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2023-03-26selftests/bpf: Report program name on parse_test_spec errorEduard Zingerman1-1/+4
Change test_loader.c:run_subtest() behavior to show BPF program name when test spec for that program can't be parsed. Signed-off-by: Eduard Zingerman <eddyz87@gmail.com> Link: https://lore.kernel.org/r/20230325025524.144043-2-eddyz87@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-03-26bpf: Treat KF_RELEASE kfuncs as KF_TRUSTED_ARGSDavid Vernet4-11/+15
KF_RELEASE kfuncs are not currently treated as having KF_TRUSTED_ARGS, even though they have a superset of the requirements of KF_TRUSTED_ARGS. Like KF_TRUSTED_ARGS, KF_RELEASE kfuncs require a 0-offset argument, and don't allow NULL-able arguments. Unlike KF_TRUSTED_ARGS which require _either_ an argument with ref_obj_id > 0, _or_ (ref->type & BPF_REG_TRUSTED_MODIFIERS) (and no unsafe modifiers allowed), KF_RELEASE only allows for ref_obj_id > 0. Because KF_RELEASE today doesn't automatically imply KF_TRUSTED_ARGS, some of these requirements are enforced in different ways that can make the behavior of the verifier feel unpredictable. For example, a KF_RELEASE kfunc with a NULL-able argument will currently fail in the verifier with a message like, "arg#0 is ptr_or_null_ expected ptr_ or socket" rather than "Possibly NULL pointer passed to trusted arg0". Our intention is the same, but the semantics are different due to implemenetation details that kfunc authors and BPF program writers should not need to care about. Let's make the behavior of the verifier more consistent and intuitive by having KF_RELEASE kfuncs imply the presence of KF_TRUSTED_ARGS. Our eventual goal is to have all kfuncs assume KF_TRUSTED_ARGS by default anyways, so this takes us a step in that direction. Note that it does not make sense to assume KF_TRUSTED_ARGS for all KF_ACQUIRE kfuncs. KF_ACQUIRE kfuncs can have looser semantics than KF_RELEASE, with e.g. KF_RCU | KF_RET_NULL. We may want to have KF_ACQUIRE imply KF_TRUSTED_ARGS _unless_ KF_RCU is specified, but that can be left to another patch set, and there are no such subtleties to address for KF_RELEASE. Signed-off-by: David Vernet <void@manifault.com> Link: https://lore.kernel.org/r/20230325213144.486885-4-void@manifault.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-03-23selftests/bpf: Test switching TCP Congestion Control algorithms.Kui-Feng Lee2-0/+240
Create a pair of sockets that utilize the congestion control algorithm under a particular name. Then switch up this congestion control algorithm to another implementation and check whether newly created connections using the same cc name now run the new implementation. Also, try to update a link with a struct_ops that is without BPF_F_LINK or with a wrong or different name. These cases should fail due to the violation of assumptions. To update a bpf_link of a struct_ops, it must be replaced with another struct_ops that is identical in type and name and has the BPF_F_LINK flag. The other test case is to create links from the same struct_ops more than once. It makes sure a struct_ops can be used repeatly. Signed-off-by: Kui-Feng Lee <kuifeng@meta.com> Link: https://lore.kernel.org/r/20230323032405.3735486-9-kuifeng@meta.com Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2023-03-23libbpf: Use .struct_ops.link section to indicate a struct_ops with a link.Kui-Feng Lee1-16/+44
Flags a struct_ops is to back a bpf_link by putting it to the ".struct_ops.link" section. Once it is flagged, the created struct_ops can be used to create a bpf_link or update a bpf_link that has been backed by another struct_ops. Signed-off-by: Kui-Feng Lee <kuifeng@meta.com> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20230323032405.3735486-8-kuifeng@meta.com Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2023-03-23libbpf: Update a bpf_link with another struct_ops.Kui-Feng Lee5-2/+46
Introduce bpf_link__update_map(), which allows to atomically update underlying struct_ops implementation for given struct_ops BPF link. Also add old_map_fd to struct bpf_link_update_opts to handle BPF_F_REPLACE feature. Signed-off-by: Kui-Feng Lee <kuifeng@meta.com> Link: https://lore.kernel.org/r/20230323032405.3735486-7-kuifeng@meta.com Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2023-03-23bpf: Update the struct_ops of a bpf_link.Kui-Feng Lee1-5/+16
By improving the BPF_LINK_UPDATE command of bpf(), it should allow you to conveniently switch between different struct_ops on a single bpf_link. This would enable smoother transitions from one struct_ops to another. The struct_ops maps passing along with BPF_LINK_UPDATE should have the BPF_F_LINK flag. Signed-off-by: Kui-Feng Lee <kuifeng@meta.com> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20230323032405.3735486-6-kuifeng@meta.com Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2023-03-23libbpf: Create a bpf_link in bpf_map__attach_struct_ops().Kui-Feng Lee1-24/+71
bpf_map__attach_struct_ops() was creating a dummy bpf_link as a placeholder, but now it is constructing an authentic one by calling bpf_link_create() if the map has the BPF_F_LINK flag. You can flag a struct_ops map with BPF_F_LINK by calling bpf_map__set_map_flags(). Signed-off-by: Kui-Feng Lee <kuifeng@meta.com> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20230323032405.3735486-5-kuifeng@meta.com Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2023-03-23bpf: Create links for BPF struct_ops maps.Kui-Feng Lee1-1/+11
