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* bpf: Avoid visit same object multiple timesYonghong Song2020-08-181-1/+2
| | | | | | | | | | | | | | | | Currently when traversing all tasks, the next tid is always increased by one. This may result in visiting the same task multiple times in a pid namespace. This patch fixed the issue by seting the next tid as pid_nr_ns(pid, ns) + 1, similar to funciton next_tgid(). Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Cc: Rik van Riel <riel@surriel.com> Link: https://lore.kernel.org/bpf/20200818222310.2181500-1-yhs@fb.com
* bpf: Fix a rcu_sched stall issue with bpf task/task_file iteratorYonghong Song2020-08-181-1/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In our production system, we observed rcu stalls when 'bpftool prog` is running. rcu: INFO: rcu_sched self-detected stall on CPU rcu: \x097-....: (20999 ticks this GP) idle=302/1/0x4000000000000000 softirq=1508852/1508852 fqs=4913 \x09(t=21031 jiffies g=2534773 q=179750) NMI backtrace for cpu 7 CPU: 7 PID: 184195 Comm: bpftool Kdump: loaded Tainted: G W 5.8.0-00004-g68bfc7f8c1b4 #6 Hardware name: Quanta Twin Lakes MP/Twin Lakes Passive MP, BIOS F09_3A17 05/03/2019 Call Trace: <IRQ> dump_stack+0x57/0x70 nmi_cpu_backtrace.cold+0x14/0x53 ? lapic_can_unplug_cpu.cold+0x39/0x39 nmi_trigger_cpumask_backtrace+0xb7/0xc7 rcu_dump_cpu_stacks+0xa2/0xd0 rcu_sched_clock_irq.cold+0x1ff/0x3d9 ? tick_nohz_handler+0x100/0x100 update_process_times+0x5b/0x90 tick_sched_timer+0x5e/0xf0 __hrtimer_run_queues+0x12a/0x2a0 hrtimer_interrupt+0x10e/0x280 __sysvec_apic_timer_interrupt+0x51/0xe0 asm_call_on_stack+0xf/0x20 </IRQ> sysvec_apic_timer_interrupt+0x6f/0x80 asm_sysvec_apic_timer_interrupt+0x12/0x20 RIP: 0010:task_file_seq_get_next+0x71/0x220 Code: 00 00 8b 53 1c 49 8b 7d 00 89 d6 48 8b 47 20 44 8b 18 41 39 d3 76 75 48 8b 4f 20 8b 01 39 d0 76 61 41 89 d1 49 39 c1 48 19 c0 <48> 8b 49 08 21 d0 48 8d 04 c1 4c 8b 08 4d 85 c9 74 46 49 8b 41 38 RSP: 0018:ffffc90006223e10 EFLAGS: 00000297 RAX: ffffffffffffffff RBX: ffff888f0d172388 RCX: ffff888c8c07c1c0 RDX: 00000000000f017b RSI: 00000000000f017b RDI: ffff888c254702c0 RBP: ffffc90006223e68 R08: ffff888be2a1c140 R09: 00000000000f017b R10: 0000000000000002 R11: 0000000000100000 R12: ffff888f23c24118 R13: ffffc90006223e60 R14: ffffffff828509a0 R15: 00000000ffffffff task_file_seq_next+0x52/0xa0 bpf_seq_read+0xb9/0x320 vfs_read+0x9d/0x180 ksys_read+0x5f/0xe0 do_syscall_64+0x38/0x60 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7f8815f4f76e Code: c0 e9 f6 fe ff ff 55 48 8d 3d 76 70 0a 00 48 89 e5 e8 36 06 02 00 66 0f 1f 44 00 00 64 8b 04 25 18 00 00 00 85 c0 75 14 0f 05 <48> 3d 00 f0 ff ff 77 52 c3 66 0f 1f 84 00 00 00 00 00 55 48 89 e5 RSP: 002b:00007fff8f9df578 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 000000000170b9c0 RCX: 00007f8815f4f76e RDX: 0000000000001000 RSI: 00007fff8f9df5b0 RDI: 0000000000000007 RBP: 00007fff8f9e05f0 R08: 0000000000000049 R09: 0000000000000010 R10: 00007f881601fa40 R11: 0000000000000246 R12: 00007fff8f9e05a8 R13: 00007fff8f9e05a8 R14: 0000000001917f90 R15: 000000000000e22e Note that `bpftool prog` actually calls a task_file bpf iterator program to establish an association between prog/map/link/btf anon files and processes. In the case where the above rcu stall occured, we had a process having 1587 tasks and each task having roughly 81305 files. This implied 129 million bpf prog invocations. Unfortunwtely none of these files are prog/map/link/btf files so bpf iterator/prog needs to traverse all these files and not able to return to user space since there are no seq_file buffer overflow. This patch fixed the issue in bpf_seq_read() to limit the number of visited objects. If the maximum number of visited objects is reached, no more objects will be visited in the current syscall. If there is nothing written in the seq_file buffer, -EAGAIN will return to the user so user can try again. The maximum number of visited objects is set at 1 million. In our Intel Xeon D-2191 2.3GHZ 18-core server, bpf_seq_read() visiting 1 million files takes around 0.18 seconds. We did not use cond_resched() since for some iterators, e.g., netlink iterator, where rcu read_lock critical section spans between consecutive seq_ops->next(), which makes impossible to do cond_resched() in the key while loop of function bpf_seq_read(). Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Cc: Paul E. McKenney <paulmck@kernel.org> Link: https://lore.kernel.org/bpf/20200818222309.2181348-1-yhs@fb.com
* bpf: Use get_file_rcu() instead of get_file() for task_file iteratorYonghong Song2020-08-171-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With latest `bpftool prog` command, we observed the following kernel panic. BUG: kernel NULL pointer dereference, address: 0000000000000000 #PF: supervisor instruction fetch in kernel mode #PF: error_code(0x0010) - not-present page PGD dfe894067 P4D dfe894067 PUD deb663067 PMD 0 Oops: 0010 [#1] SMP CPU: 9 PID: 6023 ... RIP: 0010:0x0 Code: Bad RIP value. RSP: 0000:ffffc900002b8f18 EFLAGS: 00010286 RAX: ffff8883a405f400 RBX: ffff888e46a6bf00 RCX: 000000008020000c RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff8883a405f400 RBP: ffff888e46a6bf50 R08: 0000000000000000 R09: ffffffff81129600 R10: ffff8883a405f300 R11: 0000160000000000 R12: 0000000000002710 R13: 000000e9494b690c R14: 0000000000000202 R15: 0000000000000009 FS: 00007fd9187fe700(0000) GS:ffff888e46a40000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffffffffd6 CR3: 0000000de5d33002 CR4: 0000000000360ee0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <IRQ> rcu_core+0x1a4/0x440 __do_softirq+0xd3/0x2c8 irq_exit+0x9d/0xa0 smp_apic_timer_interrupt+0x68/0x120 apic_timer_interrupt+0xf/0x20 </IRQ> RIP: 0033:0x47ce80 Code: Bad RIP value. RSP: 002b:00007fd9187fba40 EFLAGS: 00000206 ORIG_RAX: ffffffffffffff13 RAX: 0000000000000002 RBX: 00007fd931789160 RCX: 000000000000010c RDX: 00007fd9308cdfb4 RSI: 00007fd9308cdfb4 RDI: 00007ffedd1ea0a8 RBP: 00007fd9187fbab0 R08: 000000000000000e R09: 000000000000002a R10: 0000000000480210 R11: 00007fd9187fc570 R12: 00007fd9316cc400 R13: 0000000000000118 R14: 00007fd9308cdfb4 R15: 00007fd9317a9380 After further analysis, the bug is triggered by Commit eaaacd23910f ("bpf: Add task and task/file iterator targets") which introduced task_file bpf iterator, which traverses all open file descriptors for all tasks in the current namespace. The latest `bpftool prog` calls a task_file bpf program to traverse all files in the system in order to associate processes with progs/maps, etc. When traversing files for a given task, rcu read_lock is taken to access all files in a file_struct. But it used get_file() to grab a file, which is not right. It is possible file->f_count is 0 and get_file() will unconditionally increase it. Later put_file() may cause all kind of issues with the above as one of sympotoms. The failure can be reproduced with the following steps in a few seconds: $ cat t.c #include <stdio.h> #include <sys/types.h> #include <sys/stat.h> #include <fcntl.h> #include <unistd.h> #define N 10000 int fd[N]; int main() { int i; for (i = 0; i < N; i++) { fd[i] = open("./note.txt", 'r'); if (fd[i] < 0) { fprintf(stderr, "failed\n"); return -1; } } for (i = 0; i < N; i++) close(fd[i]); return 0; } $ gcc -O2 t.c $ cat run.sh #/bin/bash for i in {1..100} do while true; do ./a.out; done & done $ ./run.sh $ while true; do bpftool prog >& /dev/null; done This patch used get_file_rcu() which only grabs a file if the file->f_count is not zero. This is to ensure the file pointer is always valid. The above reproducer did not fail for more than 30 minutes. Fixes: eaaacd23910f ("bpf: Add task and task/file iterator targets") Suggested-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Reviewed-by: Josef Bacik <josef@toxicpanda.com> Link: https://lore.kernel.org/bpf/20200817174214.252601-1-yhs@fb.com
