Tizen 2.4.0 rev3 SDK Public Release
[kernel/swap-modules.git] / uprobe / arch / x86 / swap-asm / swap_uprobes.c
index d726f7e..518c304 100644 (file)
@@ -54,32 +54,36 @@ static unsigned long trampoline_addr(struct uprobe *up)
                               UPROBES_TRAMP_RET_BREAK_IDX);
 }
 
-static DEFINE_PER_CPU(struct uprobe_ctlblk, ucb) = { 0, NULL };
+unsigned long arch_tramp_by_ri(struct uretprobe_instance *ri)
+{
+       return trampoline_addr(&ri->rp->up);
+}
 
-static struct kprobe *get_current_probe(void)
+static struct uprobe_ctlblk *current_ucb(void)
 {
-       return __get_cpu_var(ucb).p;
+       /* FIXME hardcoded offset */
+       return (struct uprobe_ctlblk *)(end_of_stack(current) + 20);
 }
 
-static void set_current_probe(struct kprobe *p)
+static struct kprobe *get_current_probe(void)
 {
-       __get_cpu_var(ucb).p = p;
+       return current_ucb()->p;
 }
 
-static void reset_current_probe(void)
+static void set_current_probe(struct kprobe *p)
 {
-       set_current_probe(NULL);
+       current_ucb()->p = p;
 }
 
 static void save_current_flags(struct pt_regs *regs)
 {
-       __get_cpu_var(ucb).flags = regs->EREG(flags);
+       current_ucb()->flags = regs->flags;
 }
 
-static void restore_current_flags(struct pt_regs *regs)
+static void restore_current_flags(struct pt_regs *regs, unsigned long flags)
 {
-       regs->EREG(flags) &= ~IF_MASK;
-       regs->EREG(flags) |= __get_cpu_var(ucb).flags & IF_MASK;
+       regs->flags &= ~IF_MASK;
+       regs->flags |= flags & IF_MASK;
 }
 
 /**
@@ -97,12 +101,14 @@ int arch_prepare_uprobe(struct uprobe *up)
        enum { call_relative_opcode = 0xe8 };
 
        if (!read_proc_vm_atomic(task, (unsigned long)p->addr,
-                                tramp, MAX_INSN_SIZE))
-               panic("failed to read memory %p!\n", p->addr);
+                                tramp, MAX_INSN_SIZE)) {
+               printk(KERN_ERR "failed to read memory %p!\n", p->addr);
+               return -EINVAL;
+       }
        /* TODO: this is a workaround */
        if (tramp[0] == call_relative_opcode) {
                printk(KERN_INFO "cannot install probe: 1st instruction is call\n");
-               return -1;
+               return -EINVAL;
        }
 
        tramp[UPROBES_TRAMP_RET_BREAK_IDX] = BREAKPOINT_INSTRUCTION;
@@ -114,17 +120,20 @@ int arch_prepare_uprobe(struct uprobe *up)
 
        p->ainsn.insn = swap_slot_alloc(up->sm);
        if (p->ainsn.insn == NULL) {
-               printk(KERN_INFO "trampoline out of memory\n");
+               printk(KERN_ERR "trampoline out of memory\n");
                return -ENOMEM;
        }
 
        if (!write_proc_vm_atomic(task, (unsigned long)p->ainsn.insn,
                                  tramp, sizeof(up->atramp.tramp))) {
                swap_slot_free(up->sm, p->ainsn.insn);
-               printk("failed to write memory %p!\n", tramp);
+               printk(KERN_INFO "failed to write memory %p!\n", tramp);
                return -EINVAL;
        }
 
