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2021-10-27bpf: Use u64_stats_t in struct bpf_prog_statsEric Dumazet3-14/+20
Commit 316580b69d0a ("u64_stats: provide u64_stats_t type") fixed possible load/store tearing on 64bit arches. For instance the following C code stats->nsecs += sched_clock() - start; Could be rightfully implemented like this by a compiler, confusing concurrent readers a lot: stats->nsecs += sched_clock(); // arbitrary delay stats->nsecs -= start; Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20211026214133.3114279-4-eric.dumazet@gmail.com
2021-10-27bpf: Fixes possible race in update_prog_stats() for 32bit archesEric Dumazet1-2/+4
It seems update_prog_stats() suffers from same issue fixed in the prior patch: As it can run while interrupts are enabled, it could be re-entered and the u64_stats syncp could be mangled. Fixes: fec56f5890d9 ("bpf: Introduce BPF trampoline") Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20211026214133.3114279-3-eric.dumazet@gmail.com
2021-10-27bpf: Avoid races in __bpf_prog_run() for 32bit archesEric Dumazet1-2/+3
__bpf_prog_run() can run from non IRQ contexts, meaning it could be re entered if interrupted. This calls for the irq safe variant of u64_stats_update_{begin|end}, or risk a deadlock. This patch is a nop on 64bit arches, fortunately. syzbot report: WARNING: inconsistent lock state 5.12.0-rc3-syzkaller #0 Not tainted -------------------------------- inconsistent {IN-SOFTIRQ-W} -> {SOFTIRQ-ON-W} usage. udevd/4013 [HC0[0]:SC0[0]:HE1:SE1] takes: ff7c9dec (&(&pstats->syncp)->seq){+.?.}-{0:0}, at: sk_filter include/linux/filter.h:867 [inline] ff7c9dec (&(&pstats->syncp)->seq){+.?.}-{0:0}, at: do_one_broadcast net/netlink/af_netlink.c:1468 [inline] ff7c9dec (&(&pstats->syncp)->seq){+.?.}-{0:0}, at: netlink_broadcast_filtered+0x27c/0x4fc net/netlink/af_netlink.c:1520 {IN-SOFTIRQ-W} state was registered at: lock_acquire.part.0+0xf0/0x41c kernel/locking/lockdep.c:5510 lock_acquire+0x6c/0x74 kernel/locking/lockdep.c:5483 do_write_seqcount_begin_nested include/linux/seqlock.h:520 [inline] do_write_seqcount_begin include/linux/seqlock.h:545 [inline] u64_stats_update_begin include/linux/u64_stats_sync.h:129 [inline] bpf_prog_run_pin_on_cpu include/linux/filter.h:624 [inline] bpf_prog_run_clear_cb+0x1bc/0x270 include/linux/filter.h:755 run_filter+0xa0/0x17c net/packet/af_packet.c:2031 packet_rcv+0xc0/0x3e0 net/packet/af_packet.c:2104 dev_queue_xmit_nit+0x2bc/0x39c net/core/dev.c:2387 xmit_one net/core/dev.c:3588 [inline] dev_hard_start_xmit+0x94/0x518 net/core/dev.c:3609 sch_direct_xmit+0x11c/0x1f0 net/sched/sch_generic.c:313 qdisc_restart net/sched/sch_generic.c:376 [inline] __qdisc_run+0x194/0x7f8 net/sched/sch_generic.c:384 qdisc_run include/net/pkt_sched.h:136 [inline] qdisc_run include/net/pkt_sched.h:128 [inline] __dev_xmit_skb net/core/dev.c:3795 [inline] __dev_queue_xmit+0x65c/0xf84 net/core/dev.c:4150 dev_queue_xmit+0x14/0x18 net/core/dev.c:4215 neigh_resolve_output net/core/neighbour.c:1491 [inline] neigh_resolve_output+0x170/0x228 net/core/neighbour.c:1471 neigh_output include/net/neighbour.h:510 [inline] ip6_finish_output2+0x2e4/0x9fc net/ipv6/ip6_output.c:117 __ip6_finish_output net/ipv6/ip6_output.c:182 [inline] __ip6_finish_output+0x164/0x3f8 net/ipv6/ip6_output.c:161 ip6_finish_output+0x2c/0xb0 net/ipv6/ip6_output.c:192 NF_HOOK_COND include/linux/netfilter.h:290 [inline] ip6_output+0x74/0x294 net/ipv6/ip6_output.c:215 dst_output include/net/dst.h:448 [inline] NF_HOOK include/linux/netfilter.h:301 [inline] NF_HOOK include/linux/netfilter.h:295 [inline] mld_sendpack+0x2a8/0x7e4 net/ipv6/mcast.c:1679 mld_send_cr net/ipv6/mcast.c:1975 [inline] mld_ifc_timer_expire+0x1e8/0x494 net/ipv6/mcast.c:2474 call_timer_fn+0xd0/0x570 kernel/time/timer.c:1431 expire_timers kernel/time/timer.c:1476 [inline] __run_timers kernel/time/timer.c:1745 [inline] run_timer_softirq+0x2e4/0x384 kernel/time/timer.c:1758 __do_softirq+0x204/0x7ac kernel/softirq.c:345 do_softirq_own_stack include/asm-generic/softirq_stack.h:10 [inline] invoke_softirq kernel/softirq.c:228 [inline] __irq_exit_rcu+0x1d8/0x200 kernel/softirq.c:422 irq_exit+0x10/0x3c kernel/softirq.c:446 __handle_domain_irq+0xb4/0x120 kernel/irq/irqdesc.c:692 handle_domain_irq include/linux/irqdesc.h:176 [inline] gic_handle_irq+0x84/0xac drivers/irqchip/irq-gic.c:370 __irq_svc+0x5c/0x94 arch/arm/kernel/entry-armv.S:205 debug_smp_processor_id+0x0/0x24 lib/smp_processor_id.c:53 rcu_read_lock_held_common kernel/rcu/update.c:108 [inline] rcu_read_lock_sched_held+0x24/0x7c kernel/rcu/update.c:123 trace_lock_acquire+0x24c/0x278 include/trace/events/lock.h:13 lock_acquire+0x3c/0x74 kernel/locking/lockdep.c:5481 rcu_lock_acquire include/linux/rcupdate.h:267 [inline] rcu_read_lock include/linux/rcupdate.h:656 [inline] avc_has_perm_noaudit+0x6c/0x260 security/selinux/avc.c:1150 selinux_inode_permission+0x140/0x220 security/selinux/hooks.c:3141 security_inode_permission+0x44/0x60 security/security.c:1268 inode_permission.part.0+0x5c/0x13c fs/namei.c:521 inode_permission fs/namei.c:494 [inline] may_lookup fs/namei.c:1652 [inline] link_path_walk.part.0+0xd4/0x38c fs/namei.c:2208 link_path_walk fs/namei.c:2189 [inline] path_lookupat+0x3c/0x1b8 fs/namei.c:2419 filename_lookup+0xa8/0x1a4 fs/namei.c:2453 user_path_at_empty+0x74/0x90 fs/namei.c:2733 