- 17 Feb, 2023 15 commits
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Martin KaFai Lau authored
This patch tests the bpf_fib_lookup helper when looking up a neigh in NUD_FAILED and NUD_STALE state. It also adds test for the new BPF_FIB_LOOKUP_SKIP_NEIGH flag. Signed-off-by:
Martin KaFai Lau <martin.lau@kernel.org> Signed-off-by:
Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20230217205515.3583372-2-martin.lau@linux.dev
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Martin KaFai Lau authored
The bpf_fib_lookup() also looks up the neigh table. This was done before bpf_redirect_neigh() was added. In the use case that does not manage the neigh table and requires bpf_fib_lookup() to lookup a fib to decide if it needs to redirect or not, the bpf prog can depend only on using bpf_redirect_neigh() to lookup the neigh. It also keeps the neigh entries fresh and connected. This patch adds a bpf_fib_lookup flag, SKIP_NEIGH, to avoid the double neigh lookup when the bpf prog always call bpf_redirect_neigh() to do the neigh lookup. The params->smac output is skipped together when SKIP_NEIGH is set because bpf_redirect_neigh() will figure out the smac also. Signed-off-by:
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Pu Lehui authored
BPF trampoline is the critical infrastructure of the BPF subsystem, acting as a mediator between kernel functions and BPF programs. Numerous important features, such as using BPF program for zero overhead kernel introspection, rely on this key component. We can't wait to support bpf trampoline on RV64. The related tests have passed, as well as the test_verifier with no new failure ceses. Signed-off-by:
Pu Lehui <pulehui@huawei.com> Signed-off-by:
Björn Töpel <bjorn@rivosinc.com> Acked-by:
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Pu Lehui authored
Implement bpf_arch_text_poke for RV64. For call scenario, to make BPF trampoline compatible with the kernel and BPF context, we follow the framework of RV64 ftrace to reserve 4 nops for BPF programs as function entry, and use auipc+jalr instructions for function call. However, since auipc+jalr call instruction is non-atomic operation, we need to use stop-machine to make sure instructions patching in atomic context. Also, we use auipc+jalr pair and need to patch in stop-machine context for jump scenario. Signed-off-by:
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Pu Lehui authored
The current emit_call function is not suitable for kernel function call as it store return value to bpf R0 register. We can separate it out for common use. Meanwhile, simplify judgment logic, that is, fixed function address can use jal or auipc+jalr, while the unfixed can use only auipc+jalr. Signed-off-by:
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Pu Lehui authored
Extend patch_text for multiple instructions. This is the preparaiton for multiple instructions text patching in riscv BPF trampoline, and may be useful for other scenario. Signed-off-by:
Conor Dooley <conor.dooley@microchip.com> Acked-by:
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Martin KaFai Lau authored
This reverts commit 6c20822f. build bot failed on arch with different cache line size: https://lore.kernel.org/bpf/50c35055-afa9-d01e-9a05-ea5351280e4f@intel.com/Signed-off-by:
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Andrii Nakryiko authored
Add tests validating that it's possible to pass context arguments into global subprogs for various types of programs, including a particularly tricky KPROBE programs (which cover kprobes, uprobes, USDTs, a vast and important class of programs). Signed-off-by:
Andrii Nakryiko <andrii@kernel.org> Signed-off-by:
Stanislav Fomichev <sdf@google.com> Link: https://lore.kernel.org/bpf/20230216045954.3002473-4-andrii@kernel.org
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Andrii Nakryiko authored
Convert 17 test_global_funcs subtests into test_loader framework for easier maintenance and more declarative way to define expected failures/successes. Signed-off-by:
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Andrii Nakryiko authored