* bpf: Iterate through all PT_NOTE sections when looking for build idJiri Olsa2020-08-121-10/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently when we look for build id within bpf_get_stackid helper call, we check the first NOTE section and we fail if build id is not there. However on some system (Fedora) there can be multiple NOTE sections in binaries and build id data is not always the first one, like: $ readelf -a /usr/bin/ls ... [ 2] .note.gnu.propert NOTE 0000000000000338 00000338 0000000000000020 0000000000000000 A 0 0 8358 [ 3] .note.gnu.build-i NOTE 0000000000000358 00000358 0000000000000024 0000000000000000 A 0 0 437c [ 4] .note.ABI-tag NOTE 000000000000037c 0000037c ... So the stack_map_get_build_id function will fail on build id retrieval and fallback to BPF_STACK_BUILD_ID_IP. This patch is changing the stack_map_get_build_id code to iterate through all the NOTE sections and try to get build id data from each of them. When tracing on sched_switch tracepoint that does bpf_get_stackid helper call kernel build, I can see about 60% increase of successful build id retrieval. The rest seems fails on -EFAULT. Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Song Liu <songliubraving@fb.com> Link: https://lore.kernel.org/bpf/20200812123102.20032-1-jolsa@kernel.org
* bpf: Delete repeated words in commentsRandy Dunlap2020-08-072-2/+2
| | | | | | | | Drop repeated words in kernel/bpf/: {has, the} Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20200807033141.10437-1-rdunlap@infradead.org
* bpf: Change uapi for bpf iterator map elementsYonghong Song2020-08-063-38/+59
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit a5cbe05a6673 ("bpf: Implement bpf iterator for map elements") added bpf iterator support for map elements. The map element bpf iterator requires info to identify a particular map. In the above commit, the attr->link_create.target_fd is used to carry map_fd and an enum bpf_iter_link_info is added to uapi to specify the target_fd actually representing a map_fd: enum bpf_iter_link_info { BPF_ITER_LINK_UNSPEC = 0, BPF_ITER_LINK_MAP_FD = 1, MAX_BPF_ITER_LINK_INFO, }; This is an extensible approach as we can grow enumerator for pid, cgroup_id, etc. and we can unionize target_fd for pid, cgroup_id, etc. But in the future, there are chances that more complex customization may happen, e.g., for tasks, it could be filtered based on both cgroup_id and user_id. This patch changed the uapi to have fields __aligned_u64 iter_info; __u32 iter_info_len; for additional iter_info for link_create. The iter_info is defined as union bpf_iter_link_info { struct { __u32 map_fd; } map; }; So future extension for additional customization will be easier. The bpf_iter_link_info will be passed to target callback to validate and generic bpf_iter framework does not need to deal it any more. Note that map_fd = 0 will be considered invalid and -EBADF will be returned to user space. Fixes: a5cbe05a6673 ("bpf: Implement bpf iterator for map elements") Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andriin@fb.com> Acked-by: John Fastabend <john.fastabend@gmail.com> Link: https://lore.kernel.org/bpf/20200805055056.1457463-1-yhs@fb.com
* Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-nextDavid S. Miller2020-08-0315-202/+1088
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Daniel Borkmann says: ==================== pull-request: bpf-next 2020-08-04 The following pull-request contains BPF updates for your *net-next* tree. We've added 73 non-merge commits during the last 9 day(s) which contain a total of 135 files changed, 4603 insertions(+), 1013 deletions(-). The main changes are: 1) Implement bpf_link support for XDP. Also add LINK_DETACH operation for the BPF syscall allowing processes with BPF link FD to force-detach, from Andrii Nakryiko. 2) Add BPF iterator for map elements and to iterate all BPF programs for efficient in-kernel inspection, from Yonghong Song and Alexei Starovoitov. 3) Separate bpf_get_{stack,stackid}() helpers for perf events in BPF to avoid unwinder errors, from Song Liu. 4) Allow cgroup local storage map to be shared between programs on the same cgroup. Also extend BPF selftests with coverage, from YiFei Zhu. 5) Add BPF exception tables to ARM64 JIT in order to be able to JIT BPF_PROBE_MEM load instructions, from Jean-Philippe Brucker. 6) Follow-up fixes on BPF socket lookup in combination with reuseport group handling. Also add related BPF selftests, from Jakub Sitnicki. 7) Allow to use socket storage in BPF_PROG_TYPE_CGROUP_SOCK-typed programs for socket create/release as well as bind functions, from Stanislav Fomichev. 8) Fix an info leak in xsk_getsockopt() when retrieving XDP stats via old struct xdp_statistics, from Peilin Ye. 9) Fix PT_REGS_RC{,_CORE}() macros in libbpf for MIPS arch, from Jerry Crunchtime. 10) Extend BPF kernel test infra with skb->family and skb->{local,remote}_ip{4,6} fields and allow user space to specify skb->dev via ifindex, from Dmitry Yakunin. 11) Fix a bpftool segfault due to missing program type name and make it more robust to prevent them in future gaps, from Quentin Monnet. 12) Consolidate cgroup helper functions across selftests and fix a v6 localhost resolver issue, from John Fastabend. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
| * bpf: Add support for forced LINK_DETACH commandAndrii Nakryiko2020-08-013-1/+48
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add LINK_DETACH command to force-detach bpf_link without destroying it. It has the same behavior as auto-detaching of bpf_link due to cgroup dying for bpf_cgroup_link or net_device being destroyed for bpf_xdp_link. In such case, bpf_link is still a valid kernel object, but is defuncts and doesn't hold BPF program attached to corresponding BPF hook. This functionality allows users with enough access rights to manually force-detach attached bpf_link without killing respective owner process. This patch implements LINK_DETACH for cgroup, xdp, and netns links, mostly re-using existing link release handling code. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Song Liu <songliubraving@fb.com> Acked-by: John Fastabend <john.fastabend@gmail.com> Link: https://lore.kernel.org/bpf/20200731182830.286260-2-andriin@fb.com
| * bpf: Add missing newline characters in verifier error messagesYonghong Song2020-07-311-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | Newline characters are added in two verifier error messages, refactored in Commit afbf21dce668 ("bpf: Support readonly/readwrite buffers in verifier"). This way, they do not mix with messages afterwards. Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Song Liu <songliubraving@fb.com> Link: https://lore.kernel.org/bpf/20200728221801.1090349-1-yhs@fb.com
