Tickets: 151, 198, 200, 347. implemented unpatching tasks

diff --git a/kprobe/arch/asm-arm/dbi_kprobes.c b/kprobe/arch/asm-arm/dbi_kprobes.c
index 0ca494f..e45e1fd 100644 (file)
--- a/kprobe/arch/asm-arm/dbi_kprobes.c
+++ b/kprobe/arch/asm-arm/dbi_kprobes.c
@@ -1286,55 +1286,6 @@ no_kprobe_live:
        return 0;               // ok - life is life
 }
 
-void patch_suspended_task_ret_addr(struct task_struct *p, struct kretprobe *rp)
-{
-       struct kretprobe_instance *ri = NULL;
-       struct hlist_node *node, *tmp;
-       struct hlist_head *head;
-       unsigned long flags;
-       int found = 0;
-
-       spin_lock_irqsave (&kretprobe_lock, flags);
-       head = kretprobe_inst_table_head (p);
-       hlist_for_each_entry_safe (ri, node, tmp, head, hlist){
-               if ((ri->rp == rp) && (p == ri->task)){
-                       found = 1;
-                       break;
-               }
-       }
-       spin_unlock_irqrestore (&kretprobe_lock, flags);
-
-#ifndef task_thread_info
-#define task_thread_info(task) (task)->thread_info
-#endif // task_thread_info
-
-       if (found){
-               // update PC
-               if(thread_saved_pc(p) != (unsigned long)&kretprobe_trampoline){
-                       ri->ret_addr = (kprobe_opcode_t *)thread_saved_pc(p);
-                       task_thread_info(p)->cpu_context.pc = (unsigned long) &kretprobe_trampoline;
-               }
-               return;
-       }
-
-       spin_lock_irqsave (&kretprobe_lock, flags);
-       if ((ri = get_free_rp_inst(rp)) != NULL)
-       {
-               ri->rp = rp;
-               ri->rp2 = NULL;
-               ri->task = p;
-               ri->ret_addr = (kprobe_opcode_t *)thread_saved_pc(p);
-               task_thread_info(p)->cpu_context.pc = (unsigned long) &kretprobe_trampoline;
-               add_rp_inst (ri);
-               //              printk("change2 saved pc %p->%p for %d/%d/%p\n", ri->ret_addr, &kretprobe_trampoline, p->tgid, p->pid, p);
-       }
-       else{
-               printk("no ri for %d\n", p->pid);
-               BUG();
-       }
-       spin_unlock_irqrestore (&kretprobe_lock, flags);
-}
-
 int setjmp_pre_handler (struct kprobe *p, struct pt_regs *regs)
 {
        struct jprobe *jp = container_of (p, struct jprobe, kp);
@@ -1355,19 +1306,8 @@ int setjmp_pre_handler (struct kprobe *p, struct pt_regs *regs)
        //call handler for all kernel probes and user space ones which belong to current tgid
        if (!p->tgid || (p->tgid == current->tgid))
        {
-               if(!p->tgid && ((unsigned int)p->addr == sched_addr) && sched_rp){
-                       struct task_struct *p, *g;
-                       rcu_read_lock();
-                       //swapper task
-                       if(current != &init_task)
-                               patch_suspended_task_ret_addr(&init_task, sched_rp);
-                       // other tasks
-                       do_each_thread(g, p){
-                               if(p == current)
-                                       continue;
-                               patch_suspended_task_ret_addr(p, sched_rp);
-                       } while_each_thread(g, p);
-                       rcu_read_unlock();
+               if(!p->tgid && ((unsigned int)p->addr == sched_addr) && sched_rp) {
+                   patch_suspended_all_task_ret_addr(sched_rp);
                }
                if (pre_entry)
                        p->ss_addr = (void *)pre_entry (jp->priv_arg, regs);
@@ -1513,7 +1453,7 @@ int trampoline_probe_handler (struct kprobe *p, struct pt_regs *regs)
                }
 
