aboutsummaryrefslogtreecommitdiff
path: root/tools/testing/selftests/bpf/prog_tests/align.c
AgeCommit message (Collapse)AuthorFilesLines
2023-11-18bpf: omit default off=0 and imm=0 in register state logAndrii Nakryiko1-21/+21
Simplify BPF verifier log further by omitting default (and frequently irrelevant) off=0 and imm=0 parts for non-SCALAR_VALUE registers. As can be seen from fixed tests, this is often a visual noise for PTR_TO_CTX register and even for PTR_TO_PACKET registers. Omitting default values follows the rest of register state logic: we omit default values to keep verifier log succinct and to highlight interesting state that deviates from default one. E.g., we do the same for var_off, when it's unknown, which gives no additional information. Acked-by: Eduard Zingerman <[email protected]> Acked-by: Stanislav Fomichev <[email protected]> Signed-off-by: Andrii Nakryiko <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Alexei Starovoitov <[email protected]>
2023-10-16selftests/bpf: Make align selftests more robustAndrii Nakryiko1-120/+121
Align subtest is very specific and finicky about expected verifier log output and format. This is often completely unnecessary as in a bunch of situations test actually cares about var_off part of register state. But given how exact it is right now, any tiny verifier log changes can lead to align tests failures, requiring constant adjustment. This patch tries to make this a bit more robust by making logic first search for specified register and then allowing to match only portion of register state, not everything exactly. This will come handly with follow up changes to SCALAR register output disambiguation. Signed-off-by: Andrii Nakryiko <[email protected]> Signed-off-by: Daniel Borkmann <[email protected]> Acked-by: John Fastabend <[email protected]> Acked-by: Eduard Zingerman <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2023-03-22bpf: Fix __reg_bound_offset 64->32 var_off subreg propagationDaniel Borkmann1-2/+2
Xu reports that after commit 3f50f132d840 ("bpf: Verifier, do explicit ALU32 bounds tracking"), the following BPF program is rejected by the verifier: 0: (61) r2 = *(u32 *)(r1 +0) ; R2_w=pkt(off=0,r=0,imm=0) 1: (61) r3 = *(u32 *)(r1 +4) ; R3_w=pkt_end(off=0,imm=0) 2: (bf) r1 = r2 3: (07) r1 += 1 4: (2d) if r1 > r3 goto pc+8 5: (71) r1 = *(u8 *)(r2 +0) ; R1_w=scalar(umax=255,var_off=(0x0; 0xff)) 6: (18) r0 = 0x7fffffffffffff10 8: (0f) r1 += r0 ; R1_w=scalar(umin=0x7fffffffffffff10,umax=0x800000000000000f) 9: (18) r0 = 0x8000000000000000 11: (07) r0 += 1 12: (ad) if r0 < r1 goto pc-2 13: (b7) r0 = 0 14: (95) exit And the verifier log says: func#0 @0 0: R1=ctx(off=0,imm=0) R10=fp0 0: (61) r2 = *(u32 *)(r1 +0) ; R1=ctx(off=0,imm=0) R2_w=pkt(off=0,r=0,imm=0) 1: (61) r3 = *(u32 *)(r1 +4) ; R1=ctx(off=0,imm=0) R3_w=pkt_end(off=0,imm=0) 2: (bf) r1 = r2 ; R1_w=pkt(off=0,r=0,imm=0) R2_w=pkt(off=0,r=0,imm=0) 3: (07) r1 += 1 ; R1_w=pkt(off=1,r=0,imm=0) 4: (2d) if r1 > r3 goto pc+8 ; R1_w=pkt(off=1,r=1,imm=0) R3_w=pkt_end(off=0,imm=0) 5: (71) r1 = *(u8 *)(r2 +0) ; R1_w=scalar(umax=255,var_off=(0x0; 0xff)) R2_w=pkt(off=0,r=1,imm=0) 6: (18) r0 = 0x7fffffffffffff10 ; R0_w=9223372036854775568 8: (0f) r1 += r0 ; R0_w=9223372036854775568 R1_w=scalar(umin=9223372036854775568,umax=9223372036854775823,s32_min=-240,s32_max=15) 9: (18) r0 = 0x8000000000000000 ; R0_w=-9223372036854775808 11: (07) r0 += 1 ; R0_w=-9223372036854775807 12: (ad) if r0 < r1 goto pc-2 ; R0_w=-9223372036854775807 R1_w=scalar(umin=9223372036854775568,umax=9223372036854775809) 13: (b7) r0 = 0 ; R0_w=0 14: (95) exit from 12 to 11: R0_w=-9223372036854775807 R1_w=scalar(umin=9223372036854775810,umax=9223372036854775823,var_off=(0x8000000000000000; 0xffffffff)) R2_w=pkt(off=0,r=1,imm=0) R3_w=pkt_end(off=0,imm=0) R10=fp0 11: (07) r0 += 1 ; R0_w=-9223372036854775806 12: (ad) if r0 < r1 goto pc-2 ; R0_w=-9223372036854775806 R1_w=scalar(umin=9223372036854775810,umax=9223372036854775810,var_off=(0x8000000000000000; 0xffffffff)) 13: safe [...] from 12 to 11: R0_w=-9223372036854775795 R1=scalar(umin=9223372036854775822,umax=9223372036854775823,var_off=(0x8000000000000000; 0xffffffff)) R2=pkt(off=0,r=1,imm=0) R3=pkt_end(off=0,imm=0) R10=fp0 11: (07) r0 += 1 ; R0_w=-9223372036854775794 12: (ad) if r0 < r1 goto pc-2 ; R0_w=-9223372036854775794 R1=scalar(umin=9223372036854775822,umax=9223372036854775822,var_off=(0x8000000000000000; 0xffffffff)) 13: safe from 12 to 11: R0_w=-9223372036854775794 R1=scalar(umin=9223372036854775823,umax=9223372036854775823,var_off=(0x8000000000000000; 0xffffffff)) R2=pkt(off=0,r=1,imm=0) R3=pkt_end(off=0,imm=0) R10=fp0 11: (07) r0 += 1 ; R0_w=-9223372036854775793 12: (ad) if r0 < r1 goto pc-2 ; R0_w=-9223372036854775793 R1=scalar(umin=9223372036854775823,umax=9223372036854775823,var_off=(0x8000000000000000; 0xffffffff)) 13: safe from 12 to 11: R0_w=-9223372036854775793 R1=scalar(umin=9223372036854775824,umax=9223372036854775823,var_off=(0x8000000000000000; 0xffffffff)) R2=pkt(off=0,r=1,imm=0) R3=pkt_end(off=0,imm=0) R10=fp0 11: (07) r0 += 1 ; R0_w=-9223372036854775792 12: (ad) if r0 < r1 goto pc-2 ; R0_w=-9223372036854775792 R1=scalar(umin=9223372036854775824,umax=9223372036854775823,var_off=(0x8000000000000000; 0xffffffff)) 13: safe [...] The 64bit umin=9223372036854775810 bound continuously bumps by +1 while umax=9223372036854775823 stays as-is until the verifier complexity limit is reached and the program gets finally rejected. During this simulation, the umin also eventually surpasses umax. Looking at the first 'from 12 to 11' output line from the loop, R1 has the following state: R1_w=scalar(umin=0x8000000000000002 (9223372036854775810), umax=0x800000000000000f (9223372036854775823), var_off=(0x8000000000000000; 0xffffffff)) The var_off has technically not an inconsistent state but it's very imprecise and far off surpassing 64bit umax bounds whereas the expected output with refined known bits in var_off should have been like: R1_w=scalar(umin=0x8000000000000002 (9223372036854775810), umax=0x800000000000000f (9223372036854775823), var_off=(0x8000000000000000; 0xf)) In