Make bpf_link support struct_ops. Previously, struct_ops were always used alone without any associated links. Upon updating its value, a struct_ops would be activated automatically. Yet other BPF program types required to make a bpf_link with their instances before they could become active. Now, however, you can create an inactive struct_ops, and create a link to activate it later. With bpf_links, struct_ops has a behavior similar to other BPF program types. You can pin/unpin them from their links and the struct_ops will be deactivated when its link is removed while previously need someone to delete the value for it to be deactivated. bpf_links are responsible for registering their associated struct_ops. You can only use a struct_ops that has the BPF_F_LINK flag set to create a bpf_link, while a structs without this flag behaves in the same manner as before and is registered upon updating its value. The BPF_LINK_TYPE_STRUCT_OPS serves a dual purpose. Not only is it used to craft the links for BPF struct_ops programs, but also to create links for BPF struct_ops them-self. Since the links of BPF struct_ops programs are only used to create trampolines internally, they are never seen in other contexts. Thus, they can be reused for struct_ops themself. To maintain a reference to the map supporting this link, we add bpf_struct_ops_link as an additional type. The pointer of the map is RCU and won't be necessary until later in the patchset. Signed-off-by: Kui-Feng Lee <kuifeng@meta.com> Link: https://lore.kernel.org/r/20230323032405.3735486-4-kuifeng@meta.com Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2023-03-23selftests/bpf: Check when bounds are not in the 32-bit rangeXu Kuohai1-0/+121
Add cases to check if bound is updated correctly when 64-bit value is not in the 32-bit range. Signed-off-by: Xu Kuohai <xukuohai@huawei.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: John Fastabend <john.fastabend@gmail.com> Link: https://lore.kernel.org/bpf/20230322213056.2470-2-daniel@iogearbox.net
2023-03-23bpf: 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 <xukuohai@huaweicloud.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Reviewed-by: John Fastabend <john.fastabend@gmail.com> Link: https://lore.kernel.org/bpf/20230314203424.4015351-2-xukuohai@huaweicloud.com Link: https://lore.kernel.org/bpf/20230322213056.2470-1-daniel@iogearbox.net
2023-03-23bpf/selftests: coverage for bpf_map_ops errorsJP Kobryn2-0/+300
These tests expose the issue of being unable to properly check for errors returned from inlined bpf map helpers that make calls to the bpf_map_ops functions. At best, a check for zero or non-zero can be done but these tests show it is not possible to check for a negative value or for a specific error value. Signed-off-by: JP Kobryn <inwardvessel@gmail.com> Tested-by: Eduard Zingerman <eddyz87@gmail.com> Link: https://lore.kernel.org/r/20230322194754.185781-2-inwardvessel@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-03-22selftests/bpf: Add light skeleton test for kfunc detection.Alexei Starovoitov2-0/+16
Add light skeleton test for kfunc detection and denylist it for s390. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20230321203854.3035-5-alexei.starovoitov@gmail.com
2023-03-22libbpf: Support kfunc detection in light skeleton.Alexei Starovoitov3-22/+27
Teach gen_loader to find {btf_id, btf_obj_fd} of kernel variables and kfuncs and populate corresponding ld_imm64 and bpf_call insns. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20230321203854.3035-4-alexei.starovoitov@gmail.com
2023-03-22libbpf: Rename RELO_EXTERN_VAR/FUNC.Alexei Starovoitov1-9/+9
RELO_EXTERN_VAR/FUNC names are not correct anymore. RELO_EXTERN_VAR represent ksym symbol in ld_imm64 insn. It can point to kernel variable or kfunc. Rename RELO_EXTERN_VAR->RELO_EXTERN_LD64 and RELO_EXTERN_FUNC->RELO_EXTERN_CALL to match what they actually represent. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: David Vernet <void@manifault.com> Link: https://lore.kernel.org/bpf/20230321203854.3035-2-alexei.starovoitov@gmail.com
2023-03-22selftests/xsk: add xdp populate metadata testTushar Vyavahare4-1/+77
Add a new test in copy-mode for testing the copying of metadata from the buffer in kernel-space to user-space. This is accomplished by adding a new XDP program and using the bss map to store a counter that is written to the metadata field. This counter is incremented for every packet so that the number becomes unique and should be the same as the payload. It is store in the bss so the value can be reset between runs. The XDP program populates the metadata and the userspace program checks the value stored in the metadata field against the payload using the new is_metadata_correct() function. To turn this verification on or off, add a new parameter (use_metadata) to the ifobject structure. Signed-off-by: Tushar Vyavahare <tushar.vyavahare@intel.com> Reviewed-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com> Link: https://lore.kernel.org/r/20230320102705.306187-1-tushar.vyavahare@intel.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-03-21net: skbuff: move the fields BPF cares about directly next to the offset markerJakub Kicinski1-4/+4
