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In-Reply-To: <b9bbf73286238bb4657d855c9d50983aa17953e2.1675851111.git.chenfeiyang@loongson.cn>
From:   Huacai Chen <chenhuacai@kernel.org>
Date:   Wed, 8 Feb 2023 19:00:40 +0800
Message-ID: <CAAhV-H5AvXdpYok43xA+QNz+oDEkcmQDxRdGoZ6jWTApf9mDBw@mail.gmail.com>
Subject: Re: [PATCH v2 2/5] tools/nolibc: Add statx() and make stat() rely on
 statx() when available
To:     chris.chenfeiyang@gmail.com
Cc:     w@1wt.eu, paulmck@kernel.org,
        Feiyang Chen <chenfeiyang@loongson.cn>, arnd@arndb.de,
        jiaxun.yang@flygoat.com, loongarch@lists.linux.dev,
        linux-kernel@vger.kernel.org
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Hi, Feiyang,

On Wed, Feb 8, 2023 at 6:18 PM <chris.chenfeiyang@gmail.com> wrote:
>
> From: Feiyang Chen <chenfeiyang@loongson.cn>
>
> loongarch and riscv32 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() to make them happy.
Some bikesheddings, maybe it is better to use LoongArch here.

Huacai
>
> Signed-off-by: Feiyang Chen <chenfeiyang@loongson.cn>
> ---
>  tools/include/nolibc/sys.h | 51 ++++++++++++++++++++++++++++++++++++++
>  1 file changed, 51 insertions(+)
>
> diff --git a/tools/include/nolibc/sys.h b/tools/include/nolibc/sys.h
> index c4818a9c8823..46b6b3bb3b4e 100644
> --- a/tools/include/nolibc/sys.h
> +++ b/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"
> @@ -1048,12 +1049,61 @@ pid_t setsid(void)
>         return ret;
>  }
>
> +/*
> + * 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;
> +}
>
>  /*
>   * int stat(const char *path, struct stat *buf);
>   * Warning: the struct stat's layout is arch-dependent.
>   */
>
> +#ifdef __NR_statx
> +static __attribute__((unused))
> +int sys_stat(const char *path, struct stat *buf)
> +{
> +       struct statx stat;
> +       long ret;
> +
> +       ret = sys_statx(AT_FDCWD, path, AT_NO_AUTOMOUNT, STATX_BASIC_STATS, &stat);
> +       buf->st_dev     = ((stat.stx_dev_minor & 0xff)
> +                         | (stat.stx_dev_major << 8)
> +                         | ((stat.stx_dev_minor & ~0xff) << 12));
> +       buf->st_ino     = stat.stx_ino;
> +       buf->st_mode    = stat.stx_mode;
> +       buf->st_nlink   = stat.stx_nlink;
> +       buf->st_uid     = stat.stx_uid;
> +       buf->st_gid     = stat.stx_gid;
> +       buf->st_rdev    = ((stat.stx_rdev_minor & 0xff)
> +                         | (stat.stx_rdev_major << 8)
> +                         | ((stat.stx_rdev_minor & ~0xff) << 12));
> +       buf->st_size    = stat.stx_size;
> +       buf->st_blksize = stat.stx_blksize;
> +       buf->st_blocks  = stat.stx_blocks;
> +       buf->st_atime   = stat.stx_atime.tv_sec;
> +       buf->st_mtime   = stat.stx_mtime.tv_sec;
> +       buf->st_ctime   = stat.stx_ctime.tv_sec;
> +       return ret;
> +}
> +#else
>  static __attribute__((unused))
>  int sys_stat(const char *path, struct stat *buf)
>  {
> @@ -1083,6 +1133,7 @@ int sys_stat(const char *path, struct stat *buf)
>         buf->st_ctime   = stat.st_ctime;
>         return ret;
>  }
> +#endif /* __NR_statx */
>
>  static __attribute__((unused))
>  int stat(const char *path, struct stat *buf)
> --
> 2.39.0
>