FreeBSD/Linux Kernel Cross Reference
sys/compat/lindebugfs/lindebugfs.c

     /*-
      * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
      *
      * Copyright (c) 2016-2018, Matthew Macy <mmacy@freebsd.org>
      *
      * Redistribution and use in source and binary forms, with or without
      * modification, are permitted provided that the following conditions
      * are met:
      * 1. Redistributions of source code must retain the above copyright
     *    notice, this list of conditions and the following disclaimer.
     * 2. Redistributions in binary form must reproduce the above copyright
     *    notice, this list of conditions and the following disclaimer in the
     *    documentation and/or other materials provided with the distribution.
     *
     * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
     * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
     * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     * SUCH DAMAGE.
     *
     */
    
    #include <sys/cdefs.h>
    __FBSDID("$FreeBSD$");
    
    #include <sys/param.h>
    #include <sys/systm.h>
    #include <sys/queue.h>
    #include <sys/blist.h>
    #include <sys/conf.h>
    #include <sys/exec.h>
    #include <sys/filedesc.h>
    #include <sys/kernel.h>
    #include <sys/linker.h>
    #include <sys/malloc.h>
    #include <sys/mount.h>
    #include <sys/mutex.h>
    #include <sys/proc.h>
    #include <sys/resourcevar.h>
    #include <sys/sbuf.h>
    #include <sys/smp.h>
    #include <sys/socket.h>
    #include <sys/vnode.h>
    #include <sys/bus.h>
    #include <sys/pciio.h>
    
    #include <dev/pci/pcivar.h>
    #include <dev/pci/pcireg.h>
    
    #include <net/if.h>
    
    #include <vm/vm.h>
    #include <vm/pmap.h>
    #include <vm/vm_map.h>
    #include <vm/vm_param.h>
    #include <vm/vm_object.h>
    #include <vm/swap_pager.h>
    
    #include <machine/bus.h>
    
    #include <compat/linux/linux_ioctl.h>
    #include <compat/linux/linux_mib.h>
    #include <compat/linux/linux_util.h>
    #include <fs/pseudofs/pseudofs.h>
    
    #include <linux/compat.h>
    #include <linux/debugfs.h>
    #include <linux/fs.h>
    
    MALLOC_DEFINE(M_DFSINT, "debugfsint", "Linux debugfs internal");
    
    static struct pfs_node *debugfs_root;
    
    #define DM_SYMLINK 0x1
    #define DM_DIR 0x2
    #define DM_FILE 0x3
    
    struct dentry_meta {
            struct dentry dm_dnode;
            const struct file_operations *dm_fops;
            void *dm_data;
            umode_t dm_mode;
            int dm_type;
    };
    
    static int
    debugfs_attr(PFS_ATTR_ARGS)
    {
            struct dentry_meta *dm;
    
            dm = pn->pn_data;
    
            vap->va_mode = dm->dm_mode;
           return (0);
   }
   
   static int
   debugfs_destroy(PFS_DESTROY_ARGS)
   {
           struct dentry_meta *dm;
   
           dm = pn->pn_data;
           if (dm->dm_type == DM_SYMLINK)
                   free(dm->dm_data, M_DFSINT);
   
           free(dm, M_DFSINT);
           return (0);
   }
   
   static int
   debugfs_fill(PFS_FILL_ARGS)
   {
           struct dentry_meta *d;
           struct linux_file lf = {};
           struct vnode vn;
           char *buf;
           int rc;
           off_t off = 0;
   
           if ((rc = linux_set_current_flags(curthread, M_NOWAIT)))
                   return (rc);
   
           d = pn->pn_data;
           vn.v_data = d->dm_data;
   
           rc = d->dm_fops->open(&vn, &lf);
           if (rc < 0) {
   #ifdef INVARIANTS
                   printf("%s:%d open failed with %d\n", __FUNCTION__, __LINE__, rc);
   #endif
                   return (-rc);
           }
   
           rc = -ENODEV;
           if (uio->uio_rw == UIO_READ && d->dm_fops->read) {
                   rc = -ENOMEM;
                   buf = (char *) malloc(sb->s_size, M_DFSINT, M_ZERO | M_NOWAIT);
                   if (buf != NULL) {
                           rc = d->dm_fops->read(&lf, buf, sb->s_size, &off);
                           if (rc > 0)
                                   sbuf_bcpy(sb, buf, strlen(buf));
   