KPROBE program's user-facing context type is defined as typedef bpf_user_pt_regs_t. This leads to a problem when trying to passing kprobe/uprobe/usdt context argument into global subprog, as kernel always strip away mods and typedefs of user-supplied type, but takes expected type from bpf_ctx_convert as is, which causes mismatch. Current way to work around this is to define a fake struct with the same name as expected typedef: struct bpf_user_pt_regs_t {}; __noinline my_global_subprog(struct bpf_user_pt_regs_t *ctx) { ... } This patch fixes the issue by resolving expected type, if it's not a struct. It still leaves the above work-around working for backwards compatibility. Fixes: 91cc1a99 ("bpf: Annotate context types") Signed-off-by: -
Hengqi Chen authored
This patch fixes the following issue of function calls in JIT, like: [ 29.346981] multi-func JIT bug 105 != 103 The issus can be reproduced by running the "inline simple bpf_loop call" verifier test. This is because we are emiting 2-4 instructions for 64-bit immediate moves. During the first pass of JIT, the placeholder address is zero, emiting two instructions for it. In the extra pass, the function address is in XKVRANGE, emiting four instructions for it. This change the instruction index in JIT context. Let's always use 4 instructions for function address in JIT. So that the instruction sequences don't change between the first pass and the extra pass for function calls. Fixes: 5dc61552 ("LoongArch: Add BPF JIT support") Signed-off-by:
Hengqi Chen <hengqi.chen@gmail.com> Signed-off-by:
Tiezhu Yang <yangtiezhu@loongson.cn> Link: https://lore.kernel.org/bpf/20230214152633.2265699-1-hengqi.chen@gmail.com
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Martin KaFai Lau authored
The bpf_fib_lookup() helper does not only look up the fib (ie. route) but it also looks up the neigh. Before returning the neigh, the helper does not check for NUD_VALID. When a neigh state (neigh->nud_state) is in NUD_FAILED, its dmac (neigh->ha) could be all zeros. The helper still returns SUCCESS instead of NO_NEIGH in this case. Because of the SUCCESS return value, the bpf prog directly uses the returned dmac and ends up filling all zero in the eth header. This patch checks for NUD_VALID and returns NO_NEIGH if the neigh is not valid. Signed-off-by:
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Martin KaFai Lau authored
Some of the bpf helpers require bh disabled. eg. The bpf_fib_lookup helper that will be used in a latter selftest. In particular, it calls ___neigh_lookup_noref that expects the bh disabled. This patch disables bh before calling bpf_prog_run[_xdp], so the testing prog can also use those helpers. Signed-off-by:
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Maciej Fijalkowski authored
Xsk Tx can be triggered via either sendmsg() or poll() syscalls. These two paths share a call to common function xsk_xmit() which has two sanity checks within. A pseudo code example to show the two paths: __xsk_sendmsg() : xsk_poll(): if (unlikely(!xsk_is_bound(xs))) if (unlikely(!xsk_is_bound(xs))) return -ENXIO; return mask; if (unlikely(need_wait)) (...) return -EOPNOTSUPP; xsk_xmit() mark napi id (...) xsk_xmit() xsk_xmit(): if (unlikely(!(xs->dev->flags & IFF_UP))) return -ENETDOWN; if (unlikely(!xs->tx)) return -ENOBUFS; As it can be observed above, in sendmsg() napi id can be marked on interface that was not brought up and this causes a NULL ptr dereference: [31757.505631] BUG: kernel NULL pointer dereference, address: 0000000000000018 [31757.512710] #PF: supervisor read access in kernel mode [31757.517936] #PF: error_code(0x0000) - not-present page [31757.523149] PGD 0 P4D 0 [31757.525726] Oops: 0000 [#1] PREEMPT SMP NOPTI [31757.530154] CPU: 26 PID: 95641 Comm: xdpsock Not tainted 6.2.0-rc5+ #40 [31757.536871] Hardware name: Intel Corporation S2600WFT/S2600WFT, BIOS SE5C620.86B.02.01.0008.031920191559 03/19/2019 [31757.547457] RIP: 0010:xsk_sendmsg+0xde/0x180 [31757.551799] Code: 00 75 a2 48 8b 00 a8 04 75 9b 84 d2 74 69 8b 85 14 01 00 00 85 c0 75 1b 48 8b 85 28 03 00 00 48 8b 80 98 00 00 00 48 8b 40 20 <8b> 40 18 89 85 14 01 00 00 8b bd 14 01 00 00 81 ff 00 01 00 00 0f [31757.570840] RSP: 0018:ffffc90034f27dc0 EFLAGS: 00010246 [31757.576143] RAX: 0000000000000000 RBX: ffffc90034f27e18 RCX: 0000000000000000 [31757.583389] RDX: 0000000000000001 RSI: ffffc90034f27e18 RDI: ffff88984cf3c100 [31757.590631] RBP: ffff88984714a800 R08: ffff88984714a800 R09: 0000000000000000 [31757.597877] R10: 0000000000000001 R11: 0000000000000000 R12: 00000000fffffffa [31757.605123] R13: 