fix function 'get_insn_slot'

diff --git a/kprobe/dbi_insn_slots.c b/kprobe/dbi_insn_slots.c
index 2ce3344..cce3c62 100644 (file)
--- a/kprobe/dbi_insn_slots.c
+++ b/kprobe/dbi_insn_slots.c
@@ -41,9 +41,8 @@
  *
  * 2008-2009    Alexey Gerenkov <a.gerenkov@samsung.com> User-Space
  *              Probes initial implementation; Support x86/ARM/MIPS for both user and kernel spaces.
- * 2010         Ekaterina Gorelkina <e.gorelkina@samsung.com>: redesign module for separating core and arch parts 
+ * 2010         Ekaterina Gorelkina <e.gorelkina@samsung.com>: redesign module for separating core and arch parts
  *
-
  */
 
 #include "dbi_insn_slots.h"
@@ -70,7 +69,7 @@ struct kprobe_insn_page
 {
        struct hlist_node hlist;
        kprobe_opcode_t *insns; /* Page of instruction slots */
-       char *slot_used;        
+       char *slot_used;
        int nused;
        int ngarbage;
        int tgid;
@@ -104,7 +103,7 @@ unsigned long alloc_user_pages(struct task_struct *task, unsigned long len, unsi
                                rcu_read_unlock();
                        }
                }
-               // FIXME: its seems to be bad decision to replace 'current' pointer temporarily 
+               // FIXME: its seems to be bad decision to replace 'current' pointer temporarily
                current_thread_info()->task = task;
                ret = (unsigned long)do_mmap_pgoff(0, 0, len, prot, flags, 0);
                current_thread_info()->task = otask;
@@ -146,12 +145,15 @@ kprobe_opcode_t *get_insn_slot (struct task_struct *task, int atomic)
        }
        else {
                slots_per_page = INSNS_PER_PAGE/KPROBES_TRAMP_LEN;
-               slot_size = KPROBES_TRAMP_LEN;          
+               slot_size = KPROBES_TRAMP_LEN;
        }
 
 retry:
        hlist_for_each_entry (kip, pos, page_list, hlist)
        {
+               if( !(!task || (kip->tgid == task->tgid)) )
+                       continue;
+
                if (kip->nused < slots_per_page)
                {
                        int i;
@@ -166,8 +168,6 @@ retry:
                                        }
                                }
                        }
-                       /* Surprise!  No unused slots.  Fix kip->nused. */
-                       kip->nused = slots_per_page;
                }
        }
 
@@ -178,7 +178,7 @@ retry:
        }
        else {
                if (kprobe_garbage_slots && collect_garbage_slots(page_list, task) == 0)
-                       goto retry;             
+                       goto retry;
        }
 
        /* All out of space.  Need to allocate a new page. Use slot 0. */
@@ -193,7 +193,7 @@ retry:
        }
 
        if(task) {
-               kip->insns = (kprobe_opcode_t *)alloc_user_pages(task, PAGE_SIZE, 
+               kip->insns = (kprobe_opcode_t *)alloc_user_pages(task, PAGE_SIZE,
                                PROT_EXEC|PROT_READ|PROT_WRITE, MAP_ANONYMOUS|MAP_SHARED, atomic);
        }
        else {
@@ -204,20 +204,20 @@ retry:
                kfree (kip->slot_used);
                kfree (kip);
                return NULL;
-       }       
-       INIT_HLIST_NODE (&kip->hlist);
-       hlist_add_head (&kip->hlist, page_list);
+       }
        memset(kip->slot_used, SLOT_CLEAN, slots_per_page);
        kip->slot_used[0] = SLOT_USED;
        kip->nused = 1;
        kip->ngarbage = 0;
        kip->tgid = task ? task->tgid : 0;
+       INIT_HLIST_NODE (&kip->hlist);
+       hlist_add_head (&kip->hlist, page_list);
        return kip->insns;
 }
 
 /* Return 1 if all garbages are collected, otherwise 0. */
-static 
-int collect_one_slot (struct hlist_head *page_list, struct task_struct *task, 
+static
+int collect_one_slot (struct hlist_head *page_list, struct task_struct *task,
                struct kprobe_insn_page *kip, int idx)
 {
        kip->slot_used[idx] = SLOT_CLEAN;
@@ -240,15 +240,15 @@ int collect_one_slot (struct hlist_head *page_list, struct task_struct *task,
                else
                {
                        if(task){
-                               //E. G.: This code provides kernel dump because of rescheduling while atomic. 
-                               //As workaround, this code was commented. In this case we will have memory leaks 
-                               //for instrumented process, but instrumentation process should functionate correctly. 
-                               //Planned that good solution for this problem will be done during redesigning KProbe 
+                               //E. G.: This code provides kernel dump because of rescheduling while atomic.
+                               //As workaround, this code was commented. In this case we will have memory leaks
+                               //for instrumented process, but instrumentation process should functionate correctly.
+                               //Planned that good solution for this problem will be done during redesigning KProbe
                                //for improving supportability and performance.
 #if 0
                                //printk("collect_one_slot %p/%d\n", task, task->pid);
                                mm = get_task_mm (task);
-                               if (mm){                        
+                               if (mm){
                                        down_write (&mm->mmap_sem);
                                        do_munmap(mm, (unsigned long)(kip->insns), PAGE_SIZE);
                                        up_write (&mm->mmap_sem);
@@ -313,7 +313,7 @@ void free_insn_slot (struct hlist_head *page_list, struct task_struct *task, kpr
        struct hlist_node *pos;
        unsigned slots_per_page = INSNS_PER_PAGE, slot_size = MAX_INSN_SIZE;
 
-       if(task) {      
+       if(task) {
                slots_per_page = INSNS_PER_PAGE/UPROBES_TRAMP_LEN;
                slot_size = UPROBES_TRAMP_LEN;
        }