                           free(buf, M_DFSINT);
                   }
           } else if (uio->uio_rw == UIO_WRITE && d->dm_fops->write) {
                   sbuf_finish(sb);
                   rc = d->dm_fops->write(&lf, sbuf_data(sb), sbuf_len(sb), &off);
           }
   
           if (d->dm_fops->release)
                   d->dm_fops->release(&vn, &lf);
           else
                   single_release(&vn, &lf);
   
           if (rc < 0) {
   #ifdef INVARIANTS
                   printf("%s:%d read/write failed with %d\n", __FUNCTION__, __LINE__, rc);
   #endif
                   return (-rc);
           }
           return (0);
   }
   
   static int
   debugfs_fill_data(PFS_FILL_ARGS)
   {
           struct dentry_meta *dm;
   
           dm = pn->pn_data;
           sbuf_printf(sb, "%s", (char *)dm->dm_data);
           return (0);
   }
   
   struct dentry *
   debugfs_create_file(const char *name, umode_t mode,
       struct dentry *parent, void *data,
       const struct file_operations *fops)
   {
           struct dentry_meta *dm;
           struct dentry *dnode;
           struct pfs_node *pnode;
           int flags;
   
           dm = malloc(sizeof(*dm), M_DFSINT, M_NOWAIT | M_ZERO);
           if (dm == NULL)
                   return (NULL);
           dnode = &dm->dm_dnode;
           dm->dm_fops = fops;
           dm->dm_data = data;
           dm->dm_mode = mode;
           dm->dm_type = DM_FILE;
           if (parent != NULL)
                   pnode = parent->d_pfs_node;
           else
                   pnode = debugfs_root;
   
           flags = fops->write ? PFS_RDWR : PFS_RD;
           dnode->d_pfs_node = pfs_create_file(pnode, name, debugfs_fill,
               debugfs_attr, NULL, debugfs_destroy, flags | PFS_NOWAIT);
           if (dnode->d_pfs_node == NULL) {
                   free(dm, M_DFSINT);
                   return (NULL);
           }
           dnode->d_pfs_node->pn_data = dm;
   
           return (dnode);
   }
   
   /*
    * NOTE: Files created with the _unsafe moniker will not be protected from
    * debugfs core file removals. It is the responsibility of @fops to protect
    * its file using debugfs_file_get() and debugfs_file_put().
    *
    * FreeBSD's LinuxKPI lindebugfs does not perform file removals at the time
    * of writing. Therefore there is no difference between functions with _unsafe
    * and functions without _unsafe when using lindebugfs. Functions with _unsafe
    * exist only for Linux compatibility.
    */
   struct dentry *
   debugfs_create_file_unsafe(const char *name, umode_t mode,
       struct dentry *parent, void *data,
       const struct file_operations *fops)
   {
           return (debugfs_create_file(name, mode, parent, data, fops));
   }
   
   struct dentry *
   debugfs_create_mode_unsafe(const char *name, umode_t mode,
       struct dentry *parent, void *data,
       const struct file_operations *fops,
       const struct file_operations *fops_ro,
       const struct file_operations *fops_wo)
   {
           umode_t read = mode & S_IRUGO;
           umode_t write = mode & S_IWUGO;
   
           if (read && !write)
                   return (debugfs_create_file_unsafe(name, mode, parent, data, fops_ro));
   
           if (write && !read)
                   return (debugfs_create_file_unsafe(name, mode, parent, data, fops_wo));
   
           return (debugfs_create_file_unsafe(name, mode, parent, data, fops));
   }
   
   struct dentry *
   debugfs_create_dir(const char *name, struct dentry *parent)
   {
           struct dentry_meta *dm;
           struct dentry *dnode;
           struct pfs_node *pnode;
   
           dm = malloc(sizeof(*dm), M_DFSINT, M_NOWAIT | M_ZERO);
           if (dm == NULL)
                   return (NULL);
           dnode = &dm->dm_dnode;
           dm->dm_mode = 0700;
           dm->dm_type = DM_DIR;
           if (parent != NULL)
                   pnode = parent->d_pfs_node;
           else
                   pnode = debugfs_root;
   
           dnode->d_pfs_node = pfs_create_dir(pnode, name, debugfs_attr, NULL, debugfs_destroy, PFS_RD | PFS_NOWAIT);
           if (dnode->d_pfs_node == NULL) {
                   free(dm, M_DFSINT);
                   return (NULL);
           }
           dnode->d_pfs_node->pn_data = dm;
           return (dnode);
   }
   
   struct dentry *
   debugfs_create_symlink(const char *name, struct dentry *parent,
       const char *dest)
   {
           struct dentry_meta *dm;
           struct dentry *dnode;
           struct pfs_node *pnode;
           void *data;
   
           data = strdup_flags(dest, M_DFSINT, M_NOWAIT);
           if (data == NULL)
                   return (NULL);
           dm = malloc(sizeof(*dm), M_DFSINT, M_NOWAIT | M_ZERO);
           if (dm == NULL)
                   goto fail1;
           dnode = &dm->dm_dnode;
           dm->dm_mode = 0700;
           dm->dm_type = DM_SYMLINK;
           dm->dm_data = data;
           if (parent != NULL)
                   pnode = parent->d_pfs_node;
           else
                   pnode = debugfs_root;
   
           dnode->d_pfs_node = pfs_create_link(pnode, name, &debugfs_fill_data, NULL, NULL, NULL, PFS_NOWAIT);
           if (dnode->d_pfs_node == NULL)
                   goto fail;
           dnode->d_pfs_node->pn_data = dm;
           return (dnode);
    fail:
           free(dm, M_DFSINT);
    fail1:
           free(data, M_DFSINT);
           return (NULL);
   }
   
   void
   debugfs_remove(struct dentry *dnode)
   {
           if (dnode == NULL)
                   return;
   