                orig_ret_address = (unsigned long) ri->ret_addr;
-               recycle_rp_inst (ri, &empty_rp);
+               recycle_rp_inst (ri);
                if (orig_ret_address != trampoline_address)
                        /*
                         * This is the real return address. Any other

diff --git a/kprobe/arch/asm-arm/dbi_kprobes.h b/kprobe/arch/asm-arm/dbi_kprobes.h
index 20ad8b2..add5a6e 100644 (file)
--- a/kprobe/arch/asm-arm/dbi_kprobes.h
+++ b/kprobe/arch/asm-arm/dbi_kprobes.h
@@ -39,7 +39,7 @@ typedef unsigned long kprobe_opcode_t;
 
 #ifdef CONFIG_CPU_S3C2443
 #define BREAKPOINT_INSTRUCTION          0xe1200070
-#else 
+#else
 #define BREAKPOINT_INSTRUCTION          0xffffdeff
 #endif /* CONFIG_CPU_S3C2443 */
 
@@ -47,7 +47,7 @@ typedef unsigned long kprobe_opcode_t;
 
 #ifdef CONFIG_CPU_S3C2443
 #define UNDEF_INSTRUCTION               0xe1200071
-#else 
+#else
 #define UNDEF_INSTRUCTION               0xfffffffe
 #endif /* CONFIG_CPU_S3C2443 */
 
@@ -64,6 +64,16 @@ typedef unsigned long kprobe_opcode_t;
 # define KPROBES_TRAMP_SS_BREAK_IDX     UPROBES_TRAMP_SS_BREAK_IDX
 # define KPROBES_TRAMP_RET_BREAK_IDX   UPROBES_TRAMP_RET_BREAK_IDX
 
+static inline unsigned long arch_get_task_pc(struct task_struct *p)
+{
+       return task_thread_info(p)->cpu_context.pc;
+}
+
+static inline void arch_set_task_pc(struct task_struct *p, unsigned long val)
+{
+       task_thread_info(p)->cpu_context.pc = val;
+}
+
 static inline unsigned long dbi_get_stack_ptr(struct pt_regs *regs)
 {
        return regs->ARM_sp;
@@ -490,6 +500,4 @@ typedef kprobe_opcode_t (*entry_point_t) (unsigned long, unsigned long, unsigned
 //void gen_insn_execbuf_holder (void);
 //void pc_dep_insn_execbuf_holder (void);
 
-void patch_suspended_task_ret_addr(struct task_struct *p, struct kretprobe *rp);
-
 #endif /* _DBI_ASM_ARM_KPROBES_H */

diff --git a/kprobe/arch/asm-mips/dbi_kprobes.c b/kprobe/arch/asm-mips/dbi_kprobes.c
index b537746..0132f61 100644 (file)
--- a/kprobe/arch/asm-mips/dbi_kprobes.c
+++ b/kprobe/arch/asm-mips/dbi_kprobes.c
@@ -676,7 +676,7 @@ int trampoline_probe_handler (struct kprobe *p, struct pt_regs *regs)
                }
 
                orig_ret_address = (unsigned long) ri->ret_addr; 
-               recycle_rp_inst (ri, &empty_rp); 
+               recycle_rp_inst (ri);
                if (orig_ret_address != trampoline_address)
                        /*
                         * This is the real return address. Any other

diff --git a/kprobe/arch/asm-x86/dbi_kprobes.c b/kprobe/arch/asm-x86/dbi_kprobes.c
index adb56c4..2e93508 100644 (file)
--- a/kprobe/arch/asm-x86/dbi_kprobes.c
+++ b/kprobe/arch/asm-x86/dbi_kprobes.c
@@ -749,48 +749,6 @@ no_kprobe:
        return ret;
 }
 
