Add various utrace's for use with ktrace to the ELF runtime linker. To

activate the traces, set the LD_UTRACE (or LD_32_UTRACE) environment
variable.  This also includes code in kdump(8) to parse the traces.

Reviewed by:	kan, jdp
MFC after:	2 weeks

1 files changed, 107 insertions, 0 deletions

diff --git a/usr.bin/kdump/kdump.c b/usr.bin/kdump/kdump.c
index 5854ba8..24979d9 100644
--- a/usr.bin/kdump/kdump.c
+++ b/usr.bin/kdump/kdump.c
@@ -59,6 +59,7 @@ extern int errno;
 #include <sys/ioctl.h>
 #include <sys/ptrace.h>
 #include <sys/socket.h>
+#include <dlfcn.h>
 #include <err.h>
 #include <locale.h>
 #include <stdio.h>
@@ -975,6 +976,107 @@ ktrcsw(struct ktr_csw *cs)
 		cs->user ? "user" : "kernel");
 }
 
+#define	UTRACE_DLOPEN_START		1
+#define	UTRACE_DLOPEN_STOP		2
+#define	UTRACE_DLCLOSE_START		3
+#define	UTRACE_DLCLOSE_STOP		4
+#define	UTRACE_LOAD_OBJECT		5
+#define	UTRACE_UNLOAD_OBJECT		6
+#define	UTRACE_ADD_RUNDEP		7
+#define	UTRACE_PRELOAD_FINISHED		8
+#define	UTRACE_INIT_CALL		9
+#define	UTRACE_FINI_CALL		10
+
+struct utrace_rtld {
+	char sig[4];				/* 'RTLD' */
+	int event;
+	void *handle;
+	void *mapbase;
+	size_t mapsize;
+	int refcnt;
+	char name[MAXPATHLEN];
+};
+
+void
+ktruser_rtld(int len, unsigned char *p)
+{
+	struct utrace_rtld *ut = (struct utrace_rtld *)p;
+	void *parent;
+	int mode;
+
+	switch (ut->event) {
+	case UTRACE_DLOPEN_START:
+		mode = ut->refcnt;
+		printf("dlopen(%s, ", ut->name);
+		switch (mode & RTLD_MODEMASK) {
+		case RTLD_NOW:
+			printf("RTLD_NOW");
+			break;
+		case RTLD_LAZY:
+			printf("RTLD_LAZY");
+			break;
+		default:
+			printf("%#x", mode & RTLD_MODEMASK);
+		}
+		if (mode & RTLD_GLOBAL)
+			printf(" | RTLD_GLOBAL");
+		if (mode & RTLD_TRACE)
+			printf(" | RTLD_TRACE");
+		if (mode & ~(RTLD_MODEMASK | RTLD_GLOBAL | RTLD_TRACE))
+			printf(" | %#x", mode &
+			    ~(RTLD_MODEMASK | RTLD_GLOBAL | RTLD_TRACE));
+		printf(")\n");
+		break;
+	case UTRACE_DLOPEN_STOP:
+		printf("%p = dlopen(%s) ref %d\n", ut->handle, ut->name,
+		    ut->refcnt);
+		break;
+	case UTRACE_DLCLOSE_START:
+		printf("dlclose(%p) (%s, %d)\n", ut->handle, ut->name,
+		    ut->refcnt);
+		break;
+	case UTRACE_DLCLOSE_STOP:
+		printf("dlclose(%p) finished\n", ut->handle);
+		break;
+	case UTRACE_LOAD_OBJECT:
+		printf("RTLD: loaded   %p @ %p - %p (%s)\n", ut->handle,
+		    ut->mapbase, (char *)ut->mapbase + ut->mapsize - 1,
+		    ut->name);
+		break;
+	case UTRACE_UNLOAD_OBJECT:
+		printf("RTLD: unloaded %p @ %p - %p (%s)\n", ut->handle,
+		    ut->mapbase, (char *)ut->mapbase + ut->mapsize - 1,
+		    ut->name);
+		break;
+	case UTRACE_ADD_RUNDEP:
+		parent = ut->mapbase;
+		printf("RTLD: %p now depends on %p (%s, %d)\n", parent,
+		    ut->handle, ut->name, ut->refcnt);
+		break;
+	case UTRACE_PRELOAD_FINISHED:
+		printf("RTLD: LD_PRELOAD finished\n");
+		break;
+	case UTRACE_INIT_CALL:
+		printf("RTLD: init %p for %p (%s)\n", ut->mapbase, ut->handle,
+		    ut->name);
+		break;
+	case UTRACE_FINI_CALL:
+		printf("RTLD: fini %p for %p (%s)\n", ut->mapbase, ut->handle,
+		    ut->name);
+		break;
+	default:
+		p += 4;
+		len -= 4;
+		printf("RTLD: %d ", len);
+		while (len--)
+			if (decimal)
+				printf(" %d", *p++);
+			else
+				printf(" %02x", *p++);
+		printf("\n");
+	}
+}
+
 struct utrace_malloc {
 	void *p;
 	size_t s;
@@ -1003,6 +1105,11 @@ void
 ktruser(int len, unsigned char *p)
 {
 
+	if (len >= 8 && bcmp(p, "RTLD", 4) == 0) {
+		ktruser_rtld(len, p);
+		return;
+	}
+
 	if (len == sizeof(struct utrace_malloc)) {
 		ktruser_malloc(len, p);
 		return;