To avoid more possible BPF dependencies with moving bitfields around keep the fields BPF cares about right next to the offset marker. Signed-off-by: Jakub Kicinski <kuba@kernel.org> Link: https://lore.kernel.org/r/20230321014115.997841-4-kuba@kernel.org Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2023-03-21net: skbuff: rename __pkt_vlan_present_offset to __mono_tc_offsetJakub Kicinski1-3/+3
vlan_present is gone since commit 354259fa73e2 ("net: remove skb->vlan_present") rename the offset field to what BPF is currently looking for in this byte - mono_delivery_time and tc_at_ingress. Signed-off-by: Jakub Kicinski <kuba@kernel.org> Link: https://lore.kernel.org/r/20230321014115.997841-2-kuba@kernel.org Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2023-03-20libbpf: Explicitly call write to append content to fileLiu Pan1-5/+9
Write data to fd by calling "vdprintf", in most implementations of the standard library, the data is finally written by the writev syscall. But "uprobe_events/kprobe_events" does not allow segmented writes, so switch the "append_to_file" function to explicit write() call. Signed-off-by: Liu Pan <patteliu@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20230320030720.650-1-patteliu@gmail.com
2023-03-20selftest/bpf: Add a test case for ld_imm64 copy logic.Alexei Starovoitov1-1/+1
Add a test case to exercise {btf_id, btf_obj_fd} copy logic between ld_imm64 insns. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20230319203014.55866-2-alexei.starovoitov@gmail.com
2023-03-20libbpf: Fix ld_imm64 copy logic for ksym in light skeleton.Alexei Starovoitov1-4/+6
Unlike normal libbpf the light skeleton 'loader' program is doing btf_find_by_name_kind() call at run-time to find ksym in the kernel and populate its {btf_id, btf_obj_fd} pair in ld_imm64 insn. To avoid doing the search multiple times for the same ksym it remembers the first patched ld_imm64 insn and copies {btf_id, btf_obj_fd} from it into subsequent ld_imm64 insn. Fix a bug in copying logic, since it may incorrectly clear BPF_PSEUDO_BTF_ID flag. Also replace always true if (btf_obj_fd >= 0) check with unconditional JMP_JA to clarify the code. Fixes: d995816b77eb ("libbpf: Avoid reload of imm for weak, unresolved, repeating ksym") Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20230319203014.55866-1-alexei.starovoitov@gmail.com
2023-03-18selftests/bpf: Add --json-summary option to test_progsManu Bretelle5-6/+84
Currently, test_progs outputs all stdout/stderr as it runs, and when it is done, prints a summary. It is non-trivial for tooling to parse that output and extract meaningful information from it. This change adds a new option, `--json-summary`/`-J` that let the caller specify a file where `test_progs{,-no_alu32}` can write a summary of the run in a json format that can later be parsed by tooling. Currently, it creates a summary section with successes/skipped/failures followed by a list of failed tests and subtests. A test contains the following fields: - name: the name of the test - number: the number of the test - message: the log message that was printed by the test. - failed: A boolean indicating whether the test failed or not. Currently we only output failed tests, but in the future, successful tests could be added. - subtests: A list of subtests associated with this test. A subtest contains the following fields: - name: same as above - number: sanme as above - message: the log message that was printed by the subtest. - failed: same as above but for the subtest An example run and json content below: ``` $ sudo ./test_progs -a $(grep -v '^#' ./DENYLIST.aarch64 | awk '{print $1","}' | tr -d '\n') -j -J /tmp/test_progs.json $ jq < /tmp/test_progs.json | head -n 30 { "success": 29, "success_subtest": 23, "skipped": 3, "failed": 28, "results": [ { "name": "bpf_cookie", "number": 10, "message": "test_bpf_cookie:PASS:skel_open 0 nsec\n", "failed": true, "subtests": [ { "name": "multi_kprobe_link_api", "number": 2, "message": "kprobe_multi_link_api_subtest:PASS:load_kallsyms 0 nsec\nlibbpf: extern 'bpf_testmod_fentry_test1' (strong): not resolved\nlibbpf: failed to load object 'kprobe_multi'\nlibbpf: failed to load BPF skeleton 'kprobe_multi': -3\nkprobe_multi_link_api_subtest:FAIL:fentry_raw_skel_load unexpected error: -3\n", "failed": true }, { "name": "multi_kprobe_attach_api", "number": 3, "message": "libbpf: extern 'bpf_testmod_fentry_test1' (strong): not resolved\nlibbpf: failed to load object 'kprobe_multi'\nlibbpf: failed to load BPF skeleton 'kprobe_multi': -3\nkprobe_multi_attach_api_subtest:FAIL:fentry_raw_skel_load unexpected error: -3\n", "failed": true }, { "name": "lsm", "number": 8, "message": "lsm_subtest:PASS:lsm.link_create 0 nsec\nlsm_subtest:FAIL:stack_mprotect unexpected stack_mprotect: actual 0 != expected -1\n", "failed": true } ``` The file can then be used to print a summary of the test run and list of failing tests/subtests: ``` $ jq -r < /tmp/test_progs.json '"Success: \(.success)/\(.success_subtest), Skipped: \(.skipped), Failed: \(.failed)"' Success: 29/23, Skipped: 3, Failed: 28 $ jq -r < /tmp/test_progs.json '.results | map([ if .failed then "#\(.number) \(.name)" else empty end, ( . as {name: $tname, number: $tnum} | .subtests | map( if .failed then "#\($tnum)/\(.number) \($tname)/\(.name)" else empty end ) ) ]) | flatten | .