           pfs_destroy(dnode->d_pfs_node);
   }
   
   void
   debugfs_remove_recursive(struct dentry *dnode)
   {
           if (dnode == NULL)
                   return;
   
           pfs_destroy(dnode->d_pfs_node);
   }
   
   static int
   debugfs_bool_get(void *data, uint64_t *ullval)
   {
           bool *bval = data;
   
           if (*bval)
                   *ullval = 1;
           else
                   *ullval = 0;
   
           return (0);
   }
   
   static int
   debugfs_bool_set(void *data, uint64_t ullval)
   {
           bool *bval = data;
   
           if (ullval)
                   *bval = 1;
           else
                   *bval = 0;
   
           return (0);
   }
   
   DEFINE_DEBUGFS_ATTRIBUTE(fops_bool, debugfs_bool_get, debugfs_bool_set, "%llu\n");
   DEFINE_DEBUGFS_ATTRIBUTE(fops_bool_ro, debugfs_bool_get, NULL, "%llu\n");
   DEFINE_DEBUGFS_ATTRIBUTE(fops_bool_wo, NULL, debugfs_bool_set, "%llu\n");
   
   void
   debugfs_create_bool(const char *name, umode_t mode, struct dentry *parent, bool *value)
   {
           debugfs_create_mode_unsafe(name, mode, parent, value, &fops_bool,
               &fops_bool_ro, &fops_bool_wo);
   }
   
   
   static int
   debugfs_u8_get(void *data, uint64_t *value)
   {
           uint8_t *u8data = data;
           *value = *u8data;
           return (0);
   }
   
   static int
   debugfs_u8_set(void *data, uint64_t value)
   {
           uint8_t *u8data = data;
           *u8data = (uint8_t)value;
           return (0);
   }
   
   DEFINE_DEBUGFS_ATTRIBUTE(fops_u8, debugfs_u8_get, debugfs_u8_set, "%u\n");
   DEFINE_DEBUGFS_ATTRIBUTE(fops_u8_ro, debugfs_u8_get, NULL, "%u\n");
   DEFINE_DEBUGFS_ATTRIBUTE(fops_u8_wo, NULL, debugfs_u8_set, "%u\n");
   
   void
   debugfs_create_u8(const char *name, umode_t mode, struct dentry *parent, uint8_t *value)
   {
           debugfs_create_mode_unsafe(name, mode, parent, value, &fops_u8,
               &fops_u8_ro, &fops_u8_wo);
   }
   
   
   static int
   debugfs_ulong_get(void *data, uint64_t *value)
   {
           uint64_t *uldata = data;
           *value = *uldata;
           return (0);
   }
   
   static int
   debugfs_ulong_set(void *data, uint64_t value)
   {
           uint64_t *uldata = data;
           *uldata = value;
           return (0);
   }
   
   DEFINE_DEBUGFS_ATTRIBUTE(fops_ulong, debugfs_ulong_get, debugfs_ulong_set, "%llu\n");
   DEFINE_DEBUGFS_ATTRIBUTE(fops_ulong_ro, debugfs_ulong_get, NULL, "%llu\n");
   DEFINE_DEBUGFS_ATTRIBUTE(fops_ulong_wo, NULL, debugfs_ulong_set, "%llu\n");
   
   void
   debugfs_create_ulong(const char *name, umode_t mode, struct dentry *parent, unsigned long *value)
   {
           debugfs_create_mode_unsafe(name, mode, parent, value, &fops_ulong,
               &fops_ulong_ro, &fops_ulong_wo);
   }
   
   
   static ssize_t
   fops_blob_read(struct file *filp, char __user *ubuf, size_t read_size, loff_t *ppos)
   {
           struct debugfs_blob_wrapper *blob;
   
           blob = filp->private_data;
           if (blob == NULL)
                   return (-EINVAL);
           if (blob->size == 0 || blob->data == NULL)
                   return (-EINVAL);
   
           return (simple_read_from_buffer(ubuf, read_size, ppos, blob->data, blob->size));
   }
   
   static int
   fops_blob_open(struct inode *inode, struct file *filp)
   {
           return (simple_open(inode, filp));
   }
   
   static const struct file_operations __fops_blob_ro = {
           .owner = THIS_MODULE,
           .open = fops_blob_open,
           .read = fops_blob_read,
           .llseek = no_llseek
   };
   
   struct dentry *
   debugfs_create_blob(const char *name, umode_t mode, struct dentry *parent,
       struct debugfs_blob_wrapper *value)
   {
           /* Blobs are read-only. */
           return (debugfs_create_file(name, mode & 0444, parent, value, &__fops_blob_ro));
   }
   
   
   static int
   lindebugfs_init(PFS_INIT_ARGS)
   {
   
           debugfs_root = pi->pi_root;
   
           (void)debugfs_create_symlink("kcov", NULL, "/dev/kcov");
   
           return (0);
   }
   
   static int
   lindebugfs_uninit(PFS_INIT_ARGS)
   {
           return (0);
   }
   
   PSEUDOFS(lindebugfs, 1, VFCF_JAIL);
   MODULE_DEPEND(lindebugfs, linuxkpi, 1, 1, 1);

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