From: Chen Hui judy.chenhui@huawei.com
hulk inclusion category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I5KUFB CVE: NA
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This program can choose program by args [-W|-T|-E] to attach BPF_SCHED hooks which in preempt process and then matches task or task group which has tag TASK_TYPE_ONLINE and TASK_TYPE_OFFLINE.
This will return different value to hook function which use to indicate whether to preempt the current sched entity.
To run,
# sched_preempt [-W|-T|-E|-h]
Signed-off-by: Chen Hui judy.chenhui@huawei.com Signed-off-by: Ren Zhijie renzhijie2@huawei.com --- samples/bpf/Makefile | 3 + samples/bpf/sched_preempt_kern.c | 151 +++++++++++++++++++++++++++++++ samples/bpf/sched_preempt_user.c | 139 ++++++++++++++++++++++++++++ 3 files changed, 293 insertions(+) create mode 100644 samples/bpf/sched_preempt_kern.c create mode 100644 samples/bpf/sched_preempt_user.c
diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile index aeebf5d12f32..e473bad76549 100644 --- a/samples/bpf/Makefile +++ b/samples/bpf/Makefile @@ -54,6 +54,7 @@ tprogs-y += task_fd_query tprogs-y += xdp_sample_pkts tprogs-y += ibumad tprogs-y += hbm +tprogs-y += sched_preempt
# Libbpf dependencies LIBBPF = $(TOOLS_PATH)/lib/bpf/libbpf.a @@ -111,6 +112,7 @@ task_fd_query-objs := bpf_load.o task_fd_query_user.o $(TRACE_HELPERS) xdp_sample_pkts-objs := xdp_sample_pkts_user.o $(TRACE_HELPERS) ibumad-objs := bpf_load.o ibumad_user.o $(TRACE_HELPERS) hbm-objs := bpf_load.o hbm.o $(CGROUP_HELPERS) +sched_preempt-objs := sched_preempt_user.o
# Tell kbuild to always build the programs always-y := $(tprogs-y) @@ -172,6 +174,7 @@ always-y += ibumad_kern.o always-y += hbm_out_kern.o always-y += hbm_edt_kern.o always-y += xdpsock_kern.o +always-y += sched_preempt_kern.o
ifeq ($(ARCH), arm) # Strip all except -D__LINUX_ARM_ARCH__ option needed to handle linux diff --git a/samples/bpf/sched_preempt_kern.c b/samples/bpf/sched_preempt_kern.c new file mode 100644 index 000000000000..1e315af9e009 --- /dev/null +++ b/samples/bpf/sched_preempt_kern.c @@ -0,0 +1,151 @@ +// SPDX-License-Identifier: GPL-2.0 + +/* + * Copyright (C) 2022. Huawei Technologies Co., Ltd. All rights reserved. + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 and + * only version 2 as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ +#include <linux/version.h> +#include <linux/sched.h> +#include <uapi/linux/bpf.h> +#include <bpf/bpf_helpers.h> +#include <bpf/bpf_tracing.h> + +unsigned long idea_runtime = 1000000UL; + +enum task_type { + TASK_TYPE_OFFLINE = -1, + TASK_TYPE_NORMAL, + TASK_TYPE_ONLINE, +}; + +#define getVal(P) \ + ({ \ + typeof(P) val = 0; \ + bpf_probe_read_kernel(&val, sizeof(val), &(P)); \ + val; \ + }) + +#define bprintk(fmt, ...) \ + ({ \ + char ____fmt[] = fmt; \ + bpf_trace_printk(____fmt, sizeof(____fmt), \ + ##__VA_ARGS__); \ + }) + +SEC("sched/cfs_check_preempt_wakeup") +int BPF_PROG(sched_cfs_check_preempt_wakeup, struct task_struct *curr, struct task_struct *p) +{ + long curr_type, p_type; + int ret = 0; + + curr_type = bpf_sched_task_tag_of(curr); + p_type = bpf_sched_task_tag_of(p); + + if (curr_type == TASK_TYPE_ONLINE && p_type == TASK_TYPE_OFFLINE) + ret = -1; + + if (curr_type == TASK_TYPE_OFFLINE && p_type == TASK_TYPE_ONLINE) + ret = 1; + + bprintk("check_preempt_wakeup: curr id = %d, p id = %d, preempt result is %d\n", + getVal(curr->pid), getVal(p->pid), ret); + + return ret; +} + +SEC("sched/cfs_check_preempt_tick") +int BPF_PROG(sched_cfs_check_preempt_tick, struct sched_entity *curr, unsigned long delta_exec) +{ + long curr_type = TASK_TYPE_NORMAL; + int ret = 0, id = 0; + + if (bpf_sched_entity_is_task(curr)) { + struct task_struct *tsk = bpf_sched_entity_to_task(curr); + + if (tsk) { + curr_type = bpf_sched_task_tag_of(tsk); + id = getVal(tsk->pid); + } + bprintk("check_preempt_tick: delta = %lu,entity is task, id = %d\n", + delta_exec, id); + } else { + struct task_group *tg = bpf_sched_entity_to_tg(curr); + + if (tg) { + curr_type = bpf_sched_tg_tag_of(tg); + id = bpf_sched_entity_to_cgrpid(curr); + } + bprintk("check_preempt_tick: delta = %lu,entity is group, id = %d\n", + delta_exec, id); + } + + if (curr_type == TASK_TYPE_ONLINE) + ret = delta_exec >= idea_runtime ? 