Re: [PATCH v8 03/12] scripts/syscall.tbl: Use the common table

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 2 potential issue(s) to consider:
- [Critical] arm64: compat: ABI breakage due to omitted clone3 syscall
- [Medium] perf: silent trace breakage on RISC-V/CSKY when syncing syscall.tbl
--

commit 6f36ef0832663a9b88501de9d0a2dada0399dd37
Author: André Almeida <andrealmeid@igalia.com>

scripts/syscall.tbl: Use the common table

This patch removes duplicated syscalls from architecture-specific tables by
moving them to a common table. It creates a new scripts/syscall_common.tbl
and adjusts build scripts and Makefiles to use it.

> diff --git a/arch/arm64/kernel/Makefile.syscalls b/arch/arm64/kernel/Makefile.syscalls
> --- a/arch/arm64/kernel/Makefile.syscalls
> +++ b/arch/arm64/kernel/Makefile.syscalls
> @@ -1,6 +1,6 @@
>  # SPDX-License-Identifier: GPL-2.0
>  
>  syscall_abis_32 +=
> -syscall_abis_64 += renameat rlimit memfd_secret
> +syscall_abis_64 += renameat rlimit memfd_secret clone3

[Severity: Critical]
Does this code omit clone3 for 32-bit AArch32 compat processes?

The new scripts/syscall_common.tbl defines clone3 under the explicit ABI
name clone3 instead of common. Because syscall_abis_32 does not include
clone3 here, the build system will not generate the clone3 entry for the
32-bit compat table.

Consequently, 32-bit AArch32 binaries running on arm64 that invoke clone3
will receive -ENOSYS since the generated system call table will populate
the slot with sys_ni_syscall.

[ ... ]
> diff --git a/scripts/syscall.tbl b/scripts/syscall.tbl
> --- a/scripts/syscall.tbl
> +++ b/scripts/syscall.tbl
> @@ -344,72 +344,3 @@
>  293	common	rseq				sys_rseq
>  294	common	kexec_file_load			sys_kexec_file_load
>  # 295 through 402 are unassigned to sync up with generic numbers don't use
> -403	32	clock_gettime64			sys_clock_gettime

[Severity: Medium]
Will moving these syscalls out of scripts/syscall.tbl break perf trace
for generic architectures like RISC-V and CSKY?

The tooling script tools/perf/trace/beauty/syscalltbl.sh hardcodes reading
the main syscall.tbl when building tables for generic architectures:

tools/perf/trace/beauty/syscalltbl.sh:build_tables() {
    ...
    build_tables "$tools_dir/scripts/syscall.tbl" "$outfile" ...
    ...
}

Because it completely ignores the new scripts/syscall_common.tbl, when a
developer later syncs the modified scripts/syscall.tbl into the tools/
directory to resolve check-headers.sh build warnings, perf trace will silently
lose the capability to map IDs to names for all of these removed syscalls.

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260918-tonyk-syscall_table-v8-0-0e2d60cad13e@igalia.com?part=3