On 2021/10/30 12:59 PM, Andrii Nakryiko wrote:
> Move internal sys_bpf() helper into bpf.h and expose as public API.
> __NR_bpf definition logic is also moved. Renamed sys_bpf() into bpf() to
> follow libbpf naming conventions. Adapt internal uses accordingly.
>
> Signed-off-by: Andrii Nakryiko <andrii@xxxxxxxxxx>
> ---
> tools/lib/bpf/bpf.c | 76 ++++++++++++++-------------------------------
> tools/lib/bpf/bpf.h | 30 ++++++++++++++++++
> 2 files changed, 54 insertions(+), 52 deletions(-)
>
A little confuse about this public API. Shouldn't it be annotated with
LIBBPF_API attribute and go into libbpf.map ?
BTW, these headers can now be removed from bpf.c:
#include <stdlib.h>
#include <string.h>
#include <memory.h>
#include <unistd.h>
#include <asm/unistd.h>
#include <errno.h>
#include <linux/bpf.h>
#include "libbpf.h"
> diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c
> index c09cbb868c9f..4b4fd2dae3bf 100644
> --- a/tools/lib/bpf/bpf.c
> +++ b/tools/lib/bpf/bpf.c
> @@ -32,45 +32,17 @@
> #include "libbpf.h"
> #include "libbpf_internal.h"
>
> -/*
> - * When building perf, unistd.h is overridden. __NR_bpf is
> - * required to be defined explicitly.
> - */
> -#ifndef __NR_bpf
> -# if defined(__i386__)
> -# define __NR_bpf 357
> -# elif defined(__x86_64__)
> -# define __NR_bpf 321
> -# elif defined(__aarch64__)
> -# define __NR_bpf 280
> -# elif defined(__sparc__)
> -# define __NR_bpf 349
> -# elif defined(__s390__)
> -# define __NR_bpf 351
> -# elif defined(__arc__)
> -# define __NR_bpf 280
> -# else
> -# error __NR_bpf not defined. libbpf does not support your arch.
> -# endif
> -#endif
> -
> static inline __u64 ptr_to_u64(const void *ptr)
> {
> return (__u64) (unsigned long) ptr;
> }
>
> -static inline int sys_bpf(enum bpf_cmd cmd, union bpf_attr *attr,
> - unsigned int size)
> -{
> - return syscall(__NR_bpf, cmd, attr, size);
> -}
> -
> static inline int sys_bpf_fd(enum bpf_cmd cmd, union bpf_attr *attr,
> unsigned int size)
> {
> int fd;
>
> - fd = sys_bpf(cmd, attr, size);
> + fd = bpf(cmd, attr, size);
> return ensure_good_fd(fd);
> }
>
> @@ -465,7 +437,7 @@ int bpf_map_update_elem(int fd, const void *key, const void *value,
> attr.value = ptr_to_u64(value);
> attr.flags = flags;
>
> - ret = sys_bpf(BPF_MAP_UPDATE_ELEM, &attr, sizeof(attr));
> + ret = bpf(BPF_MAP_UPDATE_ELEM, &attr, sizeof(attr));
> return libbpf_err_errno(ret);
> }
>
> @@ -479,7 +451,7 @@ int bpf_map_lookup_elem(int fd, const void *key, void *value)
> attr.key = ptr_to_u64(key);
> attr.value = ptr_to_u64(value);
>
> - ret = sys_bpf(BPF_MAP_LOOKUP_ELEM, &attr, sizeof(attr));
> + ret = bpf(BPF_MAP_LOOKUP_ELEM, &attr, sizeof(attr));
> return libbpf_err_errno(ret);
> }
>
