diff options
Diffstat (limited to 'tools')
| -rw-r--r-- | tools/include/uapi/linux/bpf.h | 76 | ||||
| -rw-r--r-- | tools/testing/selftests/bpf/prog_tests/bpf_iter.c | 88 | ||||
| -rw-r--r-- | tools/testing/selftests/bpf/prog_tests/snprintf_btf.c | 60 | ||||
| -rw-r--r-- | tools/testing/selftests/bpf/progs/bpf_iter_task_btf.c | 50 | ||||
| -rw-r--r-- | tools/testing/selftests/bpf/progs/netif_receive_skb.c | 249 |
5 files changed, 516 insertions, 7 deletions
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index 82522f05c021..96ddb00b91dc 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -3594,6 +3594,50 @@ union bpf_attr { * the data in *dst*. This is a wrapper of **copy_from_user**\ (). * Return * 0 on success, or a negative error in case of failure. + * + * long bpf_snprintf_btf(char *str, u32 str_size, struct btf_ptr *ptr, u32 btf_ptr_size, u64 flags) + * Description + * Use BTF to store a string representation of *ptr*->ptr in *str*, + * using *ptr*->type_id. This value should specify the type + * that *ptr*->ptr points to. LLVM __builtin_btf_type_id(type, 1) + * can be used to look up vmlinux BTF type ids. Traversing the + * data structure using BTF, the type information and values are + * stored in the first *str_size* - 1 bytes of *str*. Safe copy of + * the pointer data is carried out to avoid kernel crashes during + * operation. Smaller types can use string space on the stack; + * larger programs can use map data to store the string + * representation. + * + * The string can be subsequently shared with userspace via + * bpf_perf_event_output() or ring buffer interfaces. + * bpf_trace_printk() is to be avoided as it places too small + * a limit on string size to be useful. + * + * *flags* is a combination of + * + * **BTF_F_COMPACT** + * no formatting around type information + * **BTF_F_NONAME** + * no struct/union member names/types + * **BTF_F_PTR_RAW** + * show raw (unobfuscated) pointer values; + * equivalent to printk specifier %px. + * **BTF_F_ZERO** + * show zero-valued struct/union members; they + * are not displayed by default + * + * Return + * The number of bytes that were written (or would have been + * written if output had to be truncated due to string size), + * or a negative error in cases of failure. + * + * long bpf_seq_printf_btf(struct seq_file *m, struct btf_ptr *ptr, u32 ptr_size, u64 flags) + * Description + * Use BTF to write to seq_write a string representation of + * *ptr*->ptr, using *ptr*->type_id as per bpf_snprintf_btf(). + * *flags* are identical to those used for bpf_snprintf_btf. + * Return + * 0 on success or a negative error in case of failure. */ #define __BPF_FUNC_MAPPER(FN) \ FN(unspec), \ @@ -3745,6 +3789,8 @@ union bpf_attr { FN(inode_storage_delete), \ FN(d_path), \ FN(copy_from_user), \ + FN(snprintf_btf), \ + FN(seq_printf_btf), \ /* */ /* integer value in 'imm' field of BPF_CALL instruction selects which helper @@ -4853,4 +4899,34 @@ struct bpf_sk_lookup { __u32 local_port; /* Host byte order */ }; +/* + * struct btf_ptr is used for typed pointer representation; the + * type id is used to render the pointer data as the appropriate type + * via the bpf_snprintf_btf() helper described above. A