the above log, var_off stays as var_off=(0x8000000000000000; 0xffffffff) and does not converge into a narrower mask where more bits become known, eventually transforming R1 into a constant upon umin=9223372036854775823, umax=9223372036854775823 case where the verifier would have terminated and let the program pass. The __reg_combine_64_into_32() marks the subregister unknown and propagates 64bit {s,u}min/{s,u}max bounds to their 32bit equivalents iff they are within the 32bit universe. The question came up whether __reg_combine_64_into_32() should special case the situation that when 64bit {s,u}min bounds have the same value as 64bit {s,u}max bounds to then assign the latter as well to the 32bit reg->{s,u}32_{min,max}_value. As can be seen from the above example however, that is just /one/ special case and not a /generic/ solution given above example would still not be addressed this way and remain at an imprecise var_off=(0x8000000000000000; 0xffffffff). The improvement is needed in __reg_bound_offset() to refine var32_off with the updated var64_off instead of the prior reg->var_off. The reg_bounds_sync() code first refines information about the register's min/max bounds via __update_reg_bounds() from the current var_off, then in __reg_deduce_bounds() from sign bit and with the potentially learned bits from bounds it'll update the var_off tnum in __reg_bound_offset(). For example, intersecting with the old var_off might have improved bounds slightly, e.g. if umax was 0x7f...f and var_off was (0; 0xf...fc), then new var_off will then result in (0; 0x7f...fc). The intersected var64_off holds then the universe which is a superset of var32_off. The point for the latter is not to broaden, but to further refine known bits based on the intersection of var_off with 32 bit bounds, so that we later construct the final var_off from upper and lower 32 bits. The final __update_reg_bounds() can then potentially still slightly refine bounds if more bits became known from the new var_off. After the improvement, we can see R1 converging successively: func#0 @0 0: R1=ctx(off=0,imm=0) R10=fp0 0: (61) r2 = *(u32 *)(r1 +0) ; R1=ctx(off=0,imm=0) R2_w=pkt(off=0,r=0,imm=0) 1: (61) r3 = *(u32 *)(r1 +4) ; R1=ctx(off=0,imm=0) R3_w=pkt_end(off=0,imm=0) 2: (bf) r1 = r2 ; R1_w=pkt(off=0,r=0,imm=0) R2_w=pkt(off=0,r=0,imm=0) 3: (07) r1 += 1 ; R1_w=pkt(off=1,r=0,imm=0) 4: (2d) if r1 > r3 goto pc+8 ; R1_w=pkt(off=1,r=1,imm=0) R3_w=pkt_end(off=0,imm=0) 5: (71) r1 = *(u8 *)(r2 +0) ; R1_w=scalar(umax=255,var_off=(0x0; 0xff)) R2_w=pkt(off=0,r=1,imm=0) 6: (18) r0 = 0x7fffffffffffff10 ; R0_w=9223372036854775568 8: (0f) r1 += r0 ; R0_w=9223372036854775568 R1_w=scalar(umin=9223372036854775568,umax=9223372036854775823,s32_min=-240,s32_max=15) 9: (18) r0 = 0x8000000000000000 ; R0_w=-9223372036854775808 11: (07) r0 += 1 ; R0_w=-9223372036854775807 12: (ad) if r0 < r1 goto pc-2 ; R0_w=-9223372036854775807 R1_w=scalar(umin=9223372036854775568,umax=9223372036854775809) 13: (b7) r0 = 0 ; R0_w=0 14: (95) exit from 12 to 11: R0_w=-9223372036854775807 