> @@ -494,7 +466,7 @@ int bpf_map_lookup_elem_flags(int fd, const void *key, void *value, __u64 flags)
> attr.value = ptr_to_u64(value);
> attr.flags = flags;
>
> - ret = sys_bpf(BPF_MAP_LOOKUP_ELEM, &attr, sizeof(attr));
> + ret = bpf(BPF_MAP_LOOKUP_ELEM, &attr, sizeof(attr));
> return libbpf_err_errno(ret);
> }
>
> @@ -508,7 +480,7 @@ int bpf_map_lookup_and_delete_elem(int fd, const void *key, void *value)
> attr.key = ptr_to_u64(key);
> attr.value = ptr_to_u64(value);
>
> - ret = sys_bpf(BPF_MAP_LOOKUP_AND_DELETE_ELEM, &attr, sizeof(attr));
> + ret = bpf(BPF_MAP_LOOKUP_AND_DELETE_ELEM, &attr, sizeof(attr));
> return libbpf_err_errno(ret);
> }
>
> @@ -522,7 +494,7 @@ int bpf_map_lookup_and_delete_elem_flags(int fd, const void *key, void *value, _
> attr.value = ptr_to_u64(value);
> attr.flags = flags;
>
> - return sys_bpf(BPF_MAP_LOOKUP_AND_DELETE_ELEM, &attr, sizeof(attr));
> + return bpf(BPF_MAP_LOOKUP_AND_DELETE_ELEM, &attr, sizeof(attr));
> }
>
> int bpf_map_delete_elem(int fd, const void *key)
> @@ -534,7 +506,7 @@ int bpf_map_delete_elem(int fd, const void *key)
> attr.map_fd = fd;
> attr.key = ptr_to_u64(key);
>
> - ret = sys_bpf(BPF_MAP_DELETE_ELEM, &attr, sizeof(attr));
> + ret = bpf(BPF_MAP_DELETE_ELEM, &attr, sizeof(attr));
> return libbpf_err_errno(ret);
> }
>
> @@ -548,7 +520,7 @@ int bpf_map_get_next_key(int fd, const void *key, void *next_key)
> attr.key = ptr_to_u64(key);
> attr.next_key = ptr_to_u64(next_key);
>
> - ret = sys_bpf(BPF_MAP_GET_NEXT_KEY, &attr, sizeof(attr));
> + ret = bpf(BPF_MAP_GET_NEXT_KEY, &attr, sizeof(attr));
> return libbpf_err_errno(ret);
> }
>
> @@ -560,7 +532,7 @@ int bpf_map_freeze(int fd)
> memset(&attr, 0, sizeof(attr));
> attr.map_fd = fd;
>
> - ret = sys_bpf(BPF_MAP_FREEZE, &attr, sizeof(attr));
> + ret = bpf(BPF_MAP_FREEZE, &attr, sizeof(attr));
> return libbpf_err_errno(ret);
> }
>
> @@ -585,7 +557,7 @@ static int bpf_map_batch_common(int cmd, int fd, void *in_batch,
> attr.batch.elem_flags = OPTS_GET(opts, elem_flags, 0);
> attr.batch.flags = OPTS_GET(opts, flags, 0);
>
> - ret = sys_bpf(cmd, &attr, sizeof(attr));
> + ret = bpf(cmd, &attr, sizeof(attr));
> *count = attr.batch.count;
>
> return libbpf_err_errno(ret);
> @@ -631,7 +603,7 @@ int bpf_obj_pin(int fd, const char *pathname)
> attr.pathname = ptr_to_u64((void *)pathname);
> attr.bpf_fd = fd;
>
> - ret = sys_bpf(BPF_OBJ_PIN, &attr, sizeof(attr));
> + ret = bpf(BPF_OBJ_PIN, &attr, sizeof(attr));
> return libbpf_err_errno(ret);
> }
>
> @@ -674,7 +646,7 @@ int bpf_prog_attach_xattr(int prog_fd, int target_fd,
> attr.attach_flags = OPTS_GET(opts, flags, 0);
> attr.replace_bpf_fd = OPTS_GET(opts, replace_prog_fd, 0);
>
> - ret = sys_bpf(BPF_PROG_ATTACH, &attr, sizeof(attr));
