The log buffer of common attributes would be confusing with the one in 'union bpf_attr' for BPF_BTF_LOAD.
In order to clarify the usage of these two log buffers, they both can be used for logging if: * They are same, including 'log_buf', 'log_level' and 'log_size'. * One of them is missing, then another one will be used for logging. If they both have 'log_buf' but they are not same totally, return -EUSERS. Signed-off-by: Leon Hwang <[email protected]> --- kernel/bpf/syscall.c | 31 ++++++++++++++++++++++++++++--- 1 file changed, 28 insertions(+), 3 deletions(-) diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index ce349a059d5d..14fc5738f2b9 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -6211,14 +6211,35 @@ static int copy_prog_load_log_true_size(union bpf_attr *attr, bpfptr_t uattr, un &attr->log_true_size); } -static int copy_btf_load_log_true_size(union bpf_attr *attr, bpfptr_t uattr, unsigned int size) +static int check_btf_load_log_attrs(union bpf_attr *attr, struct bpf_common_attr *common_attrs) +{ + int err; + + err = check_log_attrs(attr->btf_log_buf, attr->btf_log_size, attr->btf_log_level, + common_attrs); + if (err) + return err; + + if (!attr->btf_log_buf && common_attrs->log_buf) { + attr->btf_log_buf = common_attrs->log_buf; + attr->btf_log_size = common_attrs->log_size; + attr->btf_log_level = common_attrs->log_level; + } + + return 0; +} + +static int copy_btf_load_log_true_size(union bpf_attr *attr, bpfptr_t uattr, unsigned int size, + struct bpf_common_attr *common_attrs, bpfptr_t uattr_common, + unsigned int size_common) { if (size >= offsetofend(union bpf_attr, btf_log_true_size) && copy_to_bpfptr_offset(uattr, offsetof(union bpf_attr, btf_log_true_size), &attr->btf_log_true_size, sizeof(attr->btf_log_true_size))) return -EFAULT; - return 0; + return copy_common_attr_log_true_size(uattr_common, size_common, + &attr->btf_log_true_size); } static int __sys_bpf(enum bpf_cmd cmd, bpfptr_t uattr, unsigned int size, @@ -6328,9 +6349,13 @@ static int __sys_bpf(enum bpf_cmd cmd, bpfptr_t uattr, unsigned int size, err = bpf_raw_tracepoint_open(&attr); break; case BPF_BTF_LOAD: + err = check_btf_load_log_attrs(&attr, &common_attrs); + if (err) + break; attr.btf_log_true_size = 0; err = bpf_btf_load(&attr, uattr); - ret = copy_btf_load_log_true_size(&attr, uattr, size); + ret = copy_btf_load_log_true_size(&attr, uattr, size, &common_attrs, uattr_common, + size_common); err = ret ? ret : err; break; case BPF_BTF_GET_FD_BY_ID: -- 2.52.0
