- 04 5月, 2018 10 次提交
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由 Björn Töpel 提交于
This commit wires up the xskmap to XDP_SKB layer. Signed-off-by: NBjörn Töpel <bjorn.topel@intel.com> Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
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由 Björn Töpel 提交于
This commit wires up the xskmap to XDP_DRV layer. Signed-off-by: NBjörn Töpel <bjorn.topel@intel.com> Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
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由 Björn Töpel 提交于
The xskmap is yet another BPF map, very much inspired by dev/cpu/sockmap, and is a holder of AF_XDP sockets. A user application adds AF_XDP sockets into the map, and by using the bpf_redirect_map helper, an XDP program can redirect XDP frames to an AF_XDP socket. Note that a socket that is bound to certain ifindex/queue index will *only* accept XDP frames from that netdev/queue index. If an XDP program tries to redirect from a netdev/queue index other than what the socket is bound to, the frame will not be received on the socket. A socket can reside in multiple maps. v3: Fixed race and simplified code. v2: Removed one indirection in map lookup. Signed-off-by: NBjörn Töpel <bjorn.topel@intel.com> Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
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由 Björn Töpel 提交于
Here the actual receive functions of AF_XDP are implemented, that in a later commit, will be called from the XDP layers. There's one set of functions for the XDP_DRV side and another for XDP_SKB (generic). A new XDP API, xdp_return_buff, is also introduced. Adding xdp_return_buff, which is analogous to xdp_return_frame, but acts upon an struct xdp_buff. The API will be used by AF_XDP in future commits. Support for the poll syscall is also implemented. v2: xskq_validate_id did not update cons_tail. The entries variable was calculated twice in xskq_nb_avail. Squashed xdp_return_buff commit. Signed-off-by: NBjörn Töpel <bjorn.topel@intel.com> Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
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由 Magnus Karlsson 提交于
Here, the bind syscall is added. Binding an AF_XDP socket, means associating the socket to an umem, a netdev and a queue index. This can be done in two ways. The first way, creating a "socket from scratch". Create the umem using the XDP_UMEM_REG setsockopt and an associated fill queue with XDP_UMEM_FILL_QUEUE. Create the Rx queue using the XDP_RX_QUEUE setsockopt. Call bind passing ifindex and queue index ("channel" in ethtool speak). The second way to bind a socket, is simply skipping the umem/netdev/queue index, and passing another already setup AF_XDP socket. The new socket will then have the same umem/netdev/queue index as the parent so it will share the same umem. You must also set the flags field in the socket address to XDP_SHARED_UMEM. v2: Use PTR_ERR instead of passing error variable explicitly. Signed-off-by: NMagnus Karlsson <magnus.karlsson@intel.com> Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
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由 Björn Töpel 提交于
Another setsockopt (XDP_RX_QUEUE) is added to let the process allocate a queue, where the kernel can pass completed Rx frames from the kernel to user process. The mmapping of the queue is done using the XDP_PGOFF_RX_QUEUE offset. Signed-off-by: NBjörn Töpel <bjorn.topel@intel.com> Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
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由 Magnus Karlsson 提交于
Here, we add another setsockopt for registered user memory (umem) called XDP_UMEM_FILL_QUEUE. Using this socket option, the process can ask the kernel to allocate a queue (ring buffer) and also mmap it (XDP_UMEM_PGOFF_FILL_QUEUE) into the process. The queue is used to explicitly pass ownership of umem frames from the user process to the kernel. These frames will in a later patch be filled in with Rx packet data by the kernel. v2: Fixed potential crash in xsk_mmap. Signed-off-by: NMagnus Karlsson <magnus.karlsson@intel.com> Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
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由 Björn Töpel 提交于
In this commit the base structure of the AF_XDP address family is set up. Further, we introduce the abilty register a window of user memory to the kernel via the XDP_UMEM_REG setsockopt syscall. The memory window is viewed by an AF_XDP socket as a set of equally large frames. After a user memory registration all frames are "owned" by the user application, and not the kernel. v2: More robust checks on umem creation and unaccount on error. Call set_page_dirty_lock on cleanup. Simplified xdp_umem_reg. Co-authored-by: NMagnus Karlsson <magnus.karlsson@intel.com> Signed-off-by: NMagnus Karlsson <magnus.karlsson@intel.com> Signed-off-by: NBjörn Töpel <bjorn.topel@intel.com> Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
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由 Björn Töpel 提交于
