- 21 Jan, 2023 13 commits
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Alexei Starovoitov authored
Kumar Kartikeya Dwivedi says: ==================== This is part 2 of https://lore.kernel.org/bpf/20221018135920.726360-1-memxor@gmail.com. Changelog: ---------- v4 -> v5 v5: https://lore.kernel.org/bpf/20230120070355.1983560-1-memxor@gmail.com * Add comments, tests from Joanne * Add Joanne's acks v3 -> v4 v3: https://lore.kernel.org/bpf/20230120034314.1921848-1-memxor@gmail.com * Adopt BPF ASM tests to more readable style (Alexei) v2 -> v3 v2: https://lore.kernel.org/bpf/20230119021442.1465269-1-memxor@gmail.com * Fix slice invalidation logic for unreferenced dynptrs (Joanne) * Add selftests for precise slice invalidation on destruction * Add Joanne's acks v1 -> v2 v1: https://lore.kernel.org/bpf/20230101083403.332783-1-memxor@gmail.com * Return error early in case of overwriting referenced dynptr slots (Andrii, Joanne) * Rename destroy_stack_slots_dynptr to destroy_if_dynptr_stack_slot (Joanne) * Invalidate dynptr slices associated with dynptr in destroy_if_dynptr_stack_slot (Joanne) * Combine both dynptr_get_spi and is_spi_bounds_valid (Joanne) * Compute spi once in process_dynptr_func and pass it as parameter instead of recomputing (Joanne) * Add comments expanding REG_LIVE_WRITTEN marking in unmark_stack_slots_dynptr (Joanne) * Add comments explaining why destroy_if_dynptr_stack_slot call needs to be done for both spi and spi - 1 (Joanne) * Port BPF assembly tests from test_verifier to test_progs framework (Andrii) * Address misc feedback, rebase to bpf-next Old v1 -> v1 Old v1: https://lore.kernel.org/bpf/20221018135920.726360-1-memxor@gmail.com * Allow overwriting dynptr stack slots from dynptr init helpers * Fix a bug in alignment check where reg->var_off.value was still not included * Address other minor nits Eduard Zingerman (1): selftests/bpf: convenience macro for use with 'asm volatile' blocks ==================== Signed-off-by:
Alexei Starovoitov <ast@kernel.org>
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Kumar Kartikeya Dwivedi authored
First test that we allow overwriting dynptr slots and reinitializing them in unreferenced case, and disallow overwriting for referenced case. Include tests to ensure slices obtained from destroyed dynptrs are being invalidated on their destruction. The destruction needs to be scoped, as in slices of dynptr A should not be invalidated when dynptr B is destroyed. Next, test that MEM_UNINIT doesn't allow writing dynptr stack slots. Acked-by:
Joanne Koong <joannelkoong@gmail.com> Signed-off-by:
Kumar Kartikeya Dwivedi <memxor@gmail.com> Link: https://lore.kernel.org/r/20230121002241.2113993-13-memxor@gmail.comSigned-off-by:
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Kumar Kartikeya Dwivedi authored
Try creating a dynptr, then overwriting second slot with first slot of another dynptr. Then, the first slot of first dynptr should also be invalidated, but without our fix that does not happen. As a consequence, the unfixed case allows passing first dynptr (as the kernel check only checks for slot_type and then first_slot == true). Signed-off-by:
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Kumar Kartikeya Dwivedi authored
Ensure that variable offset is handled correctly, and verifier takes both fixed and variable part into account. Also ensures that only constant var_off is allowed. Signed-off-by:
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Kumar Kartikeya Dwivedi authored
Add verifier tests that verify the new pruning behavior for STACK_DYNPTR slots, and ensure that state equivalence takes into account changes to the old and current verifier state correctly. Also ensure that the stacksafe changes are actually enabling pruning in case states are equivalent from pruning PoV. Signed-off-by:
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Eduard Zingerman authored
A set of macros useful for writing naked BPF functions using inline assembly. E.g. as follows: struct map_struct { ... } map SEC(".maps"); SEC(...) __naked int foo_test(void) { asm volatile( "r0 = 0;" "*(u64*)(r10 - 8) = r0;" "r1 = %[map] ll;" "r2 = r10;" "r2 += -8;" "call %[bpf_map_lookup_elem];" "r0 = 0;" "exit;" : : __imm(bpf_map_lookup_elem), __imm_addr(map) : __clobber_all); } Acked-by:Andrii Nakryiko <andrii@kernel.org> Acked-by:
Yonghong Song <yhs@fb.com> Signed-off-by:
Eduard Zingerman <eddyz87@gmail.com> [ Kartikeya: Add acks, include __clobber_common from Andrii ] Signed-off-by:
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Kumar Kartikeya Dwivedi authored
Currently, process_dynptr_func first calls dynptr_get_spi and then is_dynptr_reg_valid_init and is_dynptr_reg_valid_uninit have to call it again to obtain the spi value. Instead of doing this twice, reuse the already obtained value (which is by default 0, and is only set for PTR_TO_STACK, and only used in that case in aforementioned functions). The input value for these two functions will either be -ERANGE or >= 1, and can either be permitted or rejected based on the respective check. Suggested-by:
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Kumar Kartikeya Dwivedi authored