[]' | head -n 20 #10 bpf_cookie #10/2 bpf_cookie/multi_kprobe_link_api #10/3 bpf_cookie/multi_kprobe_attach_api #10/8 bpf_cookie/lsm #15 bpf_mod_race #15/1 bpf_mod_race/ksym (used_btfs UAF) #15/2 bpf_mod_race/kfunc (kfunc_btf_tab UAF) #36 cgroup_hierarchical_stats #61 deny_namespace #61/1 deny_namespace/unpriv_userns_create_no_bpf #73 fexit_stress #83 get_func_ip_test #99 kfunc_dynptr_param #99/1 kfunc_dynptr_param/dynptr_data_null #99/4 kfunc_dynptr_param/dynptr_data_null #100 kprobe_multi_bench_attach #100/1 kprobe_multi_bench_attach/kernel #100/2 kprobe_multi_bench_attach/modules #101 kprobe_multi_test #101/1 kprobe_multi_test/skel_api ``` Signed-off-by: Manu Bretelle <chantr4@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20230317163256.3809328-1-chantr4@gmail.com
2023-03-18selftests/bpf: Add test for bpf_ksym_exists().Alexei Starovoitov1-1/+19
Add load and run time test for bpf_ksym_exists() and check that the verifier performs dead code elimination for non-existing kfunc. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Reviewed-by: Martin KaFai Lau <martin.lau@kernel.org> Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com> Acked-by: John Fastabend <john.fastabend@gmail.com> Link: https://lore.kernel.org/bpf/20230317201920.62030-5-alexei.starovoitov@gmail.com
2023-03-18libbpf: Introduce bpf_ksym_exists() macro.Alexei Starovoitov1-0/+5
Introduce bpf_ksym_exists() macro that can be used by BPF programs to detect at load time whether particular ksym (either variable or kfunc) is present in the kernel. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20230317201920.62030-4-alexei.starovoitov@gmail.com
2023-03-18libbpf: Fix relocation of kfunc ksym in ld_imm64 insn.Alexei Starovoitov1-0/+6
void *p = kfunc; -> generates ld_imm64 insn. kfunc() -> generates bpf_call insn. libbpf patches bpf_call insn correctly while only btf_id part of ld_imm64 is set in the former case. Which means that pointers to kfuncs in modules are not patched correctly and the verifier rejects load of such programs due to btf_id being out of range. Fix libbpf to patch ld_imm64 for kfunc. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20230317201920.62030-3-alexei.starovoitov@gmail.com
2023-03-17selftests/bpf: fix "metadata marker" getting overwritten by the netstackAlexander Lobakin2-4/+5
Alexei noticed xdp_do_redirect test on BPF CI started failing on BE systems after skb PP recycling was enabled: test_xdp_do_redirect:PASS:prog_run 0 nsec test_xdp_do_redirect:PASS:pkt_count_xdp 0 nsec test_xdp_do_redirect:PASS:pkt_count_zero 0 nsec test_xdp_do_redirect:FAIL:pkt_count_tc unexpected pkt_count_tc: actual 220 != expected 9998 test_max_pkt_size:PASS:prog_run_max_size 0 nsec test_max_pkt_size:PASS:prog_run_too_big 0 nsec close_netns:PASS:setns 0 nsec #289 xdp_do_redirect:FAIL Summary: 270/1674 PASSED, 30 SKIPPED, 1 FAILED and it doesn't happen on LE systems. Ilya then hunted it down to: #0 0x0000000000aaeee6 in neigh_hh_output (hh=0x83258df0, skb=0x88142200) at linux/include/net/neighbour.h:503 #1 0x0000000000ab2cda in neigh_output (skip_cache=false, skb=0x88142200, n=<optimized out>) at linux/include/net/neighbour.h:544 #2 ip6_finish_output2 (net=net@entry=0x88edba00, sk=sk@entry=0x0, skb=skb@entry=0x88142200) at linux/net/ipv6/ip6_output.c:134 #3 0x0000000000ab4cbc in __ip6_finish_output (skb=0x88142200, sk=0x0, net=0x88edba00) at linux/net/ipv6/ip6_output.c:195 #4 ip6_finish_output (net=0x88edba00, sk=0x0, skb=0x88142200) at linux/net/ipv6/ip6_output.c:206 xdp_do_redirect test places a u32 marker (0x42) right before the Ethernet header to check it then in the XDP program and return %XDP_ABORTED if it's not there. Neigh xmit code likes to round up hard header length to speed up copying the header, so it overwrites two bytes in front of the Eth header. On LE systems, 0x42 is one byte at `data - 4`, while on BE it's `data - 1`, what explains why it happens only there. It didn't happen previously due to that %XDP_PASS meant the page will be discarded and replaced by a new one, but now it can be recycled as well, while bpf_test_run code doesn't reinitialize the content of recycled pages. This mark is limited to this particular test and its setup though, so there's no need to predict 1000 different possible cases. Just move it 4 bytes to the left, still keeping it 32 bit to match on more bytes. Fixes: 9c94bbf9a87b ("xdp: recycle Page Pool backed skbs built from XDP frames") Reported-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/CAADnVQ+B_JOU+EpP=DKhbY9yXdN6GiRPnpTTXfEZ9sNkUeb-yQ@mail.gmail.com Reported-by: Ilya Leoshkevich <iii@linux.ibm.com> # + debugging Link: https://lore.kernel.org/bpf/8341c1d9f935f410438e79d3bd8a9cc50aefe105.camel@linux.ibm.com Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com> Acked-by: Toke Høiland-Jørgensen <toke@redhat.com> Tested-by: Ilya Leoshkevich <iii@linux.ibm.com> Link: https://lore.kernel.org/r/20230316175051.922550-3-aleksander.lobakin@intel.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-03-16bpf: Remove bpf_cpumask_kptr_get() kfuncDavid Vernet4-56/+0