> + ret = bpf(BPF_PROG_ATTACH, &attr, sizeof(attr));
> return libbpf_err_errno(ret);
> }
>
> @@ -687,7 +659,7 @@ int bpf_prog_detach(int target_fd, enum bpf_attach_type type)
> attr.target_fd = target_fd;
> attr.attach_type = type;
>
> - ret = sys_bpf(BPF_PROG_DETACH, &attr, sizeof(attr));
> + ret = bpf(BPF_PROG_DETACH, &attr, sizeof(attr));
> return libbpf_err_errno(ret);
> }
>
> @@ -701,7 +673,7 @@ int bpf_prog_detach2(int prog_fd, int target_fd, enum bpf_attach_type type)
> attr.attach_bpf_fd = prog_fd;
> attr.attach_type = type;
>
> - ret = sys_bpf(BPF_PROG_DETACH, &attr, sizeof(attr));
> + ret = bpf(BPF_PROG_DETACH, &attr, sizeof(attr));
> return libbpf_err_errno(ret);
> }
>
> @@ -766,7 +738,7 @@ int bpf_link_detach(int link_fd)
> memset(&attr, 0, sizeof(attr));
> attr.link_detach.link_fd = link_fd;
>
> - ret = sys_bpf(BPF_LINK_DETACH, &attr, sizeof(attr));
> + ret = bpf(BPF_LINK_DETACH, &attr, sizeof(attr));
> return libbpf_err_errno(ret);
> }
>
> @@ -785,7 +757,7 @@ int bpf_link_update(int link_fd, int new_prog_fd,
> attr.link_update.flags = OPTS_GET(opts, flags, 0);
> attr.link_update.old_prog_fd = OPTS_GET(opts, old_prog_fd, 0);
>
> - ret = sys_bpf(BPF_LINK_UPDATE, &attr, sizeof(attr));
> + ret = bpf(BPF_LINK_UPDATE, &attr, sizeof(attr));
> return libbpf_err_errno(ret);
> }
>
> @@ -814,7 +786,7 @@ int bpf_prog_query(int target_fd, enum bpf_attach_type type, __u32 query_flags,
> attr.query.prog_cnt = *prog_cnt;
> attr.query.prog_ids = ptr_to_u64(prog_ids);
>
> - ret = sys_bpf(BPF_PROG_QUERY, &attr, sizeof(attr));
> + ret = bpf(BPF_PROG_QUERY, &attr, sizeof(attr));
>
> if (attach_flags)
> *attach_flags = attr.query.attach_flags;
> @@ -837,7 +809,7 @@ int bpf_prog_test_run(int prog_fd, int repeat, void *data, __u32 size,
> attr.test.data_size_in = size;
> attr.test.repeat = repeat;
>
> - ret = sys_bpf(BPF_PROG_TEST_RUN, &attr, sizeof(attr));
> + ret = bpf(BPF_PROG_TEST_RUN, &attr, sizeof(attr));
>
> if (size_out)
> *size_out = attr.test.data_size_out;
> @@ -869,7 +841,7 @@ int bpf_prog_test_run_xattr(struct bpf_prog_test_run_attr *test_attr)
> attr.test.ctx_size_out = test_attr->ctx_size_out;
> attr.test.repeat = test_attr->repeat;
>
> - ret = sys_bpf(BPF_PROG_TEST_RUN, &attr, sizeof(attr));
> + ret = bpf(BPF_PROG_TEST_RUN, &attr, sizeof(attr));
>
> test_attr->data_size_out = attr.test.data_size_out;
> test_attr->ctx_size_out = attr.test.ctx_size_out;
> @@ -902,7 +874,7 @@ int bpf_prog_test_run_opts(int prog_fd, struct bpf_test_run_opts *opts)
> attr.test.data_in = ptr_to_u64(OPTS_GET(opts, data_in, NULL));
> attr.test.data_out = ptr_to_u64(OPTS_GET(opts, data_out, NULL));
>
> - ret = sys_bpf(BPF_PROG_TEST_RUN, &attr, sizeof(attr));
