Le 28/06/2019 à 12:43, Aleksandar Markovic a écrit :
> From: Aleksandar Rikalo <arik...@wavecomp.com>
>
> Implement support for translation of system call statx().
>
> The implementation is based on "best effort" approach: if host
> is capable of executing statx(), host statx() is used. If not,
> the implementation includes invoking a more mature system call
> fstatat() on the host side to achieve as close as possible
> functionality.
>
> Support for statx() in kernel and glibc was, however, introduced
> at different points of time (the difference is more than a year):
>
> - kernel: Linux 4.11 (30 April 2017)
> - glibc: glibc 2.28 (1 Aug 2018)
>
> In this patch, the availability of statx() support is established
> via __NR_statx (if it is defined, statx() is considered available).
> This coincedes with statx() introduction in kernel.
>
> However, the structure statx definition may not be available in
> any header for hosts with glibc older than 2.28 (and it is, by
> design, to be defined in one of glibc headers), even though the
> full statx() functionality may be supported in kernel. Hence, a
> structure "target_statx" is defined in this patch, to remove that
> dependency on glibc headers, and to use statx() functionality as
> soon as the host kernel is capable of supporting it. Such statx
> structure definition is used for both target and host structures
> statx (of course, this doesn't mean the endian arrangement is
> the same on target and host - the endian conversion is done in
> all necessary cases).
>
> Signed-off-by: Aleksandar Rikalo <arik...@wavecomp.com>
> Signed-off-by: Aleksandar Markovic <amarko...@wavecomp.com>
> Reviewed-by: Laurent Vivier <laur...@vivier.eu>
> ---
> linux-user/syscall.c | 115
> +++++++++++++++++++++++++++++++++++++++++++++-
> linux-user/syscall_defs.h | 37 +++++++++++++++
> 2 files changed, 151 insertions(+), 1 deletion(-)
>
> diff --git a/linux-user/syscall.c b/linux-user/syscall.c
> index b187c12..eeca802 100644
> --- a/linux-user/syscall.c
> +++ b/linux-user/syscall.c
> @@ -237,6 +237,7 @@ static type name (type1 arg1,type2 arg2,type3 arg3,type4
> arg4,type5 arg5, \
> #define __NR_sys_inotify_init __NR_inotify_init
> #define __NR_sys_inotify_add_watch __NR_inotify_add_watch
> #define __NR_sys_inotify_rm_watch __NR_inotify_rm_watch
> +#define __NR_sys_statx __NR_statx
>
> #if defined(__alpha__) || defined(__x86_64__) || defined(__s390x__)
> #define __NR__llseek __NR_lseek
> @@ -315,6 +316,14 @@ _syscall5(int, kcmp, pid_t, pid1, pid_t, pid2, int, type,
> unsigned long, idx1, unsigned long, idx2)
> #endif
>
> +/*
> + * It is assumed that struct statx is architecture independent.
> + */
> +#if defined(TARGET_NR_statx) && defined(__NR_statx)
> +_syscall5(int, sys_statx, int, dirfd, const char *, pathname, int, flags,
> + unsigned int, mask, struct target_statx *, statxbuf)
> +#endif
> +
> static bitmask_transtbl fcntl_flags_tbl[] = {
> { TARGET_O_ACCMODE, TARGET_O_WRONLY, O_ACCMODE, O_WRONLY, },
> { TARGET_O_ACCMODE, TARGET_O_RDWR, O_ACCMODE, O_RDWR, },
> @@ -6467,6 +6476,48 @@ static inline abi_long host_to_target_stat64(void
> *cpu_env,
> }
> #endif
>
> +#if defined(TARGET_NR_statx) && defined(__NR_statx)
