Commit a4021a35 authored by Yonghong Song's avatar Yonghong Song Committed by Alexei Starovoitov

tools/bpf: add log_level to bpf_load_program_attr

The kernel verifier has three levels of logs:
    0: no logs
    1: logs mostly useful
  > 1: verbose

Current libbpf API functions bpf_load_program_xattr() and
bpf_load_program() cannot specify log_level.
The bcc, however, provides an interface for user to
specify log_level 2 for verbose output.

This patch added log_level into structure
bpf_load_program_attr, so users, including bcc, can use
bpf_load_program_xattr() to change log_level. The
supported log_level is 0, 1, and 2.

The bpf selftest test_sock.c is modified to enable log_level = 2.
If the "verbose" in test_sock.c is changed to true,
the test will output logs like below:
  $ ./test_sock
  func#0 @0
  0: R1=ctx(id=0,off=0,imm=0) R10=fp0,call_-1
  0: (bf) r6 = r1
  1: R1=ctx(id=0,off=0,imm=0) R6_w=ctx(id=0,off=0,imm=0) R10=fp0,call_-1
  1: (61) r7 = *(u32 *)(r6 +28)
  invalid bpf_context access off=28 size=4

  Test case: bind4 load with invalid access: src_ip6 .. [PASS]
  ...
  Test case: bind6 allow all .. [PASS]
  Summary: 16 PASSED, 0 FAILED

Some test_sock tests are negative tests and verbose verifier
log will be printed out as shown in the above.
Signed-off-by: default avatarYonghong Song <yhs@fb.com>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent 62b8cea6
...@@ -215,10 +215,15 @@ int bpf_load_program_xattr(const struct bpf_load_program_attr *load_attr, ...@@ -215,10 +215,15 @@ int bpf_load_program_xattr(const struct bpf_load_program_attr *load_attr,
{ {
void *finfo = NULL, *linfo = NULL; void *finfo = NULL, *linfo = NULL;
union bpf_attr attr; union bpf_attr attr;
__u32 log_level;
__u32 name_len; __u32 name_len;
int fd; int fd;
if (!load_attr) if (!load_attr || !log_buf != !log_buf_sz)
return -EINVAL;
log_level = load_attr->log_level;
if (log_level > 2 || (log_level && !log_buf))
return -EINVAL; return -EINVAL;
name_len = load_attr->name ? strlen(load_attr->name) : 0; name_len = load_attr->name ? strlen(load_attr->name) : 0;
...@@ -229,9 +234,16 @@ int bpf_load_program_xattr(const struct bpf_load_program_attr *load_attr, ...@@ -229,9 +234,16 @@ int bpf_load_program_xattr(const struct bpf_load_program_attr *load_attr,
attr.insn_cnt = (__u32)load_attr->insns_cnt; attr.insn_cnt = (__u32)load_attr->insns_cnt;
attr.insns = ptr_to_u64(load_attr->insns); attr.insns = ptr_to_u64(load_attr->insns);
attr.license = ptr_to_u64(load_attr->license); attr.license = ptr_to_u64(load_attr->license);
attr.log_buf = ptr_to_u64(NULL);
attr.log_size = 0; attr.log_level = log_level;
attr.log_level = 0; if (log_level) {
attr.log_buf = ptr_to_u64(log_buf);
attr.log_size = log_buf_sz;
} else {
attr.log_buf = ptr_to_u64(NULL);
attr.log_size = 0;
}
attr.kern_version = load_attr->kern_version; attr.kern_version = load_attr->kern_version;
attr.prog_ifindex = load_attr->prog_ifindex; attr.prog_ifindex = load_attr->prog_ifindex;
attr.prog_btf_fd = load_attr->prog_btf_fd; attr.prog_btf_fd = load_attr->prog_btf_fd;
...@@ -287,7 +299,7 @@ int bpf_load_program_xattr(const struct bpf_load_program_attr *load_attr, ...@@ -287,7 +299,7 @@ int bpf_load_program_xattr(const struct bpf_load_program_attr *load_attr,
goto done; goto done;
} }
if (!log_buf || !log_buf_sz) if (log_level || !log_buf)
goto done; goto done;
/* Try again with log */ /* Try again with log */
......
...@@ -85,6 +85,7 @@ struct bpf_load_program_attr { ...@@ -85,6 +85,7 @@ struct bpf_load_program_attr {
__u32 line_info_rec_size; __u32 line_info_rec_size;
const void *line_info; const void *line_info;
__u32 line_info_cnt; __u32 line_info_cnt;
__u32 log_level;
}; };
/* Flags to direct loading requirements */ /* Flags to direct loading requirements */
......
...@@ -20,6 +20,7 @@ ...@@ -20,6 +20,7 @@
#define MAX_INSNS 512 #define MAX_INSNS 512
char bpf_log_buf[BPF_LOG_BUF_SIZE]; char bpf_log_buf[BPF_LOG_BUF_SIZE];
static bool verbose = false;
struct sock_test { struct sock_test {
const char *descr; const char *descr;
...@@ -325,6 +326,7 @@ static int load_sock_prog(const struct bpf_insn *prog, ...@@ -325,6 +326,7 @@ static int load_sock_prog(const struct bpf_insn *prog,
enum bpf_attach_type attach_type) enum bpf_attach_type attach_type)
{ {
struct bpf_load_program_attr attr; struct bpf_load_program_attr attr;
int ret;
memset(&attr, 0, sizeof(struct bpf_load_program_attr)); memset(&attr, 0, sizeof(struct bpf_load_program_attr));
attr.prog_type = BPF_PROG_TYPE_CGROUP_SOCK; attr.prog_type = BPF_PROG_TYPE_CGROUP_SOCK;
...@@ -332,8 +334,13 @@ static int load_sock_prog(const struct bpf_insn *prog, ...@@ -332,8 +334,13 @@ static int load_sock_prog(const struct bpf_insn *prog,
attr.insns = prog; attr.insns = prog;
attr.insns_cnt = probe_prog_length(attr.insns); attr.insns_cnt = probe_prog_length(attr.insns);
attr.license = "GPL"; attr.license = "GPL";
attr.log_level = 2;
return bpf_load_program_xattr(&attr, bpf_log_buf, BPF_LOG_BUF_SIZE); ret = bpf_load_program_xattr(&attr, bpf_log_buf, BPF_LOG_BUF_SIZE);
if (verbose && ret < 0)
fprintf(stderr, "%s\n", bpf_log_buf);
return ret;
} }
static int attach_sock_prog(int cgfd, int progfd, static int attach_sock_prog(int cgfd, int progfd,
......
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