Currently, a check on spi resides in dynptr_get_spi, while others checking its validity for being within the allocated stack slots happens in is_spi_bounds_valid. Almost always barring a couple of cases (where being beyond allocated stack slots is not an error as stack slots need to be populated), both are used together to make checks. Hence, subsume the is_spi_bounds_valid check in dynptr_get_spi, and return -ERANGE to specially distinguish the case where spi is valid but not within allocated slots in the stack state. The is_spi_bounds_valid function is still kept around as it is a generic helper that will be useful for other objects on stack similar to dynptr in the future. Suggested-by:
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Kumar Kartikeya Dwivedi authored
Consider a program like below: void prog(void) { { struct bpf_dynptr ptr; bpf_dynptr_from_mem(...); } ... { struct bpf_dynptr ptr; bpf_dynptr_from_mem(...); } } Here, the C compiler based on lifetime rules in the C standard would be well within in its rights to share stack storage for dynptr 'ptr' as their lifetimes do not overlap in the two distinct scopes. Currently, such an example would be rejected by the verifier, but this is too strict. Instead, we should allow reinitializing over dynptr stack slots and forget information about the old dynptr object. The destroy_if_dynptr_stack_slot function already makes necessary checks to avoid overwriting referenced dynptr slots. This is done to present a better error message instead of forgetting dynptr information on stack and preserving reference state, leading to an inevitable but undecipherable error at the end about an unreleased reference which has to be associated back to its allocating call instruction to make any sense to the user. Acked-by: -
Kumar Kartikeya Dwivedi authored
The previous commit implemented destroy_if_dynptr_stack_slot. It destroys the dynptr which given spi belongs to, but still doesn't invalidate the slices that belong to such a dynptr. While for the case of referenced dynptr, we don't allow their overwrite and return an error early, we still allow it and destroy the dynptr for unreferenced dynptr. To be able to enable precise and scoped invalidation of dynptr slices in this case, we must be able to associate the source dynptr of slices that have been obtained using bpf_dynptr_data. When doing destruction, only slices belonging to the dynptr being destructed should be invalidated, and nothing else. Currently, dynptr slices belonging to different dynptrs are indistinguishible. Hence, allocate a unique id to each dynptr (CONST_PTR_TO_DYNPTR and those on stack). This will be stored as part of reg->id. Whenever using bpf_dynptr_data, transfer this unique dynptr id to the returned PTR_TO_MEM_OR_NULL slice pointer, and store it in a new per-PTR_TO_MEM dynptr_id register state member. Finally, after establishing such a relationship between dynptrs and their slices, implement precise invalidation logic that only invalidates slices belong to the destroyed dynptr in destroy_if_dynptr_stack_slot. Acked-by:
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Kumar Kartikeya Dwivedi authored
Currently, while reads are disallowed for dynptr stack slots, writes are not. Reads don't work from both direct access and helpers, while writes do work in both cases, but have the effect of overwriting the slot_type. While this is fine, handling for a few edge cases is missing. Firstly, a user can overwrite the stack slots of dynptr partially. Consider the following layout: spi: [d][d][?] 2 1 0 First slot is at spi 2, second at spi 1. Now, do a write of 1 to 8 bytes for spi 1. This will essentially either write STACK_MISC for all slot_types or STACK_MISC and STACK_ZERO (in case of size < BPF_REG_SIZE partial write of zeroes). The end result is that slot is scrubbed. Now, the layout is: spi: [d][m][?] 2 1 0 Suppose if user initializes spi = 1 as dynptr. We get: spi: [d][d][d] 2 1 0 But this time, both spi 2 and spi 1 have first_slot = true. Now, when passing spi 2 to dynptr helper, it will consider it as initialized as it does not check whether second slot has first_slot == false. And spi 1 should already work as normal. This effectively replaced size + offset of first dynptr, hence allowing invalid OOB reads and writes. Make a few changes to protect against this: When writing to PTR_TO_STACK using BPF insns, when we touch spi of a STACK_DYNPTR type, mark both first and second slot (regardless of which slot we touch) as STACK_INVALID. Reads are already prevented. Second, prevent writing to stack memory from helpers if the range may contain any STACK_DYNPTR slots. Reads are already prevented. For helpers, we cannot allow it to destroy dynptrs from the writes as depending on arguments, helper may take uninit_mem and dynptr both at the same time. This would mean that helper may write to uninit_mem before it reads the dynptr, which would be bad. PTR_TO_MEM: [?????dd] Depending on the code inside the helper, it may end up overwriting the dynptr contents first and then read those as the dynptr argument. Verifier would