Commit f5e2d818 authored by Tiezhu Yang's avatar Tiezhu Yang Committed by Thomas Bogendoerfer
Browse files

MIPS: Use NOKPROBE_SYMBOL() instead of __kprobes annotation 



If define CONFIG_KPROBES, __kprobes annotation forces the whole function
into the ".kprobes.text" section, NOKPROBE_SYMBOL() only stores the given
function address in the "_kprobe_blacklist" section which is introduced
to maintain kprobes blacklist.

Modify the related code to use NOKPROBE_SYMBOL() to protect functions from
kprobes instead of __kprobes annotation under arch/mips.

No obvious functional change in this patch, some more work needs to be done
to fix the kernel panic when execute the following testcase on mips:

  # cd tools/testing/selftests/ftrace
  # ./ftracetest test.d/kprobe/multiple_kprobes.tc

Signed-off-by: default avatarTiezhu Yang <yangtiezhu@loongson.cn>
Acked-by: default avatarMasami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: default avatarThomas Bogendoerfer <tsbogend@alpha.franken.de>
parent eab691b1

arch/mips/kernel/kprobes.c

+24 −12
Original line number Diff line number Diff line
@@ -44,10 +44,11 @@ static const union mips_instruction breakpoint2_insn = { 
DEFINE_PER_CPU(struct kprobe *, current_kprobe);

DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk);



static int __kprobes insn_has_delayslot(union mips_instruction insn)

static int insn_has_delayslot(union mips_instruction insn)

{

	return __insn_has_delay_slot(insn);

}

NOKPROBE_SYMBOL(insn_has_delayslot);



/*

 * insn_has_ll_or_sc function checks whether instruction is ll or sc
@@ -56,7 +57,7 @@ static int __kprobes insn_has_delayslot(union mips_instruction insn) 
 * instructions; cannot do much about breakpoint in the middle of

 * ll/sc pair; it is upto user to avoid those places

 */

static int __kprobes insn_has_ll_or_sc(union mips_instruction insn)

static int insn_has_ll_or_sc(union mips_instruction insn)

{

	int ret = 0;
@@ -72,8 +73,9 @@ static int __kprobes insn_has_ll_or_sc(union mips_instruction insn) 
	}

	return ret;

}

NOKPROBE_SYMBOL(insn_has_ll_or_sc);



int __kprobes arch_prepare_kprobe(struct kprobe *p)

int arch_prepare_kprobe(struct kprobe *p)

{

	union mips_instruction insn;

	union mips_instruction prev_insn;
@@ -132,26 +134,30 @@ int __kprobes arch_prepare_kprobe(struct kprobe *p) 
out:

	return ret;

}

NOKPROBE_SYMBOL(arch_prepare_kprobe);



void __kprobes arch_arm_kprobe(struct kprobe *p)

void arch_arm_kprobe(struct kprobe *p)

{

	*p->addr = breakpoint_insn;

	flush_insn_slot(p);

}

NOKPROBE_SYMBOL(arch_arm_kprobe);



void __kprobes arch_disarm_kprobe(struct kprobe *p)

void arch_disarm_kprobe(struct kprobe *p)

{

	*p->addr = p->opcode;

	flush_insn_slot(p);

}

NOKPROBE_SYMBOL(arch_disarm_kprobe);



void __kprobes arch_remove_kprobe(struct kprobe *p)

void arch_remove_kprobe(struct kprobe *p)

{

	if (p->ainsn.insn) {

		free_insn_slot(p->ainsn.insn, 0);

		p->ainsn.insn = NULL;

	}

}

NOKPROBE_SYMBOL(arch_remove_kprobe);



static void save_previous_kprobe(struct kprobe_ctlblk *kcb)

{
@@ -257,7 +263,7 @@ static void prepare_singlestep(struct kprobe *p, struct pt_regs *regs, 
 * breakpoint trap. In case of branch instructions, the target

 * epc to be restored.

