Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit a11f4f0a authored by Boris Ostrovsky's avatar Boris Ostrovsky Committed by David Vrabel
Browse files

xen: xensyms support 



Export Xen symbols to dom0 via /proc/xen/xensyms (similar to
/proc/kallsyms).

Signed-off-by: default avatarBoris Ostrovsky <boris.ostrovsky@oracle.com>
Reviewed-by: default avatarDavid Vrabel <david.vrabel@citrix.com>
Signed-off-by: default avatarDavid Vrabel <david.vrabel@citrix.com>
parent cb3eb850

drivers/xen/Kconfig

+8 −0
Original line number Diff line number Diff line
@@ -280,4 +280,12 @@ config XEN_ACPI 
	def_bool y

	depends on X86 && ACPI



config XEN_SYMS

       bool "Xen symbols"

       depends on X86 && XEN_DOM0 && XENFS

       default y if KALLSYMS

       help

          Exports hypervisor symbols (along with their types and addresses) via

          /proc/xen/xensyms file, similar to /proc/kallsyms



endmenu

drivers/xen/xenfs/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -2,3 +2,4 @@ obj-$(CONFIG_XENFS) += xenfs.o 


xenfs-y			  = super.o

xenfs-$(CONFIG_XEN_DOM0) += xenstored.o

xenfs-$(CONFIG_XEN_SYMS) += xensyms.o

drivers/xen/xenfs/super.c

+3 −0
Original line number Diff line number Diff line
@@ -57,6 +57,9 @@ static int xenfs_fill_super(struct super_block *sb, void *data, int silent) 
		{ "privcmd", &xen_privcmd_fops, S_IRUSR|S_IWUSR },

		{ "xsd_kva", &xsd_kva_file_ops, S_IRUSR|S_IWUSR},

		{ "xsd_port", &xsd_port_file_ops, S_IRUSR|S_IWUSR},

#ifdef CONFIG_XEN_SYMS

		{ "xensyms", &xensyms_ops, S_IRUSR},

#endif

		{""},

	};

drivers/xen/xenfs/xenfs.h

+1 −0
Original line number Diff line number Diff line
@@ -3,5 +3,6 @@ 


extern const struct file_operations xsd_kva_file_ops;

extern const struct file_operations xsd_port_file_ops;

extern const struct file_operations xensyms_ops;



#endif	/* _XENFS_XENBUS_H */

drivers/xen/xenfs/xensyms.c

0 → 100644
+152 −0
Original line number Diff line number Diff line 
#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\n", 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

};