only simulate destruction when it does byte by byte access simulation in check_helper_call for meta.access_size, and fail to catch this case, as it happens after argument checks. The same would need to be done for any other non-trivial objects created on the stack in the future, such as bpf_list_head on stack, or bpf_rb_root on stack. A common misunderstanding in the current code is that MEM_UNINIT means writes, but note that writes may also be performed even without MEM_UNINIT in case of helpers, in that case the code after handling meta && meta->raw_mode will complain when it sees STACK_DYNPTR. So that invalid read case also covers writes to potential STACK_DYNPTR slots. The only loophole was in case of meta->raw_mode which simulated writes through instructions which could overwrite them. A future series sequenced after this will focus on the clean up of helper access checks and bugs around that. Fixes: 97e03f52 ("bpf: Add verifier support for dynptrs") Signed-off-by: -
Kumar Kartikeya Dwivedi authored
Currently, the dynptr function is not checking the variable offset part of PTR_TO_STACK that it needs to check. The fixed offset is considered when computing the stack pointer index, but if the variable offset was not a constant (such that it could not be accumulated in reg->off), we will end up a discrepency where runtime pointer does not point to the actual stack slot we mark as STACK_DYNPTR. It is impossible to precisely track dynptr state when variable offset is not constant, hence, just like bpf_timer, kptr, bpf_spin_lock, etc. simply reject the case where reg->var_off is not constant. Then, consider both reg->off and reg->var_off.value when computing the stack pointer index. A new helper dynptr_get_spi is introduced to hide over these details since the dynptr needs to be located in multiple places outside the process_dynptr_func checks, hence once we know it's a PTR_TO_STACK, we need to enforce these checks in all places. Note that it is disallowed for unprivileged users to have a non-constant var_off, so this problem should only be possible to trigger from programs having CAP_PERFMON. However, its effects can vary. Without the fix, it is possible to replace the contents of the dynptr arbitrarily by making verifier mark different stack slots than actual location and then doing writes to the actual stack address of dynptr at runtime. Fixes: 97e03f52 ("bpf: Add verifier support for dynptrs") Acked-by:
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Kumar Kartikeya Dwivedi authored
The root of the problem is missing liveness marking for STACK_DYNPTR slots. This leads to all kinds of problems inside stacksafe. The verifier by default inside stacksafe ignores spilled_ptr in stack slots which do not have REG_LIVE_READ marks. Since this is being checked in the 'old' explored state, it must have already done clean_live_states for this old bpf_func_state. Hence, it won't be receiving any more liveness marks from to be explored insns (it has received REG_LIVE_DONE marking from liveness point of view). What this means is that verifier considers that it's safe to not compare the stack slot if was never read by children states. While liveness marks are usually propagated correctly following the parentage chain for spilled registers (SCALAR_VALUE and PTR_* types), the same is not the case for STACK_DYNPTR. clean_live_states hence simply rewrites these stack slots to the type STACK_INVALID since it sees no REG_LIVE_READ marks. The end result is that we will never see STACK_DYNPTR slots in explored state. Even if verifier was conservatively matching !REG_LIVE_READ slots, very next check continuing the stacksafe loop on seeing STACK_INVALID would again prevent further checks. Now as long as verifier stores an explored state which we can compare to when reaching a pruning point, we can abuse this bug to make verifier prune search for obviously unsafe paths using STACK_DYNPTR slots thinking they are never used hence safe. Doing this in unprivileged mode is a bit challenging. add_new_state is only set when seeing BPF_F_TEST_STATE_FREQ (which requires privileges) or when jmps_processed difference is >= 2 and insn_processed difference is >= 8. So coming up with the unprivileged case requires a little more work, but it is still totally possible. The test case being discussed below triggers the heuristic even in unprivileged mode. However, it no longer works since commit 8addbfc7 ("bpf: Gate dynptr API behind CAP_BPF"). Let's try to study the test step by step. Consider the following program (C style BPF ASM): 0 r0 = 0; 1 r6 = &ringbuf_map; 3 r1 = r6; 4 r2 = 8; 5 r3 = 0; 6 r4 = r10; 7 r4 -= -16; 8 call bpf_ringbuf_reserve_dynptr; 9 if r0 == 0 goto pc+1; 10 goto pc+1; 11 *(r10 - 16) = 0xeB9F; 12 r1 = r10; 13 r1 -= -16; 14 r2 = 0; 15 call bpf_ringbuf_discard_dynptr; 16 r0 = 0; 17 exit; We know that insn 12 will be a pruning point, hence if we force add_new_state for it, it will first verify the following path as safe in straight line exploration: 0 1 3 4 5 6 7 8 9 -> 10 -> (12) 13 14 15 16 17 Then, when we arrive at insn 12 from the following path: 0 1 3 4 5 6 7 8 9 -> 11 (12) We