From cd6749cdcdc621f62ebe8ab8df2346669580b1c4 Mon Sep 17 00:00:00 2001
From: des <des@ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f>
Date: Tue, 30 Jun 2015 14:17:02 +0000
Subject: [PATCH] MFH (r277695): allow tracing dlfunc() / dlsym() events

git-svn-id: svn://svn.freebsd.org/base/stable/10@284954 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f
---
 libexec/rtld-elf/rtld.c | 17 +++++++++++++----
 usr.bin/kdump/kdump.c   |  9 +++++++++
 2 files changed, 22 insertions(+), 4 deletions(-)

diff --git a/libexec/rtld-elf/rtld.c b/libexec/rtld-elf/rtld.c
index 2157abdd0..9ebfbca67 100644
--- a/libexec/rtld-elf/rtld.c
+++ b/libexec/rtld-elf/rtld.c
@@ -279,6 +279,8 @@ bool ld_library_path_rpath = false;
 #define	UTRACE_PRELOAD_FINISHED		8
 #define	UTRACE_INIT_CALL		9
 #define	UTRACE_FINI_CALL		10
+#define	UTRACE_DLSYM_START		11
+#define	UTRACE_DLSYM_STOP		12
 
 struct utrace_rtld {
 	char sig[4];			/* 'RTLD' */
@@ -3055,6 +3057,7 @@ do_dlsym(void *handle, const char *name, void *retaddr, const Ver_Entry *ve,
 #ifndef __ia64__
     tls_index ti;
 #endif
+    void *sym;
     int res;
 
     def = NULL;
@@ -3064,6 +3067,7 @@ do_dlsym(void *handle, const char *name, void *retaddr, const Ver_Entry *ve,
     req.flags = flags | SYMLOOK_IN_PLT;
     req.lockstate = &lockstate;
 
+    LD_UTRACE(UTRACE_DLSYM_START, handle, NULL, 0, 0, name);
     rlock_acquire(rtld_bind_lock, &lockstate);
     if (sigsetjmp(lockstate.env, 0) != 0)
 	    lock_upgrade(rtld_bind_lock, &lockstate);
@@ -3073,6 +3077,7 @@ do_dlsym(void *handle, const char *name, void *retaddr, const Ver_Entry *ve,
 	if ((obj = obj_from_addr(retaddr)) == NULL) {
 	    _rtld_error("Cannot determine caller's shared object");
 	    lock_release(rtld_bind_lock, &lockstate);
+	    LD_UTRACE(UTRACE_DLSYM_STOP, handle, NULL, 0, 0, name);
 	    return NULL;
 	}
 	if (handle == NULL) {	/* Just the caller's shared object. */
@@ -3120,6 +3125,7 @@ do_dlsym(void *handle, const char *name, void *retaddr, const Ver_Entry *ve,
     } else {
 	if ((obj = dlcheck(handle)) == NULL) {
 	    lock_release(rtld_bind_lock, &lockstate);
+	    LD_UTRACE(UTRACE_DLSYM_STOP, handle, NULL, 0, 0, name);
 	    return NULL;
 	}
 
@@ -3166,23 +3172,26 @@ do_dlsym(void *handle, const char *name, void *retaddr, const Ver_Entry *ve,
 	 * the relocated value of the symbol.
 	 */
 	if (ELF_ST_TYPE(def->st_info) == STT_FUNC)
-	    return (make_function_pointer(def, defobj));
+	    sym = make_function_pointer(def, defobj);
 	else if (ELF_ST_TYPE(def->st_info) == STT_GNU_IFUNC)
-	    return (rtld_resolve_ifunc(defobj, def));
+	    sym = rtld_resolve_ifunc(defobj, def);
 	else if (ELF_ST_TYPE(def->st_info) == STT_TLS) {
 #ifdef __ia64__
 	    return (__tls_get_addr(defobj->tlsindex, def->st_value));
 #else
 	    ti.ti_module = defobj->tlsindex;
 	    ti.ti_offset = def->st_value;
-	    return (__tls_get_addr(&ti));
+	    sym = __tls_get_addr(&ti);
 #endif
 	} else
-	    return (defobj->relocbase + def->st_value);
+	    sym = defobj->relocbase + def->st_value;
+	LD_UTRACE(UTRACE_DLSYM_STOP, handle, sym, 0, 0, name);
+	return (sym);
     }
 
     _rtld_error("Undefined symbol \"%s\"", name);
     lock_release(rtld_bind_lock, &lockstate);
+    LD_UTRACE(UTRACE_DLSYM_STOP, handle, NULL, 0, 0, name);
     return NULL;
 }
 
diff --git a/usr.bin/kdump/kdump.c b/usr.bin/kdump/kdump.c
index 37edd0cc5..6afbb2a78 100644
--- a/usr.bin/kdump/kdump.c
+++ b/usr.bin/kdump/kdump.c
@@ -1452,6 +1452,8 @@ ktrcsw(struct ktr_csw *cs)
 #define	UTRACE_PRELOAD_FINISHED		8
 #define	UTRACE_INIT_CALL		9
 #define	UTRACE_FINI_CALL		10
+#define	UTRACE_DLSYM_START		11
+#define	UTRACE_DLSYM_STOP		12
 
 struct utrace_rtld {
 	char sig[4];				/* 'RTLD' */
@@ -1531,6 +1533,13 @@ ktruser_rtld(int len, void *p)
 		printf("RTLD: fini %p for %p (%s)\n", ut->mapbase, ut->handle,
 		    ut->name);
 		break;
+	case UTRACE_DLSYM_START:
+		printf("RTLD: dlsym(%p, %s)\n", ut->handle, ut->name);
+		break;
+	case UTRACE_DLSYM_STOP:
+		printf("RTLD: %p = dlsym(%p, %s)\n", ut->mapbase, ut->handle,
+		    ut->name);
+		break;
 	default:
 		cp = p;
 		cp += 4;
-- 
2.42.0