R1_w=scalar(umin=9223372036854775810,umax=9223372036854775823,var_off=(0x8000000000000000; 0xf),s32_min=0,s32_max=15,u32_max=15) R2_w=pkt(off=0,r=1,imm=0) R3_w=pkt_end(off=0,imm=0) R10=fp0 11: (07) r0 += 1 ; R0_w=-9223372036854775806 12: (ad) if r0 < r1 goto pc-2 ; R0_w=-9223372036854775806 R1_w=-9223372036854775806 13: safe from 12 to 11: R0_w=-9223372036854775806 R1_w=scalar(umin=9223372036854775811,umax=9223372036854775823,var_off=(0x8000000000000000; 0xf),s32_min=0,s32_max=15,u32_max=15) R2_w=pkt(off=0,r=1,imm=0) R3_w=pkt_end(off=0,imm=0) R10=fp0 11: (07) r0 += 1 ; R0_w=-9223372036854775805 12: (ad) if r0 < r1 goto pc-2 ; R0_w=-9223372036854775805 R1_w=-9223372036854775805 13: safe [...] from 12 to 11: R0_w=-9223372036854775798 R1=scalar(umin=9223372036854775819,umax=9223372036854775823,var_off=(0x8000000000000008; 0x7),s32_min=8,s32_max=15,u32_min=8,u32_max=15) R2=pkt(off=0,r=1,imm=0) R3=pkt_end(off=0,imm=0) R10=fp0 11: (07) r0 += 1 ; R0_w=-9223372036854775797 12: (ad) if r0 < r1 goto pc-2 ; R0_w=-9223372036854775797 R1=-9223372036854775797 13: safe from 12 to 11: R0_w=-9223372036854775797 R1=scalar(umin=9223372036854775820,umax=9223372036854775823,var_off=(0x800000000000000c; 0x3),s32_min=12,s32_max=15,u32_min=12,u32_max=15) R2=pkt(off=0,r=1,imm=0) R3=pkt_end(off=0,imm=0) R10=fp0 11: (07) r0 += 1 ; R0_w=-9223372036854775796 12: (ad) if r0 < r1 goto pc-2 ; R0_w=-9223372036854775796 R1=-9223372036854775796 13: safe from 12 to 11: R0_w=-9223372036854775796 R1=scalar(umin=9223372036854775821,umax=9223372036854775823,var_off=(0x800000000000000c; 0x3),s32_min=12,s32_max=15,u32_min=12,u32_max=15) R2=pkt(off=0,r=1,imm=0) R3=pkt_end(off=0,imm=0) R10=fp0 11: (07) r0 += 1 ; R0_w=-9223372036854775795 12: (ad) if r0 < r1 goto pc-2 ; R0_w=-9223372036854775795 R1=-9223372036854775795 13: safe from 12 to 11: R0_w=-9223372036854775795 R1=scalar(umin=9223372036854775822,umax=9223372036854775823,var_off=(0x800000000000000e; 0x1),s32_min=14,s32_max=15,u32_min=14,u32_max=15) R2=pkt(off=0,r=1,imm=0) R3=pkt_end(off=0,imm=0) R10=fp0 11: (07) r0 += 1 ; R0_w=-9223372036854775794 12: (ad) if r0 < r1 goto pc-2 ; R0_w=-9223372036854775794 R1=-9223372036854775794 13: safe from 12 to 11: R0_w=-9223372036854775794 R1=-9223372036854775793 R2=pkt(off=0,r=1,imm=0) R3=pkt_end(off=0,imm=0) R10=fp0 11: (07) r0 += 1 ; R0_w=-9223372036854775793 12: (ad) if r0 < r1 goto pc-2 last_idx 12 first_idx 12 parent didn't have regs=1 stack=0 marks: R0_rw=P-9223372036854775801 R1_r=scalar(umin=9223372036854775815,umax=9223372036854775823,var_off=(0x8000000000000000; 0xf),s32_min=0,s32_max=15,u32_max=15) R2=pkt(off=0,r=1,imm=0) R3=pkt_end(off=0,imm=0) R10=fp0 last_idx 11 first_idx 11 regs=1 stack=0 before 11: (07) r0 += 1 parent didn't have regs=1 stack=0 marks: R0_rw=P-9223372036854775805 R1_rw=scalar(umin=9223372036854775812,umax=9223372036854775823,var_off=(0x8000000000000000; 0xf),s32_min=0,s32_max=15,u32_max=15) R2_w=pkt(off=0,r=1,imm=0) R3_w=pkt_end(off=0,imm=0) R10=fp0 last_idx 12 first_idx 0 regs=1 stack=0 before 12: (ad) if r0 < r1 goto pc-2 