Re: [PATCH 0/3] sparc32: add seccomp filter support

[Magnus Lindholm]

Hi Ludwig,

On Wed, Oct 14, 2026 at 10:07 AM Ludwig Rydberg
<ludwig.rydberg@xxxxxxxxxxx> wrote:
>
> This adds SECCOMP_FILTER support for sparc32 on top of Stian Halseth's
> sparc64 series (v2):
> https://lore.kernel.org/r/20260902072745.3412940-1-stian@xxxxxx
>
> Patch 1 splits syscall_trace() into syscall_trace_enter() and
> syscall_trace_leave() as on sparc64 and most other architectures.
>
> Patch 2 adds a call to seccomp_permit_syscall() in syscall_trace_enter()
> to filter system calls. A denied syscall skips the call and goes
> through the syscall exit work with the return value already set.
>
> Patch 3 extends the seccomp_bpf selftest's SPARC support to sparc32.
>
> Testing:
> seccomp_bpf on v7.3-rc1 with the whole seccomp series applied on a
> GR-CPCI-GR740 board from Frontgrade Gaisler:
>
> - UP: pass:99 fail:0 skip:12
> - SMP with out-of-tree patches that implement the futex atomic
>   operations with CASA on LEON: pass:99 fail:0 skip:12
> - SMP without them: pass:89 fail:10 skip:12.
>   FUTEX depends on !(SPARC32 && SMP) (see 3f2bedabb62c) and glibc aborts
>   with "The futex facility returned an unexpected error code" in the 10
>   tests that use threads (KILL_thread,
>   user_notification_filter_empty_threaded, tsync_vs_dead_thread_leader and
>   the 7 TSYNC tests).
>
> The 12 skipped tests need the UPROBES which sparc32 does not have.
>
> Ludwig Rydberg (3):
>   sparc32: Split common syscall_trace() to syscall_trace_{enter|leave}()
>   sparc32: add seccomp filter support
>   selftests/seccomp: add sparc32 support
>
>  arch/sparc/Kconfig                            |  2 +-
>  arch/sparc/include/asm/thread_info_32.h       |  2 +
>  arch/sparc/kernel/entry.S                     | 33 ++++++++--------
>  arch/sparc/kernel/kernel.h                    |  3 +-
>  arch/sparc/kernel/ptrace_32.c                 | 26 ++++++++-----
>  tools/testing/selftests/seccomp/seccomp_bpf.c | 38 +++++++++++++------
>  6 files changed, 66 insertions(+), 38 deletions(-)
>
>
> base-commit: cee9395acd8043be0644b25c34bfa86623f2b935
> prerequisite-patch-id: 5772aba3cb572833df13529ec6bb03ae9e848e25
> prerequisite-patch-id: 70a54ba398c763e45f9332ff4cc06b3f2a3e7825
> --
> 2.35.3
>
>

Tested the series on a dual-CPU HyperSPARC SPARCstation 20 with
my patched v7.3-rc1 kernel, including SMP futex support.

The cross-built seccomp_bpf selftests completed on real hardware:
92 passed, 0 failed, 19 skipped. The harness timeout was increased
to 180 seconds; test workloads were unchanged. No new kernel
messages or taint appeared.

Tested-by: Magnus Lindholm <linmag7@xxxxxxxxx>