do_readlinkat+0x5c/0x12c fs/stat.c:417 __do_sys_readlink fs/stat.c:450 [inline] sys_readlink+0x24/0x28 fs/stat.c:447 ret_fast_syscall+0x0/0x2c arch/arm/mm/proc-v7.S:64 0x7eaa4974 irq event stamp: 298277 hardirqs last enabled at (298277): [<802000d0>] no_work_pending+0x4/0x34 hardirqs last disabled at (298276): [<8020c9b8>] do_work_pending+0x9c/0x648 arch/arm/kernel/signal.c:676 softirqs last enabled at (298216): [<8020167c>] __do_softirq+0x584/0x7ac kernel/softirq.c:372 softirqs last disabled at (298201): [<8024dff4>] do_softirq_own_stack include/asm-generic/softirq_stack.h:10 [inline] softirqs last disabled at (298201): [<8024dff4>] invoke_softirq kernel/softirq.c:228 [inline] softirqs last disabled at (298201): [<8024dff4>] __irq_exit_rcu+0x1d8/0x200 kernel/softirq.c:422 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&(&pstats->syncp)->seq); <Interrupt> lock(&(&pstats->syncp)->seq); *** DEADLOCK *** 1 lock held by udevd/4013: #0: 82b09c5c (rcu_read_lock){....}-{1:2}, at: sk_filter_trim_cap+0x54/0x434 net/core/filter.c:139 stack backtrace: CPU: 1 PID: 4013 Comm: udevd Not tainted 5.12.0-rc3-syzkaller #0 Hardware name: ARM-Versatile Express Backtrace: [<81802550>] (dump_backtrace) from [<818027c4>] (show_stack+0x18/0x1c arch/arm/kernel/traps.c:252) r7:00000080 r6:600d0093 r5:00000000 r4:82b58344 [<818027ac>] (show_stack) from [<81809e98>] (__dump_stack lib/dump_stack.c:79 [inline]) [<818027ac>] (show_stack) from [<81809e98>] (dump_stack+0xb8/0xe8 lib/dump_stack.c:120) [<81809de0>] (dump_stack) from [<81804a00>] (print_usage_bug.part.0+0x228/0x230 kernel/locking/lockdep.c:3806) r7:86bcb768 r6:81a0326c r5:830f96a8 r4:86bcb0c0 [<818047d8>] (print_usage_bug.part.0) from [<802bb1b8>] (print_usage_bug kernel/locking/lockdep.c:3776 [inline]) [<818047d8>] (print_usage_bug.part.0) from [<802bb1b8>] (valid_state kernel/locking/lockdep.c:3818 [inline]) [<818047d8>] (print_usage_bug.part.0) from [<802bb1b8>] (mark_lock_irq kernel/locking/lockdep.c:4021 [inline]) [<818047d8>] (print_usage_bug.part.0) from [<802bb1b8>] (mark_lock.part.0+0xc34/0x136c kernel/locking/lockdep.c:4478) r10:83278fe8 r9:82c6d748 r8:00000000 r7:82c6d2d4 r6:00000004 r5:86bcb768 r4:00000006 [<802ba584>] (mark_lock.part.0) from [<802bc644>] (mark_lock kernel/locking/lockdep.c:4442 [inline]) [<802ba584>] (mark_lock.part.0) from [<802bc644>] (mark_usage kernel/locking/lockdep.c:4391 [inline]) [<802ba584>] (mark_lock.part.0) from [<802bc644>] (__lock_acquire+0x9bc/0x3318 kernel/locking/lockdep.c:4854) r10:86bcb768 r9:86bcb0c0 r8:00000001 r7:00040000 r6:0000075a r5:830f96a8 r4:00000000 [<802bbc88>] (__lock_acquire) from [<802bfb90>] (lock_acquire.part.0+0xf0/0x41c kernel/locking/lockdep.c:5510) r10:00000000 r9:600d0013 r8:00000000 r7:00000000 r6:828a2680 r5:828a2680 r4:861e5bc8 [<802bfaa0>] (lock_acquire.part.0) from [<802bff28>] (lock_acquire+0x6c/0x74 kernel/locking/lockdep.c:5483) r10:8146137c r9:00000000 r8:00000001 r7:00000000 r6:00000000 r5:00000000 r4:ff7c9dec [<802bfebc>] (lock_acquire) from [<81381eb4>] (do_write_seqcount_begin_nested include/linux/seqlock.h:520 [inline]) [<802bfebc>] (lock_acquire) from [<81381eb4>] (do_write_seqcount_begin include/linux/seqlock.h:545 [inline]) [<802bfebc>] (lock_acquire) from [<81381eb4>] (u64_stats_update_begin include/linux/u64_stats_sync.h:129 [inline]) [<802bfebc>] (lock_acquire) from [<81381eb4>] (__bpf_prog_run_save_cb include/linux/filter.h:727 [inline]) [<802bfebc>] (lock_acquire) from [<81381eb4>] (bpf_prog_run_save_cb include/linux/filter.h:741 [inline]) [<802bfebc>] (lock_acquire) from [<81381eb4>] (sk_filter_trim_cap+0x26c/0x434 net/core/filter.c:149) r10:a4095dd0 r9:ff7c9dd0 r8:e44be000 r7:8146137c r6:00000001 r5:8611ba80 r4:00000000 [<81381c48>] (sk_filter_trim_cap) from [<8146137c>] (sk_filter include/linux/filter.h:867 [inline]) [<81381c48>] (sk_filter_trim_cap) from [<8146137c>] (do_one_broadcast net/netlink/af_netlink.c:1468 [inline]) [<81381c48>] (sk_filter_trim_cap) from [<8146137c>] (netlink_broadcast_filtered+0x27c/0x4fc net/netlink/af_netlink.c:1520) r10:00000001 r9:833d6b1c r8:00000000 r7:8572f864 r6:8611ba80 r5:8698d800 r4:8572f800 [<81461100>] (netlink_broadcast_filtered) from [<81463e60>] (netlink_broadcast net/netlink/af_netlink.c:1544 [inline]) [<81461100>] (netlink_broadcast_filtered) from [<81463e60>] (netlink_sendmsg+0x3d0/0x478 net/netlink/af_netlink.c:1925) r10:00000000 r9:00000002 r8:8698d800 r7:000000b7 r6:8611b900 r5:861e5f50 r4:86aa3000 [<81463a90>] (netlink_sendmsg) from [<81321f54>] (sock_sendmsg_nosec net/socket.c:654 [inline]) [<81463a90>] (netlink_sendmsg) from [<81321f54>] (sock_sendmsg+0x3c/0x4c net/socket.c:674) r10:00000000 r9:861e5dd4 r8:00000000 r7:86570000 r6:00000000 r5:86570000 r4:861e5f50 [<81321f18>] (sock_sendmsg) from [<813234d0>] (____sys_sendmsg+0x230/0x29c net/socket.c:2350) r5:00000040 r4:861e5f50 [<813232a0>] (____sys_sendmsg) from [<8132549c>] (___sys_sendmsg+0xac/0xe4 net/socket.c:2404) r10:00000128 r9:861e4000 r8:00000000 r7:00000000 r6:86570000 r5:861e5f50 r4:00000000 [<813253f0>] (___sys_sendmsg) from [<81325684>] (__sys_sendmsg net/socket.c:2433 [inline]) [<813253f0>] (___sys_sendmsg) from [<81325684>] (__do_sys_sendmsg net/socket.c:2442 [inline]) [<813253f0>] (___sys_sendmsg) from [<81325684>] (sys_sendmsg+0x58/0xa0 net/socket.c:2440) r8:80200224 r7:00000128 r6:00000000 r5:7eaa541c r4:86570000 [<8132562c>] (sys_sendmsg) from [<80200060>] (ret_fast_syscall+0x0/0x2c arch/arm/mm/proc-v7.S:64) Exception stack(0x861e5fa8 to 0x861e5ff0) 5fa0: 00000000 00000000 0000000c 7eaa541c 00000000 00000000 5fc0: 00000000 00000000 76fbf840 00000128 00000000 0000008f 7eaa541c 000563f8 5fe0: 00056110 7eaa53e0 00036cec 76c9bf44 r6:76fbf840 r5:00000000 r4:00000000 Fixes: 492ecee892c2 ("bpf: enable program stats") Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20211026214133.3114279-2-eric.dumazet@gmail.com
2021-10-27libbpf: Deprecate bpf_objects_listJoe Burton3-2/+15
