[PATCH v2 07/13] tools/nolibc: sys_lseek: add pure 64bit lseek

[Zhangjin Wu <falcon@tinylab.org>]

use sys_llseek instead of sys_lseek to add 64bit seek even in 32bit
platforms.

This code is based on sysdeps/unix/sysv/linux/lseek.c of glibc and
src/unistd/lseek.c of musl.

Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>
---
 tools/include/nolibc/sys.h | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/tools/include/nolibc/sys.h b/tools/include/nolibc/sys.h
index 98cfa2f6d021..d0720af84b6d 100644
--- a/tools/include/nolibc/sys.h
+++ b/tools/include/nolibc/sys.h
@@ -672,7 +672,17 @@ int link(const char *old, const char *new)
 static __attribute__((unused))
 off_t sys_lseek(int fd, off_t offset, int whence)
 {
+#if defined(__NR_llseek) || defined(__NR__llseek)
+#ifndef __NR__llseek
+#define __NR__llseek __NR_llseek
+#endif
+	off_t result;
+	return my_syscall5(__NR__llseek, fd, offset >> 32, offset, &result, whence) ?: result;
+#elif defined(__NR_lseek)
 	return my_syscall3(__NR_lseek, fd, offset, whence);
+#else
+#error None of __NR_lseek, __NR_llseek nor __NR__llseek defined, cannot implement sys_lseek()
+#endif
 }
 
 static __attribute__((unused))
-- 
2.25.1