| Message ID | 20190924152005.4659-5-cneirabustos@gmail.com |
|---|---|
| State | Changes Requested |
| Delegated to: | BPF Maintainers |
| Headers | show |
| Series | BPF: New helper to obtain namespace data from current task | expand |
On 9/24/19 8:20 AM, Carlos Neira wrote: > Self tests added for new helper > > Signed-off-by: Carlos Neira <cneirabustos@gmail.com> > --- > tools/testing/selftests/bpf/Makefile | 2 +- > tools/testing/selftests/bpf/bpf_helpers.h | 3 + > .../selftests/bpf/progs/test_pidns_kern.c | 71 ++++++++ > tools/testing/selftests/bpf/test_pidns.c | 152 ++++++++++++++++++ > 4 files changed, 227 insertions(+), 1 deletion(-) > create mode 100644 tools/testing/selftests/bpf/progs/test_pidns_kern.c > create mode 100644 tools/testing/selftests/bpf/test_pidns.c > > diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile > index 7f3196af1ae4..d86b28aa8f44 100644 > --- a/tools/testing/selftests/bpf/Makefile > +++ b/tools/testing/selftests/bpf/Makefile > @@ -28,7 +28,7 @@ TEST_GEN_PROGS = test_verifier test_tag test_maps test_lru_map test_lpm_map test > test_sock test_btf test_sockmap get_cgroup_id_user test_socket_cookie \ > test_cgroup_storage test_select_reuseport test_section_names \ > test_netcnt test_tcpnotify_user test_sock_fields test_sysctl test_hashmap \ > - test_btf_dump test_cgroup_attach xdping > + test_btf_dump test_cgroup_attach xdping test_pidns Could you fold test_pidns into test_progs? > > BPF_OBJ_FILES = $(patsubst %.c,%.o, $(notdir $(wildcard progs/*.c))) > TEST_GEN_FILES = $(BPF_OBJ_FILES) > diff --git a/tools/testing/selftests/bpf/bpf_helpers.h b/tools/testing/selftests/bpf/bpf_helpers.h > index 6c4930bc6e2e..03d0e15ae29f 100644 > --- a/tools/testing/selftests/bpf/bpf_helpers.h > +++ b/tools/testing/selftests/bpf/bpf_helpers.h > @@ -231,6 +231,9 @@ static int (*bpf_send_signal)(unsigned sig) = (void *)BPF_FUNC_send_signal; > static long long (*bpf_tcp_gen_syncookie)(struct bpf_sock *sk, void *ip, > int ip_len, void *tcp, int tcp_len) = > (void *) BPF_FUNC_tcp_gen_syncookie; > +static int (*bpf_get_ns_current_pid_tgid)(__u32 dev, __u64 inum) = > + (void *) BPF_FUNC_get_ns_current_pid_tgid; > + > > /* llvm builtin functions that eBPF C program may use to > * emit BPF_LD_ABS and BPF_LD_IND instructions > diff --git a/tools/testing/selftests/bpf/progs/test_pidns_kern.c b/tools/testing/selftests/bpf/progs/test_pidns_kern.c > new file mode 100644 > index 000000000000..96cb707db3ee > --- /dev/null > +++ b/tools/testing/selftests/bpf/progs/test_pidns_kern.c > @@ -0,0 +1,71 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* Copyright (c) 2018 Carlos Neira cneirabustos@gmail.com 2019 > + * > + * This program is free software; you can redistribute it and/or > + * modify it under the terms of version 2 of the GNU General Public > + * License as published by the Free Software Foundation. You do not need the above statement, which is covered by "SPDX-License-Identifier: GPL-2.0". > + */ > + > +#include <linux/bpf.h> > +#include "bpf_helpers.h" > + > +struct { > + __uint(type, BPF_MAP_TYPE_ARRAY); > + __uint(max_entries, 1); > + __type(key, __u32); > + __type(value, __u64); > +} ns_inum_map SEC(".maps"); > + > +struct { > + __uint(type, BPF_MAP_TYPE_ARRAY); > + __uint(max_entries, 1); > + __type(key, __u32); > + __type(value, __u32); > +} ns_dev_map SEC(".maps"); > + > +struct { > + __uint(type, BPF_MAP_TYPE_ARRAY); > + __uint(max_entries, 1); > + __type(key, __u32); > + __type(value, __u32); > +} pidmap SEC(".maps"); Can we make the value __u64 to include both pid and tid to compare both? > + > +struct { > + __uint(type, BPF_MAP_TYPE_ARRAY); > + __uint(max_entries, 1); > + __type(key, __u32); > + __type(value, __u64); > +} ns_pid_map SEC(".maps"); > + > The above four one-element maps are perfectly examples to use static global variables which are supported by the kernel. You can take a look at the patch https://patchwork.ozlabs.org/patch/1081014/ which shows how user space can modify the map values. In the future, we could have a better interface to read/update those static variable values. > + > +SEC("tracepoint/syscalls/sys_enter_nanosleep") > +int trace(void *ctx) > +{ > + __u32 key = 0, *expected_pid, *dev; expected_pid => __u64 *? > + __u64 *val, *inum, nspid; > + __u32 pid; > + > + dev = bpf_map_lookup_elem(&ns_dev_map, &key); > + if (!dev) > + return 0; > + > + inum = bpf_map_lookup_elem(&ns_inum_map, &key); > + if (!inum) > + return 0; > + > + nspid = bpf_get_ns_current_pid_tgid(*dev, *inum); > + expected_pid = bpf_map_lookup_elem(&pidmap, &key); > + > + if (!expected_pid || *expected_pid != nspid) > + return 0; > + > + val = bpf_map_lookup_elem(&ns_pid_map, &key); > + if (val) > + *val = nspid; > + > + return 0; > +} > + > +char _license[] SEC("license") = "GPL"; > +__u32 _version SEC("version") = 1; > diff --git a/tools/testing/selftests/bpf/test_pidns.c b/tools/testing/selftests/bpf/test_pidns.c > new file mode 100644 > index 000000000000..088f8025f2bf > --- /dev/null > +++ b/tools/testing/selftests/bpf/test_pidns.c > @@ -0,0 +1,152 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* Copyright (c) 2018 Carlos Neira cneirabustos@gmail.com 2019 > + * > + * This program is free software; you can redistribute it and/or > + * modify it under the terms of version 2 of the GNU General Public > + * License as published by the Free Software Foundation. ditto. you do not need the above statement. > + */ > + > +#include <stdio.h> > +#include <stdlib.h> > +#include <string.h> > +#include <errno.h> > +#include <fcntl.h> > +#include <syscall.h> > +#include <unistd.h> > +#include <linux/perf_event.h> > +#include <sys/ioctl.h> > +#include <sys/time.h> > +#include <sys/types.h> > +#include <sys/stat.h> > + > +#include <linux/bpf.h> > +#include <bpf/bpf.h> > +#include <bpf/libbpf.h> > + > +#include "cgroup_helpers.h" > +#include "bpf_rlimit.h" > + > +#define CHECK(condition, tag, format...) ({ \ > + int __ret = !!(condition); \ > + if (__ret) { \ > + printf("%s:FAIL:%s ", __func__, tag); \ > + printf(format); \ > + } else { \ > + printf("%s:PASS:%s\n", __func__, tag); \ > + } \ > + __ret; \ > +}) > + > +static int bpf_find_map(const char *test, struct bpf_object *obj, > + const char *name) > +{ > + struct bpf_map *map; > + > + map = bpf_object__find_map_by_name(obj, name); > + if (!map) > + return -1; > + return bpf_map__fd(map); The 'test' argument is not used here. Also, we have bpf_object__find_map_fd_by_name() API, you can use it and you do not need this function. > +} > + > + > +int main(int argc, char **argv) > +{ > + int pidmap_fd, ns_inum_map_fd, ns_dev_map_fd, ns_pid_map_fd; > + const char *probe_name = "syscalls/sys_enter_nanosleep"; > + const char *file = "test_pidns_kern.o"; > + int err, bytes, efd, prog_fd, pmu_fd; > + struct perf_event_attr attr = {}; > + struct bpf_object *obj; > + __u32 nspid = 0; > + __u32 key = 0, pid; > + int exit_code = 1; to make it reverse Christmas tree style? > + struct stat st; > + char buf[256]; > + > + err = bpf_prog_load(file, BPF_PROG_TYPE_TRACEPOINT, &obj, &prog_fd); > + if (CHECK(err, "bpf_prog_load", "err %d errno %d\n", err, errno)) > + goto cleanup_cgroup_env; > + > + ns_dev_map_fd = bpf_find_map(__func__, obj, "ns_dev_map"); > + if (CHECK(ns_dev_map_fd < 0, "bpf_find_map", "err %d errno %d\n", > + ns_dev_map_fd, errno)) > + goto close_prog; > + > + ns_inum_map_fd = bpf_find_map(__func__, obj, "ns_inum_map"); > + if (CHECK(ns_inum_map_fd < 0, "bpf_find_map", "err %d errno %d\n", > + ns_inum_map_fd, errno)) > + goto close_prog; > + > + ns_pid_map_fd = bpf_find_map(__func__, obj, "ns_pid_map"); > + if (CHECK(ns_pid_map_fd < 0, "bpf_find_map", "err %d errno %d\n", > + ns_pid_map_fd, errno)) > + goto close_prog; > + > + pidmap_fd = bpf_find_map(__func__, obj, "pidmap"); > + if (CHECK(pidmap_fd < 0, "bpf_find_map", "err %d errno %d\n", > + pidmap_fd, errno)) > + goto close_prog; > + > + pid = getpid(); > + bpf_map_update_elem(pidmap_fd, &key, &pid, 0); maybe id = (__u64) getpid() << 32 | gettid(); bpf_map_update_elem(pidmap_fd, &key, &id, 0); In your original above kernel code, you actually compare user space pid to kernel tid, which is okay for this program as it is the main thread and tid == pid, but the mechanism is wrong. > + > + if (stat("/proc/self/ns/pid", &st)) > + goto close_prog; > + > + bpf_map_update_elem(ns_inum_map_fd, &key, &st.st_ino, 0); > + bpf_map_update_elem(ns_dev_map_fd, &key, &st.st_dev, 0); > + > + > + snprintf(buf, sizeof(buf), > + "/sys/kernel/debug/tracing/events/%s/id", probe_name); > + efd = open(buf, O_RDONLY, 0); > + if (CHECK(efd < 0, "open", "err %d errno %d\n", efd, errno)) > + goto close_prog; > + bytes = read(efd, buf, sizeof(buf)); > + close(efd); > + if (CHECK(bytes <= 0 || bytes >= sizeof(buf), "read", > + "bytes %d errno %d\n", bytes, errno)) > + goto close_prog; > + > + attr.config = strtol(buf, NULL, 0); > + attr.type = PERF_TYPE_TRACEPOINT; > + attr.sample_type = PERF_SAMPLE_RAW; > + attr.sample_period = 1; > + attr.wakeup_events = 1; > + > + pmu_fd = syscall(__NR_perf_event_open, &attr, getpid(), -1, -1, 0); > + if (CHECK(pmu_fd < 0, "perf_event_open", "err %d errno %d\n", pmu_fd, > + errno)) > + goto close_prog; > + > + err = ioctl(pmu_fd, PERF_EVENT_IOC_ENABLE, 0); > + if (CHECK(err, "perf_event_ioc_enable", "err %d errno %d\n", err, > + errno)) > + goto close_pmu; > + > + err = ioctl(pmu_fd, PERF_EVENT_IOC_SET_BPF, prog_fd); > + if (CHECK(err, "perf_event_ioc_set_bpf", "err %d errno %d\n", err, > + errno)) > + goto close_pmu; The whole thing above related to tracepoint can be simplified. Please see prog_tests/stacktrace_map.c. > + > + /* trigger some syscalls */ > + sleep(1); > + > + err = bpf_map_lookup_elem(ns_pid_map_fd, &key, &nspid); > + if (CHECK(err, "bpf_map_lookup_elem", "err %d errno %d\n", err, errno)) > + goto close_pmu; > + > + if (CHECK(nspid != pid, "compare nspid vs pid", > + "kern nspid %u user pid %u", nspid, pid)) > + goto close_pmu; > + > + exit_code = 0; > + printf("%s:PASS\n", argv[0]); > + > +close_pmu: > + close(pmu_fd); > +close_prog: > + bpf_object__close(obj); > +cleanup_cgroup_env: > + return exit_code; > +} >
On Wed, Sep 25, 2019 at 04:07:09PM +0000, Yonghong Song wrote: > > > On 9/24/19 8:20 AM, Carlos Neira wrote: > > Self tests added for new helper > > > > Signed-off-by: Carlos Neira <cneirabustos@gmail.com> > > --- > > tools/testing/selftests/bpf/Makefile | 2 +- > > tools/testing/selftests/bpf/bpf_helpers.h | 3 + > > .../selftests/bpf/progs/test_pidns_kern.c | 71 ++++++++ > > tools/testing/selftests/bpf/test_pidns.c | 152 ++++++++++++++++++ > > 4 files changed, 227 insertions(+), 1 deletion(-) > > create mode 100644 tools/testing/selftests/bpf/progs/test_pidns_kern.c > > create mode 100644 tools/testing/selftests/bpf/test_pidns.c > > > > diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile > > index 7f3196af1ae4..d86b28aa8f44 100644 > > --- a/tools/testing/selftests/bpf/Makefile > > +++ b/tools/testing/selftests/bpf/Makefile > > @@ -28,7 +28,7 @@ TEST_GEN_PROGS = test_verifier test_tag test_maps test_lru_map test_lpm_map test > > test_sock test_btf test_sockmap get_cgroup_id_user test_socket_cookie \ > > test_cgroup_storage test_select_reuseport test_section_names \ > > test_netcnt test_tcpnotify_user test_sock_fields test_sysctl test_hashmap \ > > - test_btf_dump test_cgroup_attach xdping > > + test_btf_dump test_cgroup_attach xdping test_pidns > > Could you fold test_pidns into test_progs? > > > > > BPF_OBJ_FILES = $(patsubst %.c,%.o, $(notdir $(wildcard progs/*.c))) > > TEST_GEN_FILES = $(BPF_OBJ_FILES) > > diff --git a/tools/testing/selftests/bpf/bpf_helpers.h b/tools/testing/selftests/bpf/bpf_helpers.h > > index 6c4930bc6e2e..03d0e15ae29f 100644 > > --- a/tools/testing/selftests/bpf/bpf_helpers.h > > +++ b/tools/testing/selftests/bpf/bpf_helpers.h > > @@ -231,6 +231,9 @@ static int (*bpf_send_signal)(unsigned sig) = (void *)BPF_FUNC_send_signal; > > static long long (*bpf_tcp_gen_syncookie)(struct bpf_sock *sk, void *ip, > > int ip_len, void *tcp, int tcp_len) = > > (void *) BPF_FUNC_tcp_gen_syncookie; > > +static int (*bpf_get_ns_current_pid_tgid)(__u32 dev, __u64 inum) = > > + (void *) BPF_FUNC_get_ns_current_pid_tgid; > > + > > > > /* llvm builtin functions that eBPF C program may use to > > * emit BPF_LD_ABS and BPF_LD_IND instructions > > diff --git a/tools/testing/selftests/bpf/progs/test_pidns_kern.c b/tools/testing/selftests/bpf/progs/test_pidns_kern.c > > new file mode 100644 > > index 000000000000..96cb707db3ee > > --- /dev/null > > +++ b/tools/testing/selftests/bpf/progs/test_pidns_kern.c > > @@ -0,0 +1,71 @@ > > +// SPDX-License-Identifier: GPL-2.0 > > +/* Copyright (c) 2018 Carlos Neira cneirabustos@gmail.com > > 2019 > > > + * > > + * This program is free software; you can redistribute it and/or > > + * modify it under the terms of version 2 of the GNU General Public > > + * License as published by the Free Software Foundation. > > You do not need the above statement, which is covered by > "SPDX-License-Identifier: GPL-2.0". > > > + */ > > + > > +#include <linux/bpf.h> > > +#include "bpf_helpers.h" > > + > > +struct { > > + __uint(type, BPF_MAP_TYPE_ARRAY); > > + __uint(max_entries, 1); > > + __type(key, __u32); > > + __type(value, __u64); > > +} ns_inum_map SEC(".maps"); > > + > > +struct { > > + __uint(type, BPF_MAP_TYPE_ARRAY); > > + __uint(max_entries, 1); > > + __type(key, __u32); > > + __type(value, __u32); > > +} ns_dev_map SEC(".maps"); > > + > > +struct { > > + __uint(type, BPF_MAP_TYPE_ARRAY); > > + __uint(max_entries, 1); > > + __type(key, __u32); > > + __type(value, __u32); > > +} pidmap SEC(".maps"); > > Can we make the value __u64 to include > both pid and tid to compare both? > > > + > > +struct { > > + __uint(type, BPF_MAP_TYPE_ARRAY); > > + __uint(max_entries, 1); > > + __type(key, __u32); > > + __type(value, __u64); > > +} ns_pid_map SEC(".maps"); > > + > > > > The above four one-element maps are perfectly examples > to use static global variables which are supported > by the kernel. > > You can take a look at the patch > https://patchwork.ozlabs.org/patch/1081014/ > which shows how user space can modify the map > values. In the future, we could have a better > interface to read/update those static variable > values. > > > + > > +SEC("tracepoint/syscalls/sys_enter_nanosleep") > > +int trace(void *ctx) > > +{ > > + __u32 key = 0, *expected_pid, *dev; > > expected_pid => __u64 *? > > > + __u64 *val, *inum, nspid; > > + __u32 pid; > > + > > + dev = bpf_map_lookup_elem(&ns_dev_map, &key); > > + if (!dev) > > + return 0; > > + > > + inum = bpf_map_lookup_elem(&ns_inum_map, &key); > > + if (!inum) > > + return 0; > > + > > + nspid = bpf_get_ns_current_pid_tgid(*dev, *inum); > > + expected_pid = bpf_map_lookup_elem(&pidmap, &key); > > + > > + if (!expected_pid || *expected_pid != nspid) > > + return 0; > > + > > + val = bpf_map_lookup_elem(&ns_pid_map, &key); > > + if (val) > > + *val = nspid; > > + > > + return 0; > > +} > > + > > +char _license[] SEC("license") = "GPL"; > > +__u32 _version SEC("version") = 1; > > diff --git a/tools/testing/selftests/bpf/test_pidns.c b/tools/testing/selftests/bpf/test_pidns.c > > new file mode 100644 > > index 000000000000..088f8025f2bf > > --- /dev/null > > +++ b/tools/testing/selftests/bpf/test_pidns.c > > @@ -0,0 +1,152 @@ > > +// SPDX-License-Identifier: GPL-2.0 > > +/* Copyright (c) 2018 Carlos Neira cneirabustos@gmail.com > > 2019 > > > + * > > + * This program is free software; you can redistribute it and/or > > + * modify it under the terms of version 2 of the GNU General Public > > + * License as published by the Free Software Foundation. > > ditto. you do not need the above statement. > > > + */ > > + > > +#include <stdio.h> > > +#include <stdlib.h> > > +#include <string.h> > > +#include <errno.h> > > +#include <fcntl.h> > > +#include <syscall.h> > > +#include <unistd.h> > > +#include <linux/perf_event.h> > > +#include <sys/ioctl.h> > > +#include <sys/time.h> > > +#include <sys/types.h> > > +#include <sys/stat.h> > > + > > +#include <linux/bpf.h> > > +#include <bpf/bpf.h> > > +#include <bpf/libbpf.h> > > + > > +#include "cgroup_helpers.h" > > +#include "bpf_rlimit.h" > > + > > +#define CHECK(condition, tag, format...) ({ \ > > + int __ret = !!(condition); \ > > + if (__ret) { \ > > + printf("%s:FAIL:%s ", __func__, tag); \ > > + printf(format); \ > > + } else { \ > > + printf("%s:PASS:%s\n", __func__, tag); \ > > + } \ > > + __ret; \ > > +}) > > + > > +static int bpf_find_map(const char *test, struct bpf_object *obj, > > + const char *name) > > +{ > > + struct bpf_map *map; > > + > > + map = bpf_object__find_map_by_name(obj, name); > > + if (!map) > > + return -1; > > + return bpf_map__fd(map); > > The 'test' argument is not used here. > Also, we have bpf_object__find_map_fd_by_name() API, you can > use it and you do not need this function. > > > +} > > + > > + > > +int main(int argc, char **argv) > > +{ > > + int pidmap_fd, ns_inum_map_fd, ns_dev_map_fd, ns_pid_map_fd; > > + const char *probe_name = "syscalls/sys_enter_nanosleep"; > > + const char *file = "test_pidns_kern.o"; > > + int err, bytes, efd, prog_fd, pmu_fd; > > + struct perf_event_attr attr = {}; > > + struct bpf_object *obj; > > + __u32 nspid = 0; > > + __u32 key = 0, pid; > > + int exit_code = 1; > > to make it reverse Christmas tree style? > > > + struct stat st; > > + char buf[256]; > > + > > + err = bpf_prog_load(file, BPF_PROG_TYPE_TRACEPOINT, &obj, &prog_fd); > > + if (CHECK(err, "bpf_prog_load", "err %d errno %d\n", err, errno)) > > + goto cleanup_cgroup_env; > > + > > + ns_dev_map_fd = bpf_find_map(__func__, obj, "ns_dev_map"); > > + if (CHECK(ns_dev_map_fd < 0, "bpf_find_map", "err %d errno %d\n", > > + ns_dev_map_fd, errno)) > > + goto close_prog; > > + > > + ns_inum_map_fd = bpf_find_map(__func__, obj, "ns_inum_map"); > > + if (CHECK(ns_inum_map_fd < 0, "bpf_find_map", "err %d errno %d\n", > > + ns_inum_map_fd, errno)) > > + goto close_prog; > > + > > + ns_pid_map_fd = bpf_find_map(__func__, obj, "ns_pid_map"); > > + if (CHECK(ns_pid_map_fd < 0, "bpf_find_map", "err %d errno %d\n", > > + ns_pid_map_fd, errno)) > > + goto close_prog; > > + > > + pidmap_fd = bpf_find_map(__func__, obj, "pidmap"); > > + if (CHECK(pidmap_fd < 0, "bpf_find_map", "err %d errno %d\n", > > + pidmap_fd, errno)) > > + goto close_prog; > > + > > + pid = getpid(); > > + bpf_map_update_elem(pidmap_fd, &key, &pid, 0); > > maybe > id = (__u64) getpid() << 32 | gettid(); > bpf_map_update_elem(pidmap_fd, &key, &id, 0); > > In your original above kernel code, you actually compare user space pid > to kernel tid, which is okay for this program as it is the main thread > and tid == pid, but the mechanism is wrong. > > > + > > + if (stat("/proc/self/ns/pid", &st)) > > + goto close_prog; > > + > > + bpf_map_update_elem(ns_inum_map_fd, &key, &st.st_ino, 0); > > + bpf_map_update_elem(ns_dev_map_fd, &key, &st.st_dev, 0); > > + > > + > > + snprintf(buf, sizeof(buf), > > + "/sys/kernel/debug/tracing/events/%s/id", probe_name); > > + efd = open(buf, O_RDONLY, 0); > > + if (CHECK(efd < 0, "open", "err %d errno %d\n", efd, errno)) > > + goto close_prog; > > + bytes = read(efd, buf, sizeof(buf)); > > + close(efd); > > + if (CHECK(bytes <= 0 || bytes >= sizeof(buf), "read", > > + "bytes %d errno %d\n", bytes, errno)) > > + goto close_prog; > > + > > + attr.config = strtol(buf, NULL, 0); > > + attr.type = PERF_TYPE_TRACEPOINT; > > + attr.sample_type = PERF_SAMPLE_RAW; > > + attr.sample_period = 1; > > + attr.wakeup_events = 1; > > + > > + pmu_fd = syscall(__NR_perf_event_open, &attr, getpid(), -1, -1, 0); > > + if (CHECK(pmu_fd < 0, "perf_event_open", "err %d errno %d\n", pmu_fd, > > + errno)) > > + goto close_prog; > > + > > + err = ioctl(pmu_fd, PERF_EVENT_IOC_ENABLE, 0); > > + if (CHECK(err, "perf_event_ioc_enable", "err %d errno %d\n", err, > > + errno)) > > + goto close_pmu; > > + > > + err = ioctl(pmu_fd, PERF_EVENT_IOC_SET_BPF, prog_fd); > > + if (CHECK(err, "perf_event_ioc_set_bpf", "err %d errno %d\n", err, > > + errno)) > > + goto close_pmu; > > The whole thing above related to tracepoint can be simplified. Please > see prog_tests/stacktrace_map.c. > > > + > > + /* trigger some syscalls */ > > + sleep(1); > > + > > + err = bpf_map_lookup_elem(ns_pid_map_fd, &key, &nspid); > > + if (CHECK(err, "bpf_map_lookup_elem", "err %d errno %d\n", err, errno)) > > + goto close_pmu; > > + > > + if (CHECK(nspid != pid, "compare nspid vs pid", > > + "kern nspid %u user pid %u", nspid, pid)) > > + goto close_pmu; > > + > > + exit_code = 0; > > + printf("%s:PASS\n", argv[0]); > > + > > +close_pmu: > > + close(pmu_fd); > > +close_prog: > > + bpf_object__close(obj); > > +cleanup_cgroup_env: > > + return exit_code; > > +} > > Thanks Yonghong, I'll correct these issues on v12. Bests
diff --git a/tools/testing/selftests/bpf/Makefile b/tools/testing/selftests/bpf/Makefile index 7f3196af1ae4..d86b28aa8f44 100644 --- a/tools/testing/selftests/bpf/Makefile +++ b/tools/testing/selftests/bpf/Makefile @@ -28,7 +28,7 @@ TEST_GEN_PROGS = test_verifier test_tag test_maps test_lru_map test_lpm_map test test_sock test_btf test_sockmap get_cgroup_id_user test_socket_cookie \ test_cgroup_storage test_select_reuseport test_section_names \ test_netcnt test_tcpnotify_user test_sock_fields test_sysctl test_hashmap \ - test_btf_dump test_cgroup_attach xdping + test_btf_dump test_cgroup_attach xdping test_pidns BPF_OBJ_FILES = $(patsubst %.c,%.o, $(notdir $(wildcard progs/*.c))) TEST_GEN_FILES = $(BPF_OBJ_FILES) diff --git a/tools/testing/selftests/bpf/bpf_helpers.h b/tools/testing/selftests/bpf/bpf_helpers.h