Add a flag to `enum libbpf_strict_mode' to disable the global `bpf_objects_list', preventing race conditions when concurrent threads call bpf_object__open() or bpf_object__close(). bpf_object__next() will return NULL if this option is set. Callers may achieve the same workflow by tracking bpf_objects in application code. [0] Closes: https://github.com/libbpf/libbpf/issues/293 Signed-off-by: Joe Burton <jevburton@google.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20211026223528.413950-1-jevburton.kernel@gmail.com
2021-10-26selftests/bpf: Guess function end for test_get_branch_snapshotSong Liu3-44/+4
Function in modules could appear in /proc/kallsyms in random order. ffffffffa02608a0 t bpf_testmod_loop_test ffffffffa02600c0 t __traceiter_bpf_testmod_test_writable_bare ffffffffa0263b60 d __tracepoint_bpf_testmod_test_write_bare ffffffffa02608c0 T bpf_testmod_test_read ffffffffa0260d08 t __SCT__tp_func_bpf_testmod_test_writable_bare ffffffffa0263300 d __SCK__tp_func_bpf_testmod_test_read ffffffffa0260680 T bpf_testmod_test_write ffffffffa0260860 t bpf_testmod_test_mod_kfunc Therefore, we cannot reliably use kallsyms_find_next() to find the end of a function. Replace it with a simple guess (start + 128). This is good enough for this test. Signed-off-by: Song Liu <songliubraving@fb.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20211022234814.318457-1-songliubraving@fb.com
2021-10-26selftests/bpf: Skip all serial_test_get_branch_snapshot in vmSong Liu1-10/+6
Skipping the second half of the test is not enough to silent the warning in dmesg. Skip the whole test before we can either properly silent the warning in kernel, or fix LBR snapshot for VM. Fixes: 025bd7c753aa ("selftests/bpf: Add test for bpf_get_branch_snapshot") Fixes: aa67fdb46436 ("selftests/bpf: Skip the second half of get_branch_snapshot in vm") Signed-off-by: Song Liu <songliubraving@fb.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20211026000733.477714-1-songliubraving@fb.com
2021-10-26Merge branch 'core_reloc fixes for s390'Andrii Nakryiko14-39/+48
Ilya Leoshkevich says: ==================== v2: https://lore.kernel.org/bpf/20211025131214.731972-1-iii@linux.ibm.com/ v2 -> v3: Split the fix from the cleanup (Daniel). v1: https://lore.kernel.org/bpf/20211021234653.643302-1-iii@linux.ibm.com/ v1 -> v2: Drop bpf_core_calc_field_relo() restructuring, split the __BYTE_ORDER__ change (Andrii). Hi, this series fixes test failures in core_reloc on s390. Patch 1 fixes an endianness bug with __BYTE_ORDER vs __BYTE_ORDER__. Patches 2-5 make the rest of the code consistent in that respect. Patch 6 fixes an endianness issue in test_core_reloc_mods. Best regards, Ilya ==================== Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
2021-10-26selftests/bpf: Fix test_core_reloc_mods on big-endian machinesIlya Leoshkevich1-0/+9
This is the same as commit d164dd9a5c08 ("selftests/bpf: Fix test_core_autosize on big-endian machines"), but for test_core_reloc_mods. Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20211026010831.748682-7-iii@linux.ibm.com
2021-10-26selftests/seccomp: Use __BYTE_ORDER__Ilya Leoshkevich1-3/+3
Use the compiler-defined __BYTE_ORDER__ instead of the libc-defined __BYTE_ORDER for consistency. Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20211026010831.748682-6-iii@linux.ibm.com
2021-10-26samples: seccomp: Use __BYTE_ORDER__Ilya Leoshkevich1-4/+4
Use the compiler-defined __BYTE_ORDER__ instead of the libc-defined __BYTE_ORDER for consistency. Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20211026010831.748682-5-iii@linux.ibm.com
2021-10-26selftests/bpf: Use __BYTE_ORDER__Ilya Leoshkevich5-16/+16
Use the compiler-defined __BYTE_ORDER__ instead of the libc-defined __BYTE_ORDER for consistency. Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20211026010831.748682-4-iii@linux.ibm.com
2021-10-26libbpf: Use __BYTE_ORDER__Ilya Leoshkevich5-15/+15
Use the compiler-defined __BYTE_ORDER__ instead of the libc-defined __BYTE_ORDER for consistency. Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20211026010831.748682-3-iii@linux.ibm.com
2021-10-26libbpf: Fix endianness detection in BPF_CORE_READ_BITFIELD_PROBED()Ilya Leoshkevich1-1/+1
__BYTE_ORDER is supposed to be defined by a libc, and __BYTE_ORDER__ - by a compiler. bpf_core_read.h checks __BYTE_ORDER == __LITTLE_ENDIAN, which is true if neither are defined, leading to incorrect behavior on big-endian hosts if libc headers are not included, which is often the case. Fixes: ee26dade0e3b ("libbpf: Add support for relocatable bitfields") Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20211026010831.748682-2-iii@linux.ibm.com
2021-10-26Merge branch 'libbpf: add bpf_program__insns() accessor'Alexei Starovoitov3-15/+66
