[FIX] remove panic() from uprobe (x86)

Change-Id: I144c348d337038bc3a1020784e4850f3eccdacbe
Signed-off-by: Vyacheslav Cherkashin <v.cherkashin@samsung.com>

diff --git a/uprobe/arch/arm/swap-asm/swap_uprobes.c b/uprobe/arch/arm/swap-asm/swap_uprobes.c
index da6ae8c..9efc6d6 100644 (file)
--- a/uprobe/arch/arm/swap-asm/swap_uprobes.c
+++ b/uprobe/arch/arm/swap-asm/swap_uprobes.c
@@ -673,10 +673,9 @@ void arch_opcode_analysis_uretprobe(struct uretprobe *rp)
  *
  * @param ri Pointer to the uretprobe instance.
  * @param regs Pointer to CPU register data.
- * @return Void.
+ * @return Error code.
  */
-void arch_prepare_uretprobe(struct uretprobe_instance *ri,
-                           struct pt_regs *regs)
+int arch_prepare_uretprobe(struct uretprobe_instance *ri, struct pt_regs *regs)
 {
        ri->ret_addr = (kprobe_opcode_t *)regs->ARM_lr;
        ri->sp = (kprobe_opcode_t *)regs->ARM_sp;
@@ -689,6 +688,8 @@ void arch_prepare_uretprobe(struct uretprobe_instance *ri,
        else
                regs->ARM_lr = (unsigned long)(ri->rp->up.kp.ainsn.insn +
                                               UPROBES_TRAMP_RET_BREAK_IDX);
+
+       return 0;
 }
 
 /**

diff --git a/uprobe/arch/arm/swap-asm/swap_uprobes.h b/uprobe/arch/arm/swap-asm/swap_uprobes.h
index c38988e..51342af 100644 (file)
--- a/uprobe/arch/arm/swap-asm/swap_uprobes.h
+++ b/uprobe/arch/arm/swap-asm/swap_uprobes.h
@@ -80,8 +80,7 @@ static inline int longjmp_break_uhandler(struct kprobe *p, struct pt_regs *regs)
 }
 
 void arch_opcode_analysis_uretprobe(struct uretprobe *rp);
-void arch_prepare_uretprobe(struct uretprobe_instance *ri,
-                           struct pt_regs *regs);
+int arch_prepare_uretprobe(struct uretprobe_instance *ri, struct pt_regs *regs);
 int arch_disarm_urp_inst(struct uretprobe_instance *ri,
                         struct task_struct *task);
 

diff --git a/uprobe/arch/x86/swap-asm/swap_uprobes.c b/uprobe/arch/x86/swap-asm/swap_uprobes.c
index d726f7e..74ed296 100644 (file)
--- a/uprobe/arch/x86/swap-asm/swap_uprobes.c
+++ b/uprobe/arch/x86/swap-asm/swap_uprobes.c
@@ -97,8 +97,10 @@ 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("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");
@@ -153,8 +155,8 @@ 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("failed to read user space func arguments %lx!\n",
+                      regs->EREG(sp) + 4);
 
        if (pre_entry)
                p->ss_addr[smp_processor_id()] = (kprobe_opcode_t *)
@@ -175,22 +177,27 @@ 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);
        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));
+                                sizeof(ri->ret_addr))) {
+               printk("failed to read user space func ra %lx addr=%p!\n",
+                               regs->EREG(sp), ri->rp->up.kp.addr);
+               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));
+       if (!write_proc_vm_atomic(current, regs->EREG(sp), &ra, sizeof(ra))) {
+               printk("failed to write user space func ra %lx!\n", regs->EREG(sp));
+               return -EINVAL;
+       }
 
        add_uprobe_table(&ri->rp->up.kp);
+
+       return 0;
 }
 
 /**
@@ -282,7 +289,7 @@ static void set_user_jmp_op(void *from, void *to)
 
        if (!write_proc_vm_atomic(current, (unsigned long)from, &jop,
                                  sizeof(jop)))
-               panic("failed to write jump opcode to user space %p!\n", from);
+               printk("failed to write jump opcode to user space %p\n", from);
 }
 
 static void resume_execution(struct kprobe *p,
@@ -298,14 +305,18 @@ static void resume_execution(struct kprobe *p,
 
