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libbpf: remove prog_info_linear APIs
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Remove prog_info_linear-related APIs previously used by perf.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20220627211527.2245459-8-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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Andrii Nakryiko authored and Alexei Starovoitov committed Jun 28, 2022
1 parent 22dd7a5 commit 9a59053
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Showing 3 changed files with 0 additions and 317 deletions.
248 changes: 0 additions & 248 deletions tools/lib/bpf/libbpf.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -12509,254 +12509,6 @@ int perf_buffer__consume(struct perf_buffer *pb)
return 0;
}

struct bpf_prog_info_array_desc {
int array_offset; /* e.g. offset of jited_prog_insns */
int count_offset; /* e.g. offset of jited_prog_len */
int size_offset; /* > 0: offset of rec size,
* < 0: fix size of -size_offset
*/
};

static struct bpf_prog_info_array_desc bpf_prog_info_array_desc[] = {
[BPF_PROG_INFO_JITED_INSNS] = {
offsetof(struct bpf_prog_info, jited_prog_insns),
offsetof(struct bpf_prog_info, jited_prog_len),
-1,
},
[BPF_PROG_INFO_XLATED_INSNS] = {
offsetof(struct bpf_prog_info, xlated_prog_insns),
offsetof(struct bpf_prog_info, xlated_prog_len),
-1,
},
[BPF_PROG_INFO_MAP_IDS] = {
offsetof(struct bpf_prog_info, map_ids),
offsetof(struct bpf_prog_info, nr_map_ids),
-(int)sizeof(__u32),
},
[BPF_PROG_INFO_JITED_KSYMS] = {
offsetof(struct bpf_prog_info, jited_ksyms),
offsetof(struct bpf_prog_info, nr_jited_ksyms),
-(int)sizeof(__u64),
},
[BPF_PROG_INFO_JITED_FUNC_LENS] = {
offsetof(struct bpf_prog_info, jited_func_lens),
offsetof(struct bpf_prog_info, nr_jited_func_lens),
-(int)sizeof(__u32),
},
[BPF_PROG_INFO_FUNC_INFO] = {
offsetof(struct bpf_prog_info, func_info),
offsetof(struct bpf_prog_info, nr_func_info),
offsetof(struct bpf_prog_info, func_info_rec_size),
},
[BPF_PROG_INFO_LINE_INFO] = {
offsetof(struct bpf_prog_info, line_info),
offsetof(struct bpf_prog_info, nr_line_info),
offsetof(struct bpf_prog_info, line_info_rec_size),
},
[BPF_PROG_INFO_JITED_LINE_INFO] = {
offsetof(struct bpf_prog_info, jited_line_info),
offsetof(struct bpf_prog_info, nr_jited_line_info),
offsetof(struct bpf_prog_info, jited_line_info_rec_size),
},
[BPF_PROG_INFO_PROG_TAGS] = {
offsetof(struct bpf_prog_info, prog_tags),
offsetof(struct bpf_prog_info, nr_prog_tags),
-(int)sizeof(__u8) * BPF_TAG_SIZE,
},

};

static __u32 bpf_prog_info_read_offset_u32(struct bpf_prog_info *info,
int offset)
{
__u32 *array = (__u32 *)info;

if (offset >= 0)
return array[offset / sizeof(__u32)];
return -(int)offset;
}

static __u64 bpf_prog_info_read_offset_u64(struct bpf_prog_info *info,
int offset)
{
__u64 *array = (__u64 *)info;

if (offset >= 0)
return array[offset / sizeof(__u64)];
return -(int)offset;
}

static void bpf_prog_info_set_offset_u32(struct bpf_prog_info *info, int offset,
__u32 val)
{
__u32 *array = (__u32 *)info;

if (offset >= 0)
array[offset / sizeof(__u32)] = val;
}

static void bpf_prog_info_set_offset_u64(struct bpf_prog_info *info, int offset,
__u64 val)
{
__u64 *array = (__u64 *)info;

if (offset >= 0)
array[offset / sizeof(__u64)] = val;
}

struct bpf_prog_info_linear *
bpf_program__get_prog_info_linear(int fd, __u64 arrays)
{
struct bpf_prog_info_linear *info_linear;
struct bpf_prog_info info = {};
__u32 info_len = sizeof(info);
__u32 data_len = 0;
int i, err;
void *ptr;

if (arrays >> BPF_PROG_INFO_LAST_ARRAY)
return libbpf_err_ptr(-EINVAL);

/* step 1: get array dimensions */
err = bpf_obj_get_info_by_fd(fd, &info, &info_len);
if (err) {
pr_debug("can't get prog info: %s", strerror(errno));
return libbpf_err_ptr(-EFAULT);
}