Buildable skeleton of AF_XDP without any functionality. Just what it takes to register a new address family. Signed-off-by: NBjörn Töpel <bjorn.topel@intel.com> Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
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由 Wang YanQing 提交于
The JIT compiler emits ia32 bit instructions. Currently, It supports eBPF only. Classic BPF is supported because of the conversion by BPF core. Almost all instructions from eBPF ISA supported except the following: BPF_ALU64 | BPF_DIV | BPF_K BPF_ALU64 | BPF_DIV | BPF_X BPF_ALU64 | BPF_MOD | BPF_K BPF_ALU64 | BPF_MOD | BPF_X BPF_STX | BPF_XADD | BPF_W BPF_STX | BPF_XADD | BPF_DW It doesn't support BPF_JMP|BPF_CALL with BPF_PSEUDO_CALL at the moment. IA32 has few general purpose registers, EAX|EDX|ECX|EBX|ESI|EDI. I use EAX|EDX|ECX|EBX as temporary registers to simulate instructions in eBPF ISA, and allocate ESI|EDI to BPF_REG_AX for constant blinding, all others eBPF registers, R0-R10, are simulated through scratch space on stack. The reasons behind the hardware registers allocation policy are: 1:MUL need EAX:EDX, shift operation need ECX, so they aren't fit for general eBPF 64bit register simulation. 2:We need at least 4 registers to simulate most eBPF ISA operations on registers operands instead of on register&memory operands. 3:We need to put BPF_REG_AX on hardware registers, or constant blinding will degrade jit performance heavily. Tested on PC (Intel(R) Core(TM) i5-5200U CPU). Testing results on i5-5200U: 1) test_bpf: Summary: 349 PASSED, 0 FAILED, [319/341 JIT'ed] 2) test_progs: Summary: 83 PASSED, 0 FAILED. 3) test_lpm: OK 4) test_lru_map: OK 5) test_verifier: Summary: 828 PASSED, 0 FAILED. Above tests are all done in following two conditions separately: 1:bpf_jit_enable=1 and bpf_jit_harden=0 2:bpf_jit_enable=1 and bpf_jit_harden=2 Below are some numbers for this jit implementation: Note: I run test_progs in kselftest 100 times continuously for every condition, the numbers are in format: total/times=avg. The numbers that test_bpf reports show almost the same relation. a:jit_enable=0 and jit_harden=0 b:jit_enable=1 and jit_harden=0 test_pkt_access:PASS:ipv4:15622/100=156 test_pkt_access:PASS:ipv4:10674/100=106 test_pkt_access:PASS:ipv6:9130/100=91 test_pkt_access:PASS:ipv6:4855/100=48 test_xdp:PASS:ipv4:240198/100=2401 test_xdp:PASS:ipv4:138912/100=1389 test_xdp:PASS:ipv6:137326/100=1373 test_xdp:PASS:ipv6:68542/100=685 test_l4lb:PASS:ipv4:61100/100=611 test_l4lb:PASS:ipv4:37302/100=373 test_l4lb:PASS:ipv6:101000/100=1010 test_l4lb:PASS:ipv6:55030/100=550 c:jit_enable=1 and jit_harden=2 test_pkt_access:PASS:ipv4:10558/100=105 test_pkt_access:PASS:ipv6:5092/100=50 test_xdp:PASS:ipv4:131902/100=1319 test_xdp:PASS:ipv6:77932/100=779 test_l4lb:PASS:ipv4:38924/100=389 test_l4lb:PASS:ipv6:57520/100=575 The numbers show we get 30%~50% improvement. See Documentation/networking/filter.txt for more information. Changelog: Changes v5-v6: 1:Add do {} while (0) to RETPOLINE_RAX_BPF_JIT for consistence reason. 2:Clean up non-standard comments, reported by Daniel Borkmann. 3:Fix a memory leak issue, repoted by Daniel Borkmann. Changes v4-v5: 1:Delete is_on_stack, BPF_REG_AX is the only one on real hardware registers, so just check with it. 2:Apply commit 1612a981 ("bpf, x64: fix JIT emission for dead code"), suggested by Daniel Borkmann. Changes v3-v4: 1:Fix changelog in commit. I install llvm-6.0, then test_progs willn't report errors. I submit another patch: "bpf: fix misaligned access for BPF_PROG_TYPE_PERF_EVENT program type on x86_32 platform" to fix another problem, after that patch, test_verifier willn't report errors too. 2:Fix clear r0[1] twice unnecessarily in *BPF_IND|BPF_ABS* simulation. Changes v2-v3: 1:Move BPF_REG_AX to real hardware registers for performance reason. 3:Using bpf_load_pointer instead of bpf_jit32.S, suggested by Daniel Borkmann. 4:Delete partial codes in 1c2a088a, suggested by Daniel Borkmann. 5:Some bug fixes and comments improvement. Changes v1-v2: 1:Fix bug in emit_ia32_neg64. 2:Fix bug in emit_ia32_arsh_r64. 3:Delete filename in top level comment, suggested by Thomas Gleixner. 4:Delete unnecessary boiler plate text, suggested by Thomas Gleixner. 5:Rewrite some words in changelog. 6:CodingSytle improvement and a little more comments. Signed-off-by: NWang YanQing <udknight@gmail.com> Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
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- 02 5月, 2018 3 次提交
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由 Quentin Monnet 提交于