0000000000000000 R14: 0000000000000003 R15: 0000000000000000 [31757.612364] FS: 00007fb4c5931180(0000) GS:ffff88afdfa00000(0000) knlGS:0000000000000000 [31757.620571] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [31757.626406] CR2: 0000000000000018 CR3: 000000184b41c003 CR4: 00000000007706e0 [31757.633648] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [31757.640894] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [31757.648139] PKRU: 55555554 [31757.650894] Call Trace: [31757.653385] <TASK> [31757.655524] sock_sendmsg+0x8f/0xa0 [31757.659077] ? sockfd_lookup_light+0x12/0x70 [31757.663416] __sys_sendto+0xfc/0x170 [31757.667051] ? do_sched_setscheduler+0xdb/0x1b0 [31757.671658] __x64_sys_sendto+0x20/0x30 [31757.675557] do_syscall_64+0x38/0x90 [31757.679197] entry_SYSCALL_64_after_hwframe+0x72/0xdc [31757.687969] Code: 8e f6 ff 44 8b 4c 24 2c 4c 8b 44 24 20 41 89 c4 44 8b 54 24 28 48 8b 54 24 18 b8 2c 00 00 00 48 8b 74 24 10 8b 7c 24 08 0f 05 <48> 3d 00 f0 ff ff 77 3a 44 89 e7 48 89 44 24 08 e8 b5 8e f6 ff 48 [31757.707007] RSP: 002b:00007ffd49c73c70 EFLAGS: 00000293 ORIG_RAX: 000000000000002c [31757.714694] RAX: ffffffffffffffda RBX: 000055a996565380 RCX: 00007fb4c5727c16 [31757.721939] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003 [31757.729184] RBP: 0000000000000040 R08: 0000000000000000 R09: 0000000000000000 [31757.736429] R10: 0000000000000040 R11: 0000000000000293 R12: 0000000000000000 [31757.743673] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 [31757.754940] </TASK> To fix this, let's make xsk_xmit a function that will be responsible for generic Tx, where RCU is handled accordingly and pull out sanity checks and xs->zc handling. Populate sanity checks to __xsk_sendmsg() and xsk_poll(). Fixes: ca2e1a62 ("xsk: Mark napi_id on sendmsg()") Fixes: 18b1ab7a ("xsk: Fix race at socket teardown") Signed-off-by:Maciej Fijalkowski <maciej.fijalkowski@intel.com> Reviewed-by:
Alexander Lobakin <aleksander.lobakin@intel.com> Link: https://lore.kernel.org/r/20230215143309.13145-1-maciej.fijalkowski@intel.comSigned-off-by:
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Taichi Nishimura authored
Run spell checker on files in selftest/bpf and fixed typos. Signed-off-by:
Taichi Nishimura <awkrail01@gmail.com> Signed-off-by:
Randy Dunlap <rdunlap@infradead.org> Link: https://lore.kernel.org/bpf/20230216085537.519062-1-awkrail01@gmail.com
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- 16 Feb, 2023 14 commits
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Ilya Leoshkevich authored
Use the new type-safe wrappers around bpf_obj_get_info_by_fd(). Fix a prog/map mixup in prog_holds_map(). Signed-off-by:
Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by:
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Ilya Leoshkevich authored
Use the new type-safe wrappers around bpf_obj_get_info_by_fd(). Signed-off-by:
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Ilya Leoshkevich authored
Use the new type-safe wrappers around bpf_obj_get_info_by_fd(). Split the bpf_obj_get_info_by_fd() call in build_btf_type_table() in two, since knowing the type helps with the Memory Sanitizer. Improve map_parse_fd_and_info() type safety by using struct bpf_map_info * instead of void * for info. Signed-off-by:
Quentin Monnet <quentin@isovalent.com> Link: https://lore.kernel.org/bpf/20230214231221.249277-4-iii@linux.ibm.com
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Ilya Leoshkevich authored
Use the new type-safe wrappers around bpf_obj_get_info_by_fd(). Signed-off-by:
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Ilya Leoshkevich authored
These are type-safe wrappers around bpf_obj_get_info_by_fd(). They found one problem in selftests, and are also useful for adding Memory Sanitizer annotations. Signed-off-by:
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Alexander Lobakin authored
