tools/nolibc: Add statx() and make stat() rely on statx() if necessary

LoongArch and RISC-V 32-bit only have statx(). ARC, Hexagon, Nios2 and
OpenRISC have statx() and stat64() but not stat() or newstat(). Add
statx() and make stat() rely on statx() if necessary to make them happy.
We may just use statx() for all architectures in the future.

Signed-off-by: Feiyang Chen <chenfeiyang@loongson.cn>
Acked-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>

tools/include/nolibc/sys.h

@@ -20,6 +20,7 @@
 #include <linux/time.h>
 #include <linux/auxvec.h>
 #include <linux/fcntl.h> // for O_* and AT_*
+#include <linux/stat.h>  // for statx()
 
 #include "arch.h"
 #include "errno.h"
@@ -1090,12 +1091,66 @@ pid_t setsid(void)
 	return ret;
 }
 
+#if defined(__NR_statx)
+/*
+ * int statx(int fd, const char *path, int flags, unsigned int mask, struct statx *buf);
+ */
+
+static __attribute__((unused))
+int sys_statx(int fd, const char *path, int flags, unsigned int mask, struct statx *buf)
+{
+	return my_syscall5(__NR_statx, fd, path, flags, mask, buf);
+}
+
+static __attribute__((unused))
+int statx(int fd, const char *path, int flags, unsigned int mask, struct statx *buf)
+{
+	int ret = sys_statx(fd, path, flags, mask, buf);
+
+	if (ret < 0) {
+		SET_ERRNO(-ret);
+		ret = -1;
+	}
+	return ret;
+}
+#endif
 
 /*
  * int stat(const char *path, struct stat *buf);
  * Warning: the struct stat's layout is arch-dependent.
  */
 
+#if defined(__NR_statx) && !defined(__NR_newfstatat) && !defined(__NR_stat)
+/*
+ * Maybe we can just use statx() when available for all architectures?
+ */
+static __attribute__((unused))
+int sys_stat(const char *path, struct stat *buf)
+{
+	struct statx statx;
+	long ret;
+
+	ret = sys_statx(AT_FDCWD, path, AT_NO_AUTOMOUNT, STATX_BASIC_STATS, &statx);
+	buf->st_dev     = ((statx.stx_dev_minor & 0xff)
+			  | (statx.stx_dev_major << 8)
+			  | ((statx.stx_dev_minor & ~0xff) << 12));
+	buf->st_ino     = statx.stx_ino;
+	buf->st_mode    = statx.stx_mode;
+	buf->st_nlink   = statx.stx_nlink;
+	buf->st_uid     = statx.stx_uid;
+	buf->st_gid     = statx.stx_gid;
+	buf->st_rdev    = ((statx.stx_rdev_minor & 0xff)
+			  | (statx.stx_rdev_major << 8)
+			  | ((statx.stx_rdev_minor & ~0xff) << 12));
+	buf->st_size    = statx.stx_size;
+	buf->st_blksize = statx.stx_blksize;
+	buf->st_blocks  = statx.stx_blocks;
+	buf->st_atime   = statx.stx_atime.tv_sec;
+	buf->st_mtime   = statx.stx_mtime.tv_sec;
+	buf->st_ctime   = statx.stx_ctime.tv_sec;
+	return ret;
+}
+#else
 static __attribute__((unused))
 int sys_stat(const char *path, struct stat *buf)
 {
@@ -1125,6 +1180,7 @@ int sys_stat(const char *path, struct stat *buf)
 	buf->st_ctime   = stat.st_ctime;
 	return ret;
 }
+#endif
 
 static __attribute__((unused))
 int stat(const char *path, struct stat *buf)