/* step 2: calculate total size of all arrays */
for (i = BPF_PROG_INFO_FIRST_ARRAY; i < BPF_PROG_INFO_LAST_ARRAY; ++i) {
bool include_array = (arrays & (1UL << i)) > 0;
struct bpf_prog_info_array_desc *desc;
__u32 count, size;

desc = bpf_prog_info_array_desc + i;

/* kernel is too old to support this field */
if (info_len < desc->array_offset + sizeof(__u32) ||
info_len < desc->count_offset + sizeof(__u32) ||
(desc->size_offset > 0 && info_len < desc->size_offset))
include_array = false;

if (!include_array) {
arrays &= ~(1UL << i); /* clear the bit */
continue;
}

count = bpf_prog_info_read_offset_u32(&info, desc->count_offset);
size = bpf_prog_info_read_offset_u32(&info, desc->size_offset);

data_len += count * size;
}

/* step 3: allocate continuous memory */
data_len = roundup(data_len, sizeof(__u64));
info_linear = malloc(sizeof(struct bpf_prog_info_linear) + data_len);
if (!info_linear)
return libbpf_err_ptr(-ENOMEM);

/* step 4: fill data to info_linear->info */
info_linear->arrays = arrays;
memset(&info_linear->info, 0, sizeof(info));
ptr = info_linear->data;

for (i = BPF_PROG_INFO_FIRST_ARRAY; i < BPF_PROG_INFO_LAST_ARRAY; ++i) {
struct bpf_prog_info_array_desc *desc;
__u32 count, size;

if ((arrays & (1UL << i)) == 0)
continue;

desc = bpf_prog_info_array_desc + i;
count = bpf_prog_info_read_offset_u32(&info, desc->count_offset);
size = bpf_prog_info_read_offset_u32(&info, desc->size_offset);
bpf_prog_info_set_offset_u32(&info_linear->info,
desc->count_offset, count);
bpf_prog_info_set_offset_u32(&info_linear->info,
desc->size_offset, size);
bpf_prog_info_set_offset_u64(&info_linear->info,
desc->array_offset,
ptr_to_u64(ptr));
ptr += count * size;
}

/* step 5: call syscall again to get required arrays */
err = bpf_obj_get_info_by_fd(fd, &info_linear->info, &info_len);
if (err) {
pr_debug("can't get prog info: %s", strerror(errno));
free(info_linear);
return libbpf_err_ptr(-EFAULT);
}

/* step 6: verify the data */
for (i = BPF_PROG_INFO_FIRST_ARRAY; i < BPF_PROG_INFO_LAST_ARRAY; ++i) {
struct bpf_prog_info_array_desc *desc;
__u32 v1, v2;

if ((arrays & (1UL << i)) == 0)
continue;

desc = bpf_prog_info_array_desc + i;
v1 = bpf_prog_info_read_offset_u32(&info, desc->count_offset);
v2 = bpf_prog_info_read_offset_u32(&info_linear->info,
desc->count_offset);
if (v1 != v2)
pr_warn("%s: mismatch in element count\n", __func__);

v1 = bpf_prog_info_read_offset_u32(&info, desc->size_offset);
v2 = bpf_prog_info_read_offset_u32(&info_linear->info,
desc->size_offset);
if (v1 != v2)
pr_warn("%s: mismatch in rec size\n", __func__);
}

/* step 7: update info_len and data_len */
info_linear->info_len = sizeof(struct bpf_prog_info);
info_linear->data_len = data_len;

return info_linear;
}

void bpf_program__bpil_addr_to_offs(struct bpf_prog_info_linear *info_linear)
{
int i;

for (i = BPF_PROG_INFO_FIRST_ARRAY; i < BPF_PROG_INFO_LAST_ARRAY; ++i) {
struct bpf_prog_info_array_desc *desc;
__u64 addr, offs;

if ((info_linear->arrays & (1UL << i)) == 0)
continue;

desc = bpf_prog_info_array_desc + i;
addr = bpf_prog_info_read_offset_u64(&info_linear->info,
desc->array_offset);
offs = addr - ptr_to_u64(info_linear->data);
bpf_prog_info_set_offset_u64(&info_linear->info,
desc->array_offset, offs);
}
}

void bpf_program__bpil_offs_to_addr(struct bpf_prog_info_linear *info_linear)
{
int i;

for (i = BPF_PROG_INFO_FIRST_ARRAY; i < BPF_PROG_INFO_LAST_ARRAY; ++i) {
struct bpf_prog_info_array_desc *desc;
__u64 addr, offs;