| * bpf: Fix build without CONFIG_NET when using BPF XDP linkAndrii Nakryiko2020-07-291-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Entire net/core subsystem is not built without CONFIG_NET. linux/netdevice.h just assumes that it's always there, so the easiest way to fix this is to conditionally compile out bpf_xdp_link_attach() use in bpf/syscall.c. Fixes: aa8d3a716b59 ("bpf, xdp: Add bpf_link-based XDP attachment API") Reported-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Randy Dunlap <rdunlap@infradead.org> # build-tested Acked-by: Song Liu <songliubraving@fb.com> Link: https://lore.kernel.org/bpf/20200728190527.110830-1-andriin@fb.com
| * bpf: Fix swapped arguments in calls to check_buffer_accessColin Ian King2020-07-281-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | There are a couple of arguments of the boolean flag zero_size_allowed and the char pointer buf_info when calling to function check_buffer_access that are swapped by mistake. Fix these by swapping them to correct the argument ordering. Fixes: afbf21dce668 ("bpf: Support readonly/readwrite buffers in verifier") Addresses-Coverity: ("Array compared to 0") Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20200727175411.155179-1-colin.king@canonical.com
| * bpf, xdp: Add bpf_link-based XDP attachment APIAndrii Nakryiko2020-07-251-0/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add bpf_link-based API (bpf_xdp_link) to attach BPF XDP program through BPF_LINK_CREATE command. bpf_xdp_link is mutually exclusive with direct BPF program attachment, previous BPF program should be detached prior to attempting to create a new bpf_xdp_link attachment (for a given XDP mode). Once BPF link is attached, it can't be replaced by other BPF program attachment or link attachment. It will be detached only when the last BPF link FD is closed. bpf_xdp_link will be auto-detached when net_device is shutdown, similarly to how other BPF links behave (cgroup, flow_dissector). At that point bpf_link will become defunct, but won't be destroyed until last FD is closed. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200722064603.3350758-5-andriin@fb.com
| * bpf: Fix build on architectures with special bpf_user_pt_regs_tSong Liu2020-07-251-5/+4
| | | | | | | | | | | | | | | | | | | | | | | | Architectures like s390, powerpc, arm64, riscv have speical definition of bpf_user_pt_regs_t. So we need to cast the pointer before passing it to bpf_get_stack(). This is similar to bpf_get_stack_tp(). Fixes: 03d42fd2d83f ("bpf: Separate bpf_get_[stack|stackid] for perf events BPF") Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Song Liu <songliubraving@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200724200503.3629591-1-songliubraving@fb.com
| * bpf/local_storage: Fix build without CONFIG_CGROUPYiFei Zhu2020-07-251-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | local_storage.o has its compile guard as CONFIG_BPF_SYSCALL, which does not imply that CONFIG_CGROUP is on. Including cgroup-internal.h when CONFIG_CGROUP is off cause a compilation failure. Fixes: f67cfc233706 ("bpf: Make cgroup storages shared between programs on the same cgroup") Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: YiFei Zhu <zhuyifei@google.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200724211753.902969-1-zhuyifei1999@gmail.com
| * bpf: Make cgroup storages shared between programs on the same cgroupYiFei Zhu2020-07-253-139/+156
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This change comes in several parts: One, the restriction that the CGROUP_STORAGE map can only be used by one program is removed. This results in the removal of the field 'aux' in struct bpf_cgroup_storage_map, and removal of relevant code associated with the field, and removal of now-noop functions bpf_free_cgroup_storage and bpf_cgroup_storage_release. Second, we permit a key of type u64 as the key to the map. Providing such a key type indicates that the map should ignore attach type when comparing map keys. However, for simplicity newly linked storage will still have the attach type at link time in its key struct. cgroup_storage_check_btf is adapted to accept u64 as the type of the key. Third, because the storages are now shared, the storages cannot be unconditionally freed on program detach. There could be two ways to solve this issue: * A. Reference count the usage of the storages, and free when the last program is detached. * B. Free only when the storage is impossible to be referred to again, i.e. when either the cgroup_bpf it is attached to, or the map itself, is freed. Option A has the side effect that, when the user detach and reattach a program, whether the program gets a fresh storage depends on whether there is another program attached using that storage. This could trigger races if the user is multi-threaded, and since nondeterminism in data races is evil, go with option B. The both the map and the cgroup_bpf now tracks their associated storages, and the storage unlink and free are removed from cgroup_bpf_detach and added to cgroup_bpf_release and cgroup_storage_map_free. The latter also new holds the cgroup_mutex to prevent any races with the former. Fourth, on attach, we reuse the old storage if the key already exists in the map, via cgroup_storage_lookup. If the storage does not exist yet, we create a new one, and publish it at the last step in the attach process. This does not create a race condition because for the whole attach the cgroup_mutex is held. We keep track of an array of new storages that was allocated and if the process fails only the new storages would get freed. Signed-off-by: YiFei Zhu <zhuyifei@google.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/d5401c6106728a00890401190db40020a1f84ff1.1595565795.git.zhuyifei@google.com
| * bpf: Fail PERF_EVENT_IOC_SET_BPF when bpf_get_[stack|stackid] cannot workSong Liu2020-07-251-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | bpf_get_[stack|stackid] on perf_events with precise_ip uses callchain attached to perf_sample_data. If this callchain is not presented, do not allow attaching BPF program that calls bpf_get_[stack|stackid] to this event. In the error case, -EPROTO is returned so that libbpf can identify this error and print proper hint message. Signed-off-by: Song Liu <songliubraving@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200723180648.1429892-3-songliubraving@fb.com
| * bpf: Separate bpf_get_[stack|stackid] for perf events BPFSong Liu2020-07-251-18/+166
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Calling get_perf_callchain() on perf_events from PEBS entries may cause unwinder errors. To fix this issue, the callchain is fetched early. Such perf_events are marked with __PERF_SAMPLE_CALLCHAIN_EARLY. Similarly, calling bpf_get_[stack|stackid] on perf_events from PEBS may also cause unwinder errors. To fix this, add separate version of these two helpers, bpf_get_[stack|stackid]_pe. These two hepers use callchain in bpf_perf_event_data_kern->data->callchain. Signed-off-by: Song Liu <songliubraving@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200723180648.1429892-2-songliubraving@fb.com
