From acf61631746c01850a9df0cd5617c5c29214776c Mon Sep 17 00:00:00 2001 From: Yonghong Song Date: Sat, 9 May 2020 10:59:22 -0700 Subject: [PATCH] tools/bpf: selftests: Add iter progs for bpf_map/task/task_file The implementation is arbitrary, just to show how the bpf programs can be written for bpf_map/task/task_file. They can be costomized for specific needs. For example, for bpf_map, the iterator prints out: $ cat /sys/fs/bpf/my_bpf_map id refcnt usercnt locked_vm 3 2 0 20 6 2 0 20 9 2 0 20 12 2 0 20 13 2 0 20 16 2 0 20 19 2 0 20 %%% END %%% For task, the iterator prints out: $ cat /sys/fs/bpf/my_task tgid gid 1 1 2 2 .... 1944 1944 1948 1948 1949 1949 1953 1953 === END === For task/file, the iterator prints out: $ cat /sys/fs/bpf/my_task_file tgid gid fd file 1 1 0 ffffffff95c97600 1 1 1 ffffffff95c97600 1 1 2 ffffffff95c97600 .... 1895 1895 255 ffffffff95c8fe00 1932 1932 0 ffffffff95c8fe00 1932 1932 1 ffffffff95c8fe00 1932 1932 2 ffffffff95c8fe00 1932 1932 3 ffffffff95c185c0 This is able to print out all open files (fd and file->f_op), so user can compare f_op against a particular kernel file operations to find what it is. For example, from /proc/kallsyms, we can find ffffffff95c185c0 r eventfd_fops so we will know tgid 1932 fd 3 is an eventfd file descriptor. Signed-off-by: Yonghong Song Signed-off-by: Alexei Starovoitov Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20200509175922.2477576-1-yhs@fb.com --- .../selftests/bpf/progs/bpf_iter_bpf_map.c | 28 +++++++++++++++++++ .../selftests/bpf/progs/bpf_iter_task.c | 25 +++++++++++++++++ .../selftests/bpf/progs/bpf_iter_task_file.c | 26 +++++++++++++++++ 3 files changed, 79 insertions(+) create mode 100644 tools/testing/selftests/bpf/progs/bpf_iter_bpf_map.c create mode 100644 tools/testing/selftests/bpf/progs/bpf_iter_task.c create mode 100644 tools/testing/selftests/bpf/progs/bpf_iter_task_file.c diff --git a/tools/testing/selftests/bpf/progs/bpf_iter_bpf_map.c b/tools/testing/selftests/bpf/progs/bpf_iter_bpf_map.c new file mode 100644 index 000000000000..4867cd3445c8 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/bpf_iter_bpf_map.c @@ -0,0 +1,28 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2020 Facebook */ +#include "vmlinux.h" +#include +#include + +char _license[] SEC("license") = "GPL"; + +SEC("iter/bpf_map") +int dump_bpf_map(struct bpf_iter__bpf_map *ctx) +{ + struct seq_file *seq = ctx->meta->seq; + __u64 seq_num = ctx->meta->seq_num; + struct bpf_map *map = ctx->map; + + if (map == (void *)0) { + BPF_SEQ_PRINTF(seq, " %%%%%% END %%%%%%\n"); + return 0; + } + + if (seq_num == 0) + BPF_SEQ_PRINTF(seq, " id refcnt usercnt locked_vm\n"); + + BPF_SEQ_PRINTF(seq, "%8u %8ld %8ld %10lu\n", map->id, map->refcnt.counter, + map->usercnt.counter, + map->memory.user->locked_vm.counter); + return 0; +} diff --git a/tools/testing/selftests/bpf/progs/bpf_iter_task.c b/tools/testing/selftests/bpf/progs/bpf_iter_task.c new file mode 100644 index 000000000000..90f9011c57ca --- /dev/null +++ b/tools/testing/selftests/bpf/progs/bpf_iter_task.c @@ -0,0 +1,25 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2020 Facebook */ +#include "vmlinux.h" +#include +#include + +char _license[] SEC("license") = "GPL"; + +SEC("iter/task") +int dump_task(struct bpf_iter__task *ctx) +{ + struct seq_file *seq = ctx->meta->seq; + struct task_struct *task = ctx->task; + + if (task == (void *)0) { + BPF_SEQ_PRINTF(seq, " === END ===\n"); + return 0; + } + + if (ctx->meta->seq_num == 0) + BPF_SEQ_PRINTF(seq, " tgid gid\n"); + + BPF_SEQ_PRINTF(seq, "%8d %8d\n", task->tgid, task->pid); + return 0; +} diff --git a/tools/testing/selftests/bpf/progs/bpf_iter_task_file.c b/tools/testing/selftests/bpf/progs/bpf_iter_task_file.c new file mode 100644 index 000000000000..c6ced38f0880 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/bpf_iter_task_file.c @@ -0,0 +1,26 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2020 Facebook */ +#include "vmlinux.h" +#include +#include + +char _license[] SEC("license") = "GPL"; + +SEC("iter/task_file") +int dump_task_file(struct bpf_iter__task_file *ctx) +{ + struct seq_file *seq = ctx->meta->seq; + struct task_struct *task = ctx->task; + __u32 fd = ctx->fd; + struct file *file = ctx->file; + + if (task == (void *)0 || file == (void *)0) + return 0; + + if (ctx->meta->seq_num == 0) + BPF_SEQ_PRINTF(seq, " tgid gid fd file\n"); + + BPF_SEQ_PRINTF(seq, "%8d %8d %8d %lx\n", task->tgid, task->pid, fd, + (long)file->f_op); + return 0; +} -- 2.25.1