regs=1 stack=0 before 11: (07) r0 += 1 regs=1 stack=0 before 12: (ad) if r0 < r1 goto pc-2 regs=1 stack=0 before 11: (07) r0 += 1 regs=1 stack=0 before 12: (ad) if r0 < r1 goto pc-2 regs=1 stack=0 before 11: (07) r0 += 1 regs=1 stack=0 before 9: (18) r0 = 0x8000000000000000 last_idx 12 first_idx 12 parent didn't have regs=2 stack=0 marks: R0_rw=P-9223372036854775801 R1_r=Pscalar(umin=9223372036854775815,umax=9223372036854775823,var_off=(0x8000000000000000; 0xf),s32_min=0,s32_max=15,u32_max=15) R2=pkt(off=0,r=1,imm=0) R3=pkt_end(off=0,imm=0) R10=fp0 last_idx 11 first_idx 11 regs=2 stack=0 before 11: (07) r0 += 1 parent didn't have regs=2 stack=0 marks: R0_rw=P-9223372036854775805 R1_rw=Pscalar(umin=9223372036854775812,umax=9223372036854775823,var_off=(0x8000000000000000; 0xf),s32_min=0,s32_max=15,u32_max=15) R2_w=pkt(off=0,r=1,imm=0) R3_w=pkt_end(off=0,imm=0) R10=fp0 last_idx 12 first_idx 0 regs=2 stack=0 before 12: (ad) if r0 < r1 goto pc-2 regs=2 stack=0 before 11: (07) r0 += 1 regs=2 stack=0 before 12: (ad) if r0 < r1 goto pc-2 regs=2 stack=0 before 11: (07) r0 += 1 regs=2 stack=0 before 12: (ad) if r0 < r1 goto pc-2 regs=2 stack=0 before 11: (07) r0 += 1 regs=2 stack=0 before 9: (18) r0 = 0x8000000000000000 regs=2 stack=0 before 8: (0f) r1 += r0 regs=3 stack=0 before 6: (18) r0 = 0x7fffffffffffff10 regs=2 stack=0 before 5: (71) r1 = *(u8 *)(r2 +0) 13: safe from 4 to 13: safe verification time 322 usec stack depth 0 processed 56 insns (limit 1000000) max_states_per_insn 1 total_states 3 peak_states 3 mark_read 1 This also fixes up a test case along with this improvement where we match on the verifier log. The updated log now has a refined var_off, too. Fixes: 3f50f132d840 ("bpf: Verifier, do explicit ALU32 bounds tracking") Reported-by: Xu Kuohai <[email protected]> Signed-off-by: Daniel Borkmann <[email protected]> Signed-off-by: Andrii Nakryiko <[email protected]> Reviewed-by: John Fastabend <[email protected]> Link: https://lore.kernel.org/bpf/[email protected] Link: https://lore.kernel.org/bpf/[email protected]
2023-03-04selftests/bpf: enhance align selftest's expected log matchingAndrii Nakryiko1-6/+12
Allow to search for expected register state in all the verifier log output that's related to specified instruction number. See added comment for an example of possible situation that is happening due to a simple enhancement done in the next patch, which fixes handling of env->test_state_freq flag in state checkpointing logic. Signed-off-by: Andrii Nakryiko <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Alexei Starovoitov <[email protected]>
2022-11-04selftests/bpf: make test_align selftest more robustAndrii Nakryiko1-14/+24
