[tip: locking/futex] selftests/futex: Define SYS_futex on 32-bit architectures with 64-bit time_t

[tip-bot2 for Cynthia Huang]

The following commit has been merged into the locking/futex branch of tip:

Commit-ID:     04850819c65c8242072818655d4341e70ae998b5
Gitweb:        https://git.kernel.org/tip/04850819c65c8242072818655d4341e70ae998b5
Author:        Cynthia Huang <cynthia@xxxxxxxxxxxxx>
AuthorDate:    Thu, 10 Jul 2025 18:36:30 +08:00
Committer:     Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitterDate: Tue, 22 Jul 2025 11:18:43 +02:00

selftests/futex: Define SYS_futex on 32-bit architectures with 64-bit time_t

The kernel does not provide sys_futex() on 32-bit architectures that do not
support 32-bit time representations, such as riscv32.

As a result, glibc cannot define SYS_futex, causing compilation failures in
tests that rely on this syscall. Define SYS_futex as SYS_futex_time64 in
such cases to ensure successful compilation and compatibility.

Signed-off-by: Cynthia Huang <cynthia@xxxxxxxxxxxxx>
Signed-off-by: Ben Zong-You Xie <ben717@xxxxxxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Reviewed-by: Muhammad Usama Anjum <usama.anjum@xxxxxxxxxxxxx>
Link: https://lore.kernel.org/all/20250710103630.3156130-1-ben717@xxxxxxxxxxxxx

---
 tools/testing/selftests/futex/include/futextest.h | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/tools/testing/selftests/futex/include/futextest.h b/tools/testing/selftests/futex/include/futextest.h
index ddbcfc9..7a5fd1d 100644
--- a/tools/testing/selftests/futex/include/futextest.h
+++ b/tools/testing/selftests/futex/include/futextest.h
@@ -47,6 +47,17 @@ typedef volatile u_int32_t futex_t;
 					 FUTEX_PRIVATE_FLAG)
 #endif
 
+/*
+ * SYS_futex is expected from system C library, in glibc some 32-bit
+ * architectures (e.g. RV32) are using 64-bit time_t, therefore it doesn't have
+ * SYS_futex defined but just SYS_futex_time64. Define SYS_futex as
+ * SYS_futex_time64 in this situation to ensure the compilation and the
+ * compatibility.
+ */
+#if !defined(SYS_futex) && defined(SYS_futex_time64)
+#define SYS_futex SYS_futex_time64
+#endif
+
 /**
  * futex() - SYS_futex syscall wrapper
  * @uaddr:	address of first futex