&xdp_buff and &xdp_frame are bound in a way that xdp_buff->data_hard_start == xdp_frame It's always the case and e.g. xdp_convert_buff_to_frame() relies on this. IOW, the following: for (u32 i = 0; i < 0xdead; i++) { xdpf = xdp_convert_buff_to_frame(&xdp); xdp_convert_frame_to_buff(xdpf, &xdp); } shouldn't ever modify @xdpf's contents or the pointer itself. However, "live packet" code wrongly treats &xdp_frame as part of its context placed *before* the data_hard_start. With such flow, data_hard_start is sizeof(*xdpf) off to the right and no longer points to the XDP frame. Instead of replacing `sizeof(ctx)` with `offsetof(ctx, xdpf)` in several places and praying that there are no more miscalcs left somewhere in the code, unionize ::frm with ::data in a flex array, so that both starts pointing to the actual data_hard_start and the XDP frame actually starts being a part of it, i.e. a part of the headroom, not the context. A nice side effect is that the maximum frame size for this mode gets increased by 40 bytes, as xdp_buff::frame_sz includes everything from data_hard_start (-> includes xdpf already) to the end of XDP/skb shared info. Also update %MAX_PKT_SIZE accordingly in the selftests code. Leave it hardcoded for 64 bit && 4k pages, it can be made more flexible later on. Minor: align `&head->data` with how `head->frm` is assigned for consistency. Minor #2: rename 'frm' to 'frame' in &xdp_page_head while at it for clarity. (was found while testing XDP traffic generator on ice, which calls xdp_convert_frame_to_buff() for each XDP frame) Fixes: b530e9e1 ("bpf: Add "live packet" mode for XDP in BPF_PROG_RUN") Acked-by:Toke Høiland-Jørgensen <toke@redhat.com> Signed-off-by:
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Andrii Nakryiko authored
Anton Protopopov says: ==================== Add a new benchmark for hashmap lookups and fix several typos. In commit 3 I've patched the bench utility so that now command line options can be reused by different benchmarks. The benchmark itself is added in the last commit 7. I was using this benchmark to test map lookup productivity when using a different hash function [1]. When run with --quiet, the results can be easily plotted [2]. The results provided by the benchmark look reasonable and match the results of my different benchmarks (requiring to patch kernel to get actual statistics on map lookups). Links: [1] https://fosdem.org/2023/schedule/event/bpf_hashing/ [2] https://github.com/aspsk/bpf-bench/tree/master/hashmap-bench Changes, v1->v2: - percpu_times_index[] is of wrong size (Martin) - use base 0 for strtol (Andrii) - just use -q without argument (Andrii) - use less hacks when parsing arguments (Andrii) ==================== Signed-off-by:
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Anton Protopopov authored
Add a new benchmark which measures hashmap lookup operations speed. A user can control the following parameters of the benchmark: * key_size (max 1024): the key size to use * max_entries: the hashmap max entries * nr_entries: the number of entries to insert/lookup * nr_loops: the number of loops for the benchmark * map_flags The hashmap flags passed to BPF_MAP_CREATE The BPF program performing the benchmarks calls two nested bpf_loop: bpf_loop(nr_loops/nr_entries) bpf_loop(nr_entries) bpf_map_lookup() So the nr_loops determines the number of actual map lookups. All lookups are successful. Example (the output is generated on a AMD Ryzen 9 3950X machine): for nr_entries in `seq 4096 4096 65536`; do echo -n "$((nr_entries*100/65536))% full: "; sudo ./bench -d2 -a bpf-hashmap-lookup --key_size=4 --nr_entries=$nr_entries --max_entries=65536 --nr_loops=1000000 --map_flags=0x40 | grep cpu; done 6% full: cpu01: lookup 50.739M ± 0.018M events/sec (approximated from 32 samples of ~19ms) 12% full: cpu01: lookup 47.751M ± 0.015M events/sec (approximated from 32 samples of ~20ms) 18% full: cpu01: lookup 45.153M ± 0.013M events/sec (approximated from 32 samples of ~22ms) 25% full: cpu01: lookup 43.826M ± 0.014M events/sec (approximated from 32 samples of ~22ms) 31% full: cpu01: lookup 41.971M ± 0.012M events/sec (approximated from 32 samples of ~23ms) 37% full: cpu01: lookup 41.034M ± 0.015M events/sec (approximated from 32 samples of ~24ms) 43% full: cpu01: lookup 39.946M ± 0.012M events/sec (approximated from 32 samples of ~25ms) 50% full: cpu01: lookup 38.256M ± 0.014M events/sec (approximated from 32 samples of ~26ms) 56% full: cpu01: lookup 36.580M ± 0.018M events/sec (approximated from 32 samples of ~27ms) 62% full: cpu01: lookup 36.252M ± 0.012M events/sec (approximated from 32 samples of ~27ms) 68% full: cpu01: lookup 35.200M ± 0.012M events/sec (approximated from 32 samples of ~28ms) 75% full: cpu01: lookup 34.061M ± 0.009M events/sec (approximated from 32 samples of ~29ms) 81% full: cpu01: lookup 34.374M ± 0.010M events/sec (approximated from 32 samples of ~29ms) 87% full: cpu01: lookup 33.244M ± 0.011M events/sec (approximated from 32 samples of ~30ms) 93% full: cpu01: lookup 32.182M ± 0.013M events/sec (approximated from 32 samples of ~31ms) 100% full: cpu01: lookup 31.497M ± 0.016M events/sec (approximated from 32 samples of ~31ms) Signed-off-by:Anton Protopopov <aspsk@isovalent.com> Signed-off-by:
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Anton Protopopov authored
The bench utility will print Setting up benchmark '<bench-name>'... Benchmark '<bench-name>' started. on startup to stdout. Suppress this output if --quiet option if given. This makes it simpler to parse benchmark output by a script. Signed-off-by: -
Anton Protopopov authored
The "local-storage-tasks-trace" benchmark has a `--quiet` option. Move it to the list of common options, so that the main code and other benchmarks can use (new) env.quiet variable. Patch the run_bench_local_storage_rcu_tasks_trace.sh helper script accordingly. Signed-off-by:
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Anton Protopopov authored
The benchs/bench_bpf_hashmap_full_update.c doesn't set a custom argp, so it shouldn't include the <argp.h> header. Signed-off-by:
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Anton Protopopov authored
To parse command line the bench utility uses the argp_parse() function. This function takes as an argument a parent 'struct argp' structure which defines common command line options and an array of children 'struct argp' structures which defines additional command line options for particular benchmarks. This implementation doesn't allow benchmarks to share option names, e.g., if two benchmarks want to use, say, the --option option, then only one of them will succeed (the first one encountered in the array). This will be convenient if same option names could be used in different benchmarks (with the same semantics, e.g., --nr_loops=N). Fix this by calling the argp_parse() function twice. The first call is the same as it was before, with all children argps, and helps to find the benchmark name and to print a combined help message if anything is wrong. Given the name, we can call the argp_parse the second time, but now the children array points only to a correct benchmark thus always calling the correct parsers. (If there's no a specific list of arguments, then only one call to argp_parse will be done.) Signed-off-by:
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Anton Protopopov authored
The hashmap_report_final callback function defined in the benchs/bench_bpf_hashmap_full_update.c file should be static. Signed-off-by:
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Anton Protopopov authored
To call the bpf_hashmap_full_update benchmark, one should say: bench bpf-hashmap-ful-update The patch adds a missing 'l' to the benchmark name. Signed-off-by:
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- 15 Feb, 2023 11 commits
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Alexei Starovoitov authored
Hou Tao says: ==================== From: Hou Tao <houtao1@huawei.com> Hi, The patchset tries to fix the hard-up problem found when checking how htab handles element reuse in bpf memory allocator. The immediate reuse of freed elements will reinitialize special fields (e.g., bpf_spin_lock) in htab map value and it may corrupt lookup procedure with BFP_F_LOCK flag which acquires bpf-spin-lock during value copying, and lead to hard-lock as shown in patch #2. Patch #1 fixes it by using __GFP_ZERO when allocating the object from slab and the behavior is similar with the preallocated hash-table case. Please see individual patches for more details. And comments are always welcome. Regards, Change Log: v1: * Use __GFP_ZERO instead of ctor to avoid retpoline overhead (from Alexei) * Add comments for check_and_init_map_value() (from Alexei) * split __GFP_ZERO patches out of the original patchset to unblock the development work of others. RFC: https://lore.kernel.org/bpf/20221230041151.1231169-1-houtao@huaweicloud.com ==================== Signed-off-by:Alexei Starovoitov <ast@kernel.org>
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Hou Tao authored
