[deliverable/linux.git] / arch / sparc / kernel / ftrace.c

#include <linux/spinlock.h>
#include <linux/hardirq.h>
#include <linux/ftrace.h>
#include <linux/percpu.h>
#include <linux/init.h>
#include <linux/list.h>
#include <trace/syscall.h>

#include <asm/ftrace.h>

#ifdef CONFIG_DYNAMIC_FTRACE
static const u32 ftrace_nop = 0x01000000;

static u32 ftrace_call_replace(unsigned long ip, unsigned long addr)
{
	u32 call;
	s32 off;

	off = ((s32)addr - (s32)ip);
	call = 0x40000000 | ((u32)off >> 2);

	return call;
}

static int ftrace_modify_code(unsigned long ip, u32 old, u32 new)
{
	u32 replaced;
	int faulted;

	__asm__ __volatile__(
	"1:	cas	[%[ip]], %[old], %[new]\n"
	"	flush	%[ip]\n"
	"	mov	0, %[faulted]\n"
	"2:\n"
	"	.section .fixup,#alloc,#execinstr\n"
	"	.align	4\n"
	"3:	sethi	%%hi(2b), %[faulted]\n"
	"	jmpl	%[faulted] + %%lo(2b), %%g0\n"
	"	 mov	1, %[faulted]\n"
	"	.previous\n"
	"	.section __ex_table,\"a\"\n"
	"	.align	4\n"
	"	.word	1b, 3b\n"
	"	.previous\n"
	: "=r" (replaced), [faulted] "=r" (faulted)
	: [new] "0" (new), [old] "r" (old), [ip] "r" (ip)
	: "memory");

	if (replaced != old && replaced != new)
		faulted = 2;

	return faulted;
}

int ftrace_make_nop(struct module *mod, struct dyn_ftrace *rec, unsigned long addr)
{
	unsigned long ip = rec->ip;
	u32 old, new;

	old = ftrace_call_replace(ip, addr);
	new = ftrace_nop;
	return ftrace_modify_code(ip, old, new);
}

int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
{
	unsigned long ip = rec->ip;
	u32 old, new;

	old = ftrace_nop;
	new = ftrace_call_replace(ip, addr);
	return ftrace_modify_code(ip, old, new);
}

int ftrace_update_ftrace_func(ftrace_func_t func)
{
	unsigned long ip = (unsigned long)(&ftrace_call);
	u32 old, new;

	old = *(u32 *) &ftrace_call;
	new = ftrace_call_replace(ip, (unsigned long)func);
	return ftrace_modify_code(ip, old, new);
}

int __init ftrace_dyn_arch_init(void)
{
	return 0;
}
#endif

#ifdef CONFIG_FUNCTION_GRAPH_TRACER

#ifdef CONFIG_DYNAMIC_FTRACE
extern void ftrace_graph_call(void);

int ftrace_enable_ftrace_graph_caller(void)
{
	unsigned long ip = (unsigned long)(&ftrace_graph_call);
	u32 old, new;

	old = *(u32 *) &ftrace_graph_call;
	new = ftrace_call_replace(ip, (unsigned long) &ftrace_graph_caller);
	return ftrace_modify_code(ip, old, new);
}

int ftrace_disable_ftrace_graph_caller(void)
{
	unsigned long ip = (unsigned long)(&ftrace_graph_call);
	u32 old, new;

	old = *(u32 *) &ftrace_graph_call;
	new = ftrace_call_replace(ip, (unsigned long) &ftrace_stub);

	return ftrace_modify_code(ip, old, new);
}

#endif /* !CONFIG_DYNAMIC_FTRACE */

/*
 * Hook the return address and push it in the stack of return addrs
 * in current thread info.
 */
unsigned long prepare_ftrace_return(unsigned long parent,
				    unsigned long self_addr,
				    unsigned long frame_pointer)
{
	unsigned long return_hooker = (unsigned long) &return_to_handler;
	struct ftrace_graph_ent trace;

	if (unlikely(atomic_read(&current->tracing_graph_pause)))
		return parent + 8UL;

	if (ftrace_push_return_trace(parent, self_addr, &trace.depth,
				     frame_pointer) == -EBUSY)
		return parent + 8UL;

	trace.func = self_addr;

	/* Only trace if the calling function expects to */
	if (!ftrace_graph_entry(&trace)) {
		current->curr_ret_stack--;
		return parent + 8UL;
	}