Andrii Nakryiko says: ==================== Add libbpf APIs to access BPF program instructions. Both before and after libbpf processing (before and after bpf_object__load()). This allows to inspect what's going on with BPF program assembly instructions as libbpf performs its processing magic. But in more practical terms, this allows to do a no-brainer BPF program cloning, which is something you need when working with fentry/fexit BPF programs to be able to attach the same BPF program code to multiple kernel functions. Currently, kernel needs multiple copies of BPF programs, each loaded with its own target BTF ID. retsnoop is one such example that previously had to rely on bpf_program__set_prep() API to hijack program instructions ([0] for before and after). Speaking of bpf_program__set_prep() API and the whole concept of multiple-instance BPF programs in libbpf, all that is scheduled for deprecation in v0.7. It doesn't work well, it's cumbersome, and it will become more broken as libbpf adds more functionality. So deprecate and remove it in libbpf 1.0. It doesn't seem to be used by anyone anyways (except for that retsnoop hack, which is now much cleaner with new APIs as can be seen in [0]). [0] https://github.com/anakryiko/retsnoop/pull/1 ==================== Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2021-10-26libbpf: Deprecate ambiguously-named bpf_program__size() APIAndrii Nakryiko1-0/+1
The name of the API doesn't convey clearly that this size is in number of bytes (there needed to be a separate comment to make this clear in libbpf.h). Further, measuring the size of BPF program in bytes is not exactly the best fit, because BPF programs always consist of 8-byte instructions. As such, bpf_program__insn_cnt() is a better alternative in pretty much any imaginable case. So schedule bpf_program__size() deprecation starting from v0.7 and it will be removed in libbpf 1.0. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20211025224531.1088894-5-andrii@kernel.org
2021-10-26libbpf: Deprecate multi-instance bpf_program APIsAndrii Nakryiko2-10/+18
Schedule deprecation of a set of APIs that are related to multi-instance bpf_programs: - bpf_program__set_prep() ([0]); - bpf_program__{set,unset}_instance() ([1]); - bpf_program__nth_fd(). These APIs are obscure, very niche, and don't seem to be used much in practice. bpf_program__set_prep() is pretty useless for anything but the simplest BPF programs, as it doesn't allow to adjust BPF program load attributes, among other things. In short, it already bitrotted and will bitrot some more if not removed. With bpf_program__insns() API, which gives access to post-processed BPF program instructions of any given entry-point BPF program, it's now possible to do whatever necessary adjustments were possible with set_prep() API before, but also more. Given any such use case is automatically an advanced use case, requiring users to stick to low-level bpf_prog_load() APIs and managing their own prog FDs is reasonable. [0] Closes: https://github.com/libbpf/libbpf/issues/299 [1] Closes: https://github.com/libbpf/libbpf/issues/300 Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20211025224531.1088894-4-andrii@kernel.org
2021-10-26libbpf: Add ability to fetch bpf_program's underlying instructionsAndrii Nakryiko3-4/+46
Add APIs providing read-only access to bpf_program BPF instructions ([0]). This is useful for diagnostics purposes, but it also allows a cleaner support for cloning BPF programs after libbpf did all the FD resolution and CO-RE relocations, subprog instructions appending, etc. Currently, cloning BPF program is possible only through hijacking a half-broken bpf_program__set_prep() API, which doesn't really work well for anything but most primitive programs. For instance, set_prep() API doesn't allow adjusting BPF program load parameters which are necessary for loading fentry/fexit BPF programs (the case where BPF program cloning is a necessity if doing some sort of mass-attachment functionality). Given bpf_program__set_prep() API is set to be deprecated, having a cleaner alternative is a must. libbpf internally already keeps track of linear array of struct bpf_insn, so it's not hard to expose it. The only gotcha is that libbpf previously freed instructions array during bpf_object load time, which would make this API much less useful overall, because in between bpf_object__open() and bpf_object__load() a lot of changes to instructions are done by libbpf. So this patch makes libbpf hold onto prog->insns array even after BPF program loading. I think this is a small price for added functionality and improved introspection of BPF program code. See retsnoop PR ([1]) for how it can be used in practice and code savings compared to relying on bpf_program__set_prep(). [0] Closes: https://github.com/libbpf/libbpf/issues/298 [1] https://github.com/anakryiko/retsnoop/pull/1 Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20211025224531.1088894-3-andrii@kernel.org
2021-10-26libbpf: Fix off-by-one bug in bpf_core_apply_relo()Andrii Nakryiko1-1/+1
Fix instruction index validity check which has off-by-one error. Fixes: 3ee4f5335511 ("libbpf: Split bpf_core_apply_relo() into bpf_program independent helper.") Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20211025224531.1088894-2-andrii@kernel.org