The Python script used to parse and extract eBPF helpers documentation from include/uapi/linux/bpf.h expects a very specific formatting for the descriptions (single dot represents a space, '>' stands for a tab): /* ... *.int bpf_helper(list of arguments) *.> Description *.> > Start of description *.> > Another line of description *.> > And yet another line of description *.> Return *.> > 0 on success, or a negative error in case of failure ... */ This is too strict, and painful for developers who wants to add documentation for new helpers. Worse, it is extremely difficult to check that the formatting is correct during reviews. Change the format expected by the script and make it more flexible. The script now works whether or not the initial space (right after the star) is present, and accepts both tabs and white spaces (or a combination of both) for indenting description sections and contents. Concretely, something like the following would now be supported: /* ... *int bpf_helper(list of arguments) *......Description *.> > Start of description... *> > Another line of description *..............And yet another line of description *> Return *.> ........0 on success, or a negative error in case of failure ... */ While at it, remove unnecessary carets from each regex used with match() in the script. They are redundant, as match() tries to match from the beginning of the string by default. v2: Remove unnecessary caret when a regex is used with match(). Signed-off-by: NQuentin Monnet <quentin.monnet@netronome.com> Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
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由 Ingo Molnar 提交于
So by chance I looked into x86 assembly in arch/x86/net/bpf_jit_comp.c and noticed the weird and inconsistent comment style it mistakenly learned from the networking code: /* Multi-line comment ... * ... looks like this. */ Fix this to use the standard comment style specified in Documentation/CodingStyle and used in arch/x86/ as well: /* * Multi-line comment ... * ... looks like this. */ Also, to quote Linus's ... more explicit views about this: http://article.gmane.org/gmane.linux.kernel.cryptoapi/21066 > But no, the networking code picked *none* of the above sane formats. > Instead, it picked these two models that are just half-arsed > shit-for-brains: > > (no) > /* This is disgusting drug-induced > * crap, and should die > */ > > (no-no-no) > /* This is also very nasty > * and visually unbalanced */ > > Please. The networking code actually has the *worst* possible comment > style. You can literally find that (no-no-no) style, which is just > really horribly disgusting and worse than the otherwise fairly similar > (d) in pretty much every way. Also improve the comments and some other details while at it: - Don't mix same-line and previous-line comment style on otherwise identical code patterns within the same function, - capitalize 'BPF' and x86 register names consistently, - capitalize sentences consistently, - instead of 'x64' use 'x86-64': x64 is a Microsoft specific term, - use more consistent punctuation, - use standard coding style in macros as well, - fix typos and a few other minor details. Consistent coding style is not optional, at least in arch/x86/. No change in functionality. ( In case this commit causes conflicts with pending development code I'll be glad to help resolve any conflicts! ) Acked-by: NThomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Borislav Petkov <bp@alien8.de> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: David S. Miller <davem@davemloft.net> Cc: Eric Dumazet <edumazet@google.com> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Alexei Starovoitov <ast@fb.com> Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org> Cc: netdev@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: NIngo Molnar <mingo@kernel.org> Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
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由 Quentin Monnet 提交于
To make eBPF program load time easier to parse from "bpftool prog" output for machines, change the time format used by the program. The format now differs for plain and JSON version: - Plain version uses a string formatted according to ISO 8601. - JSON uses the number of seconds since the Epoch, wich is less friendly for humans but even easier to process. Example output: # ./bpftool prog 41298: xdp tag a04f5eef06a7f555 dev foo loaded_at 2018-04-18T17:19:47+0100 uid 0 xlated 16B not jited memlock 4096B # ./bpftool prog -p [{ "id": 41298, "type": "xdp", "tag": "a04f5eef06a7f555", "gpl_compatible": false, "dev": { "ifindex": 14, "ns_dev": 3, "ns_inode": 4026531993, "ifname": "foo" }, "loaded_at": 1524068387, "uid": 0, "bytes_xlated": 16, "jited": false, "bytes_memlock": 4096 } ] Previously, "Apr 18/17:19" would be used at both places. Suggested-by: NAlexei Starovoitov <ast@kernel.org> Signed-off-by: NQuentin Monnet <quentin.monnet@netronome.com> Acked-by: NJakub Kicinski <jakub.kicinski@netronome.com> Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
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- 30 4月, 2018 8 次提交
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由 William Tu 提交于
Bring the erspan uapi header file so BPF tunnel helpers can use it. Fixes: 933a741e ("selftests/bpf: bpf tunnel test.") Reported-by: NYonghong Song <yhs@fb.com> Signed-off-by: NWilliam Tu <u9012063@gmail.com> Acked-by: NYonghong Song <yhs@fb.com> Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
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由 Daniel Borkmann 提交于
