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authorYonghong Song <yhs@fb.com>2019-04-10 03:37:41 +0300
committerDaniel Borkmann <daniel@iogearbox.net>2019-04-10 10:46:51 +0300
commit69a0f9ecef22131982ba328e6b74ebb082bc0992 (patch)
tree75665c934bb3b1449a290394d33f2b435d16b6f9 /tools
parent6316f78306c171f5a857a2442dbeebc7baab3566 (diff)
downloadlinux-69a0f9ecef22131982ba328e6b74ebb082bc0992.tar.xz
bpf, bpftool: fix a few ubsan warnings
The issue is reported at https://github.com/libbpf/libbpf/issues/28. Basically, per C standard, for void *memcpy(void *dest, const void *src, size_t n) if "dest" or "src" is NULL, regardless of whether "n" is 0 or not, the result of memcpy is undefined. clang ubsan reported three such instances in bpf.c with the following pattern: memcpy(dest, 0, 0). Although in practice, no known compiler will cause issues when copy size is 0. Let us still fix the issue to silence ubsan warnings. Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Diffstat (limited to 'tools')
-rw-r--r--tools/lib/bpf/bpf.c19
1 files changed, 9 insertions, 10 deletions
diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c
index c039094ad3aa..dababce68f0b 100644
--- a/tools/lib/bpf/bpf.c
+++ b/tools/lib/bpf/bpf.c
@@ -79,7 +79,6 @@ static inline int sys_bpf_prog_load(union bpf_attr *attr, unsigned int size)
int bpf_create_map_xattr(const struct bpf_create_map_attr *create_attr)
{
- __u32 name_len = create_attr->name ? strlen(create_attr->name) : 0;
union bpf_attr attr;
memset(&attr, '\0', sizeof(attr));
@@ -89,8 +88,9 @@ int bpf_create_map_xattr(const struct bpf_create_map_attr *create_attr)
attr.value_size = create_attr->value_size;
attr.max_entries = create_attr->max_entries;
attr.map_flags = create_attr->map_flags;
- memcpy(attr.map_name, create_attr->name,
- min(name_len, BPF_OBJ_NAME_LEN - 1));
+ if (create_attr->name)
+ memcpy(attr.map_name, create_attr->name,
+ min(strlen(create_attr->name), BPF_OBJ_NAME_LEN - 1));
attr.numa_node = create_attr->numa_node;
attr.btf_fd = create_attr->btf_fd;
attr.btf_key_type_id = create_attr->btf_key_type_id;
@@ -155,7 +155,6 @@ int bpf_create_map_in_map_node(enum bpf_map_type map_type, const char *name,
int key_size, int inner_map_fd, int max_entries,
__u32 map_flags, int node)
{
- __u32 name_len = name ? strlen(name) : 0;
union bpf_attr attr;
memset(&attr, '\0', sizeof(attr));
@@ -166,7 +165,9 @@ int bpf_create_map_in_map_node(enum bpf_map_type map_type, const char *name,
attr.inner_map_fd = inner_map_fd;
attr.max_entries = max_entries;
attr.map_flags = map_flags;
- memcpy(attr.map_name, name, min(name_len, BPF_OBJ_NAME_LEN - 1));
+ if (name)
+ memcpy(attr.map_name, name,
+ min(strlen(name), BPF_OBJ_NAME_LEN - 1));
if (node >= 0) {
attr.map_flags |= BPF_F_NUMA_NODE;
@@ -216,7 +217,6 @@ 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 || !log_buf != !log_buf_sz)
@@ -226,8 +226,6 @@ int bpf_load_program_xattr(const struct bpf_load_program_attr *load_attr,
if (log_level > (4 | 2 | 1) || (log_level && !log_buf))
return -EINVAL;
- name_len = load_attr->name ? strlen(load_attr->name) : 0;
-
memset(&attr, 0, sizeof(attr));
attr.prog_type = load_attr->prog_type;
attr.expected_attach_type = load_attr->expected_attach_type;
@@ -253,8 +251,9 @@ int bpf_load_program_xattr(const struct bpf_load_program_attr *load_attr,
attr.line_info_rec_size = load_attr->line_info_rec_size;
attr.line_info_cnt = load_attr->line_info_cnt;
attr.line_info = ptr_to_u64(load_attr->line_info);
- memcpy(attr.prog_name, load_attr->name,
- min(name_len, BPF_OBJ_NAME_LEN - 1));
+ if (load_attr->name)
+ memcpy(attr.prog_name, load_attr->name,
+ min(strlen(load_attr->name), BPF_OBJ_NAME_LEN - 1));
fd = sys_bpf_prog_load(&attr, sizeof(attr));
if (fd >= 0)