test_stackinit: trailing_hole_runtime_all: stack fill missed target!? test_stackinit: trailing_hole_runtime_all: fill 14 wide test_stackinit: trailing_hole_runtime_all: target offset by -12 test_stackinit: packed_runtime_all: stack fill missed target!? test_stackinit: packed_runtime_all: fill 16 wide test_stackinit: packed_runtime_all: target offset by -12 test_stackinit: u8_none: stack fill missed target!? test_stackinit: u8_none: fill 1 wide test_stackinit: u8_none: target offset by 20 test_stackinit: u16_none: stack fill missed target!? test_stackinit: u16_none: fill 2 wide test_stackinit: u16_none: target offset by 20 test_stackinit: u32_none: stack fill missed target!? test_stackinit: u32_none: fill 4 wide test_stackinit: u32_none: target offset by 20 test_stackinit: u64_none: stack fill missed target!? test_stackinit: u64_none: fill 8 wide test_stackinit: u64_none: target offset by 20 test_stackinit: char_array_none: stack fill missed target!? test_stackinit: char_array_none: fill 16 wide test_stackinit: char_array_none: target offset by -12 test_stackinit: switch_1_none: stack fill missed target!? test_stackinit: switch_1_none: fill 8 wide test_stackinit: switch_1_none: target offset by 16 test_stackinit: switch_2_none: stack fill missed target!? test_stackinit: switch_2_none: fill 8 wide test_stackinit: switch_2_none: target offset by 16 test_stackinit: small_hole_none: stack fill missed target!? test_stackinit: small_hole_none: fill 14 wide test_stackinit: small_hole_none: target offset by -12 test_stackinit: big_hole_none FAIL (uninit bytes: 128) test_stackinit: trailing_hole_none: stack fill missed target!? test_stackinit: trailing_hole_none: fill 14 wide test_stackinit: trailing_hole_none: target offset by -12 test_stackinit: packed_none: stack fill missed target!? test_stackinit: packed_none: fill 16 wide test_stackinit: packed_none: target offset by -12 test_stackinit: user: stack fill missed target!? test_stackinit: user: fill 14 wide test_stackinit: user: target offset by -12 test_stackinit: failures: 42
Any idea what is wrong? I find the test code a bit hard to understand...
Also, I see comments making assumptions that are not true:
struct test_small_hole { size_t one; char two; /* 3 byte padding hole here. */ int three; unsigned long four; };
On m68k (and a few other architectures), integrals of 16-bit and larger are aligned to a 2-byte address, so the padding may be only a single byte.
Thanks!
Gr{oetje,eeting}s,
Geert
-- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org
In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds
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