Quentin Monnet says: ==================== Here is a follow-up set for eBPF helper documentation, with two patches to fix formatting issues: - One to fix an error I introduced with the initial set for the doc. - One for the newly added bpf_get_stack(), that is currently not parsed correctly with the Python script (function signature is fine, but description and return value appear as empty). There is no change to text contents in this set. ==================== Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
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由 Quentin Monnet 提交于
Bring fixes for eBPF helper documentation formatting to bpf.h under tools/ as well. Signed-off-by: NQuentin Monnet <quentin.monnet@netronome.com> Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
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由 Quentin Monnet 提交于
Fix formatting (indent) for bpf_get_stack() helper documentation, so that the doc is rendered correctly with the Python script. Fixes: c195651e ("bpf: add bpf_get_stack helper") Cc: Yonghong Song <yhs@fb.com> Signed-off-by: NQuentin Monnet <quentin.monnet@netronome.com> Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
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由 Quentin Monnet 提交于
Some edits brought to the last iteration of BPF helper functions documentation introduced an error with RST formatting. As a result, most of one paragraph is rendered in bold text when only the name of a helper should be. Fix it, and fix formatting of another function name in the same paragraph. Fixes: c6b5fb86 ("bpf: add documentation for eBPF helpers (42-50)") Signed-off-by: NQuentin Monnet <quentin.monnet@netronome.com> Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
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由 Alexei Starovoitov 提交于
tracepoints to bpf core were added as a way to provide introspection to bpf programs and maps, but after some time it became clear that this approach is inadequate, so prog_id, map_id and corresponding get_next_id, get_fd_by_id, get_info_by_fd, prog_query APIs were introduced and fully adopted by bpftool and other applications. The tracepoints in bpf core started to rot and causing syzbot warnings: WARNING: CPU: 0 PID: 3008 at kernel/trace/trace_event_perf.c:274 Kernel panic - not syncing: panic_on_warn set ... perf_trace_bpf_map_keyval+0x260/0xbd0 include/trace/events/bpf.h:228 trace_bpf_map_update_elem include/trace/events/bpf.h:274 [inline] map_update_elem kernel/bpf/syscall.c:597 [inline] SYSC_bpf kernel/bpf/syscall.c:1478 [inline] Hence this patch deletes tracepoints in bpf core. Reported-by: NEric Biggers <ebiggers3@gmail.com> Reported-by: Nsyzbot <bot+a9dbb3c3e64b62536a4bc5ee7bbd4ca627566188@syzkaller.appspotmail.com> Signed-off-by: NAlexei Starovoitov <ast@kernel.org> Acked-by: NDavid S. Miller <davem@davemloft.net> Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
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由 Yonghong Song 提交于
Commit d5a00528 ("syscalls/core, syscalls/x86: Rename struct pt_regs-based sys_*() to __x64_sys_*()") renamed a lot of syscall function sys_*() to __x64_sys_*(). This caused several kprobe based samples/bpf tests failing. This patch fixed the problem in bpf_load.c. For x86_64 architecture, function name __x64_sys_*() will be first used for kprobe event creation. If the creation is successful, it will be used. Otherwise, function name sys_*() will be used for kprobe event creation. Fixes: d5a00528 ("syscalls/core, syscalls/x86: Rename struct pt_regs-based sys_*() to __x64_sys_*()") Signed-off-by: NYonghong Song <yhs@fb.com> Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
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由 Teng Qin 提交于
Currently, the bpf_current_task_under_cgroup helper has a check where if the BPF program is running in_interrupt(), it will return -EINVAL. This prevents the helper to be used in many useful scenarios, particularly BPF programs attached to Perf Events. This commit removes the check. Tested a few NMI (Perf Event) and some softirq context, the helper returns the correct result. Signed-off-by: NTeng Qin <qinteng@fb.com> Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
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- 29 4月, 2018 14 次提交
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由 Alexei Starovoitov 提交于
Andrey Ignatov says: ==================== BPF helpers documentation in UAPI refers to kernel ctx structures when it has to refer to user visible ones. Fix it. ==================== Reviewed-by: NQuentin Monnet <quentin.monnet@netronome.com> Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
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由 Andrey Ignatov 提交于
The patch syncs bpf.h to tools/. Signed-off-by: NAndrey Ignatov <rdna@fb.com> Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
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由 Andrey Ignatov 提交于