flags field - + * potentially to specify additional details about the BTF pointer + * (rather than its mode of display) - is included for future use. + * Display flags - BTF_F_* - are passed to bpf_snprintf_btf separately. + */ +struct btf_ptr { + void *ptr; + __u32 type_id; + __u32 flags; /* BTF ptr flags; unused at present. */ +}; + +/* + * Flags to control bpf_snprintf_btf() behaviour. + * - BTF_F_COMPACT: no formatting around type information + * - BTF_F_NONAME: no struct/union member names/types + * - BTF_F_PTR_RAW: show raw (unobfuscated) pointer values; + * equivalent to %px. + * - BTF_F_ZERO: show zero-valued struct/union members; they + * are not displayed by default + */ +enum { + BTF_F_COMPACT = (1ULL << 0), + BTF_F_NONAME = (1ULL << 1), + BTF_F_PTR_RAW = (1ULL << 2), + BTF_F_ZERO = (1ULL << 3), +}; + #endif /* _UAPI__LINUX_BPF_H__ */ diff --git a/tools/testing/selftests/bpf/prog_tests/bpf_iter.c b/tools/testing/selftests/bpf/prog_tests/bpf_iter.c index fe1a83b9875c..af15630a24dd 100644 --- a/tools/testing/selftests/bpf/prog_tests/bpf_iter.c +++ b/tools/testing/selftests/bpf/prog_tests/bpf_iter.c @@ -7,6 +7,7 @@ #include "bpf_iter_task.skel.h" #include "bpf_iter_task_stack.skel.h" #include "bpf_iter_task_file.skel.h" +#include "bpf_iter_task_btf.skel.h" #include "bpf_iter_tcp4.skel.h" #include "bpf_iter_tcp6.skel.h" #include "bpf_iter_udp4.skel.h" @@ -167,6 +168,77 @@ done: bpf_iter_task_file__destroy(skel); } +#define TASKBUFSZ 32768 + +static char taskbuf[TASKBUFSZ]; + +static void do_btf_read(struct bpf_iter_task_btf *skel) +{ + struct bpf_program *prog = skel->progs.dump_task_struct; + struct bpf_iter_task_btf__bss *bss = skel->bss; + int iter_fd = -1, len = 0, bufleft = TASKBUFSZ; + struct bpf_link *link; + char *buf = taskbuf; + + link = bpf_program__attach_iter(prog, NULL); + if (CHECK(IS_ERR(link), "attach_iter", "attach_iter failed\n")) + return; + + iter_fd = bpf_iter_create(bpf_link__fd(link)); + if (CHECK(iter_fd < 0, "create_iter", "create_iter failed\n")) + goto free_link; + + do { + len = read(iter_fd, buf, bufleft); + if (len > 0) { + buf += len; + bufleft -= len; + } + } while (len > 0); + + if (bss->skip) { + printf("%s:SKIP:no __builtin_btf_type_id\n", __func__); + test__skip(); + goto free_link; + } + + if (CHECK(len < 0, "read", "read failed: %s\n", strerror(errno))) + goto free_link; + + CHECK(strstr(taskbuf, "(struct task_struct)") == NULL, + "check for btf representation of task_struct in iter data", + "struct task_struct not found"); +free_link: + if (iter_fd > 0) + close(iter_fd); + bpf_link__destroy(link); +} + +static void test_task_btf(void) +{ + struct bpf_iter_task_btf__bss *bss; + struct bpf_iter_task_btf *skel; + + skel = bpf_iter_task_btf__open_and_load(); + if (CHECK(!skel, "bpf_iter_task_btf__open_and_load", + "skeleton open_and_load failed\n")) + return; + + bss = skel->bss; + + do_btf_read(skel); + + if (CHECK(bss->tasks == 0, "check if iterated over tasks", + "no task iteration, did BPF program run?