2021-10-26Merge branch 'bpftool: Switch to libbpf's hashmap for referencing BPF objects'Andrii Nakryiko9-228/+262
Quentin Monnet says: ==================== When listing BPF objects, bpftool can print a number of properties about items holding references to these objects. For example, it can show pinned paths for BPF programs, maps, and links; or programs and maps using a given BTF object; or the names and PIDs of processes referencing BPF objects. To collect this information, bpftool uses hash maps (to be clear: the data structures, inside bpftool - we are not talking of BPF maps). It uses the implementation available from the kernel, and picks it up from tools/include/linux/hashtable.h. This patchset converts bpftool's hash maps to a distinct implementation instead, the one coming with libbpf. The main motivation for this change is that it should ease the path towards a potential out-of-tree mirror for bpftool, like the one libbpf already has. Although it's not perfect to depend on libbpf's internal components, bpftool is intimately tied with the library anyway, and this looks better than depending too much on (non-UAPI) kernel headers. The first two patches contain preparatory work on the Makefile and on the initialisation of the hash maps for collecting pinned paths for objects. Then the transition is split into several steps, one for each kind of properties for which the collection is backed by hash maps. v2: - Move hashmap cleanup for pinned paths for links from do_detach() to do_show(). - Handle errors on hashmap__append() (in three of the patches). - Rename bpftool_hash_fn() and bpftool_equal_fn() as hash_fn_for_key_id() and equal_fn_for_key_id(), respectively. - Add curly braces for hashmap__for_each_key_entry() { } in show_btf_plain() and show_btf_json(), where the flow was difficult to read. ==================== Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
2021-10-26bpftool: Switch to libbpf's hashmap for PIDs/names referencesQuentin Monnet7-65/+72
In order to show PIDs and names for processes holding references to BPF programs, maps, links, or BTF objects, bpftool creates hash maps to store all relevant information. This commit is part of a set that transitions from the kernel's hash map implementation to the one coming with libbpf. The motivation is to make bpftool less dependent of kernel headers, to ease the path to a potential out-of-tree mirror, like libbpf has. This is the third and final step of the transition, in which we convert the hash maps used for storing the information about the processes holding references to BPF objects (programs, maps, links, BTF), and at last we drop the inclusion of tools/include/linux/hashtable.h. Note: Checkpatch complains about the use of __weak declarations, and the missing empty lines after the bunch of empty function declarations when compiling without the BPF skeletons (none of these were introduced in this patch). We want to keep things as they are, and the reports should be safe to ignore. Signed-off-by: Quentin Monnet <quentin@isovalent.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20211023205154.6710-6-quentin@isovalent.com
2021-10-26bpftool: Switch to libbpf's hashmap for programs/maps in BTF listingQuentin Monnet2-68/+62
In order to show BPF programs and maps using BTF objects when the latter are being listed, bpftool creates hash maps to store all relevant items. This commit is part of a set that transitions from the kernel's hash map implementation to the one coming with libbpf. The motivation is to make bpftool less dependent of kernel headers, to ease the path to a potential out-of-tree mirror, like libbpf has. This commit focuses on the two hash maps used by bpftool when listing BTF objects to store references to programs and maps, and convert them to the libbpf's implementation. Signed-off-by: Quentin Monnet <quentin@isovalent.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20211023205154.6710-5-quentin@isovalent.com
2021-10-26bpftool: Switch to libbpf's hashmap for pinned paths of BPF objectsQuentin Monnet6-84/+111
In order to show pinned paths for BPF programs, maps, or links when listing them with the "-f" option, bpftool creates hash maps to store all relevant paths under the bpffs. So far, it would rely on the kernel implementation (from tools/include/linux/hashtable.h). We can make bpftool rely on libbpf's implementation instead. The motivation is to make bpftool less dependent of kernel headers, to ease the path to a potential out-of-tree mirror, like libbpf has. This commit is the first step of the conversion: the hash maps for pinned paths for programs, maps, and links are converted to libbpf's hashmap.{c,h}. Other hash maps used for the PIDs of process holding references to BPF objects are left unchanged for now. On the build side, this requires adding a dependency to a second header internal to libbpf, and making it a dependency for the bootstrap bpftool version as well. The rest of the changes are a rather straightforward conversion. Signed-off-by: Quentin Monnet <quentin@isovalent.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20211023205154.6710-4-quentin@isovalent.com
2021-10-26bpftool: Do not expose and init hash maps for pinned path in main.cQuentin Monnet5-18/+24
