BPF_PROG_LOAD can now provide log parameters through both union bpf_attr and struct bpf_common_attr. Define clear conflict and precedence rules:
- if both are provided and log_buf/log_size/log_level match, use them; - if only one side provides a log buffer, use that one; - if both provide log buffers but differ, return -EINVAL. Signed-off-by: Leon Hwang <[email protected]> --- include/linux/bpf_verifier.h | 3 ++- kernel/bpf/log.c | 24 ++++++++++++++++++++++-- kernel/bpf/syscall.c | 3 ++- 3 files changed, 26 insertions(+), 4 deletions(-) diff --git a/include/linux/bpf_verifier.h b/include/linux/bpf_verifier.h index c805b85b6f7a..0d106fddbbc5 100644 --- a/include/linux/bpf_verifier.h +++ b/include/linux/bpf_verifier.h @@ -638,7 +638,8 @@ struct bpf_log_attr { }; int bpf_prog_load_log_attr_init(struct bpf_log_attr *attr_log, union bpf_attr *attr, - bpfptr_t uattr, u32 size); + bpfptr_t uattr, u32 size, struct bpf_common_attr *attr_common, + bpfptr_t uattr_common, u32 size_common); int bpf_log_attr_finalize(struct bpf_log_attr *attr, struct bpf_verifier_log *log); #define BPF_MAX_SUBPROGS 256 diff --git a/kernel/bpf/log.c b/kernel/bpf/log.c index ff579fcba36f..345005ba98dd 100644 --- a/kernel/bpf/log.c +++ b/kernel/bpf/log.c @@ -873,10 +873,30 @@ static void bpf_log_attr_init(struct bpf_log_attr *attr_log, int offsetof_true_s attr_log->uattr = uattr; } +static bool bpf_log_attrs_diff(struct bpf_common_attr *common, u64 log_buf, u32 log_size, + u32 log_level) +{ + return log_buf && common->log_buf && (log_buf != common->log_buf || + log_size != common->log_size || + log_level != common->log_level); +} + int bpf_prog_load_log_attr_init(struct bpf_log_attr *attr_log, union bpf_attr *attr, - bpfptr_t uattr, u32 size) + bpfptr_t uattr, u32 size, struct bpf_common_attr *attr_common, + bpfptr_t uattr_common, u32 size_common) { - bpf_log_attr_init(attr_log, offsetof(union bpf_attr, log_true_size), uattr, size); + if (bpf_log_attrs_diff(attr_common, attr->log_buf, attr->log_size, attr->log_level)) + return -EINVAL; + + if (!attr->log_buf && attr_common->log_buf) { + attr->log_buf = attr_common->log_buf; + attr->log_size = attr_common->log_size; + attr->log_level = attr_common->log_level; + bpf_log_attr_init(attr_log, offsetof(struct bpf_common_attr, log_true_size), + uattr_common, size_common); + } else { + bpf_log_attr_init(attr_log, offsetof(union bpf_attr, log_true_size), uattr, size); + } return 0; } diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index e81199361241..7125ea445c6c 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -6232,7 +6232,8 @@ static int __sys_bpf(enum bpf_cmd cmd, bpfptr_t uattr, unsigned int size, err = map_freeze(&attr); break; case BPF_PROG_LOAD: - err = bpf_prog_load_log_attr_init(&attr_log, &attr, uattr, size); + err = bpf_prog_load_log_attr_init(&attr_log, &attr, uattr, size, &attr_common, + uattr_common, size_common); err = err ?: bpf_prog_load(&attr, uattr, &attr_log); break; case BPF_OBJ_PIN: -- 2.52.0