+       /* for uretprobe */
+       add_uprobe_table(p);
+
        return 0;
 }
 
@@ -153,8 +162,9 @@ int setjmp_upre_handler(struct kprobe *p, struct pt_regs *regs)
        /* read first 6 args from stack */
        if (!read_proc_vm_atomic(current, regs->EREG(sp) + 4,
                                 args, sizeof(args)))
-               panic("failed to read user space func arguments %lx!\n",
-                     regs->EREG(sp) + 4);
+               printk(KERN_WARNING
+                      "failed to read user space func arguments %lx!\n",
+                      regs->sp + 4);
 
        if (pre_entry)
                p->ss_addr[smp_processor_id()] = (kprobe_opcode_t *)
@@ -175,22 +185,27 @@ int setjmp_upre_handler(struct kprobe *p, struct pt_regs *regs)
  * @param regs Pointer to CPU register data.
  * @return Void.
  */
-void arch_prepare_uretprobe(struct uretprobe_instance *ri, struct pt_regs *regs)
+int arch_prepare_uretprobe(struct uretprobe_instance *ri, struct pt_regs *regs)
 {
        /* Replace the return addr with trampoline addr */
        unsigned long ra = trampoline_addr(&ri->rp->up);
+       unsigned long ret_addr;
        ri->sp = (kprobe_opcode_t *)regs->sp;
 
-       if (!read_proc_vm_atomic(current, regs->EREG(sp), &(ri->ret_addr),
-                                sizeof(ri->ret_addr)))
-               panic("failed to read user space func ra %lx!\n",
-                     regs->EREG(sp));
+       if (get_user(ret_addr, (unsigned long *)regs->sp)) {
+               pr_err("failed to read user space func ra %lx addr=%p!\n",
+                      regs->sp, ri->rp->up.kp.addr);
+               return -EINVAL;
+       }
+
+       if (put_user(ra, (unsigned long *)regs->sp)) {
+               pr_err("failed to write user space func ra %lx!\n", regs->sp);
+               return -EINVAL;
+       }
 
-       if (!write_proc_vm_atomic(current, regs->EREG(sp), &ra, sizeof(ra)))
-               panic("failed to write user space func ra %lx!\n",
-                     regs->EREG(sp));
+       ri->ret_addr = (kprobe_opcode_t *)ret_addr;
 
-       add_uprobe_table(&ri->rp->up.kp);
+       return 0;
 }
 
 /**
@@ -202,23 +217,25 @@ void arch_prepare_uretprobe(struct uretprobe_instance *ri, struct pt_regs *regs)
  * negative error code on error.
  */
 int arch_disarm_urp_inst(struct uretprobe_instance *ri,
-                        struct task_struct *task)
+                        struct task_struct *task, unsigned long tr)
 {
-       int len;
        unsigned long ret_addr;
        unsigned long sp = (unsigned long)ri->sp;
-       unsigned long tramp_addr = trampoline_addr(&ri->rp->up);
-       len = read_proc_vm_atomic(task, sp, &ret_addr, sizeof(ret_addr));
-       if (len != sizeof(ret_addr)) {
+       unsigned long tramp_addr;
+
+       if (tr == 0)
+               tramp_addr = arch_tramp_by_ri(ri);
+       else
+               tramp_addr = tr; /* ri - invalid */
+
+       if (get_user(ret_addr, (unsigned long *)sp)) {
                printk(KERN_INFO "---> %s (%d/%d): failed to read stack from %08lx\n",
                       task->comm, task->tgid, task->pid, sp);
                return -EFAULT;
        }
 
        if (tramp_addr == ret_addr) {
-               len = write_proc_vm_atomic(task, sp, &ri->ret_addr,
-                                          sizeof(ri->ret_addr));
-               if (len != sizeof(ri->ret_addr)) {
+               if (put_user((unsigned long)ri->ret_addr, (unsigned long *)sp)) {
                        printk(KERN_INFO "---> %s (%d/%d): failed to write "
                               "orig_ret_addr to %08lx",
                               task->comm, task->tgid, task->pid, sp);
@@ -270,6 +287,35 @@ void arch_remove_uprobe(struct uprobe *up)
        swap_slot_free(up->sm, p->ainsn.insn);
 }
 