BPF programs, maps, and links, can all be listed with their pinned paths by bpftool, when the "-f" option is provided. To do so, bpftool builds hash maps containing all pinned paths for each kind of objects. These three hash maps are always initialised in main.c, and exposed through main.h. There appear to be no particular reason to do so: we can just as well make them static to the files that need them (prog.c, map.c, and link.c respectively), and initialise them only when we want to show objects and the "-f" switch is provided. This may prevent unnecessary memory allocations if the implementation of the hash maps was to change in the future. Signed-off-by: Quentin Monnet <quentin@isovalent.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20211023205154.6710-3-quentin@isovalent.com
2021-10-26bpftool: Remove Makefile dep. on $(LIBBPF) for $(LIBBPF_INTERNAL_HDRS)Quentin Monnet1-2/+2
The dependency is only useful to make sure that the $(LIBBPF_HDRS_DIR) directory is created before we try to install locally the required libbpf internal header. Let's create this directory properly instead. This is in preparation of making $(LIBBPF_INTERNAL_HDRS) a dependency to the bootstrap bpftool version, in which case we want no dependency on $(LIBBPF). Signed-off-by: Quentin Monnet <quentin@isovalent.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20211023205154.6710-2-quentin@isovalent.com
2021-10-26Merge branch 'Parallelize verif_scale selftests'Alexei Starovoitov9-88/+169
Andrii Nakryiko says: ==================== Reduce amount of waiting time when running test_progs in parallel mode (-j) by splitting bpf_verif_scale selftests into multiple tests. Previously it was structured as a test with multiple subtests, but subtests are not easily parallelizable with test_progs' infra. Also in practice each scale subtest is really an independent test with nothing shared across all substest. This patch set changes how test_progs test discovery works. Now it is possible to define multiple tests within a single source code file. One of the patches also marks tc_redirect selftests as serial, because it's extremely harmful to the test system when run in parallel mode. ==================== Acked-by: Yucong Sun <sunyucong@gmail.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2021-10-26selftests/bpf: Split out bpf_verif_scale selftests into multiple testsAndrii Nakryiko1-68/+152
Instead of using subtests in bpf_verif_scale selftest, turn each scale sub-test into its own test. Each subtest is compltely independent and just reuses a bit of common test running logic, so the conversion is trivial. For convenience, keep all of BPF verifier scale tests in one file. This conversion shaves off a significant amount of time when running test_progs in parallel mode. E.g., just running scale tests (-t verif_scale): BEFORE ====== Summary: 24/0 PASSED, 0 SKIPPED, 0 FAILED real 0m22.894s user 0m0.012s sys 0m22.797s AFTER ===== Summary: 24/0 PASSED, 0 SKIPPED, 0 FAILED real 0m12.044s user 0m0.024s sys 0m27.869s Ten second saving right there. test_progs -j is not yet ready to be turned on by default, unfortunately, and some tests fail almost every time, but this is a good improvement nevertheless. Ignoring few failures, here is sequential vs parallel run times when running all tests now: SEQUENTIAL ========== Summary: 206/953 PASSED, 4 SKIPPED, 0 FAILED real 1m5.625s user 0m4.211s sys 0m31.650s PARALLEL ======== Summary: 204/952 PASSED, 4 SKIPPED, 2 FAILED real 0m35.550s user 0m4.998s sys 0m39.890s Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20211022223228.99920-5-andrii@kernel.org
2021-10-26selftests/bpf: Mark tc_redirect selftest as serialAndrii Nakryiko1-1/+1
It seems to cause a lot of harm to kprobe/tracepoint selftests. Yucong mentioned before that it does manipulate sysfs, which might be the reason. So let's mark it as serial, though ideally it would be less intrusive on the system at test. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20211022223228.99920-4-andrii@kernel.org
2021-10-26selftests/bpf: Support multiple tests per fileAndrii Nakryiko1-4/+3
Revamp how test discovery works for test_progs and allow multiple test entries per file. Any global void function with no arguments and serial_test_ or test_ prefix is considered a test. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20211022223228.99920-3-andrii@kernel.org
2021-10-26selftests/bpf: Normalize selftest entry pointsAndrii Nakryiko6-15/+13
Ensure that all test entry points are global void functions with no input arguments. Mark few subtest entry points as static. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20211022223228.99920-2-andrii@kernel.org
2021-10-23libbpf: Fix BTF header parsing checksAndrii Nakryiko1-3/+9
Original code assumed fixed and correct BTF header length. That's not always the case, though, so fix this bug with a proper additional check. And use actual header length instead of sizeof(struct btf_header) in sanity checks. Fixes: 8a138aed4a80 ("bpf: btf: Add BTF support to libbpf") Reported-by: Evgeny Vereshchagin <evvers@ya.ru> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20211023003157.726961-2-andrii@kernel.org
2021-10-23libbpf: Fix overflow in BTF sanity checksAndrii Nakryiko1-2/+2
