diff mbox series

[v12,bpf-next,01/10] bpf: Support "sk_buff" and "xdp_buff" as valid kfunc arg types

Message ID 20230226085120.3907863-2-joannelkoong@gmail.com (mailing list archive)
State Superseded
Delegated to: BPF
Headers show
Series Add skb + xdp dynptrs | expand

Checks

Context Check Description
bpf/vmtest-bpf-next-PR success PR summary
bpf/vmtest-bpf-next-VM_Test-1 success Logs for ${{ matrix.test }} on ${{ matrix.arch }} with ${{ matrix.toolchain }}
bpf/vmtest-bpf-next-VM_Test-2 success Logs for ShellCheck
bpf/vmtest-bpf-next-VM_Test-3 fail Logs for build for aarch64 with gcc
bpf/vmtest-bpf-next-VM_Test-4 fail Logs for build for aarch64 with llvm-17
bpf/vmtest-bpf-next-VM_Test-5 fail Logs for build for s390x with gcc
bpf/vmtest-bpf-next-VM_Test-6 fail Logs for build for x86_64 with gcc
bpf/vmtest-bpf-next-VM_Test-7 fail Logs for build for x86_64 with llvm-17
bpf/vmtest-bpf-next-VM_Test-8 success Logs for llvm-toolchain
bpf/vmtest-bpf-next-VM_Test-9 success Logs for set-matrix
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: 4 this patch: 4
netdev/cc_maintainers warning 11 maintainers not CCed: davem@davemloft.net jolsa@kernel.org john.fastabend@gmail.com martin.lau@linux.dev yhs@fb.com kpsingh@kernel.org song@kernel.org haoluo@google.com kuba@kernel.org hawk@kernel.org sdf@google.com
netdev/build_clang success Errors and warnings before: 0 this patch: 0
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: 4 this patch: 4
netdev/checkpatch warning WARNING: line length of 81 exceeds 80 columns
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Joanne Koong Feb. 26, 2023, 8:51 a.m. UTC 
The bpf mirror of the in-kernel sk_buff and xdp_buff data structures are
__sk_buff and xdp_md. Currently, when we pass in the program ctx to a
kfunc where the program ctx is a skb or xdp buffer, we reject the
program if the in-kernel definition is sk_buff/xdp_buff instead of
__sk_buff/xdp_md.

This change allows "sk_buff <--> __sk_buff" and "xdp_buff <--> xdp_md"
to be recognized as valid matches. The user program may pass in their
program ctx as a __sk_buff or xdp_md, and the in-kernel definition
of the kfunc may define this arg as a sk_buff or xdp_buff.

Signed-off-by: Joanne Koong <joannelkoong@gmail.com>
---
 kernel/bpf/btf.c | 4 ++++
 1 file changed, 4 insertions(+)
diff mbox series

Patch

diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c
index fa22ec79ac0e..84cca8473873 100644
--- a/kernel/bpf/btf.c
+++ b/kernel/bpf/btf.c
@@ -5683,6 +5683,10 @@  btf_get_prog_ctx_type(struct bpf_verifier_log *log, const struct btf *btf,
 	 * int socket_filter_bpf_prog(struct __sk_buff *skb)
 	 * { // no fields of skb are ever used }
 	 */
+	if (strcmp(ctx_tname, "__sk_buff") == 0 && strcmp(tname, "sk_buff") == 0)
+		return ctx_type;
+	if (strcmp(ctx_tname, "xdp_md") == 0 && strcmp(tname, "xdp_buff") == 0)
+		return ctx_type;
 	if (strcmp(ctx_tname, tname)) {
 		/* bpf_user_pt_regs_t is a typedef, so resolve it to
 		 * underlying struct and check name again