The reinitialization of spin-lock in map value after immediate reuse may corrupt lookup with BPF_F_LOCK flag and result in hard lock-up, so add one test case to demonstrate the problem. Signed-off-by:
Hou Tao <houtao1@huawei.com> Link: https://lore.kernel.org/r/20230215082132.3856544-3-houtao@huaweicloud.comSigned-off-by:
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Hou Tao authored
Currently the freed element in bpf memory allocator may be immediately reused, for htab map the reuse will reinitialize special fields in map value (e.g., bpf_spin_lock), but lookup procedure may still access these special fields, and it may lead to hard-lockup as shown below: NMI backtrace for cpu 16 CPU: 16 PID: 2574 Comm: htab.bin Tainted: G L 6.1.0+ #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), RIP: 0010:queued_spin_lock_slowpath+0x283/0x2c0 ...... Call Trace: <TASK> copy_map_value_locked+0xb7/0x170 bpf_map_copy_value+0x113/0x3c0 __sys_bpf+0x1c67/0x2780 __x64_sys_bpf+0x1c/0x20 do_syscall_64+0x30/0x60 entry_SYSCALL_64_after_hwframe+0x46/0xb0 ...... </TASK> For htab map, just like the preallocated case, these is no need to initialize these special fields in map value again once these fields have been initialized. For preallocated htab map, these fields are initialized through __GFP_ZERO in bpf_map_area_alloc(), so do the similar thing for non-preallocated htab in bpf memory allocator. And there is no need to use __GFP_ZERO for per-cpu bpf memory allocator, because __alloc_percpu_gfp() does it implicitly. Fixes: 0fd7c5d4 ("bpf: Optimize call_rcu in non-preallocated hash map.") Signed-off-by:
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Alexei Starovoitov authored
Eduard Zingerman says: ==================== This patch-set is a part of preparation work for -mcpu=v4 option for BPF C compiler (discussed in [1]). Among other things -mcpu=v4 should enable generation of BPF_ST instruction by the compiler. - Patches #1,2 adjust verifier to track values of constants written to stack using BPF_ST. Currently these are tracked imprecisely, unlike the writes using BPF_STX, e.g.: fp[-8] = 42; currently verifier assumes that fp[-8]=mmmmmmmm after such instruction, where m stands for "misc", just a note that something is written at fp[-8]. r1 = 42; verifier tracks r1=42 after this instruction. fp[-8] = r1; verifier tracks fp[-8]=42 after this instruction. This patch makes both cases equivalent. - Patches #3,4 adjust verifier.c:check_stack_write_fixed_off() to preserve STACK_ZERO marks when BPF_ST writes zero. Currently these are replaced by STACK_MISC, unlike zero writes using BPF_STX, e.g.: ... stack range [X,Y] is marked as STACK_ZERO ... r0 = ... variable offset pointer to stack with range [X,Y] ... fp[r0] = 0; currently verifier marks range [X,Y] as STACK_MISC for such instructions. r1 = 0; fp[r0] = r1; verifier keeps STACK_ZERO marks for range [X,Y]. This patch makes both cases equivalent. Motivating example for patch #1 could be found at [3]. Previous version of the patch-set is here [2], the changes are: - Explicit initialization of fake register parent link is removed from verifier.c:check_stack_write_fixed_off() as parent links are now correctly handled by verifier.c:save_register_state(). - Original patch #1 is split in patches #1 & #3. - Missing test case added for patch #3 verifier.c:check_stack_write_fixed_off() adjustment. - Test cases are updated to use .prog_type = BPF_PROG_TYPE_SK_LOOKUP, which requires return value to be in the range [0,1] (original test cases assumed that such range is always required, which is not true). - Original patch #3 with changes allowing BPF_ST writes to context is withheld for now, w/o compiler support for BPF_ST it requires some creative testing. - Original patch #5 is removed from the patch-set. This patch contained adjustments to expected verifier error messages in some tests, necessary when C compiler generates BPF_ST instruction instead of BPF_STX (changes to expected instruction indices). These changes are not necessary yet. [1] https://lore.kernel.org/bpf/01515302-c37d-2ee5-c950-2f556a4caad0@meta.com/ [2] https://lore.kernel.org/bpf/20221231163122.1360813-1-eddyz87@gmail.com/ [3] https://lore.kernel.org/bpf/f1e4282bf00aa21a72fc5906f8c3be1ae6c94a5e.camel@gmail.com/ ==================== Signed-off-by: -
Eduard Zingerman authored
