diff mbox series

[bpf] bpf: clarify a misleading verifier error message

Message ID 20250318083551.8192-1-andreaterzolo3@gmail.com (mailing list archive)
State Accepted
Commit a2598045ead99b51b00e81d46560757b9a95bd84
Delegated to: BPF
Headers show
Series [bpf] bpf: clarify a misleading verifier error message | expand

Checks

Context Check Description
bpf/vmtest-bpf-VM_Test-0 success Logs for Lint
bpf/vmtest-bpf-VM_Test-2 success Logs for Unittests
bpf/vmtest-bpf-VM_Test-1 success Logs for ShellCheck
bpf/vmtest-bpf-VM_Test-3 success Logs for Validate matrix.py
bpf/vmtest-bpf-VM_Test-5 success Logs for aarch64-gcc / build / build for aarch64 with gcc
bpf/vmtest-bpf-VM_Test-4 success Logs for aarch64-gcc / GCC BPF
bpf/vmtest-bpf-VM_Test-7 success Logs for aarch64-gcc / test (test_maps, false, 360) / test_maps on aarch64 with gcc
bpf/vmtest-bpf-VM_Test-6 success Logs for aarch64-gcc / build-release
bpf/vmtest-bpf-VM_Test-10 success Logs for aarch64-gcc / test (test_verifier, false, 360) / test_verifier on aarch64 with gcc
bpf/vmtest-bpf-VM_Test-12 success Logs for aarch64-gcc / veristat-meta
bpf/vmtest-bpf-VM_Test-11 success Logs for aarch64-gcc / veristat-kernel
bpf/vmtest-bpf-VM_Test-13 success Logs for s390x-gcc / GCC BPF
bpf/vmtest-bpf-VM_Test-14 success Logs for s390x-gcc / build / build for s390x with gcc
bpf/vmtest-bpf-VM_Test-15 success Logs for s390x-gcc / build-release
bpf/vmtest-bpf-VM_Test-19 success Logs for s390x-gcc / veristat-kernel
bpf/vmtest-bpf-VM_Test-18 success Logs for s390x-gcc / test (test_verifier, false, 360) / test_verifier on s390x with gcc
bpf/vmtest-bpf-VM_Test-20 success Logs for s390x-gcc / veristat-meta
bpf/vmtest-bpf-VM_Test-21 success Logs for set-matrix
bpf/vmtest-bpf-VM_Test-23 success Logs for x86_64-gcc / build / build for x86_64 with gcc
bpf/vmtest-bpf-VM_Test-25 success Logs for x86_64-gcc / test (test_maps, false, 360) / test_maps on x86_64 with gcc
bpf/vmtest-bpf-VM_Test-22 success Logs for x86_64-gcc / GCC BPF / GCC BPF
bpf/vmtest-bpf-VM_Test-27 success Logs for x86_64-gcc / test (test_progs_no_alu32, false, 360) / test_progs_no_alu32 on x86_64 with gcc
bpf/vmtest-bpf-VM_Test-24 success Logs for x86_64-gcc / build-release
bpf/vmtest-bpf-VM_Test-26 success Logs for x86_64-gcc / test (test_progs, false, 360) / test_progs on x86_64 with gcc
bpf/vmtest-bpf-VM_Test-28 success Logs for x86_64-gcc / test (test_progs_no_alu32_parallel, true, 30) / test_progs_no_alu32_parallel on x86_64 with gcc
bpf/vmtest-bpf-VM_Test-29 success Logs for x86_64-gcc / test (test_progs_parallel, true, 30) / test_progs_parallel on x86_64 with gcc
bpf/vmtest-bpf-VM_Test-31 fail Logs for x86_64-gcc / veristat-kernel / x86_64-gcc veristat_kernel
bpf/vmtest-bpf-VM_Test-30 success Logs for x86_64-gcc / test (test_verifier, false, 360) / test_verifier on x86_64 with gcc
bpf/vmtest-bpf-VM_Test-32 success Logs for x86_64-gcc / veristat-meta / x86_64-gcc veristat_meta
bpf/vmtest-bpf-VM_Test-33 success Logs for x86_64-llvm-17 / GCC BPF / GCC BPF
bpf/vmtest-bpf-VM_Test-34 success Logs for x86_64-llvm-17 / build / build for x86_64 with llvm-17
bpf/vmtest-bpf-VM_Test-35 success Logs for x86_64-llvm-17 / build-release / build for x86_64 with llvm-17-O2
bpf/vmtest-bpf-VM_Test-36 success Logs for x86_64-llvm-17 / test (test_maps, false, 360) / test_maps on x86_64 with llvm-17
bpf/vmtest-bpf-VM_Test-37 success Logs for x86_64-llvm-17 / test (test_progs, false, 360) / test_progs on x86_64 with llvm-17
bpf/vmtest-bpf-VM_Test-39 success Logs for x86_64-llvm-17 / test (test_verifier, false, 360) / test_verifier on x86_64 with llvm-17
bpf/vmtest-bpf-VM_Test-38 success Logs for x86_64-llvm-17 / test (test_progs_no_alu32, false, 360) / test_progs_no_alu32 on x86_64 with llvm-17
bpf/vmtest-bpf-VM_Test-40 success Logs for x86_64-llvm-17 / veristat-kernel
bpf/vmtest-bpf-VM_Test-41 success Logs for x86_64-llvm-17 / veristat-meta
bpf/vmtest-bpf-VM_Test-43 success Logs for x86_64-llvm-18 / build / build for x86_64 with llvm-18
bpf/vmtest-bpf-VM_Test-46 success Logs for x86_64-llvm-18 / test (test_progs, false, 360) / test_progs on x86_64 with llvm-18
bpf/vmtest-bpf-VM_Test-42 success Logs for x86_64-llvm-18 / GCC BPF / GCC BPF
bpf/vmtest-bpf-VM_Test-44 success Logs for x86_64-llvm-18 / build-release / build for x86_64 with llvm-18-O2
bpf/vmtest-bpf-VM_Test-45 success Logs for x86_64-llvm-18 / test (test_maps, false, 360) / test_maps on x86_64 with llvm-18
bpf/vmtest-bpf-VM_Test-48 success Logs for x86_64-llvm-18 / test (test_progs_no_alu32, false, 360) / test_progs_no_alu32 on x86_64 with llvm-18
bpf/vmtest-bpf-VM_Test-47 success Logs for x86_64-llvm-18 / test (test_progs_cpuv4, false, 360) / test_progs_cpuv4 on x86_64 with llvm-18
bpf/vmtest-bpf-VM_Test-50 success Logs for x86_64-llvm-18 / veristat-kernel
bpf/vmtest-bpf-VM_Test-49 success Logs for x86_64-llvm-18 / test (test_verifier, false, 360) / test_verifier on x86_64 with llvm-18
bpf/vmtest-bpf-VM_Test-51 success Logs for x86_64-llvm-18 / veristat-meta
bpf/vmtest-bpf-PR fail PR summary
bpf/vmtest-bpf-VM_Test-9 success Logs for aarch64-gcc / test (test_progs_no_alu32, false, 360) / test_progs_no_alu32 on aarch64 with gcc
bpf/vmtest-bpf-VM_Test-8 success Logs for aarch64-gcc / test (test_progs, false, 360) / test_progs on aarch64 with gcc
bpf/vmtest-bpf-VM_Test-16 success Logs for s390x-gcc / test (test_progs, false, 360) / test_progs on s390x with gcc
bpf/vmtest-bpf-VM_Test-17 success Logs for s390x-gcc / test (test_progs_no_alu32, false, 360) / test_progs_no_alu32 on s390x with gcc
netdev/series_format success Single patches do not need cover letters
netdev/tree_selection success Clearly marked for bpf
netdev/ynl success Generated files up to date; no warnings/errors; no diff in generated;
netdev/fixes_present fail Series targets non-next tree, but doesn't contain any Fixes tags
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 0 this patch: 0
netdev/build_tools success No tools touched, skip
netdev/cc_maintainers success CCed 13 of 13 maintainers
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: 10 this patch: 10
netdev/checkpatch warning WARNING: line length of 98 exceeds 80 columns
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Andrea Terzolo March 18, 2025, 8:35 a.m. UTC 
The current verifier error message states that tail_calls are not
allowed in non-JITed programs with BPF-to-BPF calls. While this is
accurate, it is not the only scenario where this restriction applies.
Some architectures do not support this feature combination even when
programs are JITed. This update improves the error message to better
reflect these limitations.