test_align selftest relies on BPF verifier log emitting register states for specific instructions in expected format. Unfortunately, BPF verifier precision backtracking log interferes with such expectations. And instruction on which precision propagation happens sometimes don't output full expected register states. This does indeed look like something to be improved in BPF verifier, but is beyond the scope of this patch set. So to make test_align a bit more robust, inject few dummy R4 = R5 instructions which capture desired state of R5 and won't have precision tracking logs on them. This fixes tests until we can improve BPF verifier output in the presence of precision tracking. Signed-off-by: Andrii Nakryiko <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Alexei Starovoitov <[email protected]>
2022-03-03bpf: Small BPF verifier log improvementsMykola Lysenko1-109/+109
In particular these include: 1) Remove output of inv for scalars in print_verifier_state 2) Replace inv with scalar in verifier error messages 3) Remove _value suffixes for umin/umax/s32_min/etc (except map_value) 4) Remove output of id=0 5) Remove output of ref_obj_id=0 Signed-off-by: Mykola Lysenko <[email protected]> Signed-off-by: Daniel Borkmann <[email protected]> Acked-by: Andrii Nakryiko <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2021-12-16bpf: Right align verifier states in verifier logs.Christy Lee1-77/+92
Make the verifier logs more readable, print the verifier states on the corresponding instruction line. If the previous line was not a bpf instruction, then print the verifier states on its own line. Before: Validating test_pkt_access_subprog3() func#3... 86: R1=invP(id=0) R2=ctx(id=0,off=0,imm=0) R10=fp0 ; int test_pkt_access_subprog3(int val, struct __sk_buff *skb) 86: (bf) r6 = r2 87: R2=ctx(id=0,off=0,imm=0) R6_w=ctx(id=0,off=0,imm=0) 87: (bc) w7 = w1 88: R1=invP(id=0) R7_w=invP(id=0,umax_value=4294967295,var_off=(0x0; 0xffffffff)) ; return get_skb_len(skb) * get_skb_ifindex(val, skb, get_constant(123)); 88: (bf) r1 = r6 89: R1_w=ctx(id=0,off=0,imm=0) R6_w=ctx(id=0,off=0,imm=0) 89: (85) call pc+9 Func#4 is global and valid. Skipping. 90: R0_w=invP(id=0) 90: (bc) w8 = w0 91: R0_w=invP(id=0) R8_w=invP(id=0,umax_value=4294967295,var_off=(0x0; 0xffffffff)) ; return get_skb_len(skb) * get_skb_ifindex(val, skb, get_constant(123)); 91: (b7) r1 = 123 92: R1_w=invP123 92: (85) call pc+65 Func#5 is global and valid. Skipping. 93: R0=invP(id=0) After: 86: R1=invP(id=0) R2=ctx(id=0,off=0,imm=0) R10=fp0 ; int test_pkt_access_subprog3(int val, struct __sk_buff *skb) 86: (bf) r6 = r2 ; R2=ctx(id=0,off=0,imm=0) R6_w=ctx(id=0,off=0,imm=0) 87: (bc) w7 = w1 ; R1=invP(id=0) R7_w=invP(id=0,umax_value=4294967295,var_off=(0x0; 0xffffffff)) ; return get_skb_len(skb) * get_skb_ifindex(val, skb, get_constant(123)); 88: (bf) r1 = r6 ; R1_w=ctx(id=0,off=0,imm=0) R6_w=ctx(id=0,off=0,imm=0) 89: (85) call pc+9 Func#4 is global and valid. Skipping. 90: R0_w=invP(id=0) 90: (bc) w8 = w0 ; R0_w=invP(id=0) R8_w=invP(id=0,umax_value=4294967295,var_off=(0x0; 0xffffffff)) ; return get_skb_len(skb) * get_skb_ifindex(val, skb, get_constant(123)); 91: (b7) r1 = 123 ; R1_w=invP123 92: (85) call pc+65 Func#5 is global and valid. Skipping. 93: R0=invP(id=0) Signed-off-by: Christy Lee <[email protected]> Acked-by: Andrii Nakryiko <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]>
