On Wed, Mar 26, 2025 at 4:31 AM Jan Engelhardt [off-list ref] wrote:

On Tuesday 2025-03-25 13:15, guoren@kernel.org wrote:

quoted

diff --git a/include/uapi/linux/netfilter/x_tables.h b/include/uapi/linux/netfilter/x_tables.h
index 796af83a963a..7e02e34c6fad 100644
--- a/include/uapi/linux/netfilter/x_tables.h
+++ b/include/uapi/linux/netfilter/x_tables.h

@@ -18,7 +18,11 @@ struct xt_entry_match {
                      __u8 revision;
              } user;
              struct {
+#if __riscv_xlen == 64
+                      __u64 match_size;
+#else
                      __u16 match_size;
+#endif

                      /* Used inside the kernel */
                      struct xt_match *match;

The __u16 is the common prefix of the union which is exposed to userspace.
If anything, you need to use __attribute__((aligned(8))) to move
`match` to a fixed location.

However, that sub-struct is only used inside the kernel and never exposed,
so the alignment of `match` should not play a role.

Moreover, change from u16 to u64 would break RISC-V Big-Endian. Even if there
currently is no big-endian variant, let's not introduce such breakage.

You're correct. The __u64 modification is too raw from the proof of
concept. It's not correct, so I would accept your advice.

quoted

--- a/include/uapi/linux/netfilter_ipv4/ip_tables.h
+++ b/include/uapi/linux/netfilter_ipv4/ip_tables.h

@@ -200,7 +200,14 @@ struct ipt_replace {
      /* Number of counters (must be equal to current number of entries). */
      unsigned int num_counters;
      /* The old entries' counters. */
+#if __riscv_xlen == 64
+      union {
+              struct xt_counters __user *counters;
+              __u64 __counters;
+      };
+#else
      struct xt_counters __user *counters;
+#endif

      /* The entries (hang off end: not really an array). */
      struct ipt_entry entries[];

This seems ok, but perhaps there is a better name for __riscv_xlen (ifdef
CONFIG_????ilp32), so it is not strictly tied to riscv,
in case other platform wants to try ilp32-self mode.

Yes, I want that macro, but Linus has suggested "compat stuff". I
would have to try.

Thx for the reviewing!

quoted

+#if __riscv_xlen == 64
+      union {
+              int __user *auth_flavours;              /* 1 */
+              __u64 __auth_flavours;
+      };
+#else
      int __user *auth_flavours;              /* 1 */
+#endif
};

/* bits in the flags field */

diff --git a/include/uapi/linux/ppp-ioctl.h b/include/uapi/linux/ppp-ioctl.h
index 1cc5ce0ae062..8d48eab430c1 100644
--- a/include/uapi/linux/ppp-ioctl.h
+++ b/include/uapi/linux/ppp-ioctl.h

@@ -59,7 +59,14 @@ struct npioctl {

/* Structure describing a CCP configuration option, for PPPIOCSCOMPRESS */
struct ppp_option_data {
+#if __riscv_xlen == 64
+      union {
+              __u8    __user *ptr;
+              __u64   __ptr;
+      };
+#else
      __u8    __user *ptr;
+#endif
      __u32   length;
      int     transmit;
};

diff --git a/include/uapi/linux/sctp.h b/include/uapi/linux/sctp.h
index b7d91d4cf0db..46a06fddcd2f 100644
--- a/include/uapi/linux/sctp.h
+++ b/include/uapi/linux/sctp.h

@@ -1024,6 +1024,9 @@ struct sctp_getaddrs_old {

#else
      struct sockaddr         *addrs;
#endif
+#if (__riscv_xlen == 64) && (__SIZEOF_LONG__ == 4)
+      __u32                   unused;
+#endif
};

quoted

struct sctp_getaddrs {

diff --git a/include/uapi/linux/sem.h b/include/uapi/linux/sem.h
index 75aa3b273cd9..de9f441913cd 100644
--- a/include/uapi/linux/sem.h
+++ b/include/uapi/linux/sem.h