> + ret = bpf(BPF_PROG_TEST_RUN, &attr, sizeof(attr));
>
> OPTS_SET(opts, data_size_out, attr.test.data_size_out);
> OPTS_SET(opts, ctx_size_out, attr.test.ctx_size_out);
> @@ -920,7 +892,7 @@ static int bpf_obj_get_next_id(__u32 start_id, __u32 *next_id, int cmd)
> memset(&attr, 0, sizeof(attr));
> attr.start_id = start_id;
>
> - err = sys_bpf(cmd, &attr, sizeof(attr));
> + err = bpf(cmd, &attr, sizeof(attr));
> if (!err)
> *next_id = attr.next_id;
>
> @@ -1005,7 +977,7 @@ int bpf_obj_get_info_by_fd(int bpf_fd, void *info, __u32 *info_len)
> attr.info.info_len = *info_len;
> attr.info.info = ptr_to_u64(info);
>
> - err = sys_bpf(BPF_OBJ_GET_INFO_BY_FD, &attr, sizeof(attr));
> + err = bpf(BPF_OBJ_GET_INFO_BY_FD, &attr, sizeof(attr));
>
> if (!err)
> *info_len = attr.info.info_len;
> @@ -1065,7 +1037,7 @@ int bpf_task_fd_query(int pid, int fd, __u32 flags, char *buf, __u32 *buf_len,
> attr.task_fd_query.buf = ptr_to_u64(buf);
> attr.task_fd_query.buf_len = *buf_len;
>
> - err = sys_bpf(BPF_TASK_FD_QUERY, &attr, sizeof(attr));
> + err = bpf(BPF_TASK_FD_QUERY, &attr, sizeof(attr));
>
> *buf_len = attr.task_fd_query.buf_len;
> *prog_id = attr.task_fd_query.prog_id;
> @@ -1102,6 +1074,6 @@ int bpf_prog_bind_map(int prog_fd, int map_fd,
> attr.prog_bind_map.map_fd = map_fd;
> attr.prog_bind_map.flags = OPTS_GET(opts, flags, 0);
>
> - ret = sys_bpf(BPF_PROG_BIND_MAP, &attr, sizeof(attr));
> + ret = bpf(BPF_PROG_BIND_MAP, &attr, sizeof(attr));
> return libbpf_err_errno(ret);
> }
> diff --git a/tools/lib/bpf/bpf.h b/tools/lib/bpf/bpf.h
> index 6fffb3cdf39b..6ef9e1e464c0 100644
> --- a/tools/lib/bpf/bpf.h
> +++ b/tools/lib/bpf/bpf.h
> @@ -27,6 +27,10 @@
> #include <stdbool.h>
> #include <stddef.h>
> #include <stdint.h>
> +#include <unistd.h>
> +#include <asm/unistd.h>
> +#include <sys/syscall.h>
> +#include <sys/types.h>
>
> #include "libbpf_common.h"
>
> @@ -34,6 +38,32 @@
> extern "C" {
> #endif
>
> +/*
> + * Kernel headers might be outdated, so define __NR_bpf explicitly, if necessary.
> + */
> +#ifndef __NR_bpf
> +# if defined(__i386__)
> +# define __NR_bpf 357
> +# elif defined(__x86_64__)
> +# define __NR_bpf 321
> +# elif defined(__aarch64__)
> +# define __NR_bpf 280
> +# elif defined(__sparc__)
> +# define __NR_bpf 349
> +# elif defined(__s390__)
> +# define __NR_bpf 351
> +# elif defined(__arc__)
> +# define __NR_bpf 280
> +# else
> +# error __NR_bpf not defined. libbpf does not support your arch.
> +# endif
> +#endif
> +
> +static inline long bpf(enum bpf_cmd cmd, union bpf_attr *attr, unsigned int size)
> +{
> + return syscall(__NR_bpf, cmd, attr, size);
> +}
> +
> struct bpf_create_map_attr {
> const char *name;
> enum bpf_map_type map_type;
>