2021-12-16bpf: Only print scratched registers and stack slots to verifier logs.Christy Lee1-15/+15
When printing verifier state for any log level, print full verifier state only on function calls or on errors. Otherwise, only print the registers and stack slots that were accessed. Log size differences: verif_scale_loop6 before: 234566564 verif_scale_loop6 after: 72143943 69% size reduction kfree_skb before: 166406 kfree_skb after: 55386 69% size reduction Before: 156: (61) r0 = *(u32 *)(r1 +0) 157: R0_w=invP(id=0,umax_value=4294967295,var_off=(0x0; 0xffffffff)) R1=ctx(id=0,off=0,imm=0) R2_w=invP0 R10=fp0 fp-8_w=00000000 fp-16_w=00\ 000000 fp-24_w=00000000 fp-32_w=00000000 fp-40_w=00000000 fp-48_w=00000000 fp-56_w=00000000 fp-64_w=00000000 fp-72_w=00000000 fp-80_w=00000\ 000 fp-88_w=00000000 fp-96_w=00000000 fp-104_w=00000000 fp-112_w=00000000 fp-120_w=00000000 fp-128_w=00000000 fp-136_w=00000000 fp-144_w=00\ 000000 fp-152_w=00000000 fp-160_w=00000000 fp-168_w=00000000 fp-176_w=00000000 fp-184_w=00000000 fp-192_w=00000000 fp-200_w=00000000 fp-208\ _w=00000000 fp-216_w=00000000 fp-224_w=00000000 fp-232_w=00000000 fp-240_w=00000000 fp-248_w=00000000 fp-256_w=00000000 fp-264_w=00000000 f\ p-272_w=00000000 fp-280_w=00000000 fp-288_w=00000000 fp-296_w=00000000 fp-304_w=00000000 fp-312_w=00000000 fp-320_w=00000000 fp-328_w=00000\ 000 fp-336_w=00000000 fp-344_w=00000000 fp-352_w=00000000 fp-360_w=00000000 fp-368_w=00000000 fp-376_w=00000000 fp-384_w=00000000 fp-392_w=\ 00000000 fp-400_w=00000000 fp-408_w=00000000 fp-416_w=00000000 fp-424_w=00000000 fp-432_w=00000000 fp-440_w=00000000 fp-448_w=00000000 ; return skb->len; 157: (95) exit Func#4 is safe for any args that match its prototype Validating get_constant() func#5... 158: R1=invP(id=0) R10=fp0 ; int get_constant(long val) 158: (bf) r0 = r1 159: R0_w=invP(id=1) R1=invP(id=1) R10=fp0 ; return val - 122; 159: (04) w0 += -122 160: R0_w=invP(id=0,umax_value=4294967295,var_off=(0x0; 0xffffffff)) R1=invP(id=1) R10=fp0 ; return val - 122; 160: (95) exit Func#5 is safe for any args that match its prototype Validating get_skb_ifindex() func#6... 161: R1=invP(id=0) R2=ctx(id=0,off=0,imm=0) R3=invP(id=0) R10=fp0 ; int get_skb_ifindex(int val, struct __sk_buff *skb, int var) 161: (bc) w0 = w3 162: R0_w=invP(id=0,umax_value=4294967295,var_off=(0x0; 0xffffffff)) R1=invP(id=0) R2=ctx(id=0,off=0,imm=0) R3=invP(id=0) R10=fp0 After: 156: (61) r0 = *(u32 *)(r1 +0) 157: R0_w=invP(id=0,umax_value=4294967295,var_off=(0x0; 0xffffffff)) R1=ctx(id=0,off=0,imm=0) ; return skb->len; 157: (95) exit Func#4 is safe for any args that match its prototype Validating get_constant() func#5... 158: R1=invP(id=0) R10=fp0 ; int get_constant(long val) 158: (bf) r0 = r1 159: R0_w=invP(id=1) R1=invP(id=1) ; return val - 122; 159: (04) w0 += -122 160: R0_w=invP(id=0,umax_value=4294967295,var_off=(0x0; 0xffffffff)) ; return val - 122; 160: (95) exit Func#5 is safe for any args that match its prototype Validating get_skb_ifindex() func#6... 161: R1=invP(id=0) R2=ctx(id=0,off=0,imm=0) R3=invP(id=0) R10=fp0 ; int get_skb_ifindex(int val, struct __sk_buff *skb, int var) 161: (bc) w0 = w3 162: R0_w=invP(id=0,umax_value=4294967295,var_off=(0x0; 0xffffffff)) R3=invP(id=0) Signed-off-by: Christy Lee <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]> Acked-by: Andrii Nakryiko <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2021-11-07selftests/bpf: Convert legacy prog load APIs to bpf_prog_load()Andrii Nakryiko1-3/+8