| * bpf: Implement bpf iterator for array mapsYonghong Song2020-07-252-2/+142
| | | | | | | | | | | | | | | | | | | | | | The bpf iterators for array and percpu array are implemented. Similar to hash maps, for percpu array map, bpf program will receive values from all cpus. Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200723184115.590532-1-yhs@fb.com
| * bpf: Implement bpf iterator for hash mapsYonghong Song2020-07-252-1/+217
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The bpf iterators for hash, percpu hash, lru hash and lru percpu hash are implemented. During link time, bpf_iter_reg->check_target() will check map type and ensure the program access key/value region is within the map defined key/value size limit. For percpu hash and lru hash maps, the bpf program will receive values for all cpus. The map element bpf iterator infrastructure will prepare value properly before passing the value pointer to the bpf program. This patch set supports readonly map keys and read/write map values. It does not support deleting map elements, e.g., from hash tables. If there is a user case for this, the following mechanism can be used to support map deletion for hashtab, etc. - permit a new bpf program return value, e.g., 2, to let bpf iterator know the map element should be removed. - since bucket lock is taken, the map element will be queued. - once bucket lock is released after all elements under this bucket are traversed, all to-be-deleted map elements can be deleted. Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200723184114.590470-1-yhs@fb.com
| * bpf: Implement bpf iterator for map elementsYonghong Song2020-07-252-17/+98
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The bpf iterator for map elements are implemented. The bpf program will receive four parameters: bpf_iter_meta *meta: the meta data bpf_map *map: the bpf_map whose elements are traversed void *key: the key of one element void *value: the value of the same element Here, meta and map pointers are always valid, and key has register type PTR_TO_RDONLY_BUF_OR_NULL and value has register type PTR_TO_RDWR_BUF_OR_NULL. The kernel will track the access range of key and value during verification time. Later, these values will be compared against the values in the actual map to ensure all accesses are within range. A new field iter_seq_info is added to bpf_map_ops which is used to add map type specific information, i.e., seq_ops, init/fini seq_file func and seq_file private data size. Subsequent patches will have actual implementation for bpf_map_ops->iter_seq_info. In user space, BPF_ITER_LINK_MAP_FD needs to be specified in prog attr->link_create.flags, which indicates that attr->link_create.target_fd is a map_fd. The reason for such an explicit flag is for possible future cases where one bpf iterator may allow more than one possible customization, e.g., pid and cgroup id for task_file. Current kernel internal implementation only allows the target to register at most one required bpf_iter_link_info. To support the above case, optional bpf_iter_link_info's are needed, the target can be extended to register such link infos, and user provided link_info needs to match one of target supported ones. Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200723184112.590360-1-yhs@fb.com
| * bpf: Support readonly/readwrite buffers in verifierYonghong Song2020-07-252-6/+98
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Readonly and readwrite buffer register states are introduced. Totally four states, PTR_TO_RDONLY_BUF[_OR_NULL] and PTR_TO_RDWR_BUF[_OR_NULL] are supported. As suggested by their respective names, PTR_TO_RDONLY_BUF[_OR_NULL] are for readonly buffers and PTR_TO_RDWR_BUF[_OR_NULL] for read/write buffers. These new register states will be used by later bpf map element iterator. New register states share some similarity to PTR_TO_TP_BUFFER as it will calculate accessed buffer size during verification time. The accessed buffer size will be later compared to other metrics during later attach/link_create time. Similar to reg_state PTR_TO_BTF_ID_OR_NULL in bpf iterator programs, PTR_TO_RDONLY_BUF_OR_NULL or PTR_TO_RDWR_BUF_OR_NULL reg_types can be set at prog->aux->bpf_ctx_arg_aux, and bpf verifier will retrieve the values during btf_ctx_access(). Later bpf map element iterator implementation will show how such information will be assigned during target registeration time. The verifier is also enhanced such that PTR_TO_RDONLY_BUF can be passed to ARG_PTR_TO_MEM[_OR_NULL] helper argument, and PTR_TO_RDWR_BUF can be passed to ARG_PTR_TO_MEM[_OR_NULL] or ARG_PTR_TO_UNINIT_MEM. Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200723184111.590274-1-yhs@fb.com
| * bpf: Refactor to provide aux info to bpf_iter_init_seq_priv_tYonghong Song2020-07-252-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | This patch refactored target bpf_iter_init_seq_priv_t callback function to accept additional information. This will be needed in later patches for map element targets since a particular map should be passed to traverse elements for that particular map. In the future, other information may be passed to target as well, e.g., pid, cgroup id, etc. to customize the iterator. Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200723184110.590156-1-yhs@fb.com
| * bpf: Refactor bpf_iter_reg to have separate seq_info memberYonghong Song2020-07-254-14/+30
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There is no functionality change for this patch. Struct bpf_iter_reg is used to register a bpf_iter target, which includes information for both prog_load, link_create and seq_file creation. This patch puts fields related seq_file creation into a different structure. This will be useful for map elements iterator where one iterator covers different map types and different map types may have different seq_ops, init/fini private_data function and private_data size. Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200723184109.590030-1-yhs@fb.com
| * bpf: Add bpf_prog iteratorAlexei Starovoitov2020-07-253-1/+123
| | | | | | | | | | | | | | | | | | | | | | It's mostly a copy paste of commit 6086d29def80 ("bpf: Add bpf_map iterator") that is use to implement bpf_seq_file opreations to traverse all bpf programs. v1->v2: Tweak to use build time btf_id Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Yonghong Song <yhs@fb.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net>
| * bpf: Fix pos computation for bpf_iter seq_ops->start()Yonghong Song2020-07-252-12/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, the pos pointer in bpf iterator map/task/task_file seq_ops->start() is always incremented. This is incorrect. It should be increased only if *pos is 0 (for SEQ_START_TOKEN) since these start() function actually returns the first real object. If *pos is not 0, it merely found the object based on the state in seq->private, and not really advancing the *pos. This patch fixed this issue by only incrementing *pos if it is 0. Note that the old *pos calculation, although not correct, does not affect correctness of bpf_iter as bpf_iter seq_file->read() does not support llseek. This patch also renamed "mid" in bpf_map iterator seq_file private data to "map_id" for better clarity. Fixes: 6086d29def80 ("bpf: Add bpf_map iterator") Fixes: eaaacd23910f ("bpf: Add task and task/file iterator targets") Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200722195156.4029817-1-yhs@fb.com
* | Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netDavid S. Miller2020-08-022-4/+10
|\ \ | |/ |/| | | | | | | | | Resolved kernel/bpf/btf.c using instructions from merge commit 69138b34a7248d2396ab85c8652e20c0c39beaba Signed-off-by: David S. Miller <davem@davemloft.net>
| * Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpfDavid S. Miller2020-07-312-3/+14
| |\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Daniel Borkmann says: ==================== pull-request: bpf 2020-07-31 The following pull-request contains BPF updates for your *net* tree. We've added 5 non-merge commits during the last 21 day(s) which contain a total of 5 files changed, 126 insertions(+), 18 deletions(-). The main changes are: 1) Fix a map element leak in HASH_OF_MAPS map type, from Andrii Nakryiko. 2) Fix a NULL pointer dereference in __btf_resolve_helper_id() when no btf_vmlinux is available, from Peilin Ye. 3) Init pos variable in __bpfilter_process_sockopt(), from Christoph Hellwig. 4) Fix a cgroup sockopt verifier test by specifying expected attach type, from Jean-Philippe Brucker. Note that when net gets merged into net-next later on, there is a small merge conflict in kernel/bpf/btf.c between commit 5b801dfb7feb ("bpf: Fix NULL pointer dereference in __btf_resolve_helper_id()") from the bpf tree and commit 138b9a0511c7 ("bpf: Remove btf_id helpers resolving") from the net-next tree. Resolve as follows: remove the old hunk with the __btf_resolve_helper_id() function. Change the btf_resolve_helper_id() so it actually tests for a NULL btf_vmlinux and bails out: int btf_resolve_helper_id(struct bpf_verifier_log *log, const struct bpf_func_proto *fn, int arg) { int id; if (fn->arg_type[arg] != ARG_PTR_TO_BTF_ID || !btf_vmlinux) return -EINVAL; id = fn->btf_id[arg]; if (!id || id > btf_vmlinux->nr_types) return -EINVAL; return id; } Let me know if you run into any others issues (CC'ing Jiri Olsa so he's in the loop with regards to merge conflict resolution). ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
| | * bpf: Fix map leak in HASH_OF_MAPS mapAndrii Nakryiko2020-07-301-3/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fix HASH_OF_MAPS bug of not putting inner map pointer on bpf_map_elem_update() operation. This is due to per-cpu extra_elems optimization, which bypassed free_htab_elem() logic doing proper clean ups. Make sure that inner map is put properly in optimized case as well. Fixes: 8c290e60fa2a ("bpf: fix hashmap extra_elems logic") Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Song Liu <songliubraving@fb.com> Link: https://lore.kernel.org/bpf/20200729040913.2815687-1-andriin@fb.com
| | * bpf: Fix NULL pointer dereference in __btf_resolve_helper_id()Peilin Ye2020-07-151-0/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Prevent __btf_resolve_helper_id() from dereferencing `btf_vmlinux` as NULL. This patch fixes the following syzbot bug: https://syzkaller.appspot.com/bug?id=f823224ada908fa5c207902a5a62065e53ca0fcc Reported-by: syzbot+ee09bda7017345f1fbe6@syzkaller.appspotmail.com Signed-off-by: Peilin Ye <yepeilin.cs@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20200714180904.277512-1-yepeilin.cs@gmail.com
* | | bpf: net: Use precomputed btf_id for bpf iteratorsYonghong Song2020-07-213-5/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | One additional field btf_id is added to struct bpf_ctx_arg_aux to store the precomputed btf_ids. The btf_id is computed at build time with BTF_ID_LIST or BTF_ID_LIST_GLOBAL macro definitions. All existing bpf iterators are changed to used pre-compute btf_ids. Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200720163403.1393551-1-yhs@fb.com
* | | bpf: Compute bpf_skc_to_*() helper socket btf ids at build timeYonghong Song2020-07-211-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, socket types (struct tcp_sock, udp_sock, etc.) used by bpf_skc_to_*() helpers are computed when vmlinux_btf is first built in the kernel. Commit 5a2798ab32ba ("bpf: Add BTF_ID_LIST/BTF_ID/BTF_ID_UNUSED macros") implemented a mechanism to compute btf_ids at kernel build time which can simplify kernel implementation and reduce runtime overhead by removing in-kernel btf_id calculation. This patch did exactly this, removing in-kernel btf_id computation and utilizing build-time btf_id computation. If CONFIG_DEBUG_INFO_BTF is not defined, BTF_ID_LIST will define an array with size of 5, which is not enough for btf_sock_ids. So define its own static array if CONFIG_DEBUG_INFO_BTF is not defined. Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200720163358.1393023-1-yhs@fb.com
* | | bpf: cpumap: Fix possible rcpu kthread hungLorenzo Bianconi2020-07-211-4/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fix the following cpumap kthread hung. The issue is currently occurring when __cpu_map_load_bpf_program fails (e.g if the bpf prog has not BPF_XDP_CPUMAP as expected_attach_type) $./test_progs -n 101 101/1 cpumap_with_progs:OK 101 xdp_cpumap_attach:OK Summary: 1/1 PASSED, 0 SKIPPED, 0 FAILED [ 369.996478] INFO: task cpumap/0/map:7:205 blocked for more than 122 seconds. [ 369.998463] Not tainted 5.8.0-rc4-01472-ge57892f50a07 #212 [ 370.000102] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 370.001918] cpumap/0/map:7 D 0 205 2 0x00004000 [ 370.003228] Call Trace: [ 370.003930] __schedule+0x5c7/0xf50 [ 370.004901] ? io_schedule_timeout+0xb0/0xb0 [ 370.005934] ? static_obj+0x31/0x80 [ 370.006788] ? mark_held_locks+0x24/0x90 [ 370.007752] ? cpu_map_bpf_prog_run_xdp+0x6c0/0x6c0 [ 370.008930] schedule+0x6f/0x160 [ 370.009728] schedule_preempt_disabled+0x14/0x20 [ 370.010829] kthread+0x17b/0x240 [ 370.011433] ? kthread_create_worker_on_cpu+0xd0/0xd0 [ 370.011944] ret_from_fork+0x1f/0x30 [ 370.012348] Showing all locks held in the system: [ 370.013025] 1 lock held by khungtaskd/33: [ 370.013432] #0: ffffffff82b24720 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x28/0x1c3 [ 370.014461] ============================================= Fixes: 9216477449f3 ("bpf: cpumap: Add the possibility to attach an eBPF program to cpumap") Reported-by: Jakub Sitnicki <jakub@cloudflare.com> Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Tested-by: Jakub Sitnicki <jakub@cloudflare.com> Reviewed-by: Jakub Sitnicki <jakub@cloudflare.com> Link: https://lore.kernel.org/bpf/e54f2aabf959f298939e5507b09c48f8c2e380be.1595170625.git.lorenzo@kernel.org
* | | bpf, netns: Fix build without CONFIG_INETJakub Sitnicki2020-07-211-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When CONFIG_NET is set but CONFIG_INET isn't, build fails with: ld: kernel/bpf/net_namespace.o: in function `netns_bpf_attach_type_unneed': kernel/bpf/net_namespace.c:32: undefined reference to `bpf_sk_lookup_enabled' ld: kernel/bpf/net_namespace.o: in function `netns_bpf_attach_type_need': kernel/bpf/net_namespace.c:43: undefined reference to `bpf_sk_lookup_enabled' This is because without CONFIG_INET bpf_sk_lookup_enabled symbol is not available. Wrap references to bpf_sk_lookup_enabled with preprocessor conditionals. Fixes: 1559b4aa1db4 ("inet: Run SK_LOOKUP BPF program on socket lookup") Reported-by: Randy Dunlap <rdunlap@infradead.org> Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Randy Dunlap <rdunlap@infradead.org> # build-tested Link: https://lore.kernel.org/bpf/20200721100716.720477-1-jakub@cloudflare.com