Helpers may operate on two types of ctx structures: user visible ones (e.g. `struct bpf_sock_ops`) when used in user programs, and kernel ones (e.g. `struct bpf_sock_ops_kern`) in kernel implementation. UAPI documentation must refer to only user visible structures. The patch replaces references to `_kern` structures in BPF helpers description by corresponding user visible structures. Signed-off-by: NAndrey Ignatov <rdna@fb.com> Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
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由 Alexei Starovoitov 提交于
Yonghong Song says: ==================== Currently, stackmap and bpf_get_stackid helper are provided for bpf program to get the stack trace. This approach has a limitation though. If two stack traces have the same hash, only one will get stored in the stackmap table regardless of whether BPF_F_REUSE_STACKID is specified or not, so some stack traces may be missing from user perspective. This patch implements a new helper, bpf_get_stack, will send stack traces directly to bpf program. The bpf program is able to see all stack traces, and then can do in-kernel processing or send stack traces to user space through shared map or bpf_perf_event_output. Patches #1 and #2 implemented the core kernel support. Patch #3 removes two never-hit branches in verifier. Patches #4 and #5 are two verifier improves to make bpf programming easier. Patch #6 synced the new helper to tools headers. Patch #7 moved perf_event polling code and ksym lookup code from samples/bpf to tools/testing/selftests/bpf. Patch #8 added a verifier test in tools/bpf for new verifier change. Patches #9 and #10 added tests for raw tracepoint prog and tracepoint prog respectively. Changelogs: v8 -> v9: . make function perf_event_mmap (in trace_helpers.c) extern to decouple perf_event_mmap and perf_event_poller. . add jit enabled handling for kernel stack verification in Patch #9. Since we did not have a good way to verify jit enabled kernel stack, just return true if the kernel stack is not empty. . In path #9, using raw_syscalls/sys_enter instead of sched/sched_switch, removed calling cmd "task 1 dd if=/dev/zero of=/dev/null" which is left with dangling process after the program exited. v7 -> v8: . rebase on top of latest bpf-next . simplify BPF_ARSH dst_reg->smin_val/smax_value tracking . rewrite the description of bpf_get_stack() in uapi bpf.h based on new format. v6 -> v7: . do perf callchain buffer allocation inside the verifier. so if the prog->has_callchain_buf is set, it is guaranteed that the buffer has been allocated. . change condition "trace_nr <= skip" to "trace_nr < skip" so that for zero size buffer, return 0 instead of -EFAULT v5 -> v6: . after refining return register smax_value and umax_value for helpers bpf_get_stack and bpf_probe_read_str, bounds and var_off of the return register are further refined. . added missing commit message for tools header sync commit. . removed one unnecessary empty line. v4 -> v5: . relied on dst_reg->var_off to refine umin_val/umax_val in verifier handling BPF_ARSH value range tracking, suggested by Edward. v3 -> v4: . fixed a bug when meta ptr is set to NULL in check_func_arg. . introduced tnum_arshift and added detailed comments for the underlying implementation . avoided using VLA in tools/bpf test_progs. v2 -> v3: . used meta to track helper memory size argument . implemented range checking for ARSH in verifier . moved perf event polling and ksym related functions from samples/bpf to tools/bpf . added test to compare build id's between bpf_get_stackid and bpf_get_stack v1 -> v2: . fixed compilation error when CONFIG_PERF_EVENTS is not enabled ==================== Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
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由 Yonghong Song 提交于
The test_stacktrace_map and test_stacktrace_build_id are enhanced to call bpf_get_stack in the helper to get the stack trace as well. The stack traces from bpf_get_stack and bpf_get_stackid are compared to ensure that for the same stack as represented as the same hash, their ip addresses or build id's must be the same. Acked-by: NAlexei Starovoitov <ast@kernel.org> Signed-off-by: NYonghong Song <yhs@fb.com> Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
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由 Yonghong Song 提交于
The test attached a raw_tracepoint program to raw_syscalls/sys_enter. It tested to get stack for user space, kernel space and user space with build_id request. It also tested to get user and kernel stack into the same buffer with back-to-back bpf_get_stack helper calls. If jit is not enabled, the user space application will check to ensure that the kernel function for raw_tracepoint ___bpf_prog_run is part of the stack. If jit is enabled, we did not have a reliable way to verify the kernel stack, so just assume the kernel stack is good when the kernel stack size is greater than 0. Signed-off-by: NYonghong Song <yhs@fb.com> Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
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由 Yonghong Song 提交于
The test_verifier already has a few ARSH test cases. This patch adds a new test case which takes advantage of newly improved verifier behavior for bpf_get_stack and ARSH. Signed-off-by: NYonghong Song <yhs@fb.com> Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
