Re: [PATCH 4.19 025/287] selftests/bpf: Fix test_align verifier log patterns

[Ovidiu Panait]

Hi Jean-Philippe,

On 24.08.2022 19:13, Jean-Philippe Brucker wrote:
> [Please note: This e-mail is from an EXTERNAL e-mail address]
>
> Hi,
>
> On Tue, Aug 23, 2022 at 10:23:14AM +0200, Greg Kroah-Hartman wrote:
> > From: Ovidiu Panait <ovidiu.panait@xxxxxxxxxxxxx>
> >
> > From: Stanislav Fomichev <sdf@xxxxxxxxxx>
> >
> > commit 5366d2269139ba8eb6a906d73a0819947e3e4e0a upstream.
> >
> > Commit 294f2fc6da27 ("bpf: Verifer, adjust_scalar_min_max_vals to always
> > call update_reg_bounds()") changed the way verifier logs some of its state,
> > adjust the test_align accordingly. Where possible, I tried to not copy-paste
> > the entire log line and resorted to dropping the last closing brace instead.
> >
> > Fixes: 294f2fc6da27 ("bpf: Verifer, adjust_scalar_min_max_vals to always call update_reg_bounds()")
> > Signed-off-by: Stanislav Fomichev <sdf@xxxxxxxxxx>
> > Signed-off-by: Daniel Borkmann <daniel@xxxxxxxxxxxxx>
> > Link: https://lore.kernel.org/bpf/20200515194904.229296-1-sdf@xxxxxxxxxx
> > [OP: adjust for 4.19 selftests]
> > Signed-off-by: Ovidiu Panait <ovidiu.panait@xxxxxxxxxxxxx>
> > Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> I believe this one shouldn't be applied as-is either, only partially. See
> https://lore.kernel.org/stable/20220824144327.277365-1-jean-philippe@xxxxxxxxxx/
>
> Ovidiu, do you want to resend this one with only the fixes for "bpf:
> Verifer, adjust_scalar_min_max_vals to always call update_reg_bounds()"?

Yes, I will resend the whole patchset with the selftests properly fixed.