A test case to verify that variable offset BPF_ST instruction preserves STACK_ZERO marks when writes zeros, e.g. in the following situation: *(u64*)(r10 - 8) = 0 ; STACK_ZERO marks for fp[-8] r0 = random(-7, -1) ; some random number in range of [-7, -1] r0 += r10 ; r0 is now variable offset pointer to stack *(u8*)(r0) = 0 ; BPF_ST writing zero, STACK_ZERO mark for ; fp[-8] should be preserved. Signed-off-by:Eduard Zingerman <eddyz87@gmail.com> Link: https://lore.kernel.org/r/20230214232030.1502829-5-eddyz87@gmail.comSigned-off-by:
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Eduard Zingerman authored
BPF_STX instruction preserves STACK_ZERO marks for variable offset writes in situations like below: *(u64*)(r10 - 8) = 0 ; STACK_ZERO marks for fp[-8] r0 = random(-7, -1) ; some random number in range of [-7, -1] r0 += r10 ; r0 is now a variable offset pointer to stack r1 = 0 *(u8*)(r0) = r1 ; BPF_STX writing zero, STACK_ZERO mark for ; fp[-8] is preserved This commit updates verifier.c:check_stack_write_var_off() to process BPF_ST in a similar manner, e.g. the following example: *(u64*)(r10 - 8) = 0 ; STACK_ZERO marks for fp[-8] r0 = random(-7, -1) ; some random number in range of [-7, -1] r0 += r10 ; r0 is now variable offset pointer to stack *(u8*)(r0) = 0 ; BPF_ST writing zero, STACK_ZERO mark for ; fp[-8] is preserved Signed-off-by: -
Eduard Zingerman authored
Check that verifier tracks the value of 'imm' spilled to stack by BPF_ST_MEM instruction. Cover the following cases: - write of non-zero constant to stack; - write of a zero constant to stack. Signed-off-by:
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Eduard Zingerman authored
For aligned stack writes using BPF_ST instruction track stored values in a same way BPF_STX is handled, e.g. make sure that the following commands produce similar verifier knowledge: fp[-8] = 42; r1 = 42; fp[-8] = r1; This covers two cases: - non-null values written to stack are stored as spill of fake registers; - null values written to stack are stored as STACK_ZERO marks. Previously both cases above used STACK_MISC marks instead. Some verifier test cases relied on the old logic to obtain STACK_MISC marks for some stack values. These test cases are updated in the same commit to avoid failures during bisect. Signed-off-by: -
Alexei Starovoitov authored
The compiler is optimizing out majority of unref_ptr read/writes, so the test wasn't testing much. For example, one could delete '__kptr' tag from 'struct prog_test_ref_kfunc __kptr *unref_ptr;' and the test would still "pass". Convert it to volatile stores. Confirmed by comparing bpf asm before/after. Fixes: 2cbc469a ("selftests/bpf: Add C tests for kptr") Signed-off-by:
Kumar Kartikeya Dwivedi <memxor@gmail.com> Link: https://lore.kernel.org/r/20230214235051.22938-1-alexei.starovoitov@gmail.comSigned-off-by:
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Björn Töpel authored
When the BPF selftests are cross-compiled, only the a host version of bpftool is built. This version of bpftool is used on the host-side to generate various intermediates, e.g., skeletons. The test runners are also using bpftool, so the Makefile will symlink bpftool from the selftest/bpf root, where the test runners will look the tool: | $(Q)ln -sf $(if $2,..,.)/tools/build/bpftool/bootstrap/bpftool \ | $(OUTPUT)/$(if $2,$2/)bpftool There are two problems for cross-compilation builds: 1. There is no native (cross-compilation target) of bpftool 2. The bootstrap/bpftool is never cross-compiled (by design) Make sure that a native/cross-compiled version of bpftool is built, and if CROSS_COMPILE is set, symlink the native/non-bootstrap version. Acked-by:
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David Vernet authored
In commit 7e2a9ebe ("docs, bpf: Ensure IETF's BPF mailing list gets copied for ISA doc changes"), a new MAINTAINERS entry was added for any BPF IETF documentation updates for the ongoing standardization process. I've been making it a point to try and review as many BPF documentation patches as possible, and have made a committment to Alexei to consistently review BPF standardization patches going forward. This patch adds my name as a reviewer to the MAINTAINERS entry for the standardization effort. Signed-off-by:
David Vernet <void@manifault.com> Link: https://lore.kernel.org/r/20230214223553.78353-1-void@manifault.comSigned-off-by:
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