From 86edaed379632e216a97e6bcef9f498b64522d50 Mon Sep 17 00:00:00 2001 From: Lorenz Bauer Date: Tue, 8 Jan 2019 13:58:00 +0000 Subject: [PATCH] bpf: libbpf: retry loading program on EAGAIN Commit c3494801cd17 ("bpf: check pending signals while verifying programs") makes it possible for the BPF_PROG_LOAD to fail with EAGAIN. Retry unconditionally in this case. Fixes: c3494801cd17 ("bpf: check pending signals while verifying programs") Signed-off-by: Lorenz Bauer Signed-off-by: Daniel Borkmann --- tools/lib/bpf/bpf.c | 19 +++++++++++++++---- 1 file changed, 15 insertions(+), 4 deletions(-) diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c index 3caaa3428774..88cbd110ae58 100644 --- a/tools/lib/bpf/bpf.c +++ b/tools/lib/bpf/bpf.c @@ -65,6 +65,17 @@ static inline int sys_bpf(enum bpf_cmd cmd, union bpf_attr *attr, return syscall(__NR_bpf, cmd, attr, size); } +static inline int sys_bpf_prog_load(union bpf_attr *attr, unsigned int size) +{ + int fd; + + do { + fd = sys_bpf(BPF_PROG_LOAD, attr, size); + } while (fd < 0 && errno == EAGAIN); + + return fd; +} + int bpf_create_map_xattr(const struct bpf_create_map_attr *create_attr) { __u32 name_len = create_attr->name ? strlen(create_attr->name) : 0; @@ -232,7 +243,7 @@ int bpf_load_program_xattr(const struct bpf_load_program_attr *load_attr, memcpy(attr.prog_name, load_attr->name, min(name_len, BPF_OBJ_NAME_LEN - 1)); - fd = sys_bpf(BPF_PROG_LOAD, &attr, sizeof(attr)); + fd = sys_bpf_prog_load(&attr, sizeof(attr)); if (fd >= 0) return fd; @@ -269,7 +280,7 @@ int bpf_load_program_xattr(const struct bpf_load_program_attr *load_attr, break; } - fd = sys_bpf(BPF_PROG_LOAD, &attr, sizeof(attr)); + fd = sys_bpf_prog_load(&attr, sizeof(attr)); if (fd >= 0) goto done; @@ -283,7 +294,7 @@ int bpf_load_program_xattr(const struct bpf_load_program_attr *load_attr, attr.log_size = log_buf_sz; attr.log_level = 1; log_buf[0] = 0; - fd = sys_bpf(BPF_PROG_LOAD, &attr, sizeof(attr)); + fd = sys_bpf_prog_load(&attr, sizeof(attr)); done: free(finfo); free(linfo); @@ -328,7 +339,7 @@ int bpf_verify_program(enum bpf_prog_type type, const struct bpf_insn *insns, attr.kern_version = kern_version; attr.prog_flags = prog_flags; - return sys_bpf(BPF_PROG_LOAD, &attr, sizeof(attr)); + return sys_bpf_prog_load(&attr, sizeof(attr)); } int bpf_map_update_elem(int fd, const void *key, const void *value,