Now that struct bpf_cpumask is RCU safe, there's no need for this kfunc. Rather than doing the following: private(MASK) static struct bpf_cpumask __kptr *global; int BPF_PROG(prog, s32 cpu, ...) { struct bpf_cpumask *cpumask; bpf_rcu_read_lock(); cpumask = bpf_cpumask_kptr_get(&global); if (!cpumask) { bpf_rcu_read_unlock(); return -1; } bpf_cpumask_setall(cpumask); ... bpf_cpumask_release(cpumask); bpf_rcu_read_unlock(); } Programs can instead simply do (assume same global cpumask): int BPF_PROG(prog, ...) { struct bpf_cpumask *cpumask; bpf_rcu_read_lock(); cpumask = global; if (!cpumask) { bpf_rcu_read_unlock(); return -1; } bpf_cpumask_setall(cpumask); ... bpf_rcu_read_unlock(); } In other words, no extra atomic acquire / release, and less boilerplate code. This patch removes both the kfunc, as well as its selftests and documentation. Signed-off-by: David Vernet <void@manifault.com> Link: https://lore.kernel.org/r/20230316054028.88924-5-void@manifault.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-03-16bpf/selftests: Test using global cpumask kptr with RCUDavid Vernet4-0/+102
Now that struct bpf_cpumask * is considered an RCU-safe type according to the verifier, we should add tests that validate its common usages. This patch adds those tests to the cpumask test suite. A subsequent changes will remove bpf_cpumask_kptr_get(), and will adjust the selftest and BPF documentation accordingly. Signed-off-by: David Vernet <void@manifault.com> Link: https://lore.kernel.org/r/20230316054028.88924-4-void@manifault.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-03-16libbpf: Ignore warnings about "inefficient alignment"Daniel Müller1-0/+6
Some consumers of libbpf compile the code base with different warnings enabled. In a report for perf, for example, -Wpacked was set which caused warnings about "inefficient alignment" to be emitted on a subset of supported architectures. With this change we silence specifically those warnings, as we intentionally worked with packed structs. This is a similar resolution as in b2f10cd4e805 ("perf cpumap: Fix alignment for masks in event encoding"). Fixes: 1eebcb60633f ("libbpf: Implement basic zip archive parsing support") Reported-by: Linux Kernel Functional Testing <lkft@linaro.org> Signed-off-by: Daniel Müller <deso@posteo.net> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Cc: Ian Rogers <irogers@google.com> Link: https://lore.kernel.org/bpf/CA+G9fYtBnwxAWXi2+GyNByApxnf_DtP1-6+_zOKAdJKnJBexjg@mail.gmail.com/ Link: https://lore.kernel.org/bpf/20230315171550.1551603-1-deso@posteo.net
2023-03-16selftests/bpf: Fix a fd leak in an error path in network_helpers.cMartin KaFai Lau1-1/+1
In __start_server, it leaks a fd when setsockopt(SO_REUSEPORT) fails. This patch fixes it. Fixes: eed92afdd14c ("bpf: selftest: Test batching and bpf_(get|set)sockopt in bpf tcp iter") Reported-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Yonghong Song <yhs@fb.com> Acked-by: John Fastabend <john.fastabend@gmail.com> Link: https://lore.kernel.org/bpf/20230316000726.1016773-2-martin.lau@linux.dev
2023-03-16selftests/bpf: Use ASSERT_EQ instead ASSERT_OK for testing memcmp resultMartin KaFai Lau1-2/+2
In tcp_hdr_options test, it ensures the received tcp hdr option and the sk local storage have the expected values. It uses memcmp to check that. Testing the memcmp result with ASSERT_OK is confusing because ASSERT_OK will print out the errno which is not set. This patch uses ASSERT_EQ to check for 0 instead. Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Yonghong Song <yhs@fb.com> Acked-by: John Fastabend <john.fastabend@gmail.com> Link: https://lore.kernel.org/bpf/20230316000726.1016773-1-martin.lau@linux.dev
2023-03-16bpf/selftests: Test fentry attachment to shadowed functionsViktor Malik3-0/+135
Adds a new test that tries to attach a program to fentry of two functions of the same name, one located in vmlinux and the other in bpf_testmod. To avoid conflicts with existing tests, a new function "bpf_fentry_shadow_test" was created both in vmlinux and in bpf_testmod. The previous commit fixed a bug which caused this test to fail. The verifier would always use the vmlinux function's address as the target trampoline address, hence trying to create two trampolines for a single address, which is forbidden. The test (similarly to other fentry/fexit tests) is not working on arm64 at the moment. Signed-off-by: Viktor Malik <vmalik@redhat.com> Acked-by: Jiri Olsa <jolsa@kernel.org> Link: https://lore.kernel.org/r/5fe2f364190b6f79b085066ed7c5989c5bc475fa.1678432753.git.vmalik@redhat.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-03-15selftests/bpf: Fix trace_virtqueue_add_sgs test issue with LLVM 17.Alexei Starovoitov1-0/+3
LLVM commit https://reviews.llvm.org/D143726 introduced hoistMinMax optimization that transformed (i < VIRTIO_MAX_SGS) && (i < out_sgs) into i < MIN(VIRTIO_MAX_SGS, out_sgs) and caused the verifier to stop recognizing such loop as bounded. Which resulted in the following test failure: libbpf: prog 'trace_virtqueue_add_sgs': BPF program load failed: Bad address libbpf: prog 'trace_virtqueue_add_sgs': -- BEGIN PROG LOAD LOG -- The sequence of 8193 jumps is too complex. verification time 789206 usec stack depth 56 processed 156446 insns (limit 1000000) max_states_per_insn 7 total_states 1746 peak_states 1701 mark_read 12 -- END PROG LOAD LOG -- libbpf: prog 'trace_virtqueue_add_sgs': failed to load: -14 libbpf: failed to load object 'loop6.bpf.o' Workaround the verifier limitation for now with inline asm that prevents this particular optimization. Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-03-15selftests/bpf: robustify test_xdp_do_redirect with more payload magicsAlexander Lobakin1-10/+26
