diff mbox series

[v4,bpf-next,04/12] bpf: add BPF token support to BPF_BTF_LOAD command

Message ID 20230912212906.3975866-5-andrii@kernel.org (mailing list archive)
State Superseded
Delegated to: BPF
Headers show
Series BPF token and BPF FS-based delegation | expand

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bpf/vmtest-bpf-next-VM_Test-0 success Logs for ${{ matrix.test }} on ${{ matrix.arch }} with ${{ matrix.toolchain_full }}
bpf/vmtest-bpf-next-VM_Test-3 success Logs for build for s390x with gcc
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netdev/series_format success Posting correctly formatted
netdev/tree_selection success Clearly marked for bpf-next, async
netdev/fixes_present success Fixes tag not required for -next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 3091 this patch: 3091
netdev/cc_maintainers warning 10 maintainers not CCed: martin.lau@linux.dev jolsa@kernel.org haoluo@google.com daniel@iogearbox.net ast@kernel.org sdf@google.com john.fastabend@gmail.com yonghong.song@linux.dev kpsingh@kernel.org song@kernel.org
netdev/build_clang success Errors and warnings before: 1531 this patch: 1531
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
netdev/build_allmodconfig_warn success Errors and warnings before: 3184 this patch: 3184
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 47 lines checked
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netdev/source_inline success Was 0 now: 0

Commit Message

Andrii Nakryiko Sept. 12, 2023, 9:28 p.m. UTC 
Accept BPF token FD in BPF_BTF_LOAD command to allow BTF data loading
through delegated BPF token. BTF loading is a pretty straightforward
operation, so as long as BPF token is created with allow_cmds granting
BPF_BTF_LOAD command, kernel proceeds to parsing BTF data and creating
BTF object.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
---
 include/uapi/linux/bpf.h       |  1 +
 kernel/bpf/syscall.c           | 20 ++++++++++++++++++--
 tools/include/uapi/linux/bpf.h |  1 +
 3 files changed, 20 insertions(+), 2 deletions(-)
diff mbox series

Patch

diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
index 9c399454712e..1527d861f408 100644
--- a/include/uapi/linux/bpf.h
+++ b/include/uapi/linux/bpf.h
@@ -1606,6 +1606,7 @@  union bpf_attr {
 		 * truncated), or smaller (if log buffer wasn't filled completely).
 		 */
 		__u32		btf_log_true_size;
+		__u32		btf_token_fd;
 	};
 
 	struct {
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index fbd8c82e5ec6..0d394b471ee0 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -4714,15 +4714,31 @@  static int bpf_obj_get_info_by_fd(const union bpf_attr *attr,
 	return err;
 }
 
-#define BPF_BTF_LOAD_LAST_FIELD btf_log_true_size
+#define BPF_BTF_LOAD_LAST_FIELD btf_token_fd
 
 static int bpf_btf_load(const union bpf_attr *attr, bpfptr_t uattr, __u32 uattr_size)
 {
+	struct bpf_token *token = NULL;
+
 	if (CHECK_ATTR(BPF_BTF_LOAD))
 		return -EINVAL;
 
-	if (!bpf_capable())
+	if (attr->btf_token_fd) {
+		token = bpf_token_get_from_fd(attr->btf_token_fd);
+		if (IS_ERR(token))
+			return PTR_ERR(token);
+		if (!bpf_token_allow_cmd(token, BPF_BTF_LOAD)) {
+			bpf_token_put(token);
+			token = NULL;
+		}
+	}
+
+	if (!bpf_token_capable(token, CAP_BPF)) {
+		bpf_token_put(token);
 		return -EPERM;
+	}
+
+	bpf_token_put(token);
 
 	return btf_new_fd(attr, uattr, uattr_size);
 }
diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
index 9c399454712e..1527d861f408 100644
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h
@@ -1606,6 +1606,7 @@  union bpf_attr {
 		 * truncated), or smaller (if log buffer wasn't filled completely).
 		 */
 		__u32		btf_log_true_size;
+		__u32		btf_token_fd;
 	};
 
 	struct {