+int arch_arm_uprobe(struct uprobe *p)
+{
+       int ret;
+       kprobe_opcode_t insn = BREAKPOINT_INSTRUCTION;
+       unsigned long vaddr = (unsigned long)p->kp.addr;
+
+       ret = write_proc_vm_atomic(p->task, vaddr, &insn, sizeof(insn));
+       if (!ret) {
+               pr_err("arch_arm_uprobe: failed to write memory tgid=%u vaddr=%08lx\n",
+                      p->task->tgid, vaddr);
+
+               return -EACCES;
+       }
+
+       return 0;
+}
+
+void arch_disarm_uprobe(struct kprobe *p, struct task_struct *task)
+{
+       int ret;
+       unsigned long vaddr = (unsigned long)p->addr;
+
+       ret = write_proc_vm_atomic(task, vaddr, &p->opcode, sizeof(p->opcode));
+       if (!ret) {
+               pr_err("arch_disarm_uprobe: failed to write memory tgid=%u, vaddr=%08lx\n",
+                      task->tgid, vaddr);
+       }
+}
+
 static void set_user_jmp_op(void *from, void *to)
 {
        struct __arch_jmp_op {
@@ -280,9 +326,9 @@ static void set_user_jmp_op(void *from, void *to)
        jop.raddr = (long)(to) - ((long)(from) + 5);
        jop.op = RELATIVEJUMP_INSTRUCTION;
 
-       if (!write_proc_vm_atomic(current, (unsigned long)from, &jop,
-                                 sizeof(jop)))
-               panic("failed to write jump opcode to user space %p!\n", from);
+       if (put_user(jop.op, (char *)from) ||
+           put_user(jop.raddr, (long *)(from + 1)))
+               pr_err("failed to write jump opcode to user space %p\n", from);
 }
 
 static void resume_execution(struct kprobe *p,
@@ -297,15 +343,15 @@ static void resume_execution(struct kprobe *p,
        regs->EREG(flags) &= ~TF_MASK;
 
        tos = (unsigned long *)&tos_dword;
-       if (!read_proc_vm_atomic(current, regs->EREG(sp), &tos_dword,
-                                sizeof(tos_dword)))
-               panic("failed to read dword from top of the user space stack "
-                     "%lx!\n", regs->EREG(sp));
+       if (get_user(tos_dword, (unsigned long *)regs->sp)) {
+               pr_err("failed to read from user space sp=%lx!\n", regs->sp);
+               return;
+       }
 
-       if (!read_proc_vm_atomic(current, (unsigned long)p->ainsn.insn, insns,
-                                2 * sizeof(kprobe_opcode_t)))
-               panic("failed to read first 2 opcodes of instruction copy "
-                     "from user space %p!\n", p->ainsn.insn);
+       if (get_user(*(unsigned short *)insns, (unsigned short *)p->ainsn.insn)) {
+               pr_err("failed to read first 2 opcodes %p!\n", p->ainsn.insn);
+               return;
+       }
 
        switch (insns[0]) {
        case 0x9c: /* pushfl */
@@ -327,13 +373,10 @@ static void resume_execution(struct kprobe *p,
        case 0x9a: /* call absolute -- same as call absolute, indirect */
                *tos = orig_eip + (*tos - copy_eip);
 
-               if (!write_proc_vm_atomic(current,
-                                         regs->EREG(sp),
-                                         &tos_dword,
-                                         sizeof(tos_dword)))
-                       panic("failed to write dword to top of the"
-                             " user space stack %lx!\n",
-                             regs->EREG(sp));
+               if (put_user(tos_dword, (unsigned long *)regs->sp)) {
+                       pr_err("failed to write dword to sp=%lx\n", regs->sp);
+                       return;
+               }
 
                goto no_change;
        case 0xff:
@@ -345,12 +388,10 @@ static void resume_execution(struct kprobe *p,
                         */
                        *tos = orig_eip + (*tos - copy_eip);
 
