Re: [RFC PATCH V3 01/43] rv64ilp32_abi: uapi: Reuse lp64 ABI interface

Guo Ren
2025-03-26T03:35:58Z

On Wed, Mar 26, 2025 at 4:31 AM Jan Engelhardt <ej@inai.de> wrote:
>
>
> On Tuesday 2025-03-25 13:15, guoren@kernel.org wrote:
>
> >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.

>
>
> >--- 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!

>
> >+#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
> > };
>
>
> >
> > 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