@@ -26,10 +26,29 @@ struct semid_ds {
      struct ipc_perm sem_perm;               /* permissions .. see ipc.h */
      __kernel_old_time_t sem_otime;          /* last semop time */
      __kernel_old_time_t sem_ctime;          /* create/last semctl() time */
+#if __riscv_xlen == 64
+      union {
+              struct sem      *sem_base;              /* ptr to first semaphore in array */
+              __u64 __sem_base;
+      };
+      union {
+              struct sem_queue *sem_pending;          /* pending operations to be processed */
+              __u64 __sem_pending;
+      };
+      union {
+              struct sem_queue **sem_pending_last;    /* last pending operation */
+              __u64 __sem_pending_last;
+      };
+      union {
+              struct sem_undo *undo;                  /* undo requests on this array */
+              __u64 __undo;
+      };
+#else
      struct sem      *sem_base;              /* ptr to first semaphore in array */
      struct sem_queue *sem_pending;          /* pending operations to be processed */
      struct sem_queue **sem_pending_last;    /* last pending operation */
      struct sem_undo *undo;                  /* undo requests on this array */
+#endif
      unsigned short  sem_nsems;              /* no. of semaphores in array */

};

@@ -46,10 +65,29 @@ struct sembuf {

/* arg for semctl system calls. */
union semun {
      int val;                        /* value for SETVAL */
+#if __riscv_xlen == 64
+      union {
+              struct semid_ds __user *buf;    /* buffer for IPC_STAT & IPC_SET */
+              __u64 ___buf;
+      };
+      union {
+              unsigned short __user *array;   /* array for GETALL & SETALL */
+              __u64 __array;
+      };
+      union {
+              struct seminfo __user *__buf;   /* buffer for IPC_INFO */
+              __u64 ____buf;
+      };
+      union {
+              void __user *__pad;
+              __u64 ____pad;
+      };
+#else
      struct semid_ds __user *buf;    /* buffer for IPC_STAT & IPC_SET */
      unsigned short __user *array;   /* array for GETALL & SETALL */
      struct seminfo __user *__buf;   /* buffer for IPC_INFO */
      void __user *__pad;
+#endif
};

struct  seminfo {

diff --git a/include/uapi/linux/socket.h b/include/uapi/linux/socket.h
index d3fcd3b5ec53..5f7a83649395 100644
--- a/include/uapi/linux/socket.h
+++ b/include/uapi/linux/socket.h

@@ -22,7 +22,14 @@ struct __kernel_sockaddr_storage {
                              /* space to achieve desired size, */
                              /* _SS_MAXSIZE value minus size of ss_family */
              };
+#if __riscv_xlen == 64
+              union {
+                      void *__align; /* implementation specific desired alignment */
+                      u64 ___align;
+              };
+#else
              void *__align; /* implementation specific desired alignment */
+#endif
      };

};

diff --git a/include/uapi/linux/sysctl.h b/include/uapi/linux/sysctl.h
index 8981f00204db..8ed7b29897f9 100644
--- a/include/uapi/linux/sysctl.h
+++ b/include/uapi/linux/sysctl.h

@@ -33,13 +33,45 @@
                                 member of a struct __sysctl_args to have? */

struct __sysctl_args {
+#if __riscv_xlen == 64
+      union {
+              int __user *name;
+              __u64 __name;
+      };
+#else
      int __user *name;
+#endif
      int nlen;
+#if __riscv_xlen == 64
+      union {
+              void __user *oldval;
+              __u64 __oldval;
+      };
+#else
      void __user *oldval;
+#endif
+#if __riscv_xlen == 64
+      union {
+              size_t __user *oldlenp;
+              __u64 __oldlenp;
+      };
+#else
      size_t __user *oldlenp;
+#endif
+#if __riscv_xlen == 64
+      union {
+              void __user *newval;
+              __u64 __newval;
+      };
+#else
      void __user *newval;
+#endif
      size_t newlen;
+#if __riscv_xlen == 64
+      unsigned long long __unused[4];
+#else
      unsigned long __unused[4];
+#endif
};

/* Define sysctl names first */

diff --git a/include/uapi/linux/uhid.h b/include/uapi/linux/uhid.h
index cef7534d2d19..4a774dbd3de8 100644
--- a/include/uapi/linux/uhid.h
+++ b/include/uapi/linux/uhid.h

@@ -130,7 +130,14 @@ struct uhid_create_req {
      __u8 name[128];
      __u8 phys[64];
      __u8 uniq[64];
+#if __riscv_xlen == 64
+      union {
+              __u8 __user *rd_data;
+              __u64 __rd_data;
+      };
+#else
      __u8 __user *rd_data;
+#endif
      __u16 rd_size;