-                       if (!write_proc_vm_atomic(current, regs->EREG(sp),
-                                                 &tos_dword,
-                                                 sizeof(tos_dword)))
-                               panic("failed to write dword to top of the "
-                                     "user space stack %lx!\n",
-                                     regs->EREG(sp));
+                       if (put_user(tos_dword, (unsigned long *)regs->sp)) {
+                               pr_err("failed to write dword to sp=%lx\n", regs->sp);
+                               return;
+                       }
 
                        goto no_change;
                } else if (((insns[1] & 0x31) == 0x20) || /* jmp near, absolute
@@ -370,10 +411,10 @@ static void resume_execution(struct kprobe *p,
                break;
        }
 
-       if (!write_proc_vm_atomic(current, regs->EREG(sp), &tos_dword,
-                                 sizeof(tos_dword)))
-               panic("failed to write dword to top of the user space stack "
-                     "%lx!\n", regs->EREG(sp));
+       if (put_user(tos_dword, (unsigned long *)regs->sp)) {
+               pr_err("failed to write dword to sp=%lx\n", regs->sp);
+               return;
+       }
 
        if (p->ainsn.boostable == 0) {
                if ((regs->EREG(ip) > copy_eip) && (regs->EREG(ip) - copy_eip) +
@@ -397,6 +438,27 @@ no_change:
        return;
 }
 
+static bool prepare_ss_addr(struct kprobe *p, struct pt_regs *regs)
+{
+       unsigned long *ss_addr = (long *)&p->ss_addr[smp_processor_id()];
+
+       if (*ss_addr) {
+               regs->ip = *ss_addr;
+               *ss_addr = 0;
+               return true;
+       } else {
+               regs->ip = (unsigned long)p->ainsn.insn;
+               return false;
+       }
+}
+
+static void prepare_ss(struct pt_regs *regs)
+{
+       /* set single step mode */
+       regs->flags |= TF_MASK;
+       regs->flags &= ~IF_MASK;
+}
+
 static int uprobe_handler(struct pt_regs *regs)
 {
        struct kprobe *p;
@@ -422,38 +484,38 @@ static int uprobe_handler(struct pt_regs *regs)
                return 1;
        } else {
                if (!p->pre_handler || !p->pre_handler(p, regs)) {
-
                        if (p->ainsn.boostable == 1 && !p->post_handler) {
-                               if (p->ss_addr[smp_processor_id()]) {
-                                       regs->EREG(ip) = (unsigned long)p->ss_addr[smp_processor_id()];
-                                       p->ss_addr[smp_processor_id()] = NULL;
-                               } else {
-                                       regs->EREG(ip) = (unsigned long)p->ainsn.insn;
-                               }
+                               prepare_ss_addr(p, regs);
                                return 1;
                        }
 
-                       prepare_singlestep(p, regs);
+                       if (prepare_ss_addr(p, regs) == false) {
+                               set_current_probe(p);
+                               prepare_ss(regs);
+                       }
                }
        }
 
-       set_current_probe(p);
-
        return 1;
 }
 
 static int post_uprobe_handler(struct pt_regs *regs)
 {
        struct kprobe *p = get_current_probe();
-       unsigned long flags = __get_cpu_var(ucb).flags;
+       unsigned long flags = current_ucb()->flags;
 
-       if (p == NULL)
+       if (p == NULL) {
+               printk("task[%u %u %s] current uprobe is not found\n",
+                      current->tgid, current->pid, current->comm);
                return 0;
+       }
 
        resume_execution(p, regs, flags);
-       restore_current_flags(regs);
+       restore_current_flags(regs, flags);
 
-       reset_current_probe();
+       /* clean stack */
+       current_ucb()->p = 0;
+       current_ucb()->flags = 0;
 
        return 1;
 }