\n")) + goto cleanup; + + CHECK(bss->seq_err != 0, "check for unexpected err", + "bpf_seq_printf_btf returned %ld", bss->seq_err); + +cleanup: + bpf_iter_task_btf__destroy(skel); +} + static void test_tcp4(void) { struct bpf_iter_tcp4 *skel; @@ -352,7 +424,7 @@ static void test_overflow(bool test_e2big_overflow, bool ret1) struct bpf_map_info map_info = {}; struct bpf_iter_test_kern4 *skel; struct bpf_link *link; - __u32 page_size; + __u32 iter_size; char *buf; skel = bpf_iter_test_kern4__open(); @@ -374,19 +446,19 @@ static void test_overflow(bool test_e2big_overflow, bool ret1) "map_creation failed: %s\n", strerror(errno))) goto free_map1; - /* bpf_seq_printf kernel buffer is one page, so one map + /* bpf_seq_printf kernel buffer is 8 pages, so one map * bpf_seq_write will mostly fill it, and the other map * will partially fill and then trigger overflow and need * bpf_seq_read restart. */ - page_size = sysconf(_SC_PAGE_SIZE); + iter_size = sysconf(_SC_PAGE_SIZE) << 3; if (test_e2big_overflow) { - skel->rodata->print_len = (page_size + 8) / 8; - expected_read_len = 2 * (page_size + 8); + skel->rodata->print_len = (iter_size + 8) / 8; + expected_read_len = 2 * (iter_size + 8); } else if (!ret1) { - skel->rodata->print_len = (page_size - 8) / 8; - expected_read_len = 2 * (page_size - 8); + skel->rodata->print_len = (iter_size - 8) / 8; + expected_read_len = 2 * (iter_size - 8); } else { skel->rodata->print_len = 1; expected_read_len = 2 * 8; @@ -957,6 +1029,8 @@ void test_bpf_iter(void) test_task_stack(); if (test__start_subtest("task_file")) test_task_file(); + if (test__start_subtest("task_btf")) + test_task_btf(); if (test__start_subtest("tcp4")) test_tcp4(); if (test__start_subtest("tcp6")) diff --git a/tools/testing/selftests/bpf/prog_tests/snprintf_btf.c b/tools/testing/selftests/bpf/prog_tests/snprintf_btf.c new file mode 100644 index 000000000000..3a8ecf833adc --- /dev/null +++ b/tools/testing/selftests/bpf/prog_tests/snprintf_btf.c @@ -0,0 +1,60 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <test_progs.h> +#include <linux/btf.h> +#include "netif_receive_skb.skel.h" + +/* Demonstrate that bpf_snprintf_btf succeeds and that various data types + * are formatted correctly. + */ +void test_snprintf_btf(void) +{ + struct netif_receive_skb *skel; + struct netif_receive_skb__bss *bss; + int err, duration = 0; + + skel = netif_receive_skb__open(); + if (CHECK(!skel, "skel_open", "failed to open skeleton\n")) + return; + + err = netif_receive_skb__load(skel); + if (CHECK(err, "skel_load", "failed to load skeleton: %d\n", err)) + goto cleanup; + + bss = skel->bss; + + err = netif_receive_skb__attach(skel); + if (CHECK(err, "skel_attach", "skeleton attach failed: %d\n", err)) + goto cleanup; + + /* generate receive event */ + system("ping -c 1 127.0.0.1 > /dev/null"); + + if (bss->skip) { + printf("%s:SKIP:no __builtin_btf_type_id\n", __func__); + test__skip(); + goto cleanup; + } + + /* + * Make sure netif_receive_skb program was triggered + * and it set expected return values from bpf_trace_printk()s + * and all tests ran. + */ + if (CHECK(bss->ret <= 0, + "bpf_snprintf_btf: got return value", + "ret <= 0 %ld test %d\n", bss->ret, bss->ran_subtests)) + goto cleanup; + + if (CHECK(bss->ran_subtests == 0, "check if subtests ran", + "no subtests ran, did BPF program run?")) + goto cleanup; + + if (CHECK(bss->num_subtests != bss->ran_subtests, + "check