Suggested-by: Shung-Hsi Yu <shung-hsi.yu@suse.com>
Signed-off-by: Andrea Terzolo <andreaterzolo3@gmail.com>
---
 kernel/bpf/verifier.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Shung-Hsi Yu March 18, 2025, 8:43 a.m. UTC | #1 
On Tue, Mar 18, 2025 at 09:35:45AM +0100, Andrea Terzolo wrote:
> The current verifier error message states that tail_calls are not
> allowed in non-JITed programs with BPF-to-BPF calls. While this is
> accurate, it is not the only scenario where this restriction applies.
> Some architectures do not support this feature combination even when
> programs are JITed. This update improves the error message to better
> reflect these limitations.
> 
> Suggested-by: Shung-Hsi Yu <shung-hsi.yu@suse.com>
> Signed-off-by: Andrea Terzolo <andreaterzolo3@gmail.com>

Acked-by: Shung-Hsi Yu <shung-hsi.yu@suse.com>
patchwork-bot+netdevbpf@kernel.org March 19, 2025, 2:20 a.m. UTC | #2 
Hello:

This patch was applied to bpf/bpf-next.git (master)
by Alexei Starovoitov <ast@kernel.org>:

On Tue, 18 Mar 2025 09:35:45 +0100 you wrote:
> The current verifier error message states that tail_calls are not
> allowed in non-JITed programs with BPF-to-BPF calls. While this is
> accurate, it is not the only scenario where this restriction applies.
> Some architectures do not support this feature combination even when
> programs are JITed. This update improves the error message to better
> reflect these limitations.
> 
> [...]

Here is the summary with links:
  - [bpf] bpf: clarify a misleading verifier error message
    https://git.kernel.org/bpf/bpf-next/c/a2598045ead9

You are awesome, thank you!
diff mbox series

Patch

diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 3303a3605..2e94fe5ea 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -9887,7 +9887,7 @@  static int check_map_func_compatibility(struct bpf_verifier_env *env,
 		if (map->map_type != BPF_MAP_TYPE_PROG_ARRAY)
 			goto error;
 		if (env->subprog_cnt > 1 && !allow_tail_call_in_subprogs(env)) {
-			verbose(env, "tail_calls are not allowed in non-JITed programs with bpf-to-bpf calls\n");
+			verbose(env, "mixing of tail_calls and bpf-to-bpf calls not supported\n");
 			return -EINVAL;
 		}
 		break;