From:   chris.chenfeiyang@gmail.com
To:     w@1wt.eu, paulmck@kernel.org
Cc:     Feiyang Chen <chenfeiyang@loongson.cn>, chenhuacai@kernel.org,
        jiaxun.yang@flygoat.com, arnd@arndb.de,
        chris.chenfeiyang@gmail.com, loongarch@lists.linux.dev,
        linux-kernel@vger.kernel.org
Subject: [PATCH 1/3] nolibc: Add statx() support to implement sys_stat()
Date:   Tue,  7 Feb 2023 10:09:40 +0800
Message-Id: <1af05c1441e9f96870be1cc20b1162e3f5043b2e.1675734681.git.chenfeiyang@loongson.cn>
In-Reply-To: <cover.1675734681.git.chenfeiyang@loongson.cn>
References: <cover.1675734681.git.chenfeiyang@loongson.cn>
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From: Feiyang Chen <chenfeiyang@loongson.cn>

Neither __NR_newfstatat nor __NR_stat is defined on new architecture
like LoongArch, but we can use statx() to implement sys_stat().

Signed-off-by: Feiyang Chen <chenfeiyang@loongson.cn>
---
 tools/include/nolibc/sys.h   | 36 +++++++++++++++++++++++++---
 tools/include/nolibc/types.h | 46 ++++++++++++++++++++++++++++++++++++
 2 files changed, 79 insertions(+), 3 deletions(-)

diff --git a/tools/include/nolibc/sys.h b/tools/include/nolibc/sys.h
index b5f8cd35c03b..7ff9b401008a 100644
--- a/tools/include/nolibc/sys.h
+++ b/tools/include/nolibc/sys.h
@@ -1054,6 +1054,7 @@ pid_t setsid(void)
  * Warning: the struct stat's layout is arch-dependent.
  */
 
+#if defined(__NR_newfstatat) || defined(__NR_stat)
 static __attribute__((unused))
 int sys_stat(const char *path, struct stat *buf)
 {
@@ -1063,10 +1064,8 @@ int sys_stat(const char *path, struct stat *buf)
 #ifdef __NR_newfstatat
 	/* only solution for arm64 */
 	ret = my_syscall4(__NR_newfstatat, AT_FDCWD, path, &stat, 0);
-#elif defined(__NR_stat)
+#else /* __NR_stat */
 	ret = my_syscall2(__NR_stat, path, &stat);
-#else
-#error Neither __NR_newfstatat nor __NR_stat defined, cannot implement sys_stat()
 #endif
 	buf->st_dev     = stat.st_dev;
 	buf->st_ino     = stat.st_ino;
@@ -1083,6 +1082,37 @@ int sys_stat(const char *path, struct stat *buf)
 	buf->st_ctime   = stat.st_ctime;
 	return ret;
 }
+#elif defined(__NR_statx)
+/* only solution for loongarch */
+static __attribute__((unused))
+int sys_stat(const char *path, struct stat *buf)
+{
+	struct statx statx;
+	long ret;
+
+	ret = my_syscall5(__NR_statx, AT_FDCWD, path, 0, 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
+#error None of __NR_newfstatat, __NR_stat, nor __NR_statx defined, cannot implement sys_stat()
+#endif
 
 static __attribute__((unused))
 int stat(const char *path, struct stat *buf)
diff --git a/tools/include/nolibc/types.h b/tools/include/nolibc/types.h
index fbbc0e68c001..9b244af1ec2c 100644
--- a/tools/include/nolibc/types.h
+++ b/tools/include/nolibc/types.h
@@ -193,6 +193,52 @@ struct stat {
 	time_t    st_ctime;   /* time of last status change */
 };
 
+/* for statx() */
+#ifndef STATX_BASIC_STATS
+#define STATX_BASIC_STATS (0x000007ffU)
+#endif
+
+struct statx_timestamp {
+	__s64	tv_sec;
+	__u32	tv_nsec;
+	__s32	__reserved;
+};
+
+struct statx {
+	/* 0x00 */
+	__u32	stx_mask;	/* What results were written [uncond] */
+	__u32	stx_blksize;	/* Preferred general I/O size [uncond] */
+	__u64	stx_attributes;	/* Flags conveying information about the file [uncond] */
+	/* 0x10 */
+	__u32	stx_nlink;	/* Number of hard links */
+	__u32	stx_uid;	/* User ID of owner */
+	__u32	stx_gid;	/* Group ID of owner */
+	__u16	stx_mode;	/* File mode */
+	__u16	__spare0[1];
+	/* 0x20 */
+	__u64	stx_ino;	/* Inode number */
+	__u64	stx_size;	/* File size */
+	__u64	stx_blocks;	/* Number of 512-byte blocks allocated */
+	__u64	stx_attributes_mask; /* Mask to show what's supported in stx_attributes */
+	/* 0x40 */
+	struct statx_timestamp	stx_atime;	/* Last access time */
+	struct statx_timestamp	stx_btime;	/* File creation time */
+	struct statx_timestamp	stx_ctime;	/* Last attribute change time */
+	struct statx_timestamp	stx_mtime;	/* Last data modification time */
+	/* 0x80 */
+	__u32	stx_rdev_major;	/* Device ID of special file [if bdev/cdev] */
+	__u32	stx_rdev_minor;
+	__u32	stx_dev_major;	/* ID of device containing file [uncond] */
+	__u32	stx_dev_minor;
+	/* 0x90 */
+	__u64	stx_mnt_id;
+	__u32	stx_dio_mem_align;	/* Memory buffer alignment for direct I/O */
+	__u32	stx_dio_offset_align;	/* File offset alignment for direct I/O */
+	/* 0xa0 */
+	__u64	__spare3[12];	/* Spare space for future expansion */
+	/* 0x100 */
+};
+
 /* WARNING, it only deals with the 4096 first majors and 256 first minors */
 #define makedev(major, minor) ((dev_t)((((major) & 0xfff) << 8) | ((minor) & 0xff)))
 #define major(dev) ((unsigned int)(((dev) >> 8) & 0xfff))
-- 
2.39.0