> +static inline abi_long host_to_target_statx(struct target_statx *host_stx,
> + abi_ulong target_addr)
> +{
> + struct target_statx *target_stx;
> +
> + if (!lock_user_struct(VERIFY_WRITE, target_stx, target_addr, 0)) {
> + return -TARGET_EFAULT;
> + }
> + memset(target_stx, 0, sizeof(*target_stx));
> +
> + __put_user(host_stx->stx_mask, &target_stx->stx_mask);
> + __put_user(host_stx->stx_blksize, &target_stx->stx_blksize);
> + __put_user(host_stx->stx_attributes, &target_stx->stx_attributes);
> + __put_user(host_stx->stx_nlink, &target_stx->stx_nlink);
> + __put_user(host_stx->stx_uid, &target_stx->stx_uid);
> + __put_user(host_stx->stx_gid, &target_stx->stx_gid);
> + __put_user(host_stx->stx_mode, &target_stx->stx_mode);
> + __put_user(host_stx->stx_ino, &target_stx->stx_ino);
> + __put_user(host_stx->stx_size, &target_stx->stx_size);
> + __put_user(host_stx->stx_blocks, &target_stx->stx_blocks);
> + __put_user(host_stx->stx_attributes_mask,
> &target_stx->stx_attributes_mask);
> + __put_user(host_stx->stx_atime.tv_sec, &target_stx->stx_atime.tv_sec);
> + __put_user(host_stx->stx_atime.tv_nsec, &target_stx->stx_atime.tv_nsec);
> + __put_user(host_stx->stx_btime.tv_sec, &target_stx->stx_atime.tv_sec);
> + __put_user(host_stx->stx_btime.tv_nsec, &target_stx->stx_atime.tv_nsec);
> + __put_user(host_stx->stx_ctime.tv_sec, &target_stx->stx_atime.tv_sec);
> + __put_user(host_stx->stx_ctime.tv_nsec, &target_stx->stx_atime.tv_nsec);
> + __put_user(host_stx->stx_mtime.tv_sec, &target_stx->stx_atime.tv_sec);
> + __put_user(host_stx->stx_mtime.tv_nsec, &target_stx->stx_atime.tv_nsec);
> + __put_user(host_stx->stx_rdev_major, &target_stx->stx_rdev_major);
> + __put_user(host_stx->stx_rdev_minor, &target_stx->stx_rdev_minor);
> + __put_user(host_stx->stx_dev_major, &target_stx->stx_dev_major);
> + __put_user(host_stx->stx_dev_minor, &target_stx->stx_dev_minor);
> +
> + unlock_user_struct(target_stx, target_addr, 1);
> +
> + return 0;
> +}
> +#endif
> +
> +
> /* ??? Using host futex calls even when target atomic operations
> are not really atomic probably breaks things. However implementing
> futexes locally would make futexes shared between multiple processes
> @@ -7045,7 +7096,8 @@ static abi_long do_syscall1(void *cpu_env, int num,
> abi_long arg1,
> abi_long ret;
> #if defined(TARGET_NR_stat) || defined(TARGET_NR_stat64) \
> || defined(TARGET_NR_lstat) || defined(TARGET_NR_lstat64) \
> - || defined(TARGET_NR_fstat) || defined(TARGET_NR_fstat64)
> + || defined(TARGET_NR_fstat) || defined(TARGET_NR_fstat64) \
> + || defined(TARGET_NR_statx)
> struct stat st;
> #endif
> #if defined(TARGET_NR_statfs) || defined(TARGET_NR_statfs64) \
> @@ -10123,6 +10175,67 @@ static abi_long do_syscall1(void *cpu_env, int num,
> abi_long arg1,
> ret = host_to_target_stat64(cpu_env, arg3, &st);
> return ret;
> #endif
> +#if defined(TARGET_NR_statx)
> + case TARGET_NR_statx:
> + {
> + struct target_statx *target_stx;
> + int dirfd = arg1;
> + int flags = arg3;
> +
> + p = lock_user_string(arg2);
> + if (p == NULL) {
> + return -TARGET_EFAULT;
> + }
> +#if defined(__NR_statx)
> + {
> + /*
> + * It is assumed that struct statx is architecture
> independent.