all subtests ran", + "only ran %d of %d tests\n", bss->num_subtests, + bss->ran_subtests)) + goto cleanup; + +cleanup: + netif_receive_skb__destroy(skel); +} diff --git a/tools/testing/selftests/bpf/progs/bpf_iter_task_btf.c b/tools/testing/selftests/bpf/progs/bpf_iter_task_btf.c new file mode 100644 index 000000000000..a1ddc36f13ec --- /dev/null +++ b/tools/testing/selftests/bpf/progs/bpf_iter_task_btf.c @@ -0,0 +1,50 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2020, Oracle and/or its affiliates. */ +#include "bpf_iter.h" +#include <bpf/bpf_helpers.h> +#include <bpf/bpf_tracing.h> +#include <bpf/bpf_core_read.h> + +#include <errno.h> + +char _license[] SEC("license") = "GPL"; + +long tasks = 0; +long seq_err = 0; +bool skip = false; + +SEC("iter/task") +int dump_task_struct(struct bpf_iter__task *ctx) +{ + struct seq_file *seq = ctx->meta->seq; + struct task_struct *task = ctx->task; + static struct btf_ptr ptr = { }; + long ret; + +#if __has_builtin(__builtin_btf_type_id) + ptr.type_id = bpf_core_type_id_kernel(struct task_struct); + ptr.ptr = task; + + if (ctx->meta->seq_num == 0) + BPF_SEQ_PRINTF(seq, "Raw BTF task\n"); + + ret = bpf_seq_printf_btf(seq, &ptr, sizeof(ptr), 0); + switch (ret) { + case 0: + tasks++; + break; + case -ERANGE: + /* NULL task or task->fs, don't count it as an error. */ + break; + case -E2BIG: + return 1; + default: + seq_err = ret; + break; + } +#else + skip = true; +#endif + + return 0; +} diff --git a/tools/testing/selftests/bpf/progs/netif_receive_skb.c b/tools/testing/selftests/bpf/progs/netif_receive_skb.c new file mode 100644 index 000000000000..b873d805a345 --- /dev/null +++ b/tools/testing/selftests/bpf/progs/netif_receive_skb.c @@ -0,0 +1,249 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2020, Oracle and/or its affiliates. */ + +#include "vmlinux.h" +#include <bpf/bpf_helpers.h> +#include <bpf/bpf_tracing.h> +#include <bpf/bpf_core_read.h> + +#include <errno.h> + +long ret = 0; +int num_subtests = 0; +int ran_subtests = 0; +bool skip = false; + +#define STRSIZE 2048 +#define EXPECTED_STRSIZE 256 + +#ifndef ARRAY_SIZE +#define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0])) +#endif + +struct { + __uint(type, BPF_MAP_TYPE_PERCPU_ARRAY); + __uint(max_entries, 1); + __type(key, __u32); + __type(value, char[STRSIZE]); +} strdata SEC(".maps"); + +static int __strncmp(const void *m1, const void *m2, size_t len) +{ + const unsigned char *s1 = m1; + const unsigned char *s2 = m2; + int i, delta = 0; + + for (i = 0; i < len; i++) { + delta = s1[i] - s2[i]; + if (delta || s1[i] == 0 || s2[i] == 0) + break; + } + return delta; +} + +#if __has_builtin(__builtin_btf_type_id) +#define TEST_BTF(_str, _type, _flags, _expected, ...) \ + do { \ + static const char _expectedval[EXPECTED_STRSIZE] = \ + _expected; \ + static const char _ptrtype[64] = #_type; \ + __u64 _hflags = _flags | BTF_F_COMPACT; \ + static _type _ptrdata = __VA_ARGS__; \ + static struct btf_ptr _ptr = { }; \ + int _cmp; \ + \ + ++num_subtests; \ + if (ret < 0) \ + break; \ + ++ran_subtests; \ + _ptr.ptr = &_ptrdata; \ + _ptr.type_id = bpf_core_type_id_kernel(_type); \ + if (_ptr.type_id <= 0) { \ + ret = -EINVAL; \ + break; \ + } \ + ret = bpf_snprintf_btf(_str, STRSIZE, \ + &_ptr, sizeof(_ptr), _hflags); \ + if (ret) \ + break; \ + _cmp = __strncmp(_str, _expectedval, EXPECTED_STRSIZE); \ + if (_cmp != 0) { \ + bpf_printk("(%d) got %s", _cmp, _str); \ + bpf_printk("(%d) expected %s", _cmp, \ + _expectedval); \ + ret = -EBADMSG; \ + break; \ + } \ + } while (0) +#endif + +/* Use where expected data string matches its stringified declaration */ +#define TEST_BTF_C(_str, _type, _flags, ...) \ + TEST_BTF(_str, _type, _flags, "(" #_type ")" #__VA_ARGS__, \ + __VA_ARGS__) + +/* TRACE_EVENT(netif_receive_skb, + * TP_PROTO(struct sk_buff *skb), + */ +SEC("tp_btf/netif_receive_skb") +int BPF_PROG(trace_netif_receive_skb, struct sk_buff *skb) +{ + static __u64 flags[] = { 0, BTF_F_COMPACT, BTF_F_ZERO, BTF_F_PTR_RAW, + BTF_F_NONAME, BTF_F_COMPACT | BTF_F_ZERO | + BTF_F_PTR_RAW | BTF_F_NONAME }; + static struct btf_ptr p = { }; + __u32 key = 0; + int i, __ret; + char *str; + +#if __has_builtin(__builtin_btf_type_id) + str = bpf_map_lookup_elem(&strdata, &key); + if (!str) + return 0; + + /* Ensure we can write skb string representation */ + p.type_id = bpf_core_type_id_kernel(struct sk_buff); + p.ptr = skb; + for (i = 0; i < ARRAY_SIZE(flags); i++) { + ++num_subtests; + ret = bpf_snprintf_btf(str, STRSIZE, &p, sizeof(p), 0); + if (ret < 0) + bpf_printk("returned %d when writing skb", ret); + ++ran_subtests; + } + + /* Check invalid ptr value */ + p.ptr = 0; + __ret = bpf_snprintf_btf(str, STRSIZE, &p, sizeof(p), 0); + if (__ret >= 0) { + bpf_printk("printing NULL should generate error, got (%d)", + __ret); + ret = -ERANGE; + } + + /* Verify type display for various types. */ + + /* simple int */ + TEST_BTF_C(str, int, 0, 1234); + TEST_BTF(str, int, BTF_F_NONAME, "1234", 1234); + /* zero value should be printed at toplevel */ + TEST_BTF(str, int, 0, "(int)0", 0); + TEST_BTF(str, int, BTF_F_NONAME, "0", 0); + TEST_BTF(str, int, BTF_F_ZERO, "(int)0", 0); + TEST_BTF(str, int, BTF_F_NONAME | BTF_F_ZERO, "0", 0); + TEST_BTF_C(str, int, 0, -4567); + TEST_BTF(str, int, BTF_F_NONAME, "-4567", -4567); + + /* simple char */ + TEST_BTF_C(str, char, 0, 100); + TEST_BTF(str, char, BTF_F_NONAME, "100", 100); + /* zero value should be printed at toplevel */ + TEST_BTF(str, char, 0, "(char)0", 0); + TEST_BTF(str, char, BTF_F_NONAME, "0", 0); + TEST_BTF(str, char, BTF_F_ZERO, "(char)0", 0); + TEST_BTF(str, char, BTF_F_NONAME | BTF_F_ZERO, "0", 0); + + /* simple typedef */ + TEST_BTF_C(str, uint64_t, 0, 100); + TEST_BTF(str, u64, BTF_F_NONAME, "1", 1); + /* zero value should be printed at toplevel */ + TEST_BTF(str, u64, 0, "(u64)0", 0); + TEST_BTF(str, u64, BTF_F_NONAME, "0", 0); + TEST_BTF(str, u64, BTF_F_ZERO, "(u64)0", 0); + TEST_BTF(str, u64, BTF_F_NONAME|BTF_F_ZERO, "0", 0); + + /* typedef struct */ + TEST_BTF_C(str, atomic_t, 0, {.counter = (int)1,}); + TEST_BTF(str, atomic_t, BTF_F_NONAME, "{1,}", {.counter = 1,}); + /* typedef with 0 value should be printed at toplevel */ + TEST_BTF(str, atomic_t, 0, "(atomic_t){}", {.counter = 0,}); + TEST_BTF(str, atomic_t, BTF_F_NONAME, "{}", {.counter = 0,}); + TEST_BTF(str, atomic_t, BTF_F_ZERO, "(atomic_t){.counter = (int)0,}", + {.counter = 