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From:   Zhangjin Wu <falcon@tinylab.org>
To:     w@1wt.eu
Cc:     arnd@arndb.de, falcon@tinylab.org, linux-kernel@vger.kernel.org,
        linux-kselftest@vger.kernel.org, linux-riscv@lists.infradead.org,
        thomas@t-8ch.de
Subject: [PATCH v2 07/13] tools/nolibc: sys_lseek: add pure 64bit lseek
Date:   Tue, 30 May 2023 03:54:23 +0800
Message-Id: <2f5c3338898da65210ad3f62d7b7773a96f6d251.1685387484.git.falcon@tinylab.org>
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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