* | | inet: Run SK_LOOKUP BPF program on socket lookupJakub Sitnicki2020-07-171-1/+31
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Run a BPF program before looking up a listening socket on the receive path. Program selects a listening socket to yield as result of socket lookup by calling bpf_sk_assign() helper and returning SK_PASS code. Program can revert its decision by assigning a NULL socket with bpf_sk_assign(). Alternatively, BPF program can also fail the lookup by returning with SK_DROP, or let the lookup continue as usual with SK_PASS on return, when no socket has been selected with bpf_sk_assign(). This lets the user match packets with listening sockets freely at the last possible point on the receive path, where we know that packets are destined for local delivery after undergoing policing, filtering, and routing. With BPF code selecting the socket, directing packets destined to an IP range or to a port range to a single socket becomes possible. In case multiple programs are attached, they are run in series in the order in which they were attached. The end result is determined from return codes of all the programs according to following rules: 1. If any program returned SK_PASS and selected a valid socket, the socket is used as result of socket lookup. 2. If more than one program returned SK_PASS and selected a socket, last selection takes effect. 3. If any program returned SK_DROP, and no program returned SK_PASS and selected a socket, socket lookup fails with -ECONNREFUSED. 4. If all programs returned SK_PASS and none of them selected a socket, socket lookup continues to htable-based lookup. Suggested-by: Marek Majkowski <marek@cloudflare.com> Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200717103536.397595-5-jakub@cloudflare.com
* | | bpf: Introduce SK_LOOKUP program type with a dedicated attach pointJakub Sitnicki2020-07-173-3/+24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add a new program type BPF_PROG_TYPE_SK_LOOKUP with a dedicated attach type BPF_SK_LOOKUP. The new program kind is to be invoked by the transport layer when looking up a listening socket for a new connection request for connection oriented protocols, or when looking up an unconnected socket for a packet for connection-less protocols. When called, SK_LOOKUP BPF program can select a socket that will receive the packet. This serves as a mechanism to overcome the limits of what bind() API allows to express. Two use-cases driving this work are: (1) steer packets destined to an IP range, on fixed port to a socket 192.0.2.0/24, port 80 -> NGINX socket (2) steer packets destined to an IP address, on any port to a socket 198.51.100.1, any port -> L7 proxy socket In its run-time context program receives information about the packet that triggered the socket lookup. Namely IP version, L4 protocol identifier, and address 4-tuple. Context can be further extended to include ingress interface identifier. To select a socket BPF program fetches it from a map holding socket references, like SOCKMAP or SOCKHASH, and calls bpf_sk_assign(ctx, sk, ...) helper to record the selection. Transport layer then uses the selected socket as a result of socket lookup. In its basic form, SK_LOOKUP acts as a filter and hence must return either SK_PASS or SK_DROP. If the program returns with SK_PASS, transport should look for a socket to receive the packet, or use the one selected by the program if available, while SK_DROP informs the transport layer that the lookup should fail. This patch only enables the user to attach an SK_LOOKUP program to a network namespace. Subsequent patches hook it up to run on local delivery path in ipv4 and ipv6 stacks. Suggested-by: Marek Majkowski <marek@cloudflare.com> Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200717103536.397595-3-jakub@cloudflare.com
* | | bpf, netns: Handle multiple link attachmentsJakub Sitnicki2020-07-172-9/+136
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Extend the BPF netns link callbacks to rebuild (grow/shrink) or update the prog_array at given position when link gets attached/updated/released. This let's us lift the limit of having just one link attached for the new attach type introduced by subsequent patch. No functional changes intended. Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/20200717103536.397595-2-jakub@cloudflare.com
* | | bpf: cpumap: Implement XDP_REDIRECT for eBPF programs attached to map entriesLorenzo Bianconi2020-07-161-2/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Introduce XDP_REDIRECT support for eBPF programs attached to cpumap entries. This patch has been tested on Marvell ESPRESSObin using a modified version of xdp_redirect_cpu sample in order to attach a XDP program to CPUMAP entries to perform a redirect on the mvneta interface. In particular the following scenario has been tested: rq (cpu0) --> mvneta - XDP_REDIRECT (cpu0) --> CPUMAP - XDP_REDIRECT (cpu1) --> mvneta $./xdp_redirect_cpu -p xdp_cpu_map0 -d eth0 -c 1 -e xdp_redirect \ -f xdp_redirect_kern.o -m tx_port -r eth0 tx: 285.2 Kpps rx: 285.2 Kpps Attaching a simple XDP program on eth0 to perform XDP_TX gives comparable results: tx: 288.4 Kpps rx: 288.4 Kpps Co-developed-by: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Jesper Dangaard Brouer <brouer@redhat.com> Link: https://lore.kernel.org/bpf/2cf8373a731867af302b00c4ff16c122630c4980.1594734381.git.lorenzo@kernel.org
* | | bpf: cpumap: Add the possibility to attach an eBPF program to cpumapLorenzo Bianconi2020-07-161-13/+108
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Introduce the capability to attach an eBPF program to cpumap entries. The idea behind this feature is to add the possibility to define on which CPU run the eBPF program if the underlying hw does not support RSS. Current supported verdicts are XDP_DROP and XDP_PASS. This patch has been tested on Marvell ESPRESSObin using xdp_redirect_cpu sample available in the kernel tree to identify possible performance regressions. Results show there are no observable differences in packet-per-second: $./xdp_redirect_cpu --progname xdp_cpu_map0 --dev eth0 --cpu 1 rx: 354.8 Kpps rx: 356.0 Kpps rx: 356.8 Kpps rx: 356.3 Kpps rx: 356.6 Kpps rx: 356.6 Kpps rx: 356.7 Kpps rx: 355.8 Kpps rx: 356.8 Kpps rx: 356.8 Kpps Co-developed-by: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Jesper Dangaard Brouer <brouer@redhat.com> Link: https://lore.kernel.org/bpf/5c9febdf903d810b3415732e5cd98491d7d9067a.1594734381.git.lorenzo@kernel.org
* | | cpumap: Formalize map value as a named structLorenzo Bianconi2020-07-161-13/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | As it has been already done for devmap, introduce 'struct bpf_cpumap_val' to formalize the expected values that can be passed in for a CPUMAP. Update cpumap code to use the struct. Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Jesper Dangaard Brouer <brouer@redhat.com> Link: https://lore.kernel.org/bpf/754f950674665dae6139c061d28c1d982aaf4170.1594734381.git.lorenzo@kernel.org
