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Commit 3fd996a2 authored by Namhyung Kim's avatar Namhyung Kim Committed by Steven Rostedt
Browse files

tracing/probes: Implement 'stack' fetch method for uprobes 



Use separate method to fetch from stack.  Move existing functions to
trace_kprobe.c and make them static.  Also add new stack fetch
implementation for uprobes.

Acked-by: default avatarOleg Nesterov <oleg@redhat.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: zhangwei(Jovi) <jovi.zhangwei@huawei.com>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: default avatarNamhyung Kim <namhyung@kernel.org>
parent 34fee3a1

kernel/trace/trace_kprobe.c

+15 −0
Original line number Diff line number Diff line
@@ -88,6 +88,21 @@ static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs); 
static int kretprobe_dispatcher(struct kretprobe_instance *ri,

				struct pt_regs *regs);



/*

 * Kprobes-specific fetch functions

 */

#define DEFINE_FETCH_stack(type)					\

static __kprobes void FETCH_FUNC_NAME(stack, type)(struct pt_regs *regs,\

					  void *offset, void *dest)	\

{									\

	*(type *)dest = (type)regs_get_kernel_stack_nth(regs,		\

				(unsigned int)((unsigned long)offset));	\

}

DEFINE_BASIC_FETCH_FUNCS(stack)

/* No string on the stack entry */

#define fetch_stack_string	NULL

#define fetch_stack_string_size	NULL



/* Fetch type information table */

const struct fetch_type kprobes_fetch_type_table[] = {

	/* Special types */

kernel/trace/trace_probe.c

+0 −22
Original line number Diff line number Diff line
@@ -70,16 +70,6 @@ __kprobes int PRINT_TYPE_FUNC_NAME(string)(struct trace_seq *s, 


const char PRINT_TYPE_FMT_NAME(string)[] = "\\\"%s\\\"";



/*

 * Define macro for basic types - we don't need to define s* types, because

 * we have to care only about bitwidth at recording time.

 */

#define DEFINE_BASIC_FETCH_FUNCS(method) \

DEFINE_FETCH_##method(u8)		\

DEFINE_FETCH_##method(u16)		\

DEFINE_FETCH_##method(u32)		\

DEFINE_FETCH_##method(u64)



#define CHECK_FETCH_FUNCS(method, fn)			\

	(((FETCH_FUNC_NAME(method, u8) == fn) ||	\

	  (FETCH_FUNC_NAME(method, u16) == fn) ||	\
@@ -102,18 +92,6 @@ DEFINE_BASIC_FETCH_FUNCS(reg) 
#define fetch_reg_string	NULL

#define fetch_reg_string_size	NULL



#define DEFINE_FETCH_stack(type)					\

__kprobes void FETCH_FUNC_NAME(stack, type)(struct pt_regs *regs,	\

					  void *offset, void *dest)	\

{									\

	*(type *)dest = (type)regs_get_kernel_stack_nth(regs,		\

				(unsigned int)((unsigned long)offset));	\

}

DEFINE_BASIC_FETCH_FUNCS(stack)

/* No string on the stack entry */

#define fetch_stack_string	NULL

#define fetch_stack_string_size	NULL



#define DEFINE_FETCH_retval(type)					\

__kprobes void FETCH_FUNC_NAME(retval, type)(struct pt_regs *regs,	\

					  void *dummy, void *dest)	\

kernel/trace/trace_probe.h

+10 −4
Original line number Diff line number Diff line
@@ -167,10 +167,6 @@ DECLARE_BASIC_FETCH_FUNCS(reg); 
#define fetch_reg_string			NULL

#define fetch_reg_string_size			NULL



DECLARE_BASIC_FETCH_FUNCS(stack);

#define fetch_stack_string			NULL

#define fetch_stack_string_size			NULL



DECLARE_BASIC_FETCH_FUNCS(retval);

#define fetch_retval_string			NULL

#define fetch_retval_string_size		NULL
@@ -191,6 +187,16 @@ DECLARE_BASIC_FETCH_FUNCS(bitfield); 
#define fetch_bitfield_string			NULL

#define fetch_bitfield_string_size		NULL



/*

 * Define macro for basic types - we don't need to define s* types, because

 * we have to care only about bitwidth at recording time.

 */

#define DEFINE_BASIC_FETCH_FUNCS(method) \

DEFINE_FETCH_##method(u8)		\

DEFINE_FETCH_##method(u16)		\

DEFINE_FETCH_##method(u32)		\

DEFINE_FETCH_##method(u64)



/* Default (unsigned long) fetch type */

#define __DEFAULT_FETCH_TYPE(t) u##t

#define _DEFAULT_FETCH_TYPE(t) __DEFAULT_FETCH_TYPE(t)

kernel/trace/trace_uprobe.c

+41 −0
Original line number Diff line number Diff line
@@ -74,6 +74,47 @@ static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs); 
static int uretprobe_dispatcher(struct uprobe_consumer *con,

				unsigned long func, struct pt_regs *regs);



#ifdef CONFIG_STACK_GROWSUP

static unsigned long adjust_stack_addr(unsigned long addr, unsigned int n)

{

	return addr - (n * sizeof(long));

}

#else

static unsigned long adjust_stack_addr(unsigned long addr, unsigned int n)

{

	return addr + (n * sizeof(long));

}

#endif



static unsigned long get_user_stack_nth(struct pt_regs *regs, unsigned int n)

{

	unsigned long ret;

	unsigned long addr = user_stack_pointer(regs);



	addr = adjust_stack_addr(addr, n);



	if (copy_from_user(&ret, (void __force __user *) addr, sizeof(ret)))

		return 0;



	return ret;

}



/*

 * Uprobes-specific fetch functions

 */

#define DEFINE_FETCH_stack(type)					\

static __kprobes void FETCH_FUNC_NAME(stack, type)(struct pt_regs *regs,\

					  void *offset, void *dest)	\

{									\

	*(type *)dest = (type)get_user_stack_nth(regs,			\

					      ((unsigned long)offset)); \

}

DEFINE_BASIC_FETCH_FUNCS(stack)

/* No string on the stack entry */

#define fetch_stack_string	NULL

#define fetch_stack_string_size	NULL





/* Fetch type information table */

const struct fetch_type uprobes_fetch_type_table[] = {

	/* Special types */