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

// SPDX-License-Identifier: GPL-2.0
#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;

	trace.func = self_addr;
	trace.depth = current->curr_ret_stack + 1;

	/* Only trace if the calling function expects to */
	if (!ftrace_graph_entry(&trace))
		return parent + 8UL;

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

	return return_hooker;
}
#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
Commit	Line	Data
b2441318	1	// SPDX-License-Identifier: GPL-2.0
d05f5f99 DM	2	#include <linux/spinlock.h>
	3	#include <linux/hardirq.h>
	4	#include <linux/ftrace.h>
	5	#include <linux/percpu.h>
	6	#include <linux/init.h>
	7	#include <linux/list.h>
c658ad1b	8	#include <trace/syscall.h>
d05f5f99	9
395a59d0 AS	10	#include <asm/ftrace.h>
395a59d0 AS	11
9be12f9b	12	#ifdef CONFIG_DYNAMIC_FTRACE
d05f5f99 DM	13	static const u32 ftrace_nop = 0x01000000;
d05f5f99 DM	14
9be12f9b	15	static u32 ftrace_call_replace(unsigned long ip, unsigned long addr)
d05f5f99	16	{
d96478d5	17	u32 call;
d05f5f99 DM	18	s32 off;
	19
	20	off = ((s32)addr - (s32)ip);
	21	call = 0x40000000 \| ((u32)off >> 2);
	22
9be12f9b	23	return call;
d05f5f99 DM	24	}
d05f5f99 DM	25
9be12f9b	26	static int ftrace_modify_code(unsigned long ip, u32 old, u32 new)
d05f5f99	27	{
d05f5f99 DM	28	u32 replaced;
	29	int faulted;
	30
	31	__asm__ __volatile__(
	32	"1: cas [%[ip]], %[old], %[new]\n"
	33	" flush %[ip]\n"
	34	" mov 0, %[faulted]\n"
	35	"2:\n"
	36	" .section .fixup,#alloc,#execinstr\n"
	37	" .align 4\n"
	38	"3: sethi %%hi(2b), %[faulted]\n"
	39	" jmpl %[faulted] + %%lo(2b), %%g0\n"
	40	" mov 1, %[faulted]\n"
	41	" .previous\n"
	42	" .section __ex_table,\"a\"\n"
	43	" .align 4\n"
	44	" .word 1b, 3b\n"
	45	" .previous\n"
	46	: "=r" (replaced), [faulted] "=r" (faulted)
	47	: [new] "0" (new), [old] "r" (old), [ip] "r" (ip)
	48	: "memory");
	49
	50	if (replaced != old && replaced != new)
	51	faulted = 2;
	52
	53	return faulted;
	54	}
	55
9be12f9b DM	56	int ftrace_make_nop(struct module mod, struct dyn_ftrace rec, unsigned long addr)
	57	{
	58	unsigned long ip = rec->ip;
	59	u32 old, new;
	60
	61	old = ftrace_call_replace(ip, addr);
	62	new = ftrace_nop;
	63	return ftrace_modify_code(ip, old, new);
	64	}
	65
	66	int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
	67	{
	68	unsigned long ip = rec->ip;
	69	u32 old, new;
	70
	71	old = ftrace_nop;
	72	new = ftrace_call_replace(ip, addr);
	73	return ftrace_modify_code(ip, old, new);
	74	}
	75
15adc048	76	int ftrace_update_ftrace_func(ftrace_func_t func)
d05f5f99 DM	77	{
d05f5f99 DM	78	unsigned long ip = (unsigned long)(&ftrace_call);
9be12f9b	79	u32 old, new;
d05f5f99	80
9be12f9b	81	old = (u32 ) &ftrace_call;
d05f5f99 DM	82	new = ftrace_call_replace(ip, (unsigned long)func);
	83	return ftrace_modify_code(ip, old, new);
	84	}
	85
3a36cb11	86	int __init ftrace_dyn_arch_init(void)
d05f5f99	87	{
d05f5f99 DM	88	return 0;
d05f5f99 DM	89	}
9be12f9b	90	#endif
9960e9e8 DM	91
	92	#ifdef CONFIG_FUNCTION_GRAPH_TRACER
	93
	94	#ifdef CONFIG_DYNAMIC_FTRACE
	95	extern void ftrace_graph_call(void);
	96
	97	int ftrace_enable_ftrace_graph_caller(void)
	98	{
	99	unsigned long ip = (unsigned long)(&ftrace_graph_call);
	100	u32 old, new;
	101
	102	old = (u32 ) &ftrace_graph_call;
	103	new = ftrace_call_replace(ip, (unsigned long) &ftrace_graph_caller);
	104	return ftrace_modify_code(ip, old, new);
	105	}
	106
	107	int ftrace_disable_ftrace_graph_caller(void)
	108	{
	109	unsigned long ip = (unsigned long)(&ftrace_graph_call);
	110	u32 old, new;
	111
	112	old = (u32 ) &ftrace_graph_call;
	113	new = ftrace_call_replace(ip, (unsigned long) &ftrace_stub);
	114
	115	return ftrace_modify_code(ip, old, new);
	116	}
	117
	118	#endif /* !CONFIG_DYNAMIC_FTRACE */
	119
	120	/*
	121	* Hook the return address and push it in the stack of return addrs
	122	* in current thread info.
	123	*/
	124	unsigned long prepare_ftrace_return(unsigned long parent,
	125	unsigned long self_addr,
	126	unsigned long frame_pointer)
	127	{
	128	unsigned long return_hooker = (unsigned long) &return_to_handler;
	129	struct ftrace_graph_ent trace;
	130
	131	if (unlikely(atomic_read(&current->tracing_graph_pause)))
	132	return parent + 8UL;
	133
9960e9e8	134	trace.func = self_addr;
48078d2d	135	trace.depth = current->curr_ret_stack + 1;
9960e9e8 DM	136
9960e9e8 DM	137	/* Only trace if the calling function expects to */
48078d2d LH	138	if (!ftrace_graph_entry(&trace))
	139	return parent + 8UL;
	140
	141	if (ftrace_push_return_trace(parent, self_addr, &trace.depth,
	142	frame_pointer, NULL) == -EBUSY)
9960e9e8	143	return parent + 8UL;
9960e9e8 DM	144
	145	return return_hooker;
	146	}
	147	#endif /* CONFIG_FUNCTION_GRAPH_TRACER */