      __u16 bus;

diff --git a/include/uapi/linux/uio.h b/include/uapi/linux/uio.h
index 649739e0c404..27dfd6032dc6 100644
--- a/include/uapi/linux/uio.h
+++ b/include/uapi/linux/uio.h

@@ -16,8 +16,19 @@

struct iovec
{
+#if __riscv_xlen == 64
+      union {
+              void __user *iov_base;  /* BSD uses caddr_t (1003.1g requires void *) */
+              __u64 __iov_base;
+      };
+      union {
+              __kernel_size_t iov_len; /* Must be size_t (1003.1g) */
+              __u64 __iov_len;
+      };
+#else
      void __user *iov_base;  /* BSD uses caddr_t (1003.1g requires void *) */
      __kernel_size_t iov_len; /* Must be size_t (1003.1g) */
+#endif
};

struct dmabuf_cmsg {

diff --git a/include/uapi/linux/usb/tmc.h b/include/uapi/linux/usb/tmc.h
index d791cc58a7f0..443ec5356caf 100644
--- a/include/uapi/linux/usb/tmc.h
+++ b/include/uapi/linux/usb/tmc.h

@@ -51,7 +51,14 @@ struct usbtmc_request {

struct usbtmc_ctrlrequest {
      struct usbtmc_request req;
+#if __riscv_xlen == 64
+      union {
+              void __user *data; /* pointer to user space */
+              __u64 __data; /* pointer to user space */
+      };
+#else
      void __user *data; /* pointer to user space */
+#endif
} __attribute__ ((packed));

struct usbtmc_termchar {

@@ -70,7 +77,14 @@ struct usbtmc_message {
      __u32 transfer_size; /* size of bytes to transfer */
      __u32 transferred; /* size of received/written bytes */
      __u32 flags; /* bit 0: 0 = synchronous; 1 = asynchronous */
+#if __riscv_xlen == 64
+      union {
+              void __user *message; /* pointer to header and data in user space */
+              __u64 __message;
+      };
+#else
      void __user *message; /* pointer to header and data in user space */
+#endif

} __attribute__ ((packed));

/* Request values for USBTMC driver's ioctl entry point */

diff --git a/include/uapi/linux/usbdevice_fs.h b/include/uapi/linux/usbdevice_fs.h
index 74a84e02422a..8c8efef74c3c 100644
--- a/include/uapi/linux/usbdevice_fs.h
+++ b/include/uapi/linux/usbdevice_fs.h

@@ -44,14 +44,28 @@ struct usbdevfs_ctrltransfer {
      __u16 wIndex;
      __u16 wLength;
      __u32 timeout;  /* in milliseconds */
+#if __riscv_xlen == 64
+      union {
+              void __user *data;
+              __u64 __data;
+      };
+#else
      void __user *data;
+#endif

};

struct usbdevfs_bulktransfer {
      unsigned int ep;
      unsigned int len;
      unsigned int timeout; /* in milliseconds */
+#if __riscv_xlen == 64
+      union {
+              void __user *data;
+              __u64 __data;
+      };
+#else
      void __user *data;
+#endif
};

struct usbdevfs_setinterface {

@@ -61,7 +75,14 @@ struct usbdevfs_setinterface {

struct usbdevfs_disconnectsignal {
      unsigned int signr;
+#if __riscv_xlen == 64
+      union {
+              void __user *context;
+              __u64 __context;
+      };
+#else
      void __user *context;
+#endif
};

#define USBDEVFS_MAXDRIVERNAME 255

@@ -119,7 +140,14 @@ struct usbdevfs_urb {
      unsigned char endpoint;
      int status;
      unsigned int flags;
+#if __riscv_xlen == 64
+      union {
+              void __user *buffer;
+              __u64 __buffer;
+      };
+#else
      void __user *buffer;
+#endif
      int buffer_length;
      int actual_length;
      int start_frame;

@@ -130,7 +158,14 @@ struct usbdevfs_urb {
      int error_count;
      unsigned int signr;     /* signal to be sent on completion,
                                or 0 if none should be sent. */
+#if __riscv_xlen == 64
+      union {
+              void __user *usercontext;
+              __u64 __usercontext;
+      };
+#else
      void __user *usercontext;
+#endif
      struct usbdevfs_iso_packet_desc iso_frame_desc[];