if ((info_linear->arrays & (1UL << i)) == 0)
continue;

desc = bpf_prog_info_array_desc + i;
offs = bpf_prog_info_read_offset_u64(&info_linear->info,
desc->array_offset);
addr = offs + ptr_to_u64(info_linear->data);
bpf_prog_info_set_offset_u64(&info_linear->info,
desc->array_offset, addr);
}
}

int bpf_program__set_attach_target(struct bpf_program *prog,
int attach_prog_fd,
const char *attach_func_name)
Expand Down
66 changes: 0 additions & 66 deletions tools/lib/bpf/libbpf.h
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Original file line number Diff line number Diff line change
Expand Up @@ -1396,72 +1396,6 @@ LIBBPF_API int libbpf_probe_bpf_map_type(enum bpf_map_type map_type, const void
LIBBPF_API int libbpf_probe_bpf_helper(enum bpf_prog_type prog_type,
enum bpf_func_id helper_id, const void *opts);

/*
* Get bpf_prog_info in continuous memory
*
* struct bpf_prog_info has multiple arrays. The user has option to choose
* arrays to fetch from kernel. The following APIs provide an uniform way to
* fetch these data. All arrays in bpf_prog_info are stored in a single
* continuous memory region. This makes it easy to store the info in a
* file.
*
* Before writing bpf_prog_info_linear to files, it is necessary to
* translate pointers in bpf_prog_info to offsets. Helper functions
* bpf_program__bpil_addr_to_offs() and bpf_program__bpil_offs_to_addr()
* are introduced to switch between pointers and offsets.
*
* Examples:
* # To fetch map_ids and prog_tags:
* __u64 arrays = (1UL << BPF_PROG_INFO_MAP_IDS) |
* (1UL << BPF_PROG_INFO_PROG_TAGS);
* struct bpf_prog_info_linear *info_linear =
* bpf_program__get_prog_info_linear(fd, arrays);
*
* # To save data in file
* bpf_program__bpil_addr_to_offs(info_linear);
* write(f, info_linear, sizeof(*info_linear) + info_linear->data_len);
*
* # To read data from file
* read(f, info_linear, <proper_size>);
* bpf_program__bpil_offs_to_addr(info_linear);
*/
enum bpf_prog_info_array {
BPF_PROG_INFO_FIRST_ARRAY = 0,
BPF_PROG_INFO_JITED_INSNS = 0,
BPF_PROG_INFO_XLATED_INSNS,
BPF_PROG_INFO_MAP_IDS,
BPF_PROG_INFO_JITED_KSYMS,
BPF_PROG_INFO_JITED_FUNC_LENS,
BPF_PROG_INFO_FUNC_INFO,
BPF_PROG_INFO_LINE_INFO,
BPF_PROG_INFO_JITED_LINE_INFO,
BPF_PROG_INFO_PROG_TAGS,
BPF_PROG_INFO_LAST_ARRAY,
};

struct bpf_prog_info_linear {
/* size of struct bpf_prog_info, when the tool is compiled */
__u32 info_len;
/* total bytes allocated for data, round up to 8 bytes */
__u32 data_len;
/* which arrays are included in data */
__u64 arrays;
struct bpf_prog_info info;
__u8 data[];
};

LIBBPF_DEPRECATED_SINCE(0, 6, "use a custom linear prog_info wrapper")
LIBBPF_API struct bpf_prog_info_linear *
bpf_program__get_prog_info_linear(int fd, __u64 arrays);

LIBBPF_DEPRECATED_SINCE(0, 6, "use a custom linear prog_info wrapper")
LIBBPF_API void
bpf_program__bpil_addr_to_offs(struct bpf_prog_info_linear *info_linear);

LIBBPF_DEPRECATED_SINCE(0, 6, "use a custom linear prog_info wrapper")
LIBBPF_API void
bpf_program__bpil_offs_to_addr(struct bpf_prog_info_linear *info_linear);

/**
* @brief **libbpf_num_possible_cpus()** is a helper function to get the
* number of possible CPUs that the host kernel supports and expects.
Expand Down
3 changes: 0 additions & 3 deletions tools/lib/bpf/libbpf.map
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Original file line number Diff line number Diff line change
Expand Up @@ -118,9 +118,6 @@ LIBBPF_0.0.2 {
btf_ext__free;
btf_ext__get_raw_data;
btf_ext__new;
bpf_program__get_prog_info_linear;
bpf_program__bpil_addr_to_offs;
bpf_program__bpil_offs_to_addr;
} LIBBPF_0.0.1;

LIBBPF_0.0.3 {
Expand Down

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