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由 Yonghong Song 提交于
There is no functionality change in this patch. The common-purpose trace functions, including perf_event polling and ksym lookup, are moved from trace_output_user.c and bpf_load.c to selftests/bpf/trace_helpers.c so that these function can be reused later in selftests. Acked-by: NAlexei Starovoitov <ast@fb.com> Signed-off-by: NYonghong Song <yhs@fb.com> Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
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由 Yonghong Song 提交于
The tools header file bpf.h is synced with kernel uapi bpf.h. The new helper is also added to bpf_helpers.h. Signed-off-by: NYonghong Song <yhs@fb.com> Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
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由 Yonghong Song 提交于
When helpers like bpf_get_stack returns an int value and later on used for arithmetic computation, the LSH and ARSH operations are often required to get proper sign extension into 64-bit. For example, without this patch: 54: R0=inv(id=0,umax_value=800) 54: (bf) r8 = r0 55: R0=inv(id=0,umax_value=800) R8_w=inv(id=0,umax_value=800) 55: (67) r8 <<= 32 56: R8_w=inv(id=0,umax_value=3435973836800,var_off=(0x0; 0x3ff00000000)) 56: (c7) r8 s>>= 32 57: R8=inv(id=0) With this patch: 54: R0=inv(id=0,umax_value=800) 54: (bf) r8 = r0 55: R0=inv(id=0,umax_value=800) R8_w=inv(id=0,umax_value=800) 55: (67) r8 <<= 32 56: R8_w=inv(id=0,umax_value=3435973836800,var_off=(0x0; 0x3ff00000000)) 56: (c7) r8 s>>= 32 57: R8=inv(id=0, umax_value=800,var_off=(0x0; 0x3ff)) With better range of "R8", later on when "R8" is added to other register, e.g., a map pointer or scalar-value register, the better register range can be derived and verifier failure may be avoided. In our later example, ...... usize = bpf_get_stack(ctx, raw_data, max_len, BPF_F_USER_STACK); if (usize < 0) return 0; ksize = bpf_get_stack(ctx, raw_data + usize, max_len - usize, 0); ...... Without improving ARSH value range tracking, the register representing "max_len - usize" will have smin_value equal to S64_MIN and will be rejected by verifier. Acked-by: NAlexei Starovoitov <ast@kernel.org> Signed-off-by: NYonghong Song <yhs@fb.com> Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
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由 Yonghong Song 提交于
In verifier function adjust_scalar_min_max_vals, when src_known is false and the opcode is BPF_LSH/BPF_RSH, early return will happen in the function. So remove the branch in handling BPF_LSH/BPF_RSH when src_known is false. Acked-by: NAlexei Starovoitov <ast@kernel.org> Signed-off-by: NYonghong Song <yhs@fb.com> Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
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由 Yonghong Song 提交于
The special property of return values for helpers bpf_get_stack and bpf_probe_read_str are captured in verifier. Both helpers return a negative error code or a length, which is equal to or smaller than the buffer size argument. This additional information in the verifier can avoid the condition such as "retval > bufsize" in the bpf program. For example, for the code blow, usize = bpf_get_stack(ctx, raw_data, max_len, BPF_F_USER_STACK); if (usize < 0 || usize > max_len) return 0; The verifier may have the following errors: 52: (85) call bpf_get_stack#65 R0=map_value(id=0,off=0,ks=4,vs=1600,imm=0) R1_w=ctx(id=0,off=0,imm=0) R2_w=map_value(id=0,off=0,ks=4,vs=1600,imm=0) R3_w=inv800 R4_w=inv256 R6=ctx(id=0,off=0,imm=0) R7=map_value(id=0,off=0,ks=4,vs=1600,imm=0) R9_w=inv800 R10=fp0,call_-1 53: (bf) r8 = r0 54: (bf) r1 = r8 55: (67) r1 <<= 32 56: (bf) r2 = r1 57: (77) r2 >>= 32 58: (25) if r2 > 0x31f goto pc+33 R0=inv(id=0) R1=inv(id=0,smax_value=9223372032559808512, umax_value=18446744069414584320, var_off=(0x0; 0xffffffff00000000)) R2=inv(id=0,umax_value=799,var_off=(0x0; 0x3ff)) R6=ctx(id=0,off=0,imm=0) R7=map_value(id=0,off=0,ks=4,vs=1600,imm=0) R8=inv(id=0) R9=inv800 R10=fp0,call_-1 59: (1f) r9 -= r8 60: (c7) r1 s>>= 32 61: (bf) r2 = r7 62: (0f) r2 += r1 math between map_value pointer and register with unbounded min value is not allowed The failure is due to llvm compiler optimization where register "r2", which is a copy of "r1", is tested for condition while later on "r1" is used for map_ptr operation. The verifier is not able to track such inst sequence effectively. Without the "usize > max_len" condition, there is no llvm optimization and the below generated code passed verifier: 52: (85) call bpf_get_stack#65 R0=map_value(id=0,off=0,ks=4,vs=1600,imm=0) R1_w=ctx(id=0,off=0,imm=0) R2_w=map_value(id=0,off=0,ks=4,vs=1600,imm=0) R3_w=inv800 R4_w=inv256 R6=ctx(id=0,off=0,imm=0) R7=map_value(id=0,off=0,ks=4,vs=1600,imm=0) R9_w=inv800 R10=fp0,call_-1 53: (b7) r1 = 0 54: (bf) r8 = r0 55: (67) r8 <<= 32 56: (c7) r8 s>>= 32 57: (6d) if r1 s> r8 goto pc+24 R0=inv(id=0,umax_value=800,var_off=(0x0; 0x3ff)) R1=inv0 R6=ctx(id=0,off=0,imm=0) R7=map_value(id=0,off=0,ks=4,vs=1600,imm=0) R8=inv(id=0,umax_value=800,var_off=(0x0; 0x3ff)) R9=inv800 R10=fp0,call_-1 58: (bf) r2 = r7 59: (0f) r2 += r8 60: (1f) r9 -= r8 61: (bf) r1 = r6 Acked-by: NAlexei Starovoitov <ast@kernel.org> Signed-off-by: NYonghong Song <yhs@fb.com> Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