Currently, the test relies on that only dropped ("xmitted") frames will be recycled and if a frame became an skb, it will be freed later by the stack and never come back to its page_pool. So, it easily gets broken by trying to recycle skbs[0]: test_xdp_do_redirect:PASS:pkt_count_xdp 0 nsec test_xdp_do_redirect:FAIL:pkt_count_zero unexpected pkt_count_zero: actual 9936 != expected 2 test_xdp_do_redirect:PASS:pkt_count_tc 0 nsec That huge mismatch happened because after the TC ingress hook zeroes the magic, the page gets recycled when skb is freed, not returned to the MM layer. "Live frames" mode initializes only new pages and keeps the recycled ones as is by design, so they appear with zeroed magic on the Rx path again. Expand the possible magic values from two: 0 (was "xmitted"/dropped or did hit the TC hook) and 0x42 (hit the input XDP prog) to three: the new one will mark frames hit the TC hook, so that they will elide both @pkt_count_zero and @pkt_count_xdp. They can then be recycled to their page_pool or returned to the page allocator, this won't affect the counters anyhow. Just make sure to mark them as "input" (0x42) when they appear on the Rx path again. Also make an enum from those magics, so that they will be always visible and can be changed in just one place anytime. This also eases adding any new marks later on. Link: https://github.com/kernel-patches/bpf/actions/runs/4386538411/jobs/7681081789 Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com> Link: https://lore.kernel.org/r/20230313215553.1045175-2-aleksander.lobakin@intel.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-03-14selftests/bpf: Add various tests to check helper access into ptr_to_btf_id.Alexei Starovoitov2-0/+40
Add various tests to check helper access into ptr_to_btf_id. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: David Vernet <void@manifault.com> Link: https://lore.kernel.org/r/20230313235845.61029-4-alexei.starovoitov@gmail.com Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2023-03-14selftests/bpf: use canonical ftrace pathRoss Zwisler11-22/+64
The canonical location for the tracefs filesystem is at /sys/kernel/tracing. But, from Documentation/trace/ftrace.rst: Before 4.1, all ftrace tracing control files were within the debugfs file system, which is typically located at /sys/kernel/debug/tracing. For backward compatibility, when mounting the debugfs file system, the tracefs file system will be automatically mounted at: /sys/kernel/debug/tracing Many tests in the bpf selftest code still refer to this older debugfs path, so let's update them to avoid confusion. Signed-off-by: Ross Zwisler <zwisler@google.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org> Link: https://lore.kernel.org/r/20230313205628.1058720-3-zwisler@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-03-14bpf: use canonical ftrace pathRoss Zwisler1-4/+4
The canonical location for the tracefs filesystem is at /sys/kernel/tracing. But, from Documentation/trace/ftrace.rst: Before 4.1, all ftrace tracing control files were within the debugfs file system, which is typically located at /sys/kernel/debug/tracing. For backward compatibility, when mounting the debugfs file system, the tracefs file system will be automatically mounted at: /sys/kernel/debug/tracing Many comments and samples in the bpf code still refer to this older debugfs path, so let's update them to avoid confusion. There are a few spots where the bpf code explicitly checks both tracefs and debugfs (tools/bpf/bpftool/tracelog.c and tools/lib/api/fs/fs.c) and I've left those alone so that the tools can continue to work with both paths. Signed-off-by: Ross Zwisler <zwisler@google.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org> Link: https://lore.kernel.org/r/20230313205628.1058720-2-zwisler@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-03-11selftests/bpf: Add local kptr stashing testDave Marchevsky2-0/+168
Add a new selftest, local_kptr_stash, which uses bpf_kptr_xchg to stash a bpf_obj_new-allocated object in a map. Test the following scenarios: * Stash two rb_nodes in an arraymap, don't unstash them, rely on map free to destruct them * Stash two rb_nodes in an arraymap, unstash the second one in a separate program, rely on map free to destruct first Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com> Link: https://lore.kernel.org/r/20230310230743.2320707-4-davemarchevsky@fb.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-03-10selftests/bpf: Add local-storage-create benchmarkMartin KaFai Lau4-0/+202