-void patch_suspended_task_ret_addr(struct task_struct *p, struct kretprobe *rp)
-{
-       struct kretprobe_instance *ri = NULL;
-       struct hlist_node *node, *tmp;
-       struct hlist_head *head;
-       unsigned long flags;
-       int found = 0;
-
-       spin_lock_irqsave(&kretprobe_lock, flags);
-       head = kretprobe_inst_table_head(p);
-       hlist_for_each_entry_safe(ri, node, tmp, head, hlist) {
-               if ((ri->rp == rp) && (p == ri->task)) {
-                       found = 1;
-                       break;
-               }
-       }
-       spin_unlock_irqrestore(&kretprobe_lock, flags);
-
-       if (found) {
-               /* update PC */
-               if (p->thread.ip != &kretprobe_trampoline) {
-                       ri->ret_addr = (kprobe_opcode_t *)p->thread.ip;
-                       p->thread.ip = &kretprobe_trampoline;
-               }
-               return;
-       }
-
-       spin_lock_irqsave(&kretprobe_lock, flags);
-       if ((ri = get_free_rp_inst(rp)) != NULL) {
-               ri->rp = rp;
-               ri->rp2 = NULL;
-               ri->task = p;
-               ri->ret_addr = (kprobe_opcode_t *)p->thread.ip;
-               p->thread.ip = &kretprobe_trampoline;
-               add_rp_inst(ri);
-       } else {
-               printk("no ri for %d\n", p->pid);
-               BUG();
-       }
-       spin_unlock_irqrestore(&kretprobe_lock, flags);
-}
-
 int setjmp_pre_handler (struct kprobe *p, struct pt_regs *regs) 
 {
        struct jprobe *jp = container_of (p, struct jprobe, kp);
@@ -807,21 +765,7 @@ int setjmp_pre_handler (struct kprobe *p, struct pt_regs *regs)
        if (!p->tgid || (p->tgid == current->tgid)) {
                /* handle __switch_to probe */
                if(!p->tgid && (p->addr == sched_addr) && sched_rp) {
-                       struct task_struct *p, *g;
-                       rcu_read_lock();
-                       //swapper task
-                       if(current != &init_task)
-                               patch_suspended_task_ret_addr(&init_task, sched_rp);
-                       // other tasks
-                       do_each_thread(g, p){
-                               if(current != p)
-                                       patch_suspended_task_ret_addr(p, sched_rp);
-                       } while_each_thread(g, p);
-                       /* workaround for do_exit probe on x86 targets */
-                       if ((current->flags & PF_EXITING) ||
-                                       (current->flags & PF_EXITPIDONE))
-                               patch_suspended_task_ret_addr(current, sched_rp);
-                       rcu_read_unlock();
+                       patch_suspended_all_task_ret_addr(sched_rp);
                }
        }
 
@@ -1343,7 +1287,7 @@ int trampoline_probe_handler (struct kprobe *p, struct pt_regs *regs)
                }
 
                orig_ret_address = (unsigned long) ri->ret_addr; 
-               recycle_rp_inst (ri, &empty_rp); 
+               recycle_rp_inst (ri);
                if (orig_ret_address != trampoline_address)
                        /*
                         * This is the real return address. Any other

diff --git a/kprobe/arch/asm-x86/dbi_kprobes.h b/kprobe/arch/asm-x86/dbi_kprobes.h
index a27d3a0..0797e87 100644 (file)
--- a/kprobe/arch/asm-x86/dbi_kprobes.h
+++ b/kprobe/arch/asm-x86/dbi_kprobes.h
@@ -44,7 +44,7 @@
  *
  * 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
  *
 
  */
@@ -73,7 +73,7 @@ typedef u8 kprobe_opcode_t;
 #define XREG(rg)                x##rg
 #define ORIG_EAX_REG            orig_eax
 
-#else 
+#else
 
 #define EREG(rg)                rg
 #define XREG(rg)                rg
@@ -91,6 +91,16 @@ typedef u8 kprobe_opcode_t;
 #define KPROBES_TRAMP_LEN              MAX_INSN_SIZE
 #define KPROBES_TRAMP_INSN_IDX          0
 