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由 Yonghong Song 提交于
Currently, stackmap and bpf_get_stackid helper are provided for bpf program to get the stack trace. This approach has a limitation though. If two stack traces have the same hash, only one will get stored in the stackmap table, so some stack traces are missing from user perspective. This patch implements a new helper, bpf_get_stack, will send stack traces directly to bpf program. The bpf program is able to see all stack traces, and then can do in-kernel processing or send stack traces to user space through shared map or bpf_perf_event_output. Acked-by: NAlexei Starovoitov <ast@fb.com> Signed-off-by: NYonghong Song <yhs@fb.com> Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
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由 Yonghong Song 提交于
This patch didn't incur functionality change. The function prototype got changed so that the same function can be reused later. Signed-off-by: NYonghong Song <yhs@fb.com> Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
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- 27 4月, 2018 5 次提交
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由 Leo Yan 提交于
When CONFIG_BPF_JIT_ALWAYS_ON is enabled, kernel has limitation for bpf_jit_enable, so it has fixed value 1 and we cannot set it to 2 for JIT opcode dumping; this patch is to update the doc for it. Suggested-by: NDaniel Borkmann <daniel@iogearbox.net> Signed-off-by: NLeo Yan <leo.yan@linaro.org> Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
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git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next由 David S. Miller 提交于
Daniel Borkmann says: ==================== pull-request: bpf-next 2018-04-27 The following pull-request contains BPF updates for your *net-next* tree. The main changes are: 1) Add extensive BPF helper description into include/uapi/linux/bpf.h and a new script bpf_helpers_doc.py which allows for generating a man page out of it. Thus, every helper in BPF now comes with proper function signature, detailed description and return code explanation, from Quentin. 2) Migrate the BPF collect metadata tunnel tests from BPF samples over to the BPF selftests and further extend them with v6 vxlan, geneve and ipip tests, simplify the ipip tests, improve documentation and convert to bpf_ntoh*() / bpf_hton*() api, from William. 3) Currently, helpers that expect ARG_PTR_TO_MAP_{KEY,VALUE} can only access stack and packet memory. Extend this to allow such helpers to also use map values, which enabled use cases where value from a first lookup can be directly used as a key for a second lookup, from Paul. 4) Add a new helper bpf_skb_get_xfrm_state() for tc BPF programs in order to retrieve XFRM state information containing SPI, peer address and reqid values, from Eyal. 5) Various optimizations in nfp driver's BPF JIT in order to turn ADD and SUB instructions with negative immediate into the opposite operation with a positive immediate such that nfp can better fit small immediates into instructions. Savings in instruction count up to 4% have been observed, from Jakub. 6) Add the BPF prog's gpl_compatible flag to struct bpf_prog_info and add support for dumping this through bpftool, from Jiri. 7) Move the BPF sockmap samples over into BPF selftests instead since sockmap was rather a series of tests than sample anyway and this way this can be run from automated bots, from John. 8) Follow-up fix for bpf_adjust_tail() helper in order to make it work with generic XDP, from Nikita. 9) Some follow-up cleanups to BTF, namely, removing unused defines from BTF uapi header and renaming 'name' struct btf_* members into name_off to make it more clear they are offsets into string section, from Martin. 10) Remove test_sock_addr from TEST_GEN_PROGS in BPF selftests since not run directly but invoked from test_sock_addr.sh, from Yonghong. 11) Remove redundant ret assignment in sample BPF loader, from Wang. 12) Add couple of missing files to BPF selftest's gitignore, from Anders. There are two trivial merge conflicts while pulling: 1) Remove samples/sockmap/Makefile since all sockmap tests have been moved to selftests. 2) Add both hunks from tools/testing/selftests/bpf/.gitignore to the file since git should ignore all of them. ==================== Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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由 Wang Sheng-Hui 提交于