This patch tests how many kmallocs is needed to create and free a batch of UDP sockets and each socket has a 64bytes bpf storage. It also measures how fast the UDP sockets can be created. The result is from my qemu setup. Before bpf_mem_cache_alloc/free: ./bench -p 1 local-storage-create Setting up benchmark 'local-storage-create'... Benchmark 'local-storage-create' started. Iter 0 ( 73.193us): creates 213.552k/s (213.552k/prod), 3.09 kmallocs/create Iter 1 (-20.724us): creates 211.908k/s (211.908k/prod), 3.09 kmallocs/create Iter 2 ( 9.280us): creates 212.574k/s (212.574k/prod), 3.12 kmallocs/create Iter 3 ( 11.039us): creates 213.209k/s (213.209k/prod), 3.12 kmallocs/create Iter 4 (-11.411us): creates 213.351k/s (213.351k/prod), 3.12 kmallocs/create Iter 5 ( -7.915us): creates 214.754k/s (214.754k/prod), 3.12 kmallocs/create Iter 6 ( 11.317us): creates 210.942k/s (210.942k/prod), 3.12 kmallocs/create Summary: creates 212.789 ± 1.310k/s (212.789k/prod), 3.12 kmallocs/create After bpf_mem_cache_alloc/free: ./bench -p 1 local-storage-create Setting up benchmark 'local-storage-create'... Benchmark 'local-storage-create' started. Iter 0 ( 68.265us): creates 243.984k/s (243.984k/prod), 1.04 kmallocs/create Iter 1 ( 30.357us): creates 238.424k/s (238.424k/prod), 1.04 kmallocs/create Iter 2 (-18.712us): creates 232.963k/s (232.963k/prod), 1.04 kmallocs/create Iter 3 (-15.885us): creates 238.879k/s (238.879k/prod), 1.04 kmallocs/create Iter 4 ( 5.590us): creates 237.490k/s (237.490k/prod), 1.04 kmallocs/create Iter 5 ( 8.577us): creates 237.521k/s (237.521k/prod), 1.04 kmallocs/create Iter 6 ( -6.263us): creates 238.508k/s (238.508k/prod), 1.04 kmallocs/create Summary: creates 237.298 ± 2.198k/s (237.298k/prod), 1.04 kmallocs/create Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org> Link: https://lore.kernel.org/r/20230308065936.1550103-18-martin.lau@linux.dev Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-03-10selftests/bpf: Check freeing sk->sk_local_storage with ↵Martin KaFai Lau1-9/+20
sk_local_storage->smap is NULL This patch tweats the socket_bind bpf prog to test the local_storage->smap == NULL case in the bpf_local_storage_free() code path. The idea is to create the local_storage with the sk_storage_map's selem first. Then add the sk_storage_map2's selem and then delete the earlier sk_storeage_map's selem. Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org> Link: https://lore.kernel.org/r/20230308065936.1550103-17-martin.lau@linux.dev Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-03-10selftests/bpf: Replace CHECK with ASSERT in test_local_storageMartin KaFai Lau1-30/+17
This patch migrates the CHECK macro to ASSERT macro. Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org> Link: https://lore.kernel.org/r/20230308065936.1550103-16-martin.lau@linux.dev Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-03-10bpf/selftests: Fix send_signal tracepoint testsDavid Vernet1-1/+5
The send_signal tracepoint tests are non-deterministically failing in CI. The test works as follows: 1. Two pairs of file descriptors are created using the pipe() function. One pair is used to communicate between a parent process -> child process, and the other for the reverse direction. 2. A child is fork()'ed. The child process registers a signal handler, notifies its parent that the signal handler is registered, and then and waits for its parent to have enabled a BPF program that sends a signal. 3. The parent opens and loads a BPF skeleton with programs that send signals to the child process. The different programs are triggered by different perf events (either NMI or normal perf), or by regular tracepoints. The signal is delivered to the child whenever the child triggers the program. 4. The child's signal handler is invoked, which sets a flag saying that the signal handler was reached. The child then signals to the parent that it received the signal, and the test ends. The perf testcases (send_signal_perf{_thread} and send_signal_nmi{_thread}) work 100% of the time, but the tracepoint testcases fail non-deterministically because the tracepoint is not always being fired for the child. There are two tracepoint programs registered in the test: 'tracepoint/sched/sched_switch', and 'tracepoint/syscalls/sys_enter_nanosleep'. The child never intentionally blocks, nor sleeps, so neither tracepoint is guaranteed to be triggered. To fix this, we can have the child trigger the nanosleep program with a usleep(). Before this patch, the test would fail locally every 2-3 runs. Now, it doesn't fail after more than 1000 runs. Signed-off-by: David Vernet <void@manifault.com> Link: https://lore.kernel.org/r/20230310061909.1420887-1-void@manifault.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-03-10selftests/bpf: make BPF compiler flags stricterAndrii Nakryiko1-2/+2
We recently added -Wuninitialized, but it's not enough to catch various silly mistakes or omissions. Let's go all the way to -Wall, just like we do for user-space code. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20230309054015.4068562-5-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-03-10selftests/bpf: fix lots of silly mistakes pointed out by compilerAndrii Nakryiko81-187/+90
Once we enable -Wall for BPF sources, compiler will complain about lots of unused variables, variables that are set but never read, etc. Fix all these issues first before enabling -Wall in Makefile. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20230309054015.4068562-4-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-03-10selftests/bpf: add __sink() macro to fake variable consumptionAndrii Nakryiko1-0/+3