1 : -1; + + bprintk("check_preempt_tick: preempt result = %d\n", ret); + return ret; +} + +SEC("sched/cfs_wakeup_preempt_entity") +int BPF_PROG(sched_cfs_wakeup_preempt_entity, struct sched_entity *curr, struct sched_entity *se) +{ + long curr_type = TASK_TYPE_NORMAL; + long p_type = TASK_TYPE_NORMAL; + int curr_id = 0, p_id = 0; + int ret = 0; + + if (bpf_sched_entity_is_task(curr)) { + struct task_struct *tsk = bpf_sched_entity_to_task(curr); + + if (tsk) { + curr_type = bpf_sched_task_tag_of(tsk); + curr_id = getVal(tsk->pid); + bprintk("wakeup_preempt_entity: curr entity is task, id = %d\n", curr_id); + } + } else { + struct task_group *tg = bpf_sched_entity_to_tg(curr); + + if (tg) { + curr_type = bpf_sched_tg_tag_of(tg); + curr_id = bpf_sched_entity_to_cgrpid(curr); + bprintk("wakeup_preempt_entity: curr entity is group, id = %d\n", curr_id); + } + } + + if (bpf_sched_entity_is_task(se)) { + struct task_struct *p = bpf_sched_entity_to_task(se); + + if (p) { + p_type = bpf_sched_task_tag_of(p); + p_id = getVal(p->pid); + bprintk("wakeup_preempt_entity: se entity is task, id = %d\n", p_id); + } + } else { + struct task_group *tg1 = bpf_sched_entity_to_tg(se); + + if (tg1) { + p_type = bpf_sched_tg_tag_of(tg1); + p_id = bpf_sched_entity_to_cgrpid(se); + bprintk("wakeup_preempt_entity: se entity is group, id = %d\n", p_id); + } + } + + if (curr_type == TASK_TYPE_ONLINE && p_type == TASK_TYPE_OFFLINE) + ret = -1; + + if (curr_type == TASK_TYPE_OFFLINE && p_type == TASK_TYPE_ONLINE) + ret = 1; + + bprintk("wakeup_preempt_entity: preempt result = %d\n", ret); + + return ret; +} + +char _license[] SEC("license") = "GPL"; diff --git a/samples/bpf/sched_preempt_user.c b/samples/bpf/sched_preempt_user.c new file mode 100644 index 000000000000..26f1f36d4558 --- /dev/null +++ b/samples/bpf/sched_preempt_user.c @@ -0,0 +1,139 @@ +// SPDX-License-Identifier: GPL-2.0 + +/* + * Copyright (C) 2022. Huawei Technologies Co., Ltd. All rights reserved. + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 and + * only version 2 as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <assert.h> +#include <errno.h> +#include <fcntl.h> +#include <unistd.h> +#include <sys/resource.h> +#include <bpf/libbpf.h> + +#define MAX_PROGS (3) +#define TRACE_DIR "/sys/kernel/debug/tracing/" +#define BUF_SIZE (4096) + +int progindex[MAX_PROGS]; + +static void usage(void) +{ + printf("USAGE: sched_preempt [...]\n"); + printf(" -W # Test sched preempt wakeup\n"); + printf(" -T # Test sched preempt tick\n"); + printf(" -E # Test wakeup preempt entity\n"); + printf(" -h # Display this help\n"); +} + +/* read trace logs from debug fs */ +static void read_trace_pipe(void) +{ + int trace_fd; + + trace_fd = open(TRACE_DIR "trace_pipe", O_RDONLY, 0); + if (trace_fd < 0) + return; + + while (1) { + static char buf[BUF_SIZE]; + ssize_t sz; + + sz = read(trace_fd, buf, sizeof(buf) - 1); + if (sz > 0) { + buf[sz] = 0; + puts(buf); + } + } +} + +static inline bool check_attach_prog(int index) +{ + return progindex[index] ? true : false; +} + +int main(int argc, char **argv) +{ + int opt; + int index; + char filename[256]; + struct bpf_object *obj; + struct bpf_program *prog; + struct bpf_link *link = NULL; + + char prognames[MAX_PROGS][256] = { + "sched_cfs_check_preempt_wakeup", + "sched_cfs_check_preempt_tick", + "sched_cfs_wakeup_preempt_entity", + }; + + while ((opt = getopt(argc, argv, "WTEh")) != -1) { + switch (opt) { + case 'W': + progindex[0] = 1; + break; + case 'T': + progindex[1] = 1; + break; + case 'E': + progindex[2] = 1; + break; + case 'h': + default: + usage(); + goto out; + } + } + + snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]); + obj = bpf_object__open_file(filename, NULL); + if (libbpf_get_error(obj)) { + fprintf(stderr, "ERROR: opening BPF object file failed\n"); + goto out; + } + + /* load BPF program */ + if (bpf_object__load(obj)) { + fprintf(stderr, "ERROR: loading BPF object file failed\n"); + goto cleanup; + } + + for (index = 0; index < MAX_PROGS; ++index) { + if (check_attach_prog(index)) { + prog = bpf_object__find_program_by_name(obj, prognames[index]); + if (libbpf_get_error(prog)) { + fprintf(stderr, "ERROR: finding a prog:%s in obj file failed\n", + prognames[index]); + goto cleanup; + } + + link = bpf_program__attach(prog); + if (libbpf_get_error(link)) { + fprintf(stderr, "ERROR: bpf_program__attach failed\n"); + link = NULL; + goto cleanup; + } + } + } + + printf("preempt BPF started, hit Ctrl+C to stop!\n"); + + read_trace_pipe(); + +cleanup: + bpf_link__destroy(link); + bpf_object__close(obj); + +out: + return 0; +}