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kernel/linux-rt-4.4.41/drivers/xen/xenfs/xensyms.c 3.11 KB
5113f6f70   김현기   kernel add
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  #include <linux/module.h>
  #include <linux/init.h>
  #include <linux/seq_file.h>
  #include <linux/fs.h>
  #include <linux/mm.h>
  #include <linux/proc_fs.h>
  #include <linux/slab.h>
  #include <xen/interface/platform.h>
  #include <asm/xen/hypercall.h>
  #include <xen/xen-ops.h>
  #include "xenfs.h"
  
  
  #define XEN_KSYM_NAME_LEN 127 /* Hypervisor may have different name length */
  
  struct xensyms {
  	struct xen_platform_op op;
  	char *name;
  	uint32_t namelen;
  };
  
  /* Grab next output page from the hypervisor */
  static int xensyms_next_sym(struct xensyms *xs)
  {
  	int ret;
  	struct xenpf_symdata *symdata = &xs->op.u.symdata;
  	uint64_t symnum;
  
  	memset(xs->name, 0, xs->namelen);
  	symdata->namelen = xs->namelen;
  
  	symnum = symdata->symnum;
  
  	ret = HYPERVISOR_dom0_op(&xs->op);
  	if (ret < 0)
  		return ret;
  
  	/*
  	 * If hypervisor's symbol didn't fit into the buffer then allocate
  	 * a larger buffer and try again.
  	 */
  	if (unlikely(symdata->namelen > xs->namelen)) {
  		kfree(xs->name);
  
  		xs->namelen = symdata->namelen;
  		xs->name = kzalloc(xs->namelen, GFP_KERNEL);
  		if (!xs->name)
  			return -ENOMEM;
  
  		set_xen_guest_handle(symdata->name, xs->name);
  		symdata->symnum--; /* Rewind */
  
  		ret = HYPERVISOR_dom0_op(&xs->op);
  		if (ret < 0)
  			return ret;
  	}
  
  	if (symdata->symnum == symnum)
  		/* End of symbols */
  		return 1;
  
  	return 0;
  }
  
  static void *xensyms_start(struct seq_file *m, loff_t *pos)
  {
  	struct xensyms *xs = (struct xensyms *)m->private;
  
  	xs->op.u.symdata.symnum = *pos;
  
  	if (xensyms_next_sym(xs))
  		return NULL;
  
  	return m->private;
  }
  
  static void *xensyms_next(struct seq_file *m, void *p, loff_t *pos)
  {
  	struct xensyms *xs = (struct xensyms *)m->private;
  
  	xs->op.u.symdata.symnum = ++(*pos);
  
  	if (xensyms_next_sym(xs))
  		return NULL;
  
  	return p;
  }
  
  static int xensyms_show(struct seq_file *m, void *p)
  {
  	struct xensyms *xs = (struct xensyms *)m->private;
  	struct xenpf_symdata *symdata = &xs->op.u.symdata;
  
  	seq_printf(m, "%016llx %c %s
  ", symdata->address,
  		   symdata->type, xs->name);
  
  	return 0;
  }
  
  static void xensyms_stop(struct seq_file *m, void *p)
  {
  }
  
  static const struct seq_operations xensyms_seq_ops = {
  	.start = xensyms_start,
  	.next = xensyms_next,
  	.show = xensyms_show,
  	.stop = xensyms_stop,
  };
  
  static int xensyms_open(struct inode *inode, struct file *file)
  {
  	struct seq_file *m;
  	struct xensyms *xs;
  	int ret;
  
  	ret = seq_open_private(file, &xensyms_seq_ops,
  			       sizeof(struct xensyms));
  	if (ret)
  		return ret;
  
  	m = file->private_data;
  	xs = (struct xensyms *)m->private;
  
  	xs->namelen = XEN_KSYM_NAME_LEN + 1;
  	xs->name = kzalloc(xs->namelen, GFP_KERNEL);
  	if (!xs->name) {
  		seq_release_private(inode, file);
  		return -ENOMEM;
  	}
  	set_xen_guest_handle(xs->op.u.symdata.name, xs->name);
  	xs->op.cmd = XENPF_get_symbol;
  	xs->op.u.symdata.namelen = xs->namelen;
  
  	return 0;
  }
  
  static int xensyms_release(struct inode *inode, struct file *file)
  {
  	struct seq_file *m = file->private_data;
  	struct xensyms *xs = (struct xensyms *)m->private;
  
  	kfree(xs->name);
  	return seq_release_private(inode, file);
  }
  
  const struct file_operations xensyms_ops = {
  	.open = xensyms_open,
  	.read = seq_read,
  	.llseek = seq_lseek,
  	.release = xensyms_release
  };