will find a state that has been verified as safe already at insn 12. Since register state is same at this point, regsafe will pass. Next, in stacksafe, for spi = 0 and spi = 1 (location of our dynptr) is skipped seeing !REG_LIVE_READ. The rest matches, so stacksafe returns true. Next, refsafe is also true as reference state is unchanged in both states. The states are considered equivalent and search is pruned. Hence, we are able to construct a dynptr with arbitrary contents and use the dynptr API to operate on this arbitrary pointer and arbitrary size + offset. To fix this, first define a mark_dynptr_read function that propagates liveness marks whenever a valid initialized dynptr is accessed by dynptr helpers. REG_LIVE_WRITTEN is marked whenever we initialize an uninitialized dynptr. This is done in mark_stack_slots_dynptr. It allows screening off mark_reg_read and not propagating marks upwards from that point. This ensures that we either set REG_LIVE_READ64 on both dynptr slots, or none, so clean_live_states either sets both slots to STACK_INVALID or none of them. This is the invariant the checks inside stacksafe rely on. Next, do a complete comparison of both stack slots whenever they have STACK_DYNPTR. Compare the dynptr type stored in the spilled_ptr, and also whether both form the same first_slot. Only then is the later path safe. Fixes: 97e03f52 ("bpf: Add verifier support for dynptrs") Acked-by:
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- 20 Jan, 2023 4 commits
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Alexei Starovoitov authored
Jiri Olsa says: ==================== hi, sending new version of [1] patchset posted originally by Zhen Lei. It contains 2 changes that improove search performance for livepatch and bpf. v3 changes: - fixed off by 1 issue, simplified condition, added acks [Song] - added module attach as subtest [Andrii] v2 changes: - reworked the bpf change and meassured the performance - adding new selftest to benchmark kprobe multi module attachment - skipping patch 3 as requested by Zhen Lei - added Reviewed-by for patch 1 [Petr Mladek] thanks, jirka [1] https://lore.kernel.org/bpf/20221230112729.351-1-thunder.leizhen@huawei.com/ --- Jiri Olsa (2): selftests/bpf: Add serial_test_kprobe_multi_bench_attach_kernel/module tests bpf: Change modules resolving for kprobe multi link ==================== Signed-off-by:
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Jiri Olsa authored
We currently use module_kallsyms_on_each_symbol that iterates all modules/symbols and we try to lookup each such address in user provided symbols/addresses to get list of used modules. This fix instead only iterates provided kprobe addresses and calls __module_address on each to get list of used modules. This turned out to be simpler and also bit faster. On my setup with workload (executed 10 times): # test_progs -t kprobe_multi_bench_attach/modules Current code: Performance counter stats for './test.sh' (5 runs): 76,081,161,596 cycles:k ( +- 0.47% ) 18.3867 +- 0.0992 seconds time elapsed ( +- 0.54% ) With the fix: Performance counter stats for './test.sh' (5 runs): 74,079,889,063 cycles:k ( +- 0.04% ) 17.8514 +- 0.0218 seconds time elapsed ( +- 0.12% ) Signed-off-by:Jiri Olsa <jolsa@kernel.org> Reviewed-by:
Zhen Lei <thunder.leizhen@huawei.com> Reviewed-by:
Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20230116101009.23694-4-jolsa@kernel.orgSigned-off-by:
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Jiri Olsa authored
Add bench test for module portion of the symbols as well. # ./test_progs -v -t kprobe_multi_bench_attach_module bpf_testmod.ko is already unloaded. Loading bpf_testmod.ko... Successfully loaded bpf_testmod.ko. test_kprobe_multi_bench_attach:PASS:get_syms 0 nsec test_kprobe_multi_bench_attach:PASS:kprobe_multi_empty__open_and_load 0 nsec test_kprobe_multi_bench_attach:PASS:bpf_program__attach_kprobe_multi_opts 0 nsec test_kprobe_multi_bench_attach: found 26620 functions test_kprobe_multi_bench_attach: attached in 0.182s test_kprobe_multi_bench_attach: detached in 0.082s #96 kprobe_multi_bench_attach_module:OK Summary: 1/0 PASSED, 0 SKIPPED, 0 FAILED Successfully unloaded bpf_testmod.ko. It's useful for testing kprobe multi link modules resolving. Acked-by:
Song Liu <song@kernel.org> Signed-off-by:
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Zhen Lei authored
Currently we traverse all symbols of all modules to find the specified function for the specified module. But in reality, we just need to find the given module and then traverse all the symbols in it. Let's add a new parameter 'const char *modname' to function module_kallsyms_on_each_symbol(), then we can compare the module names directly in this function and call hook 'fn' after matching. If 'modname' is NULL, the symbols of all modules are still traversed for compatibility with other usage cases. Phase1: mod1-->mod2..(subsequent modules do not need to be compared) | Phase2: -->f1-->f2-->f3 Assuming that there are m modules, each module has n symbols on average, then the time complexity is reduced from O(m * n) to O(m) + O(n). Reviewed-by:Miroslav Benes <mbenes@suse.cz> Reviewed-by:
Luis Chamberlain <mcgrof@kernel.org> Link: https://lore.kernel.org/r/20230116101009.23694-2-jolsa@kernel.orgSigned-off-by:
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- 18 Jan, 2023 3 commits
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Tiezhu Yang authored
If CONFIG_NF_CONNTRACK=m, there are no definitions of NF_NAT_MANIP_SRC and NF_NAT_MANIP_DST in vmlinux.h, build test_bpf_nf.c failed. $ make -C tools/testing/selftests/bpf/ CLNG-BPF [test_maps] test_bpf_nf.bpf.o progs/test_bpf_nf.c:160:42: error: use of undeclared identifier 'NF_NAT_MANIP_SRC' bpf_ct_set_nat_info(ct, &saddr, sport, NF_NAT_MANIP_SRC); ^ progs/test_bpf_nf.c:163:42: error: use of undeclared identifier 'NF_NAT_MANIP_DST' bpf_ct_set_nat_info(ct, &daddr, dport, NF_NAT_MANIP_DST); ^ 2 errors generated. Copy the definitions in include/net/netfilter/nf_nat.h to test_bpf_nf.c, in order to avoid redefinitions if CONFIG_NF_CONNTRACK=y, rename them with ___local suffix. This is similar with commit 1058b6a7 ("selftests/bpf: Do not fail build if CONFIG_NF_CONNTRACK=m/n"). Fixes: b06b45e8 ("selftests/bpf: add tests for bpf_ct_set_nat_info kfunc") Signed-off-by:Tiezhu Yang <yangtiezhu@loongson.cn> Acked-by:
Martin KaFai Lau <martin.lau@kernel.org>
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Jiri Olsa authored
Adding verifier tests for loading all types od allowed sleepable programs plus reject for tp_btf type. Acked-by:
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Jiri Olsa authored
Currently we allow to load any tracing program as sleepable, but BPF_TRACE_RAW_TP can't sleep. Making the check explicit for tracing programs attach types, so sleepable BPF_TRACE_RAW_TP will fail to load. Updating the verifier error to mention iter programs as well. Acked-by:
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- 17 Jan, 2023 1 commit
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Martin Rodriguez Reboredo authored
Version 1.24 of pahole has the capability to exclude compilation units (CUs) of specific languages [1] [2]. Rust, as of writing, is not currently supported by pahole and if it's used with a build that has BTF debugging enabled it results in malformed kernel and module binaries [3]. So it's better for pahole to exclude Rust CUs until support for it arrives. Co-developed-by:
Eric Curtin <ecurtin@redhat.com> Signed-off-by:
Martin Rodriguez Reboredo <yakoyoku@gmail.com> Signed-off-by:
Daniel Borkmann <daniel@iogearbox.net> Tested-by:
Neal Gompa <neal@gompa.dev> Acked-by:
Miguel Ojeda <ojeda@kernel.org> Acked-by:
Arnaldo Carvalho de Melo <acme@redhat.com> Link: https://git.kernel.org/pub/scm/devel/pahole/pahole.git/commit/?id=49358dfe2aaae4e90b072332c3e324019826783f [1] Link: https://git.kernel.org/pub/scm/devel/pahole/pahole.git/commit/?id=8ee363790b7437283c53090a85a9fec2f0b0fbc4 [2] Link: https://github.com/Rust-for-Linux/linux/issues/735 [3] Link: https://lore.kernel.org/bpf/20230111152050.559334-1-yakoyoku@gmail.com
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- 15 Jan, 2023 14 commits
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Alexei Starovoitov authored
"Daniel T. Lee" says: ==================== Currently, there are many programs under samples/bpf to test the various functionality of BPF that have been developed for a long time. However, the kernel (BPF) has changed a lot compared to the 2016 when some of these test programs were first introduced. Therefore, some of these programs use the deprecated function of BPF, and some programs no longer work normally due to changes in the API. To list some of the kernel changes that this patch set is focusing on, - legacy BPF map declaration syntax support had been dropped [1] - bpf_trace_printk() always append newline at the end [2] - deprecated styled BPF section header (bpf_load style) [3] - urandom_read tracepoint is removed (used for testing overhead) [4] - ping sends packet with SOCK_DGRAM instead of SOCK_RAW [5]* - use "vmlinux.h" instead of including individual headers In addition to this, this patchset tries to modernize the existing testing scripts a bit. And for network-related testing programs, a separate header file was created and applied. (To use the Endianness conversion function from xdp_sample and bunch of constants) [1]: https://github.com/libbpf/libbpf/issues/282 [2]: commit ac5a72ea ("bpf: Use dedicated bpf_trace_printk event instead of trace_printk()") [3]: commit ceb5dea5 ("samples: bpf: Remove bpf_load loader completely") [4]: commit 14c17463 ("random: remove unused tracepoints") [5]: https://lwn.net/Articles/422330/ *: This is quite old, but I'm not sure why the code was initially developed to filter only SOCK_RAW. ==================== Signed-off-by:
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Daniel T. Lee authored
This commit changes the _kern suffix to .bpf with the BPF test programs. With this modification, test programs will inherit the benefit of the new CLANG-BPF compile target. Signed-off-by:
Daniel T. Lee <danieltimlee@gmail.com> Link: https://lore.kernel.org/r/20230115071613.125791-11-danieltimlee@gmail.comSigned-off-by:
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Daniel T. Lee authored
This commit applies vmlinux.h to BPF functionality testing program. Macros that were not defined despite migration to "vmlinux.h" were defined separately in individual files. Signed-off-by:
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Daniel T. Lee authored
This commit applies "net_shared.h" to BPF programs to remove existing network related header dependencies. Also, this commit removes unnecessary headers before applying "vmlinux.h" to the BPF programs. Mostly, endianness conversion function has been applied to the source. In addition, several macros have been defined to fulfill the INET, TC-related constants. Signed-off-by:
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Daniel T. Lee authored
Currently, many programs under sample/bpf often include individual macros by directly including the header under "linux/" rather than using the "vmlinux.h" header. However, there are some problems with migrating to "vmlinux.h" because there is no definition for utility functions such as endianness conversion (ntohs/htons). Fortunately, the xdp_sample program already has a function that can be replaced to solve this problem. Therefore, this commit attempts to separate these functions into a file called net_shared.h to make them universally available. Additionally, this file includes network-related macros that are not defined in "vmlinux.h". (inspired by 'selftests' bpf_tracing_net.h) Signed-off-by:
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Daniel T. Lee authored
With libbpf 1.0 release, support for legacy BPF map declaration syntax had been dropped. If you run a program using legacy BPF in the latest libbpf, the following error will be output. libbpf: map 'lwt_len_hist_map' (legacy): legacy map definitions are deprecated, use BTF-defined maps instead libbpf: Use of BPF_ANNOTATE_KV_PAIR is deprecated, use BTF-defined maps in .maps section instead This commit replaces legacy map with the BTF-defined map. Signed-off-by: -
Daniel T. Lee authored
The test_overhead bpf program is designed to compare performance between tracepoint and kprobe. Initially it used task_rename and urandom_read tracepoint. However, commit 14c17463 ("random: remove unused tracepoints") removed urandom_read tracepoint, and for this reason the test_overhead got broken. This commit introduces new microbenchmark using fib_table_lookup. This microbenchmark sends UDP packets to localhost in order to invoke fib_table_lookup. In a nutshell: fd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP); addr.sin_addr.s_addr = inet_addr(DUMMY_IP); addr.sin_port = htons(DUMMY_PORT); for() { sendto(fd, buf, strlen(buf), 0, (struct sockaddr *)&addr, sizeof(addr)); } on 4 cpus in parallel: lookup per sec base (no tracepoints, no kprobes) 381k with kprobe at fib_table_lookup() 325k with tracepoint at fib:fib_table_lookup 330k with raw_tracepoint at fib:fib_table_lookup 365k Fixes: 14c17463 ("random: remove unused tracepoints") Signed-off-by:
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Daniel T. Lee authored
Currently, executing test_cgrp2_sock2 fails due to wrong section header. This 'cgroup/sock1' style section is previously used at 'samples/bpf_load' (deprecated) BPF loader. Because this style isn't supported in libbpf, this commit fixes this problem by correcting the section header. $ sudo ./test_cgrp2_sock2.sh libbpf: prog 'bpf_prog1': missing BPF prog type, check ELF section name 'cgroup/sock1' libbpf: prog 'bpf_prog1': failed to load: -22 libbpf: failed to load object './sock_flags_kern.o' ERROR: loading BPF object file failed In addition, this BPF program filters ping packets by comparing whether the socket type uses SOCK_RAW. However, after the ICMP socket[1] was developed, ping sends ICMP packets using SOCK_DGRAM. Therefore, in this commit, the packet filtering is changed to use SOCK_DGRAM instead of SOCK_RAW. $ strace --trace socket ping -6 -c1 -w1 ::1 socket(AF_INET6, SOCK_DGRAM, IPPROTO_ICMPV6) = 3 [1]: https://lwn.net/Articles/422330/Signed-off-by: -
Daniel T. Lee authored
The test_lwt_bpf is a script that tests the functionality of BPF through the output of the ftrace with bpf_trace_printk. Currently, this program is not operating normally for several reasons. First of all, this test script can't parse the ftrace results properly. GNU sed tries to be as greedy as possible when attempting pattern matching. Due to this, cutting metadata (such as timestamp) from the log entry of ftrace doesn't work properly, and also desired log isn't extracted properly. To make sed stripping clearer, 'nocontext-info' option with the ftrace has been used to remove metadata from the log. Also, instead of using unclear pattern matching, this commit specifies an explicit parse pattern. Also, unlike before when this test was introduced, the way bpf_trace_printk behaves has changed[1]. The previous bpf_trace_printk had to always have '\n' in order to print newline, but now that the bpf_trace_printk call includes newline by default, so '\n' is no longer needed. Lastly with the lwt ENCAP_BPF out, the context information with the sk_buff protocol is preserved. Therefore, this commit changes the previous test result from 'protocol 0' to 'protocol 8', which means ETH_P_IP. [1]: commit ac5a72ea ("bpf: Use dedicated bpf_trace_printk event instead of trace_printk()") Signed-off-by:
