[vlc-devel] [PATCH] linux/thread: Use SYS_futex instead of __NR_futex

[Khem Raj]

SYS_futex it expected from system C library.
in glibc (/usr/include/bits/syscall.h defines it in terms of of NR_futex)
some newer 32bit architectures e.g. riscv32 are using 64bit time_t from
get go unlike other 32bit architectures in glibc, therefore it wont have
NR_futex defined but just NR_futex_time64 this aliases it to NR_futex so
that SYS_futex is then defined for rv32

Upstream-Status: Submitted [https://github.com/videolan/vlc/pull/117]
Signed-off-by: Khem Raj <raj.khem at gmail.com>
---
 src/linux/thread.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/src/linux/thread.c b/src/linux/thread.c
index 20da296..30639a3 100644
--- a/src/linux/thread.c
+++ b/src/linux/thread.c
@@ -30,6 +30,11 @@
 #include <sys/syscall.h>
 #include <linux/futex.h>
 
+/* 32bit architectures with 64bit time_t do not define __NR_futex syscall */
+#if !defined(SYS_futex) && defined(SYS_futex_time64)
+#define SYS_futex SYS_futex_time64
+#endif
+
 #ifndef FUTEX_PRIVATE_FLAG
 #define FUTEX_WAKE_PRIVATE FUTEX_WAKE
 #define FUTEX_WAIT_PRIVATE FUTEX_WAIT
@@ -50,7 +55,7 @@ unsigned long vlc_thread_id(void)
 static int sys_futex(void *addr, int op, unsigned val,
                      const struct timespec *to, void *addr2, int val3)
 {
-    return syscall(__NR_futex, addr, op, val, to, addr2, val3);
+    return syscall(SYS_futex, addr, op, val, to, addr2, val3);
 }
 
 static int vlc_futex_wake(void *addr, int nr)
-- 
2.29.2