2 redundant ret assignments removed: * 'ret = 1' before the logic 'if (data_maps)', and if any errors jump to label 'done'. No 'ret = 1' needed before the error jump. * After the '/* load programs */' part, if everything goes well, then the BPF code will be loaded and 'ret' set to 0 by load_and_attach(). If something goes wrong, 'ret' set to none-O, the redundant 'ret = 0' after the for clause will make the error skipped. For example, if some BPF code cannot provide supported program types in ELF SEC("unknown"), the for clause will not call load_and_attach() to load the BPF code. 1 should be returned to callees instead of 0. Signed-off-by: NWang Sheng-Hui <shhuiw@foxmail.com> Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
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由 Daniel Borkmann 提交于
Quentin Monnet says: ==================== eBPF helper functions can be called from within eBPF programs to perform a variety of tasks that would be otherwise hard or impossible to do with eBPF itself. There is a growing number of such helper functions in the kernel, but documentation is scarce. The main user space header file does contain a short commented description of most helpers, but it is somewhat outdated and not complete. It is more a "cheat sheet" than a real documentation accessible to new eBPF developers. This commit attempts to improve the situation by replacing the existing overview for the helpers with a more developed description. Furthermore, a Python script is added to generate a manual page for eBPF helpers. The workflow is the following, and requires the rst2man utility: $ ./scripts/bpf_helpers_doc.py \ --filename include/uapi/linux/bpf.h > /tmp/bpf-helpers.rst $ rst2man /tmp/bpf-helpers.rst > /tmp/bpf-helpers.7 $ man /tmp/bpf-helpers.7 The objective is to keep all documentation related to the helpers in a single place, and to be able to generate from here a manual page that could be packaged in the man-pages repository and shipped with most distributions. Additionally, parsing the prototypes of the helper functions could hopefully be reused, with a different Printer object, to generate header files needed in some eBPF-related projects. Regarding the description of each helper, it comprises several items: - The function prototype. - A description of the function and of its arguments (except for a couple of cases, when there are no arguments and the return value makes the function usage really obvious). - A description of return values (if not void). Additional items such as the list of compatible eBPF program and map types for each helper, Linux kernel version that introduced the helper, GPL-only restriction, and commit hash could be added in the future, but it was decided on the mailing list to leave them aside for now. For several helpers, descriptions are inspired (at times, nearly copied) from the commit logs introducing them in the kernel--Many thanks to their respective authors! Some sentences were also adapted from comments from the reviews, thanks to the reviewers as well. Descriptions were completed as much as possible, the objective being to have something easily accessible even for people just starting with eBPF. There is probably a bit more work to do in this direction for some helpers. Some RST formatting is used in the descriptions (not in function prototypes, to keep them readable, but the Python script provided in order to generate the RST for the manual page does add formatting to prototypes, to produce something pretty) to get "bold" and "italics" in manual pages. Hopefully, the descriptions in bpf.h file remains perfectly readable. Note that the few trailing white spaces are intentional, removing them would break paragraphs for rst2man. The descriptions should ideally be updated each time someone adds a new helper, or updates the behaviour (new socket option supported, ...) or the interface (new flags available, ...) of existing ones. To ease the review process, the documentation has been split into several patches. v3 -> v4: - Add a patch (#9) for newly added BPF helpers. - Add a patch (#10) to update UAPI bpf.h version under tools/. - Use SPDX tag in Python script. - Several fixes on man page header and footer, and helpers documentation. Please refer to individual patches for details. RFC v2 -> PATCH v3: Several fixes on man page header and footer, and helpers documentation. Please refer to individual patches for details. RFC v1 -> RFC v2: - Remove "For" (compatible program and map types), "Since" (minimal Linux kernel version required), "GPL only" sections and commit hashes for the helpers. - Add comment on top of the description list to explain how this documentation is supposed to be processed. - Update Python script accordingly (remove the same sections, and remove paragraphs on program types and GPL restrictions from man page header). - Split series into several patches. ==================== Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net> Cc: linux-doc@vger.kernel.org Cc: linux-man@vger.kernel.org
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由 Quentin Monnet 提交于
Update tools/include/uapi/linux/bpf.h file in order to reflect the changes for BPF helper functions documentation introduced in previous commits. Signed-off-by: NQuentin Monnet <quentin.monnet@netronome.com> Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>
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