From f2d55ea45b009e6f5019e55fa6a1057846d02b91 Mon Sep 17 00:00:00 2001
From: Alexander Aksenov <a.aksenov@samsung.com>
Date: Tue, 6 Nov 2012 21:33:29 +0400
Subject: [PATCH] Optimized plt instrumentation

---
 driver/storage.c      |  5 ++--
 driver/storage.h      |  1 +
 driver/us_proc_inst.c | 74 +++++++++++++++++++++++----------------------------
 3 files changed, 38 insertions(+), 42 deletions(-)

diff --git a/driver/storage.c b/driver/storage.c
index c22d5a4..67fbf29 100644
--- a/driver/storage.c
+++ b/driver/storage.c
@@ -971,6 +971,7 @@ void unlink_bundle(void)
 			}
 			d_lib->plt_count = 0;
 			kfree((void*) d_lib->p_plt);
+			us_proc_info.is_plt = 0;
 		}
 		kfree ((void *) us_proc_info.p_libs);
 		us_proc_info.p_libs = 0;
@@ -1080,6 +1081,7 @@ int link_bundle()
 	len = *(u_int32_t *)p; /* App path len */
 	p += sizeof(u_int32_t);
 
+	us_proc_info.is_plt = 0;
 	if ( len == 0 )
 	{
 	    us_proc_info.path = NULL;
@@ -1147,8 +1149,6 @@ int link_bundle()
 			DPRINTF("d_lib->path = %s", d_lib->path);
 			p += lib_name_len;
 
-            printk("+++ lib_name = %s\n", d_lib->path);
-
 			if ( i != 0 ) {
 				lib_name_len = *(u_int32_t *)p;
 				p += sizeof(u_int32_t);
@@ -1287,6 +1287,7 @@ int link_bundle()
 			if (d_lib->plt_count > 0)
 			{
 				int j;
+                us_proc_info.is_plt = 1;
 				d_lib->p_plt = kmalloc(d_lib->plt_count * sizeof(us_proc_plt_t), GFP_KERNEL);
 				if (!d_lib->p_plt)
 				{
diff --git a/driver/storage.h b/driver/storage.h
index 4d0d4e4..d9dfc96 100644
--- a/driver/storage.h
+++ b/driver/storage.h
@@ -221,6 +221,7 @@ typedef struct
 	unsigned unres_vtps_count;
 	unsigned unres_otg_ips_count;
 	//kprobe_opcode_t *mapped_codelets;
+	int is_plt;
 	unsigned libs_count;
 	us_proc_lib_t *p_libs;
 #ifdef __ANDROID
diff --git a/driver/us_proc_inst.c b/driver/us_proc_inst.c
index 0867341..5b84cd4 100644
--- a/driver/us_proc_inst.c
+++ b/driver/us_proc_inst.c
@@ -1571,7 +1571,7 @@ void find_plt_address(struct kretprobe_instance *probe, us_proc_ip_t * ip)
 		// If lib only instrumentation
 		task_inst_info = get_task_inst_node(current);
 	}
-	if (task_inst_info != NULL)
+	if ((task_inst_info != NULL) && (task_inst_info->is_plt != 0))
 	{
 		for (i = 0; i < task_inst_info->libs_count; i++)
 		{
@@ -1581,55 +1581,49 @@ void find_plt_address(struct kretprobe_instance *probe, us_proc_ip_t * ip)
 				break;
 			}
 		}
-	}
-	else
-	{
-		printk("task_inst_info not found!\n");
-		return;
-	}
-
-	if (p_lib != NULL)
-	{
-		for (i = 0; i < p_lib->plt_count; i++)
+		if (p_lib != NULL)
 		{
-			if (addr == p_lib->p_plt[i].func_addr + p_lib->vma_start)
+			for (i = 0; i < p_lib->plt_count; i++)
 			{
-				unsigned real_got;
-				if (strcmp(p_lib->path, task_inst_info->path))
-				{
-					real_got = p_lib->p_plt[i].got_addr + p_lib->vma_start;
-				}
-				else
-				{
-					real_got = p_lib->p_plt[i].got_addr;
-				}
-				if (!read_proc_vm_atomic(current, (unsigned long)(real_got), &real_addr, sizeof(unsigned long)))
-				{
-					printk("Failed to read got %p at memory address %p!\n", p_lib->p_plt[i].got_addr, real_got);
-					break;
-				}
-				if (real_addr != p_lib->p_plt[i].real_func_addr)
+				if (addr == p_lib->p_plt[i].func_addr + p_lib->vma_start)
 				{
-					p_lib->p_plt[i].real_func_addr =  real_addr;
-					vma = find_vma(current->mm, real_addr);
-					if ((vma->vm_start <= real_addr) && (vma->vm_end > real_addr))
+					unsigned real_got;
+					if (strcmp(p_lib->path, task_inst_info->path))
 					{
-						if (vma->vm_file != NULL)
-						{
-							szLibPath = &(vma->vm_file->f_dentry->d_iname);
-						}
+						real_got = p_lib->p_plt[i].got_addr + p_lib->vma_start;
 					}
-
-					if (szLibPath)
+					else
 					{
-						pack_event_info(PLT_ADDR_PROBE_ID, RECORD_RET, "ppsp", addr, real_addr, szLibPath, real_addr - vma->vm_start);
-						break;
+						real_got = p_lib->p_plt[i].got_addr;
 					}
-					else
+					if (!read_proc_vm_atomic(current, (unsigned long)(real_got), &real_addr, sizeof(unsigned long)))
 					{
-						pack_event_info(PLT_ADDR_PROBE_ID, RECORD_RET, "ppp", addr, real_addr, real_addr - vma->vm_start);
+						printk("Failed to read got %p at memory address %p!\n", p_lib->p_plt[i].got_addr, real_got);
 						break;
 					}
+					if (real_addr != p_lib->p_plt[i].real_func_addr)
+					{
+						p_lib->p_plt[i].real_func_addr =  real_addr;
+						vma = find_vma(current->mm, real_addr);
+						if ((vma->vm_start <= real_addr) && (vma->vm_end > real_addr))
+						{
+							if (vma->vm_file != NULL)
+							{
+								szLibPath = &(vma->vm_file->f_dentry->d_iname);
+							}
+						}
+	
+						if (szLibPath)
+						{
+							pack_event_info(PLT_ADDR_PROBE_ID, RECORD_RET, "ppsp", addr, real_addr, szLibPath, real_addr - vma->vm_start);
+							break;
+						}
+						else
+						{
+							pack_event_info(PLT_ADDR_PROBE_ID, RECORD_RET, "ppp", addr, real_addr, real_addr - vma->vm_start);
+							break;
+						}
+					}
 				}
 			}
 		}
-- 
2.7.4