+static inline unsigned long arch_get_task_pc(struct task_struct *p)
+{
+       return p->thread.ip;
+}
+
+static inline void arch_set_task_pc(struct task_struct *p, unsigned long val)
+{
+       p->thread.ip = val;
+}
+
 static inline unsigned long dbi_get_stack_ptr(struct pt_regs *regs)
 {
        return regs->EREG(sp);

diff --git a/kprobe/arch/dbi_kprobes.h b/kprobe/arch/dbi_kprobes.h
index 30821cc..582dba2 100644 (file)
--- a/kprobe/arch/dbi_kprobes.h
+++ b/kprobe/arch/dbi_kprobes.h
@@ -45,7 +45,7 @@
  * 2006-2007    Ekaterina Gorelkina <e.gorelkina@samsung.com>: initial implementation for ARM and MIPS
  * 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
  *
  */
 
@@ -81,6 +81,7 @@ extern void arch_disarm_uprobe (struct kprobe *p, struct task_struct *tsk);
 extern void arch_disarm_uretprobe (struct kretprobe *p, struct task_struct *tsk);
 extern int arch_init_kprobes (void);
 extern void dbi_arch_exit_kprobes (void);
+extern void patch_suspended_all_task_ret_addr(struct kretprobe *rp);
 
 void dbi_arch_uprobe_return (void);
 
@@ -106,6 +107,4 @@ int trampoline_probe_handler (struct kprobe *p, struct pt_regs *regs);
 int arch_init_module_dependencies(void);
 int asm_init_module_dependencies(void);
 
-
-
 #endif                         /* _DBI_ARCH_KPROBES_H */

diff --git a/kprobe/dbi_kprobes.c b/kprobe/dbi_kprobes.c
index 8eeae24..5ddab49 100644 (file)
--- a/kprobe/dbi_kprobes.c
+++ b/kprobe/dbi_kprobes.c
@@ -320,7 +320,7 @@ void add_rp_inst (struct kretprobe_instance *ri)
 }
 
 /* Called with kretprobe_lock held */
-void recycle_rp_inst (struct kretprobe_instance *ri, struct hlist_head *head)
+void recycle_rp_inst (struct kretprobe_instance *ri)
 {
        if (ri->rp)
        {
@@ -724,6 +724,8 @@ int dbi_register_kretprobe (struct kretprobe *rp)
        return ret;
 }
 
+static void unpatch_suspended_all_task_ret_addr(struct kretprobe *rp);
+
 void dbi_unregister_kretprobe (struct kretprobe *rp)
 {
        unsigned long flags;
@@ -731,8 +733,10 @@ void dbi_unregister_kretprobe (struct kretprobe *rp)
 
        dbi_unregister_kprobe (&rp->kp, 0);
 
-       if((unsigned int)rp->kp.addr == sched_addr)
+       if((unsigned int)rp->kp.addr == sched_addr) {
+               unpatch_suspended_all_task_ret_addr(rp);
                sched_rp = NULL;
+       }
 
        /* No race here */
        spin_lock_irqsave (&kretprobe_lock, flags);
@@ -778,6 +782,118 @@ struct kretprobe * clone_kretprobe (struct kretprobe *rp)
 }
 