0,}); + TEST_BTF(str, atomic_t, BTF_F_NONAME|BTF_F_ZERO, + "{0,}", {.counter = 0,}); + + /* enum where enum value does (and does not) exist */ + TEST_BTF_C(str, enum bpf_cmd, 0, BPF_MAP_CREATE); + TEST_BTF(str, enum bpf_cmd, 0, "(enum bpf_cmd)BPF_MAP_CREATE", 0); + TEST_BTF(str, enum bpf_cmd, BTF_F_NONAME, "BPF_MAP_CREATE", + BPF_MAP_CREATE); + TEST_BTF(str, enum bpf_cmd, BTF_F_NONAME|BTF_F_ZERO, + "BPF_MAP_CREATE", 0); + + TEST_BTF(str, enum bpf_cmd, BTF_F_ZERO, "(enum bpf_cmd)BPF_MAP_CREATE", + BPF_MAP_CREATE); + TEST_BTF(str, enum bpf_cmd, BTF_F_NONAME|BTF_F_ZERO, + "BPF_MAP_CREATE", BPF_MAP_CREATE); + TEST_BTF_C(str, enum bpf_cmd, 0, 2000); + TEST_BTF(str, enum bpf_cmd, BTF_F_NONAME, "2000", 2000); + + /* simple struct */ + TEST_BTF_C(str, struct btf_enum, 0, + {.name_off = (__u32)3,.val = (__s32)-1,}); + TEST_BTF(str, struct btf_enum, BTF_F_NONAME, "{3,-1,}", + { .name_off = 3, .val = -1,}); + TEST_BTF(str, struct btf_enum, BTF_F_NONAME, "{-1,}", + { .name_off = 0, .val = -1,}); + TEST_BTF(str, struct btf_enum, BTF_F_NONAME|BTF_F_ZERO, "{0,-1,}", + { .name_off = 0, .val = -1,}); + /* empty struct should be printed */ + TEST_BTF(str, struct btf_enum, 0, "(struct btf_enum){}", + { .name_off = 0, .val = 0,}); + TEST_BTF(str, struct btf_enum, BTF_F_NONAME, "{}", + { .name_off = 0, .val = 0,}); + TEST_BTF(str, struct btf_enum, BTF_F_ZERO, + "(struct btf_enum){.name_off = (__u32)0,.val = (__s32)0,}", + { .name_off = 0, .val = 0,}); + + /* struct with pointers */ + TEST_BTF(str, struct list_head, BTF_F_PTR_RAW, + "(struct list_head){.next = (struct list_head *)0x0000000000000001,}", + { .next = (struct list_head *)1 }); + /* NULL pointer should not be displayed */ + TEST_BTF(str, struct list_head, BTF_F_PTR_RAW, + "(struct list_head){}", + { .next = (struct list_head *)0 }); + + /* struct with char array */ + TEST_BTF(str, struct bpf_prog_info, 0, + "(struct bpf_prog_info){.name = (char[])['f','o','o',],}", + { .name = "foo",}); + TEST_BTF(str, struct bpf_prog_info, BTF_F_NONAME, + "{['f','o','o',],}", + {.name = "foo",}); + /* leading null char means do not display string */ + TEST_BTF(str, struct bpf_prog_info, 0, + "(struct bpf_prog_info){}", + {.name = {'\0', 'f', 'o', 'o'}}); + /* handle non-printable characters */ + TEST_BTF(str, struct bpf_prog_info, 0, + "(struct bpf_prog_info){.name = (char[])[1,2,3,],}", + { .name = {1, 2, 3, 0}}); + + /* struct with non-char array */ + TEST_BTF(str, struct __sk_buff, 0, + "(struct __sk_buff){.cb = (__u32[])[1,2,3,4,5,],}", + { .cb = {1, 2, 3, 4, 5,},}); + TEST_BTF(str, struct __sk_buff, BTF_F_NONAME, + "{[1,2,3,4,5,],}", + { .cb = { 1, 2, 3, 4, 5},}); + /* For non-char, arrays, show non-zero values only */ + TEST_BTF(str, struct __sk_buff, 0, + "(struct __sk_buff){.cb = (__u32[])[1,],}", + { .cb = { 0, 0, 1, 0, 0},}); + + /* struct with bitfields */ + TEST_BTF_C(str, struct bpf_insn, 0, + {.code = (__u8)1,.dst_reg = (__u8)0x2,.src_reg = (__u8)0x3,.off = (__s16)4,.imm = (__s32)5,}); + TEST_BTF(str, struct bpf_insn, BTF_F_NONAME, "{1,0x2,0x3,4,5,}", + {.code = 1, .dst_reg = 0x2, .src_reg = 0x3, .off = 4, + .imm = 5,}); +#else + skip = true; +#endif + + return 0; +} + +char _license[] SEC("license") = "GPL"; |