PERFORCE change 154110 for review

[Marko Zec]

http://perforce.freebsd.org/chv.cgi?CH=154110

Change 154110 by zec at zec_tca51 on 2008/12/05 13:55:17

	Extend kldsym(9) lookups to resolve queries for virtualized
	variables, but only for those that have been explicitly exported
	via VNET_SYMMAP constructs.

Affected files ...

.. //depot/projects/vimage-commit2/src/sys/kern/kern_linker.c#4 edit
.. //depot/projects/vimage-commit2/src/sys/kern/kern_vimage.c#2 edit
.. //depot/projects/vimage-commit2/src/sys/net/if.c#28 edit
.. //depot/projects/vimage-commit2/src/sys/sys/vimage.h#24 edit

Differences ...

==== //depot/projects/vimage-commit2/src/sys/kern/kern_linker.c#4 (text+ko) ====

@@ -51,6 +51,7 @@
 #include <sys/vnode.h>
 #include <sys/syscallsubr.h>
 #include <sys/sysctl.h>
+#include <sys/vimage.h>
 
 #include <security/mac/mac_framework.h>
 
@@ -1278,8 +1279,24 @@
 				break;
 			}
 		}
+#ifndef VIMAGE_GLOBALS
+		/*
+		 * If the symbol is not found in global namespace, look up
+		 * for it in the current vimage.
+		 */
+		if (lf == NULL) {
+			CURVNET_SET(TD_TO_VNET(td));
+			error = vi_symlookup(&lookup, symstr);
+			CURVNET_RESTORE();
+			if (error == 0) {
+				error = copyout(&lookup, uap->data,
+						sizeof(lookup));
+			}
+		}
+#else
 		if (lf == NULL)
 			error = ENOENT;
+#endif
 	}
 	KLD_UNLOCK();
 out:

==== //depot/projects/vimage-commit2/src/sys/kern/kern_vimage.c#2 (text+ko) ====

@@ -28,3 +28,68 @@
  * SUCH DAMAGE.
  */
 
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD: $"
+);
+
+#include <sys/param.h>
+#include <sys/types.h>
+#include <sys/kernel.h>
+#include <sys/linker.h>
+#include <sys/malloc.h>
+#include <sys/systm.h>
+#include <sys/vimage.h>
+
+#ifndef VIMAGE_GLOBALS
+
+MALLOC_DEFINE(M_VIMAGE, "vimage", "vimage resource container");
+
+static TAILQ_HEAD(vnet_modlink_head, vnet_modlink) vnet_modlink_head;
+
+void
+vnet_mod_register(const struct vnet_modinfo *vmi)
+{
+	struct vnet_modlink *vml, *vml_iter;
+	
+	/* Do not register the same module instance more than once */
+	TAILQ_FOREACH(vml_iter, &vnet_modlink_head, vml_mod_le)
+		if (vml_iter->vml_modinfo == vmi)
+			break;
+	if (vml_iter != NULL)
+		panic("attempt to register an already registered vnet module");
+	vml = malloc(sizeof(struct vnet_modlink), M_VIMAGE, M_NOWAIT);
+
+	vml->vml_modinfo = vmi;
+}
+
+/*
+ * vi_symlookup() attempts to resolve name to address queries for
+ * variables which have been moved from global namespace to virtualization
+ * container structures, but are still directly accessed from legacy
+ * userspace processes via kldsym(2) and kmem(4) interfaces.
+ */
+int
+vi_symlookup(struct kld_sym_lookup *lookup, char *symstr)
+{
+	struct vnet_modlink *vml;
+
+	TAILQ_FOREACH(vml, &vnet_modlink_head, vml_mod_le) {
+		struct vnet_symmap *mapentry;
+
+		if (vml->vml_modinfo->vmi_symmap == NULL)
+			continue;
+
+		for (mapentry = vml->vml_modinfo->vmi_symmap;
+		     mapentry->name != NULL; mapentry++) {
+			if (strcmp(symstr, mapentry->name) == 0) {
+				lookup->symvalue = (u_long) mapentry->base;
+				lookup->symsize = mapentry->size;
+				return 0;
+			}
+		}
+	}
+
+	return ENOENT;
+}
+
+#endif /* !VIMAGE_GLOBALS */

==== //depot/projects/vimage-commit2/src/sys/net/if.c#28 (text+ko) ====

@@ -159,6 +159,19 @@
 static struct filterops netdev_filtops =
     { 1, NULL, filt_netdetach, filt_netdev };
 
+#ifndef VIMAGE_GLOBALS
+static struct vnet_symmap vnet_net_symmap[] = {
+        VNET_SYMMAP(net, ifnet),
+        VNET_SYMMAP(net, rt_tables),
+        VNET_SYMMAP(net, rtstat),
+        VNET_SYMMAP(net, rttrash),
+        VNET_SYMMAP_END
+};
+
+VNET_MOD_DECLARE(NET, net, vnet_net_iattach, vnet_net_idetach,
+    NONE, vnet_net_symmap)
+#endif
+
 /*
  * System initialization
  */
@@ -359,6 +372,10 @@
 {
 	INIT_VNET_NET(curvnet);
 
+#ifndef VIMAGE_GLOBALS
+	vnet_mod_register(&vnet_net_modinfo);
+#endif
+
 	V_if_index = 0;
 	V_ifindex_table = NULL;
 	V_if_indexlim = 8;

==== //depot/projects/vimage-commit2/src/sys/sys/vimage.h#24 (text+ko) ====

@@ -33,12 +33,49 @@
 #ifndef	_SYS_VIMAGE_H_
 #define	_SYS_VIMAGE_H_
 
+#include <sys/queue.h>
+
+struct vnet_modinfo;
+struct kld_sym_lookup;
+
+int	vi_symlookup(struct kld_sym_lookup *, char *);
+void	vnet_mod_register(const struct vnet_modinfo *);
+
+struct vnet_symmap {
+	char	*name;
+	void	*base;
+	size_t	size;
+};
+
+struct vnet_modinfo {
+	char				*vmi_name;
+	struct vnet_symmap		*vmi_symmap;
+};
+
+struct vnet_modlink {
+	TAILQ_ENTRY(vnet_modlink)	vml_mod_le;
+	const struct vnet_modinfo	*vml_modinfo;
+};
+
+#define VNET_MOD_DECLARE(m_name_uc, m_name_lc, m_iattach, m_idetach, 	\
+    m_dependson, m_symmap)						\
+	static const struct vnet_modinfo vnet_##m_name_lc##_modinfo = {	\
+		.vmi_name		= #m_name_lc,			\
+		.vmi_symmap		= m_symmap			\
+};
+
 #ifdef VIMAGE_GLOBALS
 #define	VSYM(base, sym) (sym)
 #else
 #define	VSYM(base, sym) (base ## _0._ ## sym)
 #endif
 
+#define VNET_SYMMAP(mod, name)						\
+	{ #name, &(vnet_ ## mod ## _0._ ## name),			\
+	sizeof(vnet_ ## mod ## _0._ ## name) }
+
+#define VNET_SYMMAP_END		{ NULL, 0 }
+
 /* Non-VIMAGE null-macros */
 #define	CURVNET_SET(arg)
 #define	CURVNET_SET_QUIET(arg)