 
+static void inline set_task_trampoline(struct task_struct *p, struct kretprobe_instance *ri, unsigned long tramp_addr)
+{
+       ri->ret_addr = arch_get_task_pc(p);
+       arch_set_task_pc(p, tramp_addr);
+}
+
+static void inline rm_task_trampoline(struct task_struct *p, struct kretprobe_instance *ri)
+{
+       arch_set_task_pc(p, ri->ret_addr);
+}
+
+static struct kretprobe_instance* find_ri_pc_mod(struct task_struct *p, struct kretprobe *rp)
+{
+       struct kretprobe_instance *ri;
+       struct hlist_node *node, *tmp;
+       struct hlist_head *head;
+       unsigned long flags;
+
+       spin_lock_irqsave (&kretprobe_lock, flags);
+       head = kretprobe_inst_table_head (p);
+       hlist_for_each_entry_safe (ri, node, tmp, head, hlist) {
+               if ((ri->rp == rp) && (p == ri->task)) {
+                       spin_unlock_irqrestore (&kretprobe_lock, flags);
+                       return ri;
+               }
+       }
+       spin_unlock_irqrestore (&kretprobe_lock, flags);
+
+       return NULL;
+}
+
+static void add_ri_pc_mod(struct task_struct *p, struct kretprobe *rp, unsigned long tramp_addr)
+{
+       struct kretprobe_instance *ri;
+       unsigned long flags;
+
+       spin_lock_irqsave(&kretprobe_lock, flags);
+       if ((ri = get_free_rp_inst(rp)) != NULL) {
+               ri->rp = rp;
+               ri->rp2 = NULL;
+               ri->task = p;
+               // set PC
+               set_task_trampoline(p, ri, tramp_addr);
+               add_rp_inst(ri);
+       } else {
+               printk("no ri for %d\n", p->pid);
+               BUG();
+       }
+       spin_unlock_irqrestore(&kretprobe_lock, flags);
+}
+
+static void patch_suspended_task_ret_addr(struct task_struct *p, struct kretprobe *rp)
+{
+       unsigned long flags;
+       struct kretprobe_instance *ri = find_ri_pc_mod(p, rp);
+
+       if(ri) {
+               // update PC
+               if( arch_get_task_pc(p) != (unsigned long) &kretprobe_trampoline)
+                       set_task_trampoline(p, ri, (unsigned long) &kretprobe_trampoline);
+       } else {
+               add_ri_pc_mod(p, rp, (unsigned long) &kretprobe_trampoline);
+       }
+}
+
+static void unpatch_suspended_task_ret_addr(struct task_struct *p, struct kretprobe *rp)
+{
+       struct kretprobe_instance *ri;
+
+       if( arch_get_task_pc(p) == (unsigned long)&kretprobe_trampoline )
+       {
+               ri = find_ri_pc_mod(p, rp);
+               if(ri) {
+                       rm_task_trampoline(p, ri);
+                       recycle_rp_inst(ri);
+               }
+       }
+}
+
+void patch_suspended_all_task_ret_addr(struct kretprobe *rp)
+{
+       struct task_struct *p, *g;
+
+       rcu_read_lock();
+       // swapper task
+       if(current != &init_task)
+               patch_suspended_task_ret_addr(&init_task, rp);
+
+       // other tasks
+       do_each_thread(g, p) {
+               if(p == current)
+                       continue;
+               patch_suspended_task_ret_addr(p, rp);
+       } while_each_thread(g, p);
+       rcu_read_unlock();
+}
+
+static void unpatch_suspended_all_task_ret_addr(struct kretprobe *rp)
+{
+       struct task_struct *p, *g;
+
+       rcu_read_lock();
+       // swapper task
+       unpatch_suspended_task_ret_addr(&init_task, rp);
+
+       // other tasks
+       do_each_thread(g, p) {
+               unpatch_suspended_task_ret_addr(p, rp);
+       } while_each_thread(g, p);
+       rcu_read_unlock();
+}
+
 int __init init_kprobes (void)
 {
        int i, err = 0;

diff --git a/kprobe/dbi_kprobes.h b/kprobe/dbi_kprobes.h
index 2e7bbe0..6eeddbd 100644 (file)
--- a/kprobe/dbi_kprobes.h
+++ b/kprobe/dbi_kprobes.h
@@ -259,7 +259,7 @@ struct kretprobe_instance *get_free_rp_inst (struct kretprobe *rp);
 struct kretprobe_instance *get_free_rp_inst_no_alloc (struct kretprobe *rp);
 void free_rp_inst (struct kretprobe *rp);
 void add_rp_inst (struct kretprobe_instance *ri);
-void recycle_rp_inst (struct kretprobe_instance *ri, struct hlist_head *head);
+void recycle_rp_inst (struct kretprobe_instance *ri);
 
 //void kretprobe_trampoline_holder (void);
 int trampoline_probe_handler (struct kprobe *p, struct pt_regs *regs);