index 6c4930bc6e2e..03d0e15ae29f 100644 --- a/tools/testing/selftests/bpf/bpf_helpers.h +++ b/tools/testing/selftests/bpf/bpf_helpers.h @@ -231,6 +231,9 @@ static int (*bpf_send_signal)(unsigned sig) = (void *)BPF_FUNC_send_signal; static long long (*bpf_tcp_gen_syncookie)(struct bpf_sock *sk, void *ip, int ip_len, void *tcp, int tcp_len) = (void *) BPF_FUNC_tcp_gen_syncookie; +static int (*bpf_get_ns_current_pid_tgid)(__u32 dev, __u64 inum) = + (void *) BPF_FUNC_get_ns_current_pid_tgid; + /* llvm builtin functions that eBPF C program may use to * emit BPF_LD_ABS and BPF_LD_IND instructions diff --git a/tools/testing/selftests/bpf/progs/test_pidns_kern.c b/tools/testing/selftests/bpf/progs/test_pidns_kern.c new file mode 100644 index 000000000000..96cb707db3ee --- /dev/null +++ b/tools/testing/selftests/bpf/progs/test_pidns_kern.c @@ -0,0 +1,71 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2018 Carlos Neira cneirabustos@gmail.com + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of version 2 of the GNU General Public + * License as published by the Free Software Foundation. + */ + +#include <linux/bpf.h> +#include "bpf_helpers.h" + +struct { + __uint(type, BPF_MAP_TYPE_ARRAY); + __uint(max_entries, 1); + __type(key, __u32); + __type(value, __u64); +} ns_inum_map SEC(".maps"); + +struct { + __uint(type, BPF_MAP_TYPE_ARRAY); + __uint(max_entries, 1); + __type(key, __u32); + __type(value, __u32); +} ns_dev_map SEC(".maps"); + +struct { + __uint(type, BPF_MAP_TYPE_ARRAY); + __uint(max_entries, 1); + __type(key, __u32); + __type(value, __u32); +} pidmap SEC(".maps"); + +struct { + __uint(type, BPF_MAP_TYPE_ARRAY); + __uint(max_entries, 1); + __type(key, __u32); + __type(value, __u64); +} ns_pid_map SEC(".maps"); + + + +SEC("tracepoint/syscalls/sys_enter_nanosleep") +int trace(void *ctx) +{ + __u32 key = 0, *expected_pid, *dev; + __u64 *val, *inum, nspid; + __u32 pid; + + dev = bpf_map_lookup_elem(&ns_dev_map, &key); + if (!dev) + return 0; + + inum = bpf_map_lookup_elem(&ns_inum_map, &key); + if (!inum) + return 0; + + nspid = bpf_get_ns_current_pid_tgid(*dev, *inum); + expected_pid = bpf_map_lookup_elem(&pidmap, &key); + + if (!expected_pid || *expected_pid != nspid) + return 0; + + val = bpf_map_lookup_elem(&ns_pid_map, &key); + if (val) + *val = nspid; + + return 0; +} + +char _license[] SEC("license") = "GPL"; +__u32 _version SEC("version") = 1; diff --git a/tools/testing/selftests/bpf/test_pidns.c b/tools/testing/selftests/bpf/test_pidns.c new file mode 100644 index 000000000000..088f8025f2bf --- /dev/null +++ b/tools/testing/selftests/bpf/test_pidns.c @@ -0,0 +1,152 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2018 Carlos Neira cneirabustos@gmail.com + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of version 2 of the GNU General Public + * License as published by the Free Software Foundation. + */ + +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <errno.h> +#include <fcntl.h> +#include <syscall.h> +#include <unistd.h> +#include <linux/perf_event.h> +#include <sys/ioctl.h> +#include <sys/time.h> +#include <sys/types.h> +#include <sys/stat.h> + +#include <linux/bpf.h> +#include <bpf/bpf.h> +#include <bpf/libbpf.h> + +#include "cgroup_helpers.h" +#include "bpf_rlimit.h" + +#define CHECK(condition, tag, format...) ({ \ + int __ret = !!