* | | cpumap: Use non-locked version __ptr_ring_consume_batchedJesper Dangaard Brouer2020-07-161-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 77361825bb01 ("bpf: cpumap use ptr_ring_consume_batched") changed away from using single frame ptr_ring dequeue (__ptr_ring_consume) to consume a batched, but it uses a locked version, which as the comment explain isn't needed. Change to use the non-locked version __ptr_ring_consume_batched. Fixes: 77361825bb01 ("bpf: cpumap use ptr_ring_consume_batched") Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/a9c7d06f9a009e282209f0c8c7b2c5d9b9ad60b9.1594734381.git.lorenzo@kernel.org
* | | Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-nextDavid S. Miller2020-07-133-93/+18
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Alexei Starovoitov says: ==================== pull-request: bpf-next 2020-07-13 The following pull-request contains BPF updates for your *net-next* tree. We've added 36 non-merge commits during the last 7 day(s) which contain a total of 62 files changed, 2242 insertions(+), 468 deletions(-). The main changes are: 1) Avoid trace_printk warning banner by switching bpf_trace_printk to use its own tracing event, from Alan. 2) Better libbpf support on older kernels, from Andrii. 3) Additional AF_XDP stats, from Ciara. 4) build time resolution of BTF IDs, from Jiri. 5) BPF_CGROUP_INET_SOCK_RELEASE hook, from Stanislav. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
| * | | bpf: Use BTF_ID to resolve bpf_ctx_convert structJiri Olsa2020-07-131-8/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This way the ID is resolved during compile time, and we can remove the runtime name search. Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Tested-by: Andrii Nakryiko <andriin@fb.com> Acked-by: Andrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/20200711215329.41165-7-jolsa@kernel.org
| * | | bpf: Remove btf_id helpers resolvingJiri Olsa2020-07-131-84/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now when we moved the helpers btf_id arrays into .BTF_ids section, we can remove the code that resolve those IDs in runtime. Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Tested-by: Andrii Nakryiko <andriin@fb.com> Acked-by: Andrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/20200711215329.41165-6-jolsa@kernel.org
| * | | bpf: Resolve BTF IDs in vmlinux imageJiri Olsa2020-07-131-1/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Using BTF_ID_LIST macro to define lists for several helpers using BTF arguments. And running resolve_btfids on vmlinux elf object during linking, so the .BTF_ids section gets the IDs resolved. Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Tested-by: Andrii Nakryiko <andriin@fb.com> Acked-by: Andrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/20200711215329.41165-5-jolsa@kernel.org
| * | | bpf: Add BPF_CGROUP_INET_SOCK_RELEASE hookStanislav Fomichev2020-07-081-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Sometimes it's handy to know when the socket gets freed. In particular, we'd like to try to use a smarter allocation of ports for bpf_bind and explore the possibility of limiting the number of SOCK_DGRAM sockets the process can have. Implement BPF_CGROUP_INET_SOCK_RELEASE hook that triggers on inet socket release. It triggers only for userspace sockets (not in-kernel ones) and therefore has the same semantics as the existing BPF_CGROUP_INET_SOCK_CREATE. Signed-off-by: Stanislav Fomichev <sdf@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Andrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/20200706230128.4073544-2-sdf@google.com
* | | | Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netDavid S. Miller2020-07-116-100/+188
|\ \ \ \ | |/ / / |/| / / | |/ / | | | | | | | | | All conflicts seemed rather trivial, with some guidance from Saeed Mameed on the tc_ct.c one. Signed-off-by: David S. Miller <davem@davemloft.net>
| * | Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netLinus Torvalds2020-07-106-84/+167
| |\| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull networking fixes from David Miller: 1) Restore previous behavior of CAP_SYS_ADMIN wrt loading networking BPF programs, from Maciej Żenczykowski. 2) Fix dropped broadcasts in mac80211 code, from Seevalamuthu Mariappan. 3) Slay memory leak in nl80211 bss color attribute parsing code, from Luca Coelho. 4) Get route from skb properly in ip_route_use_hint(), from Miaohe Lin. 5) Don't allow anything other than ARPHRD_ETHER in llc code, from Eric Dumazet. 6) xsk code dips too deeply into DMA mapping implementation internals. Add dma_need_sync and use it. From Christoph Hellwig 7) Enforce power-of-2 for BPF ringbuf sizes. From Andrii Nakryiko. 8) Check for disallowed attributes when loading flow dissector BPF programs. From Lorenz Bauer. 9) Correct packet injection to L3 tunnel devices via AF_PACKET, from Jason A. Donenfeld. 10) Don't advertise checksum offload on ipa devices that don't support it. From Alex Elder. 11) Resolve several issues in TCP MD5 signature support. Missing memory barriers, bogus options emitted when using syncookies, and failure to allow md5 key changes in established states. All from Eric Dumazet. 12) Fix interface leak in hsr code, from Taehee Yoo. 13) VF reset fixes in hns3 driver, from Huazhong Tan. 14) Make loopback work again with ipv6 anycast, from David Ahern. 15) Fix TX starvation under high load in fec driver, from Tobias Waldekranz. 16) MLD2 payload lengths not checked properly in bridge multicast code, from Linus Lüssing. 17) Packet scheduler code that wants to find the inner protocol currently only works for one level of VLAN encapsulation. Allow Q-in-Q situations to work properly here, from Toke Høiland-Jørgensen. 18) Fix route leak in l2tp, from Xin Long. 19) Resolve conflict between the sk->sk_user_data usage of bpf reuseport support and various protocols. From Martin KaFai Lau. 20) Fix socket cgroup v2 reference counting in some situations, from Cong Wang. 21) Cure memory leak in mlx5 connection tracking offload support, from Eli Britstein. * git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (146 commits) mlxsw: pci: Fix use-after-free in case of failed devlink reload mlxsw: spectrum_router: Remove inappropriate usage of WARN_ON() net: macb: fix call to pm_runtime in the suspend/resume functions net: macb: fix macb_suspend() by removing call to netif_carrier_off() net: macb: fix macb_get/set_wol() when moving to phylink net: macb: mark device wake capable when "magic-packet" property present net: macb: fix wakeup test in runtime suspend/resume routines bnxt_en: fix NULL dereference in case SR-IOV configuration fails libbpf: Fix libbpf hashmap on (I)LP32 architectures net/mlx5e: CT: Fix memory leak in cleanup net/mlx5e: Fix port buffers cell size value net/mlx5e: Fix 50G per lane indication net/mlx5e: Fix CPU mapping after function reload to avoid aRFS RX crash net/mlx5e: Fix VXLAN configuration restore after function reload net/mlx5e: Fix usage of rcu-protected pointer net/mxl5e: Verify that rpriv is not NULL net/mlx5: E-Switch, Fix vlan or qos setting in legacy mode net/mlx5: Fix eeprom support for SFP module cgroup: Fix sock_cgroup_data on big-endian. selftests: bpf: Fix detach from sockmap tests ...