        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));
+                                sizeof(tos_dword))) {
+               printk("failed to read dword from top of the user space stack "
+                      "%lx!\n", regs->EREG(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);
+                                2 * sizeof(kprobe_opcode_t))) {
+               printk("failed to read first 2 opcodes of instruction copy "
+                      "from user space %p!\n", p->ainsn.insn);
+               return;
+       }
 
        switch (insns[0]) {
        case 0x9c: /* pushfl */
@@ -330,10 +341,11 @@ static void resume_execution(struct kprobe *p,
                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));
+                                         sizeof(tos_dword))) {
+                       printk("failed to write dword to top of the"
+                              " user space stack %lx!\n", regs->EREG(sp));
+                       return;
+               }
 
                goto no_change;
        case 0xff:
@@ -347,10 +359,12 @@ static void resume_execution(struct kprobe *p,
 
                        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));
+                                                 sizeof(tos_dword))) {
+                               printk("failed to write dword to top of the "
+                                      "user space stack %lx!\n",
+                                      regs->EREG(sp));
+                               return;
+                       }
 
                        goto no_change;
                } else if (((insns[1] & 0x31) == 0x20) || /* jmp near, absolute
@@ -371,9 +385,11 @@ static void resume_execution(struct kprobe *p,
        }
 
        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));
+                                 sizeof(tos_dword))) {
+               printk("failed to write dword to top of the user space stack "
+                      "%lx!\n", regs->EREG(sp));
+               return;
+       }
 
        if (p->ainsn.boostable == 0) {
                if ((regs->EREG(ip) > copy_eip) && (regs->EREG(ip) - copy_eip) +

diff --git a/uprobe/arch/x86/swap-asm/swap_uprobes.h b/uprobe/arch/x86/swap-asm/swap_uprobes.h
index 40345df..faef033 100644 (file)
--- a/uprobe/arch/x86/swap-asm/swap_uprobes.h
+++ b/uprobe/arch/x86/swap-asm/swap_uprobes.h
@@ -84,8 +84,7 @@ static inline int arch_opcode_analysis_uretprobe(struct uretprobe *rp)
        return 0;
 }
 
-void arch_prepare_uretprobe(struct uretprobe_instance *ri,
-                           struct pt_regs *regs);
+int arch_prepare_uretprobe(struct uretprobe_instance *ri, struct pt_regs *regs);
 int arch_disarm_urp_inst(struct uretprobe_instance *ri,
                         struct task_struct *task);
 unsigned long arch_get_trampoline_addr(struct kprobe *p, struct pt_regs *regs);

diff --git a/uprobe/swap_uprobes.c b/uprobe/swap_uprobes.c
index 7f078c0..a94b0b7 100644 (file)
--- a/uprobe/swap_uprobes.c
+++ b/uprobe/swap_uprobes.c
@@ -761,15 +761,20 @@ static int pre_handler_uretprobe(struct kprobe *p, struct pt_regs *regs)
        /* TODO: test - remove retprobe after func entry but before its exit */
        ri = get_free_urp_inst(rp);
        if (ri != NULL) {
+               int ret;
+
                ri->rp = rp;
                ri->task = current;
 
                if (rp->entry_handler)
                        rp->entry_handler(ri, regs);
 
-               arch_prepare_uretprobe(ri, regs);
-
+               ret = arch_prepare_uretprobe(ri, regs);
                add_urp_inst(ri);
+               if (ret) {
+                       recycle_urp_inst(ri);
+                       ++rp->nmissed;
+               }
        } else {
                ++rp->nmissed;
        }