 */

static void __kprobes resume_execution(struct kprobe *p,

static void resume_execution(struct kprobe *p,

				       struct pt_regs *regs,

				       struct kprobe_ctlblk *kcb)

{
@@ -268,8 +274,9 @@ static void __kprobes resume_execution(struct kprobe *p, 
		regs->cp0_epc = orig_epc + 4;

	}

}

NOKPROBE_SYMBOL(resume_execution);



static int __kprobes kprobe_handler(struct pt_regs *regs)

static int kprobe_handler(struct pt_regs *regs)

{

	struct kprobe *p;

	int ret = 0;
@@ -367,6 +374,7 @@ static int __kprobes kprobe_handler(struct pt_regs *regs) 
	return ret;



}

NOKPROBE_SYMBOL(kprobe_handler);



static inline int post_kprobe_handler(struct pt_regs *regs)

{
@@ -415,7 +423,7 @@ int kprobe_fault_handler(struct pt_regs *regs, int trapnr) 
/*

 * Wrapper routine for handling exceptions.

 */

int __kprobes kprobe_exceptions_notify(struct notifier_block *self,

int kprobe_exceptions_notify(struct notifier_block *self,

				       unsigned long val, void *data)

{
@@ -446,6 +454,7 @@ int __kprobes kprobe_exceptions_notify(struct notifier_block *self, 
	}

	return ret;

}

NOKPROBE_SYMBOL(kprobe_exceptions_notify);



/*

 * Function return probe trampoline:
@@ -469,7 +478,7 @@ static void __used kretprobe_trampoline_holder(void) 


void __kretprobe_trampoline(void);



void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri,

void arch_prepare_kretprobe(struct kretprobe_instance *ri,

				      struct pt_regs *regs)

{

	ri->ret_addr = (kprobe_opcode_t *) regs->regs[31];
@@ -478,11 +487,12 @@ void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri, 
	/* Replace the return addr with trampoline addr */

	regs->regs[31] = (unsigned long)__kretprobe_trampoline;

}

NOKPROBE_SYMBOL(arch_prepare_kretprobe);



/*

 * Called when the probe at kretprobe trampoline is hit

 */

static int __kprobes trampoline_probe_handler(struct kprobe *p,

static int trampoline_probe_handler(struct kprobe *p,

						struct pt_regs *regs)

{

	instruction_pointer(regs) = __kretprobe_trampoline_handler(regs, NULL);
@@ -493,14 +503,16 @@ static int __kprobes trampoline_probe_handler(struct kprobe *p, 
	 */

	return 1;

}

NOKPROBE_SYMBOL(trampoline_probe_handler);



int __kprobes arch_trampoline_kprobe(struct kprobe *p)

int arch_trampoline_kprobe(struct kprobe *p)

{

	if (p->addr == (kprobe_opcode_t *)__kretprobe_trampoline)

		return 1;



	return 0;

}

NOKPROBE_SYMBOL(arch_trampoline_kprobe);



static struct kprobe trampoline_p = {

	.addr = (kprobe_opcode_t *)__kretprobe_trampoline,

arch/mips/mm/fault.c

+4 −2
Original line number Diff line number Diff line
@@ -35,7 +35,7 @@ int show_unhandled_signals = 1; 
 * and the problem, and then passes it off to one of the appropriate

 * routines.

 */

static void __kprobes __do_page_fault(struct pt_regs *regs, unsigned long write,

static void __do_page_fault(struct pt_regs *regs, unsigned long write,

	unsigned long address)

{

	struct vm_area_struct * vma = NULL;
@@ -322,8 +322,9 @@ static void __kprobes __do_page_fault(struct pt_regs *regs, unsigned long write, 
	}

#endif

}

NOKPROBE_SYMBOL(__do_page_fault);



asmlinkage void __kprobes do_page_fault(struct pt_regs *regs,

asmlinkage void do_page_fault(struct pt_regs *regs,

	unsigned long write, unsigned long address)

{

	enum ctx_state prev_state;
@@ -332,3 +333,4 @@ asmlinkage void __kprobes do_page_fault(struct pt_regs *regs, 
	__do_page_fault(regs, write, address);

	exception_exit(prev_state);

}

NOKPROBE_SYMBOL(do_page_fault);