[PATCH 08/13] tools/nolibc: sys_lseek: riscv: use __NR_llseek for rv32

Zhangjin Wu
2023-05-24T17:56:33Z

riscv uses the generic include/uapi/asm-generic/unistd.h, it has code
like this:

#if __BITS_PER_LONG == 64 && !defined(__SYSCALL_COMPAT)
#define __NR_lseek __NR3264_lseek
#else
#define __NR_llseek __NR3264_lseek
#endif

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@tinylab.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>
---
tools/include/nolibc/std.h | 1 +
tools/include/nolibc/sys.h | 18 ++++++++++++++++++
2 files changed, 19 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 d5792a5de70b..0ff77c0a06d7 100644
--- a/tools/include/nolibc/sys.h
+++ b/tools/include/nolibc/sys.h
@@ -671,7 +671,25 @@ 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 result;
+ off_t retval;
+ int ret;
+
+ ret = my_syscall5(__NR_llseek, fd, (long) (((uint64_t) (offset)) >> 32), (long) offset, &result, whence);
+ if (ret)
+ return ret;
+
+ retval = (off_t) result;
+ if (retval != result)
+ return -EOVERFLOW;
+
+ return retval;
+#else
+#error Neither __NR_lseek nor __NR_llseek defined, cannot implement sys_lseek()
+#endif
}

static __attribute__((unused))
--
2.25.1