Add __sink(expr) macro that forces compiler to believe that passed in expression is both read and written. It used a simple embedded asm for this. This is useful in a lot of tests where we assign value to some variable to trigger some action, but later don't read variable, causing compiler to complain (if corresponding compiler warnings are turned on, which we'll do in the next patch). Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20230309054015.4068562-3-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-03-10selftests/bpf: prevent unused variable warning in bpf_for()Andrii Nakryiko1-3/+6
Add __attribute__((unused)) to inner __p variable inside bpf_for(), bpf_for_each(), and bpf_repeat() macros to avoid compiler warnings about unused variable. Reported-by: Tejun Heo <tj@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20230309054015.4068562-2-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-03-10selftests/bpf: Workaround verification failure for ↵Yonghong Song1-1/+1
fexit_bpf2bpf/func_replace_return_code With latest llvm17, selftest fexit_bpf2bpf/func_replace_return_code has the following verification failure: 0: R1=ctx(off=0,imm=0) R10=fp0 ; int connect_v4_prog(struct bpf_sock_addr *ctx) 0: (bf) r7 = r1 ; R1=ctx(off=0,imm=0) R7_w=ctx(off=0,imm=0) 1: (b4) w6 = 0 ; R6_w=0 ; memset(&tuple.ipv4.saddr, 0, sizeof(tuple.ipv4.saddr)); ... ; return do_bind(ctx) ? 1 : 0; 179: (bf) r1 = r7 ; R1=ctx(off=0,imm=0) R7=ctx(off=0,imm=0) 180: (85) call pc+147 Func#3 is global and valid. Skipping. 181: R0_w=scalar() 181: (bc) w6 = w0 ; R0_w=scalar() R6_w=scalar(umax=4294967295,var_off=(0x0; 0xffffffff)) 182: (05) goto pc-129 ; } 54: (bc) w0 = w6 ; R0_w=scalar(umax=4294967295,var_off=(0x0; 0xffffffff)) R6_w=scalar(umax=4294967295,var_off=(0x0; 0xffffffff)) 55: (95) exit At program exit the register R0 has value (0x0; 0xffffffff) should have been in (0x0; 0x1) processed 281 insns (limit 1000000) max_states_per_insn 1 total_states 26 peak_states 26 mark_read 13 -- END PROG LOAD LOG -- libbpf: prog 'connect_v4_prog': failed to load: -22 The corresponding source code: __attribute__ ((noinline)) int do_bind(struct bpf_sock_addr *ctx) { struct sockaddr_in sa = {}; sa.sin_family = AF_INET; sa.sin_port = bpf_htons(0); sa.sin_addr.s_addr = bpf_htonl(SRC_REWRITE_IP4); if (bpf_bind(ctx, (struct sockaddr *)&sa, sizeof(sa)) != 0) return 0; return 1; } ... SEC("cgroup/connect4") int connect_v4_prog(struct bpf_sock_addr *ctx) { ... return do_bind(ctx) ? 1 : 0; } Insn 180 is a call to 'do_bind'. The call's return value is also the return value for the program. Since do_bind() returns 0/1, so it is legitimate for compiler to optimize 'return do_bind(ctx) ? 1 : 0' to 'return do_bind(ctx)'. However, such optimization breaks verifier as the return value of 'do_bind()' is marked as any scalar which violates the requirement of prog return value 0/1. There are two ways to fix this problem, (1) changing 'return 1' in do_bind() to e.g. 'return 10' so the compiler has to do 'do_bind(ctx) ? 1 :0', or (2) suggested by Andrii, marking do_bind() with __weak attribute so the compiler cannot make any assumption on do_bind() return value. This patch adopted adding __weak approach which is simpler and more resistant to potential compiler optimizations. Suggested-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20230310012410.2920570-1-yhs@fb.com
2023-03-09selftests/bpf: Improve error logs in XDP compliance test toolLorenzo Bianconi1-7/+16
Improve some error logs reported in the XDP compliance test tool. Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/212fc5bd214ff706f6ef1acbe7272cf4d803ca9c.1678382940.git.lorenzo@kernel.org
2023-03-09selftests/bpf: Use ifname instead of ifindex in XDP compliance test toolLorenzo Bianconi1-17/+27
Rely on interface name instead of interface index in error messages or logs from XDP compliance test tool. Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/7dc5a8ff56c252b1a7ae29b059d0b2b1543c8b5d.1678382940.git.lorenzo@kernel.org
2023-03-09bpf: Fix a typo for BPF_F_ANY_ALIGNMENT in bpf.hMichael Weiß1-1/+1
Fix s/BPF_PROF_LOAD/BPF_PROG_LOAD/ typo in the documentation comment for BPF_F_ANY_ALIGNMENT in bpf.h. Signed-off-by: Michael Weiß <michael.weiss@aisec.fraunhofer.de> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20230309133823.944097-1-michael.weiss@aisec.fraunhofer.de
2023-03-09selftests/bpf: Fix flaky fib_lookup testMartin KaFai Lau1-2/+10
There is a report that fib_lookup test is flaky when running in parallel. A symptom of slowness or delay. An example: Testing IPv6 stale neigh set_lookup_params:PASS:inet_pton(IPV6_IFACE_ADDR) 0 nsec test_fib_lookup:PASS:bpf_prog_test_run_opts 0 nsec test_fib_lookup:FAIL:fib_lookup_ret unexpected fib_lookup_ret: actual 0 != expected 7 test_fib_lookup:FAIL:dmac not match unexpected dmac not match: actual 1 != expected 0 dmac expected 11:11:11:11:11:11 actual 00:00:00:00:00:00 [ Note that the "fib_lookup_ret unexpected fib_lookup_ret actual 0 ..." is reversed in terms of expected and actual value. Fixing in this patch also. ] One possibility is the testing stale neigh entry was marked dead by the gc (in neigh_periodic_work). The default gc_stale_time sysctl is 60s. This patch increases it to 15 mins. It also: - fixes the reversed arg (actual vs expected) in one of the ASSERT_EQ test - removes the nodad command arg when adding v4 neigh entry which currently has a warning. Fixes: 168de0233586 ("selftests/bpf: Add bpf_fib_lookup test") Reported-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20230309060244.3242491-1-martin.lau@linux.dev