btf_header's str_off+str_len or type_off+type_len can overflow as they are u32s. This will lead to bypassing the sanity checks during BTF parsing, resulting in crashes afterwards. Fix by using 64-bit signed integers for comparison. Fixes: d8123624506c ("libbpf: Fix BTF data layout checks and allow empty BTF") Reported-by: Evgeny Vereshchagin <evvers@ya.ru> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20211023003157.726961-1-andrii@kernel.org
2021-10-23Merge branch 'bpf: add support for BTF_KIND_DECL_TAG typedef'Alexei Starovoitov4-13/+89
Yonghong Song says: ==================== Latest upstream llvm-project added support for btf_decl_tag attributes for typedef declarations ([1], [2]). Similar to other btf_decl_tag cases, func/func_param/global_var/struct/union/field, btf_decl_tag with typedef declaration can carry information from kernel source to clang compiler and then to dwarf/BTF, for bpf verification or other use cases. This patch set added kernel support for BTF_KIND_DECL_TAG to typedef declaration (Patch 1). Additional selftests are added to cover unit testing, dedup, or bpf program usage of btf_decl_tag with typedef. (Patches 2, 3 and 4). The btf documentation is updated to include BTF_KIND_DECL_TAG typedef (Patch 5). [1] https://reviews.llvm.org/D110127 [2] https://reviews.llvm.org/D112259 ==================== Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2021-10-23docs/bpf: Update documentation for BTF_KIND_DECL_TAG typedef supportYonghong Song1-3/+3
Add BTF_KIND_DECL_TAG typedef support in btf.rst. Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20211021195649.4020514-1-yhs@fb.com
2021-10-23selftests/bpf: Add BTF_KIND_DECL_TAG typedef example in tag.cYonghong Song1-2/+7
Change value type in progs/tag.c to a typedef with a btf_decl_tag. With `bpftool btf dump file tag.o`, we have ... [14] TYPEDEF 'value_t' type_id=17 [15] DECL_TAG 'tag1' type_id=14 component_idx=-1 [16] DECL_TAG 'tag2' type_id=14 component_idx=-1 [17] STRUCT '(anon)' size=8 vlen=2 'a' type_id=2 bits_offset=0 'b' type_id=2 bits_offset=32 ... The btf_tag selftest also succeeded: $ ./test_progs -t tag #21 btf_tag:OK Summary: 1/0 PASSED, 0 SKIPPED, 0 FAILED Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20211021195643.4020315-1-yhs@fb.com
2021-10-23selftests/bpf: Test deduplication for BTF_KIND_DECL_TAG typedefYonghong Song1-6/+41
Add unit tests for deduplication of BTF_KIND_DECL_TAG to typedef types. Also changed a few comments from "tag" to "decl_tag" to match BTF_KIND_DECL_TAG enum value name. Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20211021195638.4019770-1-yhs@fb.com
2021-10-23selftests/bpf: Add BTF_KIND_DECL_TAG typedef unit testsYonghong Song1-0/+36
Test good and bad variants of typedef BTF_KIND_DECL_TAG encoding. Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20211021195633.4019472-1-yhs@fb.com
2021-10-23bpf: Add BTF_KIND_DECL_TAG typedef supportYonghong Song1-2/+2
The llvm patches ([1], [2]) added support to attach btf_decl_tag attributes to typedef declarations. This patch added support in kernel. [1] https://reviews.llvm.org/D110127 [2] https://reviews.llvm.org/D112259 Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20211021195628.4018847-1-yhs@fb.com
2021-10-23Merge branch 'libbpf: use func name when pinning programs with ↵Andrii Nakryiko5-22/+32
LIBBPF_STRICT_SEC_NAME' Stanislav Fomichev says: ==================== Commit 15669e1dcd75 ("selftests/bpf: Normalize all the rest SEC() uses") broke flow dissector tests. With the strict section names, bpftool isn't able to pin all programs of the objects (all section names are the same now). To bring it back to life let's do the following: - teach libbpf to pin by func name with LIBBPF_STRICT_SEC_NAME - enable strict mode in bpftool (breaking cli change) - fix custom flow_dissector loader to use strict mode - fix flow_dissector tests to use new pin names (func vs sec) v5: - get rid of error when retrying with '/' (Quentin Monnet) v4: - fix comment spelling (Quentin Monnet) - retry progtype without / (Quentin Monnet) v3: - clarify program pinning in LIBBPF_STRICT_SEC_NAME, for real this time (Andrii Nakryiko) - fix possible segfault in __bpf_program__pin_name (Andrii Nakryiko) v2: - add github issue (Andrii Nakryiko) - remove sec_name from bpf_program.pin_name comment (Andrii Nakryiko) - add cover letter (Andrii Nakryiko) ==================== Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
2021-10-23selftests/bpf: Fix flow dissector testsStanislav Fomichev3-20/+18
- update custom loader to search by name, not section name - update bpftool commands to use proper pin path Signed-off-by: Stanislav Fomichev <sdf@google.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20211021214814.1236114-4-sdf@google.com
2021-10-23libbpf: Use func name when pinning programs with LIBBPF_STRICT_SEC_NAMEStanislav Fomichev2-2/+14
We can't use section name anymore because they are not unique and pinning objects with multiple programs with the same progtype/secname will fail. [0] Closes: https://github.com/libbpf/libbpf/issues/273 Fixes: 33a2c75c55e2 ("libbpf: add internal pin_name") Signed-off-by: Stanislav Fomichev <sdf@google.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Reviewed-by: Quentin Monnet <quentin@isovalent.com> Link: https://lore.kernel.org/bpf/20211021214814.1236114-2-sdf@google.com
2021-10-23bpftool: Avoid leaking the JSON writer prepared for program metadataQuentin Monnet1-7/+9