> + */
> + struct target_statx host_stx;
> + int mask = arg4;
> +
> + ret = get_errno(sys_statx(dirfd, p, flags, mask, &host_stx));
> + if (!is_error(ret)) {
> + if (host_to_target_statx(&host_stx, arg5) != 0) {
> + unlock_user(p, arg2, 0);
> + return -TARGET_EFAULT;
> + }
> + }
> +
> + if (ret != -TARGET_ENOSYS) {
> + unlock_user(p, arg2, 0);
> + return ret;
> + }
> + }
> +#endif
> + ret = get_errno(fstatat(dirfd, path(p), &st, flags));
> + unlock_user(p, arg2, 0);
> +
> + if (!is_error(ret)) {
> + if (!lock_user_struct(VERIFY_WRITE, target_stx, arg5, 0)) {
> + return -TARGET_EFAULT;
> + }
> + memset(target_stx, 0, sizeof(*target_stx));
> + __put_user(major(st.st_dev), &target_stx->stx_dev_major);
> + __put_user(minor(st.st_dev), &target_stx->stx_dev_minor);
> + __put_user(st.st_ino, &target_stx->stx_ino);
> + __put_user(st.st_mode, &target_stx->stx_mode);
> + __put_user(st.st_uid, &target_stx->stx_uid);
> + __put_user(st.st_gid, &target_stx->stx_gid);
> + __put_user(st.st_nlink, &target_stx->stx_nlink);
> + __put_user(major(st.st_rdev), &target_stx->stx_rdev_major);
> + __put_user(minor(st.st_rdev), &target_stx->stx_rdev_minor);
> + __put_user(st.st_size, &target_stx->stx_size);
> + __put_user(st.st_blksize, &target_stx->stx_blksize);
> + __put_user(st.st_blocks, &target_stx->stx_blocks);
> + __put_user(st.st_atime, &target_stx->stx_atime.tv_sec);
> + __put_user(st.st_mtime, &target_stx->stx_mtime.tv_sec);
> + __put_user(st.st_ctime, &target_stx->stx_ctime.tv_sec);
> + unlock_user_struct(target_stx, arg5, 1);
> + }
> + }
> + return ret;
> +#endif
> #ifdef TARGET_NR_lchown
> case TARGET_NR_lchown:
> if (!(p = lock_user_string(arg1)))
> diff --git a/linux-user/syscall_defs.h b/linux-user/syscall_defs.h
> index 7f141f6..170c4dd 100644
> --- a/linux-user/syscall_defs.h
> +++ b/linux-user/syscall_defs.h
> @@ -2536,4 +2536,41 @@ struct target_user_cap_data {
> /* Return size of the log buffer */
> #define TARGET_SYSLOG_ACTION_SIZE_BUFFER 10
>
> +struct target_statx_timestamp {
> + int64_t tv_sec;
> + uint32_t tv_nsec;
> + int32_t __reserved;
> +};
> +
> +struct target_statx {
> + /* 0x00 */
> + uint32_t stx_mask; /* What results were written [uncond] */
> + uint32_t stx_blksize; /* Preferred general I/O size [uncond] */
> + uint64_t stx_attributes; /* Flags conveying information about the file */
> + /* 0x10 */
> + uint32_t stx_nlink; /* Number of hard links */
> + uint32_t stx_uid; /* User ID of owner */
> + uint32_t stx_gid; /* Group ID of owner */
> + uint16_t stx_mode; /* File mode */
> + uint16_t __spare0[1];
> + /* 0x20 */
> + uint64_t stx_ino; /* Inode number */
> + uint64_t stx_size; /* File size */
> + uint64_t stx_blocks; /* Number of 512-byte blocks allocated */
> + uint64_t stx_attributes_mask; /* Mask to show what is supported */
> + /* 0x40 */
> + struct target_statx_timestamp stx_atime; /* Last access time */
> + struct target_statx_timestamp stx_btime; /* File creation time */
> + struct target_statx_timestamp stx_ctime; /* Last attribute change time
> */
> + struct target_statx_timestamp stx_mtime; /* Last data modification time
> */
> + /* 0x80 */
> + uint32_t stx_rdev_major; /* Device ID of special file [if bdev/cdev] */
> + uint32_t stx_rdev_minor;
> + uint32_t stx_dev_major; /* ID of device containing file [uncond] */
> + uint32_t stx_dev_minor;
> + /* 0x90 */
> + uint64_t __spare2[14]; /* Spare space for future expansion */
> + /* 0x100 */
> +};
> +
> #endif
>
Applied to my linux-user branch.
Thanks,
Laurent