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Daniel T. Lee authored
Currently, some test scripts are experiencing minor errors related to executing tests. $ sudo ./test_cgrp2_sock.sh ./test_cgrp2_sock.sh: 22: test_cgrp2_sock: not found This problem occurs because the path to the execution target is not properly specified. Therefore, this commit solves this problem by specifying a relative path to its executables. This commit also makes a concise refactoring of hard-coded BPF program names. Signed-off-by: -
Daniel T. Lee authored
Currently, a few of BPF tests use ipv6 functionality. The problem here is that if ipv6 is disabled, these tests will fail, and even if the test fails, it will not tell you why it failed. $ sudo ./test_cgrp2_sock2.sh RTNETLINK answers: Permission denied In order to fix this, this commit ensures ipv6 is enabled prior to running tests. Signed-off-by: -
Martin KaFai Lau authored
Ziyang Xuan says: ==================== Add ipip6 and ip6ip decap support for bpf_skb_adjust_room(). Main use case is for using cls_bpf on ingress hook to decapsulate IPv4 over IPv6 and IPv6 over IPv4 tunnel packets. And add ipip6 and ip6ip decap testcases to verify that bpf_skb_adjust_room() correctly decapsulate ipip6 and ip6ip tunnel packets. $./test_tc_tunnel.sh ipip encap 192.168.1.1 to 192.168.1.2, type ipip, mac none len 100 test basic connectivity 0 test bpf encap without decap (expect failure) Ncat: TIMEOUT. 1 test bpf encap with tunnel device decap 0 test bpf encap with bpf decap 0 OK ipip6 encap 192.168.1.1 to 192.168.1.2, type ipip6, mac none len 100 test basic connectivity 0 test bpf encap without decap (expect failure) Ncat: TIMEOUT. 1 test bpf encap with tunnel device decap 0 test bpf encap with bpf decap 0 OK ip6ip6 encap fd::1 to fd::2, type ip6tnl, mac none len 100 test basic connectivity 0 test bpf encap without decap (expect failure) Ncat: TIMEOUT. 1 test bpf encap with tunnel device decap 0 test bpf encap with bpf decap 0 OK sit encap fd::1 to fd::2, type sit, mac none len 100 test basic connectivity 0 test bpf encap without decap (expect failure) Ncat: TIMEOUT. 1 test bpf encap with tunnel device decap 0 test bpf encap with bpf decap 0 OK ... OK. All tests passed v3: - Fix compilation failure of selftests/bpf. - Combine two new branches in bpf_skb_adjust_room(). - Simplify description for new flags BPF_F_ADJ_ROOM_DECAP_L3_IP*. v2: - Use decap flags to indicate the new IP header. Do not rely on skb->encapsulation. ==================== Signed-off-by: -
Ziyang Xuan authored
Add ipip6 and ip6ip decap testcases. Verify that bpf_skb_adjust_room() correctly decapsulate ipip6 and ip6ip tunnel packets. Signed-off-by:
Ziyang Xuan <william.xuanziyang@huawei.com> Reviewed-by:
Willem de Bruijn <willemb@google.com> Link: https://lore.kernel.org/r/dfd2d8cfdf9111bd129170d4345296f53bee6a67.1673574419.git.william.xuanziyang@huawei.comSigned-off-by:
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Ziyang Xuan authored
Add ipip6 and ip6ip decap support for bpf_skb_adjust_room(). Main use case is for using cls_bpf on ingress hook to decapsulate IPv4 over IPv6 and IPv6 over IPv4 tunnel packets. Add two new flags BPF_F_ADJ_ROOM_DECAP_L3_IPV{4,6} to indicate the new IP header version after decapsulating the outer IP header. Suggested-by:
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- 13 Jan, 2023 3 commits
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Roberto Valenzuela authored
Add the missing space after 'dest' variable assignment. This change will resolve the following checkpatch.pl script error: ERROR: spaces required around that '+=' (ctx:VxW) Signed-off-by:
Roberto Valenzuela <valenzuelarober@gmail.com> Signed-off-by:
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Menglong Dong authored
'.' is not allowed in the event name of kprobe. Therefore, we will get a EINVAL if the kernel function name has a '.' in legacy kprobe attach case, such as 'icmp_reply.constprop.0'. In order to adapt this case, we need to replace the '.' with other char in gen_kprobe_legacy_event_name(). And I use '_' for this propose. Signed-off-by:
Menglong Dong <imagedong@tencent.com> Signed-off-by:
Alan Maguire <alan.maguire@oracle.com> Link: https://lore.kernel.org/bpf/20230113093427.1666466-1-imagedong@tencent.com
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Holger Hoffstätte authored