};

@@ -139,7 +174,14 @@ struct usbdevfs_ioctl {
      int     ifno;           /* interface 0..N ; negative numbers reserved */
      int     ioctl_code;     /* MUST encode size + direction of data so the
                               * macros in <asm/ioctl.h> give correct values */
+#if __riscv_xlen == 64
+      union {
+              void __user *data;      /* param buffer (in, or out) */
+              __u64 __pad;
+      };
+#else
      void __user *data;      /* param buffer (in, or out) */
+#endif

};

/* You can do most things with hubs just through control messages,

@@ -195,9 +237,17 @@ struct usbdevfs_streams {

#define USBDEVFS_SUBMITURB         _IOR('U', 10, struct usbdevfs_urb)
#define USBDEVFS_SUBMITURB32       _IOR('U', 10, struct usbdevfs_urb32)
#define USBDEVFS_DISCARDURB        _IO('U', 11)
+#if __riscv_xlen == 64
+#define USBDEVFS_REAPURB           _IOW('U', 12, __u64)
+#else
#define USBDEVFS_REAPURB           _IOW('U', 12, void *)
+#endif
#define USBDEVFS_REAPURB32         _IOW('U', 12, __u32)
+#if __riscv_xlen == 64
+#define USBDEVFS_REAPURBNDELAY     _IOW('U', 13, __u64)
+#else
#define USBDEVFS_REAPURBNDELAY     _IOW('U', 13, void *)
+#endif
#define USBDEVFS_REAPURBNDELAY32   _IOW('U', 13, __u32)
#define USBDEVFS_DISCSIGNAL        _IOR('U', 14, struct usbdevfs_disconnectsignal)
#define USBDEVFS_DISCSIGNAL32      _IOR('U', 14, struct usbdevfs_disconnectsignal32)

diff --git a/include/uapi/linux/uvcvideo.h b/include/uapi/linux/uvcvideo.h
index f86185456dc5..3ccb99039a43 100644
--- a/include/uapi/linux/uvcvideo.h
+++ b/include/uapi/linux/uvcvideo.h

@@ -54,7 +54,14 @@ struct uvc_xu_control_mapping {
      __u32 v4l2_type;
      __u32 data_type;

+#if __riscv_xlen == 64
+      union {
+              struct uvc_menu_info __user *menu_info;
+              __u64 __menu_info;
+      };
+#else
      struct uvc_menu_info __user *menu_info;
+#endif
      __u32 menu_count;

      __u32 reserved[4];

@@ -66,7 +73,14 @@ struct uvc_xu_control_query {
      __u8 query;             /* Video Class-Specific Request Code, */
                              /* defined in linux/usb/video.h A.8.  */
      __u16 size;
+#if __riscv_xlen == 64
+      union {
+              __u8 __user *data;
+              __u64 __data;
+      };
+#else
      __u8 __user *data;
+#endif

};

#define UVCIOC_CTRL_MAP               _IOWR('u', 0x20, struct uvc_xu_control_mapping)

diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h
index c8dbf8219c4f..0a1dc2a780fb 100644
--- a/include/uapi/linux/vfio.h
+++ b/include/uapi/linux/vfio.h

@@ -1570,7 +1570,14 @@ struct vfio_iommu_type1_dma_map {

struct vfio_bitmap {
      __u64        pgsize;    /* page size for bitmap in bytes */
      __u64        size;      /* in bytes */
+      #if __riscv_xlen == 64
+      union {
+              __u64 __user *data;     /* one bit per page */
+              __u64 __data;
+      };
+      #else
      __u64 __user *data;     /* one bit per page */
+      #endif
};

/**

diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
index e7c4dce39007..8e5391f07626 100644
--- a/include/uapi/linux/videodev2.h
+++ b/include/uapi/linux/videodev2.h

@@ -1898,7 +1898,14 @@ struct v4l2_ext_controls {
      __u32 error_idx;
      __s32 request_fd;
      __u32 reserved[1];
+#if __riscv_xlen == 64
+      union {
+              struct v4l2_ext_control *controls;
+              __u64 __controls;
+      };
+#else
      struct v4l2_ext_control *controls;
+#endif

};

#define V4L2_CTRL_ID_MASK       (0x0fffffff)
--
2.40.1

-- 
Best Regards
 Guo Ren