[PATCH v3 1/3] tools headers: Go back to include asm-generic/unistd.h for arm64

Leo Yan
2025-12-22T18:07:12Z

The header unistd.h is included under Arm64's uAPI folder (see
tools/arch/arm64/include/uapi/asm/), but it does not include its
dependent header unistd_64.h. The intention is for unistd_64.h to be
generated dynamically using scripts/Makefile.asm-headers.

However, this dynamic approach causes problems because the header is not
available early enough, even though it is widely included throughout
tools. Using the perf build as an example:

1) Feature detection: Perf first runs feature tests.

The BPF feature program test-bpf.c includes unistd.h. Since
unistd_64.h has not been generated yet, the program fails to build,
and the BPF feature ends up being disabled.

2) libperf build:

The libperf Makefile later generates unistd_64.h on the fly, so
libperf itself builds successfully.

3) Final perf build:

Although the perf binary can build successfully using the generated
header, we never get a chance to build BPF skeleton programs,
because BPF support was already disabled earlier.

To fix the issue, it restores to include asm-generic/unistd.h. This is
consistent with other architectures and ensures the header is available
from the start.

Fixes: 22f72088ffe6 ("tools headers: Update the syscall table with the kernel sources")
Signed-off-by: Leo Yan <leo.yan@arm.com>
---
tools/arch/arm64/include/uapi/asm/unistd.h | 24 +++++++++++++++++++++++-
1 file changed, 23 insertions(+), 1 deletion(-)

diff --git a/tools/arch/arm64/include/uapi/asm/unistd.h b/tools/arch/arm64/include/uapi/asm/unistd.h
index df36f23876e863ff0a9e88473d5339f7ab69516d..9306726337fe005e3cf3e1ffd38dc6356191fa95 100644
--- a/tools/arch/arm64/include/uapi/asm/unistd.h
+++ b/tools/arch/arm64/include/uapi/asm/unistd.h
@@ -1,2 +1,24 @@
/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
-#include <asm/unistd_64.h>
+/*
+ * Copyright (C) 2012 ARM Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#define __ARCH_WANT_RENAMEAT
+#define __ARCH_WANT_NEW_STAT
+#define __ARCH_WANT_SET_GET_RLIMIT
+#define __ARCH_WANT_TIME32_SYSCALLS
+#define __ARCH_WANT_MEMFD_SECRET
+
+#include <asm-generic/unistd.h>

--
2.34.1