Thanks,
Ovidiu
> Thanks,
> Jean
>
>
> > ---
> >   tools/testing/selftests/bpf/test_align.c |   41 +++++++++++++++----------------
> >   1 file changed, 21 insertions(+), 20 deletions(-)
> >
> > --- a/tools/testing/selftests/bpf/test_align.c
> > +++ b/tools/testing/selftests/bpf/test_align.c
> > @@ -359,15 +359,15 @@ static struct bpf_align_test tests[] = {
> >                         * is still (4n), fixed offset is not changed.
> >                         * Also, we create a new reg->id.
> >                         */
> > -                     {29, "R5_w=pkt(id=4,off=18,r=0,umax_value=2040,var_off=(0x0; 0x7fc))"},
> > +                     {29, "R5_w=pkt(id=4,off=18,r=0,umax_value=2040,var_off=(0x0; 0x7fc)"},
> >                        /* At the time the word size load is performed from R5,
> >                         * its total fixed offset is NET_IP_ALIGN + reg->off (18)
> >                         * which is 20.  Then the variable offset is (4n), so
> >                         * the total offset is 4-byte aligned and meets the
> >                         * load's requirements.
> >                         */
> > -                     {33, "R4=pkt(id=4,off=22,r=22,umax_value=2040,var_off=(0x0; 0x7fc))"},
> > -                     {33, "R5=pkt(id=4,off=18,r=22,umax_value=2040,var_off=(0x0; 0x7fc))"},
> > +                     {33, "R4=pkt(id=4,off=22,r=22,umax_value=2040,var_off=(0x0; 0x7fc)"},
> > +                     {33, "R5=pkt(id=4,off=18,r=22,umax_value=2040,var_off=(0x0; 0x7fc)"},
> >                },
> >        },
> >        {
> > @@ -410,15 +410,15 @@ static struct bpf_align_test tests[] = {
> >                        /* Adding 14 makes R6 be (4n+2) */
> >                        {9, "R6_w=inv(id=0,umin_value=14,umax_value=1034,var_off=(0x2; 0x7fc))"},
> >                        /* Packet pointer has (4n+2) offset */
> > -                     {11, "R5_w=pkt(id=1,off=0,r=0,umin_value=14,umax_value=1034,var_off=(0x2; 0x7fc))"},
> > -                     {13, "R4=pkt(id=1,off=4,r=0,umin_value=14,umax_value=1034,var_off=(0x2; 0x7fc))"},
> > +                     {11, "R5_w=pkt(id=1,off=0,r=0,umin_value=14,umax_value=1034,var_off=(0x2; 0x7fc)"},
> > +                     {13, "R4=pkt(id=1,off=4,r=0,umin_value=14,umax_value=1034,var_off=(0x2; 0x7fc)"},
> >                        /* At the time the word size load is performed from R5,
> >                         * its total fixed offset is NET_IP_ALIGN + reg->off (0)
> >                         * which is 2.  Then the variable offset is (4n+2), so
> >                         * the total offset is 4-byte aligned and meets the
> >                         * load's requirements.
> >                         */
> > -                     {15, "R5=pkt(id=1,off=0,r=4,umin_value=14,umax_value=1034,var_off=(0x2; 0x7fc))"},
> > +                     {15, "R5=pkt(id=1,off=0,r=4,umin_value=14,umax_value=1034,var_off=(0x2; 0x7fc)"},
> >                        /* Newly read value in R6 was shifted left by 2, so has
> >                         * known alignment of 4.
> >                         */
> > @@ -426,15 +426,15 @@ static struct bpf_align_test tests[] = {
> >                        /* Added (4n) to packet pointer's (4n+2) var_off, giving
> >                         * another (4n+2).
> >                         */
> > -                     {19, "R5_w=pkt(id=2,off=0,r=0,umin_value=14,umax_value=2054,var_off=(0x2; 0xffc))"},
> > -                     {21, "R4=pkt(id=2,off=4,r=0,umin_value=14,umax_value=2054,var_off=(0x2; 0xffc))"},
> > +                     {19, "R5_w=pkt(id=2,off=0,r=0,umin_value=14,umax_value=2054,var_off=(0x2; 0xffc)"},
> > +                     {21, "R4=pkt(id=2,off=4,r=0,umin_value=14,umax_value=2054,var_off=(0x2; 0xffc)"},
> >                        /* At the time the word size load is performed from R5,
> >                         * its total fixed offset is NET_IP_ALIGN + reg->off (0)
> >                         * which is 2.  Then the variable offset is (4n+2), so
> >                         * the total offset is 4-byte aligned and meets the
> >                         * load's requirements.
> >                         */
> > -                     {23, "R5=pkt(id=2,off=0,r=4,umin_value=14,umax_value=2054,var_off=(0x2; 0xffc))"},
> > +                     {23, "R5=pkt(id=2,off=0,r=4,umin_value=14,umax_value=2054,var_off=(0x2; 0xffc)"},
> >                },
> >        },
> >        {
> > @@ -469,16 +469,16 @@ static struct bpf_align_test tests[] = {
> >                .matches = {
> >                        {4, "R5_w=pkt_end(id=0,off=0,imm=0)"},
> >                        /* (ptr - ptr) << 2 == unknown, (4n) */
> > -                     {6, "R5_w=inv(id=0,smax_value=9223372036854775804,umax_value=18446744073709551612,var_off=(0x0; 0xfffffffffffffffc))"},
> > +                     {6, "R5_w=inv(id=0,smax_value=9223372036854775804,umax_value=18446744073709551612,var_off=(0x0; 0xfffffffffffffffc)"},
> >                        /* (4n) + 14 == (4n+2).  We blow our bounds, because
> >                         * the add could overflow.
