^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) // SPDX-License-Identifier: GPL-2.0 OR MIT
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) /******************************************************************************
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) * privcmd-buf.c
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) * Mmap of hypercall buffers.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) * Copyright (c) 2018 Juergen Gross
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) #define pr_fmt(fmt) "xen:" KBUILD_MODNAME ": " fmt
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) #include <linux/kernel.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) #include <linux/module.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) #include <linux/list.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) #include <linux/miscdevice.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) #include <linux/mm.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) #include <linux/slab.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) #include "privcmd.h"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) MODULE_LICENSE("GPL");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) struct privcmd_buf_private {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) struct mutex lock;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) struct list_head list;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) struct privcmd_buf_vma_private {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) struct privcmd_buf_private *file_priv;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) struct list_head list;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) unsigned int users;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) unsigned int n_pages;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) struct page *pages[];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) static int privcmd_buf_open(struct inode *ino, struct file *file)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) struct privcmd_buf_private *file_priv;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) file_priv = kzalloc(sizeof(*file_priv), GFP_KERNEL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) if (!file_priv)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) return -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) mutex_init(&file_priv->lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) INIT_LIST_HEAD(&file_priv->list);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) file->private_data = file_priv;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) static void privcmd_buf_vmapriv_free(struct privcmd_buf_vma_private *vma_priv)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) unsigned int i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) list_del(&vma_priv->list);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) for (i = 0; i < vma_priv->n_pages; i++)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) __free_page(vma_priv->pages[i]);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) kfree(vma_priv);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) static int privcmd_buf_release(struct inode *ino, struct file *file)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) struct privcmd_buf_private *file_priv = file->private_data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) struct privcmd_buf_vma_private *vma_priv;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) mutex_lock(&file_priv->lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) while (!list_empty(&file_priv->list)) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) vma_priv = list_first_entry(&file_priv->list,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) struct privcmd_buf_vma_private,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) list);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) privcmd_buf_vmapriv_free(vma_priv);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79) mutex_unlock(&file_priv->lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) kfree(file_priv);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) static void privcmd_buf_vma_open(struct vm_area_struct *vma)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) struct privcmd_buf_vma_private *vma_priv = vma->vm_private_data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) if (!vma_priv)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) mutex_lock(&vma_priv->file_priv->lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) vma_priv->users++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95) mutex_unlock(&vma_priv->file_priv->lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) static void privcmd_buf_vma_close(struct vm_area_struct *vma)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) struct privcmd_buf_vma_private *vma_priv = vma->vm_private_data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) struct privcmd_buf_private *file_priv;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) if (!vma_priv)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104) return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) file_priv = vma_priv->file_priv;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) mutex_lock(&file_priv->lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110) vma_priv->users--;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) if (!vma_priv->users)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) privcmd_buf_vmapriv_free(vma_priv);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) mutex_unlock(&file_priv->lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) static vm_fault_t privcmd_buf_vma_fault(struct vm_fault *vmf)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) pr_debug("fault: vma=%p %lx-%lx, pgoff=%lx, uv=%p\n",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120) vmf->vma, vmf->vma->vm_start, vmf->vma->vm_end,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) vmf->pgoff, (void *)vmf->address);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) return VM_FAULT_SIGBUS;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) static const struct vm_operations_struct privcmd_buf_vm_ops = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) .open = privcmd_buf_vma_open,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) .close = privcmd_buf_vma_close,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) .fault = privcmd_buf_vma_fault,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) static int privcmd_buf_mmap(struct file *file, struct vm_area_struct *vma)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134) struct privcmd_buf_private *file_priv = file->private_data;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) struct privcmd_buf_vma_private *vma_priv;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) unsigned long count = vma_pages(vma);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) unsigned int i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) int ret = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) if (!(vma->vm_flags & VM_SHARED))
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) return -EINVAL;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) vma_priv = kzalloc(struct_size(vma_priv, pages, count), GFP_KERNEL);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) if (!vma_priv)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) return -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) for (i = 0; i < count; i++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) vma_priv->pages[i] = alloc_page(GFP_KERNEL | __GFP_ZERO);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149) if (!vma_priv->pages[i])
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) vma_priv->n_pages++;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) mutex_lock(&file_priv->lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) vma_priv->file_priv = file_priv;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) vma_priv->users = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) vma->vm_flags |= VM_IO | VM_DONTEXPAND;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) vma->vm_ops = &privcmd_buf_vm_ops;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) vma->vm_private_data = vma_priv;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163) list_add(&vma_priv->list, &file_priv->list);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) if (vma_priv->n_pages != count)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) ret = -ENOMEM;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) ret = vm_map_pages_zero(vma, vma_priv->pages,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) vma_priv->n_pages);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) if (ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 172) privcmd_buf_vmapriv_free(vma_priv);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 173)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 174) mutex_unlock(&file_priv->lock);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 175)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 176) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 177) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 178)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 179) const struct file_operations xen_privcmdbuf_fops = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 180) .owner = THIS_MODULE,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 181) .open = privcmd_buf_open,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 182) .release = privcmd_buf_release,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 183) .mmap = privcmd_buf_mmap,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 184) };
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 185) EXPORT_SYMBOL_GPL(xen_privcmdbuf_fops);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 186)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 187) struct miscdevice xen_privcmdbuf_dev = {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 188) .minor = MISC_DYNAMIC_MINOR,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 189) .name = "xen/hypercall",
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 190) .fops = &xen_privcmdbuf_fops,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 191) };
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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