From a4021a3579c52d5a5131820aeb94f531a7b082a7 Mon Sep 17 00:00:00 2001 From: Yonghong Song Date: Thu, 7 Feb 2019 09:34:51 -0800 Subject: 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: Yonghong Song Signed-off-by: Alexei Starovoitov --- tools/lib/bpf/bpf.c | 22 +++++++++++++++++----- tools/lib/bpf/bpf.h | 1 + 2 files changed, 18 insertions(+), 5 deletions(-) (limited to 'tools/lib/bpf') diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c index 92fd27fe0599..a5261f39e2bd 100644 --- a/tools/lib/bpf/bpf.c +++ b/tools/lib/bpf/bpf.c @@ -215,10 +215,15 @@ int bpf_load_program_xattr(const struct bpf_load_program_attr *load_attr, { void *finfo = NULL, *linfo = NULL; union bpf_attr attr; + __u32 log_level; __u32 name_len; 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; 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, attr.insn_cnt = (__u32)load_attr->insns_cnt; attr.insns = ptr_to_u64(load_attr->insns); attr.license = ptr_to_u64(load_attr->license); - attr.log_buf = ptr_to_u64(NULL); - attr.log_size = 0; - attr.log_level = 0; + + attr.log_level = log_level; + 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.prog_ifindex = load_attr->prog_ifindex; 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, goto done; } - if (!log_buf || !log_buf_sz) + if (log_level || !log_buf) goto done; /* Try again with log */ diff --git a/tools/lib/bpf/bpf.h b/tools/lib/bpf/bpf.h index ed09eed2dc3b..6ffdd79bea89 100644 --- a/tools/lib/bpf/bpf.h +++ b/tools/lib/bpf/bpf.h @@ -85,6 +85,7 @@ struct bpf_load_program_attr { __u32 line_info_rec_size; const void *line_info; __u32 line_info_cnt; + __u32 log_level; }; /* Flags to direct loading requirements */ -- cgit v1.2.3-59-g8ed1b