> >                         */
> > -                     {7, "R5=inv(id=0,var_off=(0x2; 0xfffffffffffffffc))"},
> > +                     {7, "R5=inv(id=0,smin_value=-9223372036854775806,smax_value=9223372036854775806,umin_value=2,umax_value=18446744073709551614,var_off=(0x2; 0xfffffffffffffffc)"},
> >                        /* Checked s>=0 */
> > -                     {9, "R5=inv(id=0,umin_value=2,umax_value=9223372036854775806,var_off=(0x2; 0x7ffffffffffffffc))"},
> > +                     {9, "R5=inv(id=0,umin_value=2,umax_value=9223372034707292158,var_off=(0x2; 0x7fffffff7ffffffc)"},
> >                        /* packet pointer + nonnegative (4n+2) */
> > -                     {11, "R6_w=pkt(id=1,off=0,r=0,umin_value=2,umax_value=9223372036854775806,var_off=(0x2; 0x7ffffffffffffffc))"},
> > -                     {13, "R4=pkt(id=1,off=4,r=0,umin_value=2,umax_value=9223372036854775806,var_off=(0x2; 0x7ffffffffffffffc))"},
> > +                     {11, "R6_w=pkt(id=1,off=0,r=0,umin_value=2,umax_value=9223372034707292158,var_off=(0x2; 0x7fffffff7ffffffc)"},
> > +                     {13, "R4=pkt(id=1,off=4,r=0,umin_value=2,umax_value=9223372034707292158,var_off=(0x2; 0x7fffffff7ffffffc)"},
> >                        /* NET_IP_ALIGN + (4n+2) == (4n), alignment is fine.
> >                         * We checked the bounds, but it might have been able
> >                         * to overflow if the packet pointer started in the
> > @@ -486,7 +486,7 @@ static struct bpf_align_test tests[] = {
> >                         * So we did not get a 'range' on R6, and the access
> >                         * attempt will fail.
> >                         */
> > -                     {15, "R6=pkt(id=1,off=0,r=0,umin_value=2,umax_value=9223372036854775806,var_off=(0x2; 0x7ffffffffffffffc))"},
> > +                     {15, "R6=pkt(id=1,off=0,r=0,umin_value=2,umax_value=9223372034707292158,var_off=(0x2; 0x7fffffff7ffffffc)"},
> >                }
> >        },
> >        {
> > @@ -528,7 +528,7 @@ static struct bpf_align_test tests[] = {
> >                        /* New unknown value in R7 is (4n) */
> >                        {11, "R7_w=inv(id=0,umax_value=1020,var_off=(0x0; 0x3fc))"},
> >                        /* Subtracting it from R6 blows our unsigned bounds */
> > -                     {12, "R6=inv(id=0,smin_value=-1006,smax_value=1034,var_off=(0x2; 0xfffffffffffffffc))"},
> > +                     {12, "R6=inv(id=0,smin_value=-1006,smax_value=1034,umin_value=2,umax_value=18446744073709551614,var_off=(0x2; 0xfffffffffffffffc)"},
> >                        /* Checked s>= 0 */
> >                        {14, "R6=inv(id=0,umin_value=2,umax_value=1034,var_off=(0x2; 0x7fc))"},
> >                        /* At the time the word size load is performed from R5,
> > @@ -537,7 +537,8 @@ static struct bpf_align_test tests[] = {
> >                         * the total offset is 4-byte aligned and meets the
> >                         * load's requirements.
> >                         */
> > -                     {20, "R5=pkt(id=1,off=0,r=4,umin_value=2,umax_value=1034,var_off=(0x2; 0x7fc))"},
> > +                     {20, "R5=pkt(id=1,off=0,r=4,umin_value=2,umax_value=1034,var_off=(0x2; 0x7fc)"},
> > +
> >                },
> >        },
> >        {
> > @@ -579,18 +580,18 @@ static struct bpf_align_test tests[] = {
> >                        /* Adding 14 makes R6 be (4n+2) */
> >                        {11, "R6_w=inv(id=0,umin_value=14,umax_value=74,var_off=(0x2; 0x7c))"},
> >                        /* Subtracting from packet pointer overflows ubounds */
> > -                     {13, "R5_w=pkt(id=1,off=0,r=8,umin_value=18446744073709551542,umax_value=18446744073709551602,var_off=(0xffffffffffffff82; 0x7c))"},
> > +                     {13, "R5_w=pkt(id=1,off=0,r=8,umin_value=18446744073709551542,umax_value=18446744073709551602,var_off=(0xffffffffffffff82; 0x7c)"},
> >                        /* New unknown value in R7 is (4n), >= 76 */
> >                        {15, "R7_w=inv(id=0,umin_value=76,umax_value=1096,var_off=(0x0; 0x7fc))"},
> >                        /* Adding it to packet pointer gives nice bounds again */
> > -                     {16, "R5_w=pkt(id=2,off=0,r=0,umin_value=2,umax_value=1082,var_off=(0x2; 0x7fc))"},
> > +                     {16, "R5_w=pkt(id=2,off=0,r=0,umin_value=2,umax_value=1082,var_off=(0x2; 0xfffffffc)"},
> >                        /* At the time the word size load is performed from R5,
> >                         * its total fixed offset is NET_IP_ALIGN + reg->off (0)
> >                         * which is 2.  Then the variable offset is (4n+2), so
> >                         * the total offset is 4-byte aligned and meets the
> >                         * load's requirements.
> >                         */
> > -                     {20, "R5=pkt(id=2,off=0,r=4,umin_value=2,umax_value=1082,var_off=(0x2; 0x7fc))"},
> > +                     {20, "R5=pkt(id=2,off=0,r=4,umin_value=2,umax_value=1082,var_off=(0x2; 0xfffffffc)"},
> >                },
> >        },
> >   };