[PATCH 2/2] tools/nolibc: riscv: Support __NR_llseek for rv32

[Zhangjin Wu]

There is no __NR_lseek for rv32, use __NR_llseek instead.

This code is based on sysdeps/unix/sysv/linux/lseek.c of glibc.

Signed-off-by: Zhangjin Wu <falcon at tinylab.org>
---
 tools/include/nolibc/std.h |  1 +
 tools/include/nolibc/sys.h | 19 +++++++++++++++++++
 2 files changed, 20 insertions(+)

diff --git a/tools/include/nolibc/std.h b/tools/include/nolibc/std.h
index 933bc0be7e1c..83c0b0cb9564 100644
--- a/tools/include/nolibc/std.h
+++ b/tools/include/nolibc/std.h
@@ -32,5 +32,6 @@ typedef   signed long         off_t;
 typedef   signed long     blksize_t;
 typedef   signed long      blkcnt_t;
 typedef   signed long        time_t;
+typedef     long long        loff_t;
 
 #endif /* _NOLIBC_STD_H */
diff --git a/tools/include/nolibc/sys.h b/tools/include/nolibc/sys.h
index 5d624dc63a42..ab32f3c0a460 100644
--- a/tools/include/nolibc/sys.h
+++ b/tools/include/nolibc/sys.h
@@ -668,7 +668,26 @@ int link(const char *old, const char *new)
 static __attribute__((unused))
 off_t sys_lseek(int fd, off_t offset, int whence)
 {
+#ifdef __NR_lseek
 	return my_syscall3(__NR_lseek, fd, offset, whence);
+#elif defined(__NR_llseek)
+	loff_t res;
+	off_t retval;
+
+	int rc = my_syscall5(__NR_llseek, fd, (long) (((uint64_t) (offset)) >> 32), (long) offset, &res, whence);
+
+	if (rc)
+		return rc;
+
+	retval = (off_t) res;
+	if (retval == res)
+		return retval;
+
+	SET_ERRNO(EOVERFLOW);
+	return (off_t) -1;
+#else
+#error Neither __NR_lseek nor __NR_llseek defined, cannot implement sys_lseek()
+#endif
 }
 
 static __attribute__((unused))
-- 
2.25.1