When the clang toolchain has stack protection enabled in order to be consistent with gcc - which just happens to be the case on Gentoo - the bpftool build fails: [...] clang \ -I. \ -I/tmp/portage/dev-util/bpftool-6.0.12/work/linux-6.0/tools/include/uapi/ \ -I/tmp/portage/dev-util/bpftool-6.0.12/work/linux-6.0/tools/bpf/bpftool/bootstrap/libbpf/include \ -g -O2 -Wall -target bpf -c skeleton/pid_iter.bpf.c -o pid_iter.bpf.o clang \ -I. \ -I/tmp/portage/dev-util/bpftool-6.0.12/work/linux-6.0/tools/include/uapi/ \ -I/tmp/portage/dev-util/bpftool-6.0.12/work/linux-6.0/tools/bpf/bpftool/bootstrap/libbpf/include \ -g -O2 -Wall -target bpf -c skeleton/profiler.bpf.c -o profiler.bpf.o skeleton/profiler.bpf.c:40:14: error: A call to built-in function '__stack_chk_fail' is not supported. int BPF_PROG(fentry_XXX) ^ skeleton/profiler.bpf.c:94:14: error: A call to built-in function '__stack_chk_fail' is not supported. int BPF_PROG(fexit_XXX) ^ 2 errors generated. [...] Since stack-protector makes no sense for the BPF bits just unconditionally disable it. Bug: https://bugs.gentoo.org/890638Signed-off-by:Holger Hoffstätte <holger@applied-asynchrony.com> Signed-off-by:
Quentin Monnet <quentin@isovalent.com> Link: https://lore.kernel.org/bpf/74cd9d2e-6052-312a-241e-2b514a75c92c@applied-asynchrony.com
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- 12 Jan, 2023 2 commits
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Alexei Starovoitov authored
Magnus Karlsson says: ==================== This is a patch set of various performance improvements, fixes, and the introduction of more than one XDP program to the xsk selftests framework so we can test more things in the future such as upcoming multi-buffer and metadata support for AF_XDP. The new programs just reuse the framework that all the other eBPF selftests use. The new feature is used to implement one new test that does XDP_DROP on every other packet. More tests using this will be added in future commits. Contents: * The run-time of the test suite is cut by 10x when executing the tests on a real NIC, by only attaching the XDP program once per mode tested, instead of once per test program. * Over 700 lines of code have been removed. The xsk.c control file was moved straight over from libbpf when the xsk support was deprecated there. As it is now not used as library code that has to work with all kinds of versions of Linux, a lot of code could be dropped or simplified. * Add a new command line option "-d" that can be used when a test fails and you want to debug it with gdb or some other debugger. The option creates the two veth netdevs and prints them to the screen without deleting them afterwards. This way these veth netdevs can be used when running xskxceiver in a debugger. * Implemented the possibility to load external XDP programs so we can have more than the default one. This feature is used to implement a test where every other packet is dropped. Good exercise for the recycling mechanism of the xsk buffer pool used in zero-copy mode. * Various clean-ups and small fixes in patches 1 to 5. None of these fixes has any impact on the correct execution of the tests when they pass, though they can be irritating when a test fails. IMHO, they do not need to go to bpf as they will not fix anything there. The first version of patches 1, 2, and 4 where previously sent to bpf, but has now been included here. v2 -> v3: * Fixed compilation error for llvm [David] * Made the function xsk_is_in_drv_mode(ifobj) more generic by changing it to xsk_is_in_mode(ifobj, xdp_mode) [Maciej] * Added Maciej's acks to all the patches v1 -> v2: * Fixed spelling error in commit message of patch #6 [Björn] * Added explanation on why it is safe to use C11 atomics in patch #7 [Daniel] * Put all XDP programs in the same file so that adding more XDP programs to xskxceiver.c becomes more scalable in patches #11 and #12 [Maciej] * Removed more dead code in patch #8 [Maciej] * Removed stale %s specifier in error print, patch #9 [Maciej] * Changed name of XDP_CONSUMES_SOME_PACKETS to XDP_DROP_HALF to hopefully make it clearer [Maciej] * ifobj_rx and ifobj_tx name changes in patch #13 [Maciej] * Simplified XDP attachment code in patch #15 [Maciej] Patches: 1-5: Small fixes and clean-ups 6: New convenient debug option when using a debugger such as gdb 7-8: Removal of unnecessary code 9: Add the ability to load external XDP programs 10-11: Removal of more unnecessary code 12: Implement a new test where every other packet is XDP_DROP:ed 13: Unify the thread dispatching code 14-15: Simplify the way tests are written when using custom packet_streams or custom XDP programs Thanks: Magnus ==================== Signed-off-by: -
Magnus Karlsson authored
Implement automatic switching of XDP programs and execution modes if needed by a test. This makes it much simpler to write a test as it only has to say what XDP program it needs if it is not the default one. This also makes it possible to remove the initial explicit attachment of the XDP program as well as the explicit mode switch in the code. These are now handled by the same code that just checks if a switch is necessary, so no special cases are needed. The default XDP program for all tests is one that sends all packets to the AF_XDP socket. If you need another one, please use the new function test_spec_set_xdp_prog() to specify what XDP programs and maps to use for this test. Signed-off-by:
Magnus Karlsson <magnus.karlsson@intel.com> Acked-by:
Maciej Fijalkowski <maciej.fijalkowski@intel.com> Link: https://lore.kernel.org/r/20230111093526.11682-16-magnus.karlsson@gmail.comSigned-off-by:
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