| | * bpf: net: Avoid incorrect bpf_sk_reuseport_detach callMartin KaFai Lau2020-07-091-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | bpf_sk_reuseport_detach is currently called when sk->sk_user_data is not NULL. It is incorrect because sk->sk_user_data may not be managed by the bpf's reuseport_array. It has been reported in [1] that, the bpf_sk_reuseport_detach() which is called from udp_lib_unhash() has corrupted the sk_user_data managed by l2tp. This patch solves it by using another bit (defined as SK_USER_DATA_BPF) of the sk_user_data pointer value. It marks that a sk_user_data is managed/owned by BPF. The patch depends on a PTRMASK introduced in commit f1ff5ce2cd5e ("net, sk_msg: Clear sk_user_data pointer on clone if tagged"). [ Note: sk->sk_user_data is used by bpf's reuseport_array only when a sk is added to the bpf's reuseport_array. i.e. doing setsockopt(SO_REUSEPORT) and having "sk->sk_reuseport == 1" alone will not stop sk->sk_user_data being used by other means. ] [1]: https://lore.kernel.org/netdev/20200706121259.GA20199@katalix.com/ Fixes: 5dc4c4b7d4e8 ("bpf: Introduce BPF_MAP_TYPE_REUSEPORT_SOCKARRAY") Reported-by: James Chapman <jchapman@katalix.com> Reported-by: syzbot+9f092552ba9a5efca5df@syzkaller.appspotmail.com Signed-off-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Tested-by: James Chapman <jchapman@katalix.com> Acked-by: James Chapman <jchapman@katalix.com> Link: https://lore.kernel.org/bpf/20200709061110.4019316-1-kafai@fb.com
| | * bpf: net: Avoid copying sk_user_data of reuseport_array during sk_cloneMartin KaFai Lau2020-07-091-4/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It makes little sense for copying sk_user_data of reuseport_array during sk_clone_lock(). This patch reuses the SK_USER_DATA_NOCOPY bit introduced in commit f1ff5ce2cd5e ("net, sk_msg: Clear sk_user_data pointer on clone if tagged"). It is used to mark the sk_user_data is not supposed to be copied to its clone. Although the cloned sk's sk_user_data will not be used/freed in bpf_sk_reuseport_detach(), this change can still allow the cloned sk's sk_user_data to be used by some other means. Freeing the reuseport_array's sk_user_data does not require a rcu grace period. Thus, the existing rcu_assign_sk_user_data_nocopy() is not used. Fixes: 5dc4c4b7d4e8 ("bpf: Introduce BPF_MAP_TYPE_REUSEPORT_SOCKARRAY") Signed-off-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Jakub Sitnicki <jakub@cloudflare.com> Link: https://lore.kernel.org/bpf/20200709061104.4018798-1-kafai@fb.com
| | * bpf: Fix an incorrect branch elimination by verifierYonghong Song2020-06-301-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Wenbo reported an issue in [1] where a checking of null pointer is evaluated as always false. In this particular case, the program type is tp_btf and the pointer to compare is a PTR_TO_BTF_ID. The current verifier considers PTR_TO_BTF_ID always reprents a non-null pointer, hence all PTR_TO_BTF_ID compares to 0 will be evaluated as always not-equal, which resulted in the branch elimination. For example, struct bpf_fentry_test_t { struct bpf_fentry_test_t *a; }; int BPF_PROG(test7, struct bpf_fentry_test_t *arg) { if (arg == 0) test7_result = 1; return 0; } int BPF_PROG(test8, struct bpf_fentry_test_t *arg) { if (arg->a == 0) test8_result = 1; return 0; } In above bpf programs, both branch arg == 0 and arg->a == 0 are removed. This may not be what developer expected. The bug is introduced by Commit cac616db39c2 ("bpf: Verifier track null pointer branch_taken with JNE and JEQ"), where PTR_TO_BTF_ID is considered to be non-null when evaluting pointer vs. scalar comparison. This may be added considering we have PTR_TO_BTF_ID_OR_NULL in the verifier as well. PTR_TO_BTF_ID_OR_NULL is added to explicitly requires a non-NULL testing in selective cases. The current generic pointer tracing framework in verifier always assigns PTR_TO_BTF_ID so users does not need to check NULL pointer at every pointer level like a->b->c->d. We may not want to assign every PTR_TO_BTF_ID as PTR_TO_BTF_ID_OR_NULL as this will require a null test before pointer dereference which may cause inconvenience for developers. But we could avoid branch elimination to preserve original code intention. This patch simply removed PTR_TO_BTD_ID from reg_type_not_null() in verifier, which prevented the above branches from being eliminated. [1]: https://lore.kernel.org/bpf/79dbb7c0-449d-83eb-5f4f-7af0cc269168@fb.com/T/ Fixes: cac616db39c2 ("bpf: Verifier track null pointer branch_taken with JNE and JEQ") Reported-by: Wenbo Zhang <ethercflow@gmail.com> Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Andrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/20200630171240.2523722-1-yhs@fb.com
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