Bpftool creates a new JSON object for writing program metadata in plain text mode, regardless of metadata being present or not. Then this writer is freed if any metadata has been found and printed, but it leaks otherwise. We cannot destroy the object unconditionally, because the destructor prints an undesirable line break. Instead, make sure the writer is created only after we have found program metadata to print. Found with valgrind. Fixes: aff52e685eb3 ("bpftool: Support dumping metadata") Signed-off-by: Quentin Monnet <quentin@isovalent.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20211022094743.11052-1-quentin@isovalent.com
2021-10-23Merge branch 'libbpf: Add btf__type_cnt() and btf__raw_data() APIs'Andrii Nakryiko18-83/+97
Hengqi Chen says: ==================== Add btf__type_cnt() and btf__raw_data() APIs and deprecate btf__get_nr_type() and btf__get_raw_data() since the old APIs don't follow libbpf naming convention. Also update tools/selftests to use these new APIs. This is part of effort towards libbpf v1.0 v1->v2: - Update commit message, deprecate the old APIs in libbpf v0.7 (Andrii) - Separate changes in tools/ to individual patches (Andrii) ==================== Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
2021-10-23selftests/bpf: Switch to new btf__type_cnt/btf__raw_data APIsHengqi Chen8-22/+22
Replace the calls to btf__get_nr_types/btf__get_raw_data in selftests with new APIs btf__type_cnt/btf__raw_data. The old APIs will be deprecated in libbpf v0.7+. Signed-off-by: Hengqi Chen <hengqi.chen@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20211022130623.1548429-6-hengqi.chen@gmail.com
2021-10-23bpftool: Switch to new btf__type_cnt APIHengqi Chen2-8/+8
Replace the call to btf__get_nr_types with new API btf__type_cnt. The old API will be deprecated in libbpf v0.7+. No functionality change. Signed-off-by: Hengqi Chen <hengqi.chen@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20211022130623.1548429-5-hengqi.chen@gmail.com
2021-10-23tools/resolve_btfids: Switch to new btf__type_cnt APIHengqi Chen1-2/+2
Replace the call to btf__get_nr_types with new API btf__type_cnt. The old API will be deprecated in libbpf v0.7+. No functionality change. Signed-off-by: Hengqi Chen <hengqi.chen@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20211022130623.1548429-4-hengqi.chen@gmail.com
2021-10-23perf bpf: Switch to new btf__raw_data APIHengqi Chen1-1/+1
Replace the call to btf__get_raw_data with new API btf__raw_data. The old APIs will be deprecated in libbpf v0.7+. No functionality change. Signed-off-by: Hengqi Chen <hengqi.chen@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20211022130623.1548429-3-hengqi.chen@gmail.com
2021-10-23libbpf: Add btf__type_cnt() and btf__raw_data() APIsHengqi Chen6-50/+64
Add btf__type_cnt() and btf__raw_data() APIs and deprecate btf__get_nr_type() and btf__get_raw_data() since the old APIs don't follow the libbpf naming convention for getters which omit 'get' in the name (see [0]). btf__raw_data() is just an alias to the existing btf__get_raw_data(). btf__type_cnt() now returns the number of all types of the BTF object including 'void'. [0] Closes: https://github.com/libbpf/libbpf/issues/279 Signed-off-by: Hengqi Chen <hengqi.chen@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20211022130623.1548429-2-hengqi.chen@gmail.com
2021-10-23libbpf: Fix memory leak in btf__dedup()Mauricio Vásquez1-2/+4
Free btf_dedup if btf_ensure_modifiable() returns error. Fixes: 919d2b1dbb07 ("libbpf: Allow modification of BTF and add btf__add_str API") Signed-off-by: Mauricio Vásquez <mauricio@kinvolk.io> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20211022202035.48868-1-mauricio@kinvolk.io
2021-10-23selftests/bpf: Make perf_buffer selftests work on 4.9 kernel againAndrii Nakryiko2-2/+23
Recent change to use tp/syscalls/sys_enter_nanosleep for perf_buffer selftests causes this selftest to fail on 4.9 kernel in libbpf CI ([0]): libbpf: prog 'handle_sys_enter': failed to attach to perf_event FD 6: Invalid argument libbpf: prog 'handle_sys_enter': failed to attach to tracepoint 'syscalls/sys_enter_nanosleep': Invalid argument It's not exactly clear why, because perf_event itself is created for this tracepoint, but I can't even compile 4.9 kernel locally, so it's hard to figure this out. If anyone has better luck and would like to help investigating this, I'd really appreciate this. For now, unblock CI by switching back to raw_syscalls/sys_enter, but reduce amount of unnecessary samples emitted by filter by process ID. Use explicit ARRAY map for that to make it work on 4.9 as well, because global data isn't yet supported there. Fixes: aa274f98b269 ("selftests/bpf: Fix possible/online index mismatch in perf_buffer test") Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20211022201342.3490692-1-andrii@kernel.org
2021-10-23libbpf: Fix the use of aligned attributeAndrii Nakryiko1-1/+1
Building libbpf sources out of kernel tree (in Github repo) we run into compilation error due to unknown __aligned attribute. It must be coming from some kernel header, which is not available to Github sources. Use explicit __attribute__((aligned(16))) instead. Fixes: 961632d54163 ("libbpf: Fix dumping non-aligned __int128") Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20211022192502.2975553-1-andrii@kernel.org
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