(condition); \ + if (__ret) { \ + printf("%s:FAIL:%s ", __func__, tag); \ + printf(format); \ + } else { \ + printf("%s:PASS:%s\n", __func__, tag); \ + } \ + __ret; \ +}) + +static int bpf_find_map(const char *test, struct bpf_object *obj, + const char *name) +{ + struct bpf_map *map; + + map = bpf_object__find_map_by_name(obj, name); + if (!map) + return -1; + return bpf_map__fd(map); +} + + +int main(int argc, char **argv) +{ + int pidmap_fd, ns_inum_map_fd, ns_dev_map_fd, ns_pid_map_fd; + const char *probe_name = "syscalls/sys_enter_nanosleep"; + const char *file = "test_pidns_kern.o"; + int err, bytes, efd, prog_fd, pmu_fd; + struct perf_event_attr attr = {}; + struct bpf_object *obj; + __u32 nspid = 0; + __u32 key = 0, pid; + int exit_code = 1; + struct stat st; + char buf[256]; + + err = bpf_prog_load(file, BPF_PROG_TYPE_TRACEPOINT, &obj, &prog_fd); + if (CHECK(err, "bpf_prog_load", "err %d errno %d\n", err, errno)) + goto cleanup_cgroup_env; + + ns_dev_map_fd = bpf_find_map(__func__, obj, "ns_dev_map"); + if (CHECK(ns_dev_map_fd < 0, "bpf_find_map", "err %d errno %d\n", + ns_dev_map_fd, errno)) + goto close_prog; + + ns_inum_map_fd = bpf_find_map(__func__, obj, "ns_inum_map"); + if (CHECK(ns_inum_map_fd < 0, "bpf_find_map", "err %d errno %d\n", + ns_inum_map_fd, errno)) + goto close_prog; + + ns_pid_map_fd = bpf_find_map(__func__, obj, "ns_pid_map"); + if (CHECK(ns_pid_map_fd < 0, "bpf_find_map", "err %d errno %d\n", + ns_pid_map_fd, errno)) + goto close_prog; + + pidmap_fd = bpf_find_map(__func__, obj, "pidmap"); + if (CHECK(pidmap_fd < 0, "bpf_find_map", "err %d errno %d\n", + pidmap_fd, errno)) + goto close_prog; + + pid = getpid(); + bpf_map_update_elem(pidmap_fd, &key, &pid, 0); + + if (stat("/proc/self/ns/pid", &st)) + goto close_prog; + + bpf_map_update_elem(ns_inum_map_fd, &key, &st.st_ino, 0); + bpf_map_update_elem(ns_dev_map_fd, &key, &st.st_dev, 0); + + + snprintf(buf, sizeof(buf), + "/sys/kernel/debug/tracing/events/%s/id", probe_name); + efd = open(buf, O_RDONLY, 0); + if (CHECK(efd < 0, "open", "err %d errno %d\n", efd, errno)) + goto close_prog; + bytes = read(efd, buf, sizeof(buf)); + close(efd); + if (CHECK(bytes <= 0 || bytes >= sizeof(buf), "read", + "bytes %d errno %d\n", bytes, errno)) + goto close_prog; + + attr.config = strtol(buf, NULL, 0); + attr.type = PERF_TYPE_TRACEPOINT; + attr.sample_type = PERF_SAMPLE_RAW; + attr.sample_period = 1; + attr.wakeup_events = 1; + + pmu_fd = syscall(__NR_perf_event_open, &attr, getpid(), -1, -1, 0); + if (CHECK(pmu_fd < 0, "perf_event_open", "err %d errno %d\n", pmu_fd, + errno)) + goto close_prog; + + err = ioctl(pmu_fd, PERF_EVENT_IOC_ENABLE, 0); + if (CHECK(err, "perf_event_ioc_enable", "err %d errno %d\n", err, + errno)) + goto close_pmu; + + err = ioctl(pmu_fd, PERF_EVENT_IOC_SET_BPF, prog_fd); + if (CHECK(err, "perf_event_ioc_set_bpf", "err %d errno %d\n", err, + errno)) + goto close_pmu; + + /* trigger some syscalls */ + sleep(1); + + err = bpf_map_lookup_elem(ns_pid_map_fd, &key, &nspid); + if (CHECK(err, "bpf_map_lookup_elem", "err %d errno %d\n", err, errno)) + goto close_pmu; + + if (CHECK(nspid != pid, "compare nspid vs pid", + "kern nspid %u user pid %u", nspid, pid)) + goto close_pmu; + + exit_code = 0; + printf("%s:PASS\n", argv[0]); + +close_pmu: + close(pmu_fd); +close_prog: + bpf_object__close(obj); +cleanup_cgroup_env: + return exit_code; +}
Self tests added for new helper Signed-off-by: Carlos Neira <cneirabustos@gmail.com> --- tools/testing/selftests/bpf/Makefile | 2 +- tools/testing/selftests/bpf/bpf_helpers.h | 3 + .../selftests/bpf/progs/test_pidns_kern.c | 71 ++++++++ tools/testing/selftests/bpf/test_pidns.c | 152 ++++++++++++++++++ 4 files changed, 227 insertions(+), 1 deletion(-) create mode 100644 tools/testing/selftests/bpf/progs/test_pidns_kern.c create mode 100644 tools/testing/selftests/bpf/test_pidns.c