Convert all the uses of legacy low-level BPF program loading APIs (mostly bpf_load_program_xattr(), but also some bpf_verify_program()) to bpf_prog_load() uses. Signed-off-by: Andrii Nakryiko <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2020-12-10selftests/bpf: Fix "dubious pointer arithmetic" testJean-Philippe Brucker1-4/+4
The verifier trace changed following a bugfix. After checking the 64-bit sign, only the upper bit mask is known, not bit 31. Update the test accordingly. Signed-off-by: Jean-Philippe Brucker <[email protected]> Acked-by: John Fastabend <[email protected]> Signed-off-by: Alexei Starovoitov <[email protected]>
2020-10-09bpf: Propagate scalar ranges through register assignments.Alexei Starovoitov1-8/+8
The llvm register allocator may use two different registers representing the same virtual register. In such case the following pattern can be observed: 1047: (bf) r9 = r6 1048: (a5) if r6 < 0x1000 goto pc+1 1050: ... 1051: (a5) if r9 < 0x2 goto pc+66 1052: ... 1053: (bf) r2 = r9 /* r2 needs to have upper and lower bounds */ This is normal behavior of greedy register allocator. The slides 137+ explain why regalloc introduces such register copy: http://llvm.org/devmtg/2018-04/slides/Yatsina-LLVM%20Greedy%20Register%20Allocator.pdf There is no way to tell llvm 'not to do this'. Hence the verifier has to recognize such patterns. In order to track this information without backtracking allocate ID for scalars in a similar way as it's done for find_good_pkt_pointers(). When the verifier encounters r9 = r6 assignment it will assign the same ID to both registers. Later if either register range is narrowed via conditional jump propagate the register state into the other register. Clear register ID in adjust_reg_min_max_vals() for any alu instruction. The register ID is ignored for scalars in regsafe() and doesn't affect state pruning. mark_reg_unknown() clears the ID. It's used to process call, endian and other instructions. Hence ID is explicitly cleared only in adjust_reg_min_max_vals() and in 32-bit mov. Signed-off-by: Alexei Starovoitov <[email protected]> Signed-off-by: Daniel Borkmann <[email protected]> Acked-by: Andrii Nakryiko <[email protected]> Acked-by: John Fastabend <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
2020-05-16selftests/bpf: Move test_align under test_progsStanislav Fomichev1-0/+666
There is a much higher chance we can see the regressions if the test is part of test_progs. Signed-off-by: Stanislav Fomichev <[email protected]> Signed-off-by: Daniel Borkmann <[email protected]> Link: https://lore.kernel.org/bpf/[email protected]
Powered by cgit, Gruvboxed by Blaster4385.