	return return_hooker;
}
#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
Commit	Line	Data
d05f5f99 DM	1	#include <linux/spinlock.h>
	2	#include <linux/hardirq.h>
	3	#include <linux/ftrace.h>
	4	#include <linux/percpu.h>
	5	#include <linux/init.h>
	6	#include <linux/list.h>
c658ad1b	7	#include <trace/syscall.h>
d05f5f99	8
395a59d0 AS	9	#include <asm/ftrace.h>
395a59d0 AS	10
9be12f9b	11	#ifdef CONFIG_DYNAMIC_FTRACE
d05f5f99 DM	12	static const u32 ftrace_nop = 0x01000000;
d05f5f99 DM	13
9be12f9b	14	static u32 ftrace_call_replace(unsigned long ip, unsigned long addr)
d05f5f99	15	{
d96478d5	16	u32 call;
d05f5f99 DM	17	s32 off;
	18
	19	off = ((s32)addr - (s32)ip);
	20	call = 0x40000000 \| ((u32)off >> 2);
	21
9be12f9b	22	return call;
d05f5f99 DM	23	}
d05f5f99 DM	24
9be12f9b	25	static int ftrace_modify_code(unsigned long ip, u32 old, u32 new)
d05f5f99	26	{
d05f5f99 DM	27	u32 replaced;
	28	int faulted;
	29
	30	__asm__ __volatile__(
	31	"1: cas [%[ip]], %[old], %[new]\n"
	32	" flush %[ip]\n"
	33	" mov 0, %[faulted]\n"
	34	"2:\n"
	35	" .section .fixup,#alloc,#execinstr\n"
	36	" .align 4\n"
	37	"3: sethi %%hi(2b), %[faulted]\n"
	38	" jmpl %[faulted] + %%lo(2b), %%g0\n"
	39	" mov 1, %[faulted]\n"
	40	" .previous\n"
	41	" .section __ex_table,\"a\"\n"
	42	" .align 4\n"
	43	" .word 1b, 3b\n"
	44	" .previous\n"
	45	: "=r" (replaced), [faulted] "=r" (faulted)
	46	: [new] "0" (new), [old] "r" (old), [ip] "r" (ip)
	47	: "memory");
	48
	49	if (replaced != old && replaced != new)
	50	faulted = 2;
	51
	52	return faulted;
	53	}
	54
9be12f9b DM	55	int ftrace_make_nop(struct module mod, struct dyn_ftrace rec, unsigned long addr)
	56	{
	57	unsigned long ip = rec->ip;
	58	u32 old, new;
	59
	60	old = ftrace_call_replace(ip, addr);
	61	new = ftrace_nop;
	62	return ftrace_modify_code(ip, old, new);
	63	}
	64
	65	int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
	66	{
	67	unsigned long ip = rec->ip;
	68	u32 old, new;
	69
	70	old = ftrace_nop;
	71	new = ftrace_call_replace(ip, addr);
	72	return ftrace_modify_code(ip, old, new);
	73	}
	74
15adc048	75	int ftrace_update_ftrace_func(ftrace_func_t func)
d05f5f99 DM	76	{
d05f5f99 DM	77	unsigned long ip = (unsigned long)(&ftrace_call);
9be12f9b	78	u32 old, new;
d05f5f99	79
9be12f9b	80	old = (u32 ) &ftrace_call;
d05f5f99 DM	81	new = ftrace_call_replace(ip, (unsigned long)func);
	82	return ftrace_modify_code(ip, old, new);
	83	}
	84
3a36cb11	85	int __init ftrace_dyn_arch_init(void)
d05f5f99	86	{
d05f5f99 DM	87	return 0;
d05f5f99 DM	88	}
9be12f9b	89	#endif
9960e9e8 DM	90
	91	#ifdef CONFIG_FUNCTION_GRAPH_TRACER
	92
	93	#ifdef CONFIG_DYNAMIC_FTRACE
	94	extern void ftrace_graph_call(void);
	95
	96	int ftrace_enable_ftrace_graph_caller(void)
	97	{
	98	unsigned long ip = (unsigned long)(&ftrace_graph_call);
	99	u32 old, new;
	100
	101	old = (u32 ) &ftrace_graph_call;
	102	new = ftrace_call_replace(ip, (unsigned long) &ftrace_graph_caller);
	103	return ftrace_modify_code(ip, old, new);
	104	}
	105
	106	int ftrace_disable_ftrace_graph_caller(void)
	107	{
	108	unsigned long ip = (unsigned long)(&ftrace_graph_call);
	109	u32 old, new;
	110
	111	old = (u32 ) &ftrace_graph_call;
	112	new = ftrace_call_replace(ip, (unsigned long) &ftrace_stub);
	113
	114	return ftrace_modify_code(ip, old, new);
	115	}
	116
	117	#endif /* !CONFIG_DYNAMIC_FTRACE */
	118
	119	/*
	120	* Hook the return address and push it in the stack of return addrs
	121	* in current thread info.
	122	*/
	123	unsigned long prepare_ftrace_return(unsigned long parent,
	124	unsigned long self_addr,
	125	unsigned long frame_pointer)
	126	{
	127	unsigned long return_hooker = (unsigned long) &return_to_handler;
	128	struct ftrace_graph_ent trace;
	129
	130	if (unlikely(atomic_read(&current->tracing_graph_pause)))
	131	return parent + 8UL;
	132
	133	if (ftrace_push_return_trace(parent, self_addr, &trace.depth,
	134	frame_pointer) == -EBUSY)
	135	return parent + 8UL;
	136
	137	trace.func = self_addr;
	138
	139	/* Only trace if the calling function expects to */
	140	if (!ftrace_graph_entry(&trace)) {
	141	current->curr_ret_stack--;
	142	return parent + 8UL;
	143	}
	144
	145	return return_hooker;
	146	}
	147	#endif /* CONFIG_FUNCTION_GRAPH_TRACER */