[linux-2.6-block.git] / samples / ftrace / ftrace-direct-too.c

// SPDX-License-Identifier: GPL-2.0-only
#include <linux/module.h>

#include <linux/mm.h> /* for handle_mm_fault() */
#include <linux/ftrace.h>
#if !defined(CONFIG_ARM64) && !defined(CONFIG_PPC32)
#include <asm/asm-offsets.h>
#endif

extern void my_direct_func(struct vm_area_struct *vma, unsigned long address,
			   unsigned int flags, struct pt_regs *regs);

void my_direct_func(struct vm_area_struct *vma, unsigned long address,
		    unsigned int flags, struct pt_regs *regs)
{
	trace_printk("handle mm fault vma=%p address=%lx flags=%x regs=%p\n",
		     vma, address, flags, regs);
}

extern void my_tramp(void *);

#ifdef CONFIG_RISCV
#include <asm/asm.h>

asm (
"       .pushsection    .text, \"ax\", @progbits\n"
"       .type           my_tramp, @function\n"
"       .globl          my_tramp\n"
"   my_tramp:\n"
"       addi	sp,sp,-5*"SZREG"\n"
"       "REG_S"	a0,0*"SZREG"(sp)\n"
"       "REG_S"	a1,1*"SZREG"(sp)\n"
"       "REG_S"	a2,2*"SZREG"(sp)\n"
"       "REG_S"	t0,3*"SZREG"(sp)\n"
"       "REG_S"	ra,4*"SZREG"(sp)\n"
"       call	my_direct_func\n"
"       "REG_L"	a0,0*"SZREG"(sp)\n"
"       "REG_L"	a1,1*"SZREG"(sp)\n"
"       "REG_L"	a2,2*"SZREG"(sp)\n"
"       "REG_L"	t0,3*"SZREG"(sp)\n"
"       "REG_L"	ra,4*"SZREG"(sp)\n"
"       addi	sp,sp,5*"SZREG"\n"
"       jr	t0\n"
"       .size           my_tramp, .-my_tramp\n"
"       .popsection\n"
);

#endif /* CONFIG_RISCV */

#ifdef CONFIG_X86_64

#include <asm/ibt.h>
#include <asm/nospec-branch.h>

asm (
"	.pushsection    .text, \"ax\", @progbits\n"
"	.type		my_tramp, @function\n"
"	.globl		my_tramp\n"
"   my_tramp:"
	ASM_ENDBR
"	pushq %rbp\n"
"	movq %rsp, %rbp\n"
	CALL_DEPTH_ACCOUNT
"	pushq %rdi\n"
"	pushq %rsi\n"
"	pushq %rdx\n"
"	pushq %rcx\n"
"	call my_direct_func\n"
"	popq %rcx\n"
"	popq %rdx\n"
"	popq %rsi\n"
"	popq %rdi\n"
"	leave\n"
	ASM_RET
"	.size		my_tramp, .-my_tramp\n"
"	.popsection\n"
);

#endif /* CONFIG_X86_64 */

#ifdef CONFIG_S390

asm (
"	.pushsection	.text, \"ax\", @progbits\n"
"	.type		my_tramp, @function\n"
"	.globl		my_tramp\n"
"   my_tramp:"
"	lgr		%r1,%r15\n"
"	stmg		%r0,%r5,"__stringify(__SF_GPRS)"(%r15)\n"
"	stg		%r14,"__stringify(__SF_GPRS+8*8)"(%r15)\n"
"	aghi		%r15,"__stringify(-STACK_FRAME_OVERHEAD)"\n"
"	stg		%r1,"__stringify(__SF_BACKCHAIN)"(%r15)\n"
"	brasl		%r14,my_direct_func\n"
"	aghi		%r15,"__stringify(STACK_FRAME_OVERHEAD)"\n"
"	lmg		%r0,%r5,"__stringify(__SF_GPRS)"(%r15)\n"
"	lg		%r14,"__stringify(__SF_GPRS+8*8)"(%r15)\n"
"	lgr		%r1,%r0\n"
"	br		%r1\n"
"	.size		my_tramp, .-my_tramp\n"
"	.popsection\n"
);

#endif /* CONFIG_S390 */

#ifdef CONFIG_ARM64

asm (
"	.pushsection	.text, \"ax\", @progbits\n"
"	.type		my_tramp, @function\n"
"	.globl		my_tramp\n"
"   my_tramp:"
"	hint	34\n" // bti	c
"	sub	sp, sp, #48\n"
"	stp	x9, x30, [sp]\n"
"	stp	x0, x1, [sp, #16]\n"
"	stp	x2, x3, [sp, #32]\n"
"	bl	my_direct_func\n"
"	ldp	x30, x9, [sp]\n"
"	ldp	x0, x1, [sp, #16]\n"
"	ldp	x2, x3, [sp, #32]\n"
"	add	sp, sp, #48\n"
"	ret	x9\n"
"	.size		my_tramp, .-my_tramp\n"
"	.popsection\n"
);

#endif /* CONFIG_ARM64 */

#ifdef CONFIG_LOONGARCH

asm (
"	.pushsection	.text, \"ax\", @progbits\n"
"	.type		my_tramp, @function\n"
"	.globl		my_tramp\n"
"   my_tramp:\n"
"	addi.d	$sp, $sp, -48\n"
"	st.d	$a0, $sp, 0\n"
"	st.d	$a1, $sp, 8\n"
"	st.d	$a2, $sp, 16\n"
"	st.d	$t0, $sp, 24\n"
"	st.d	$ra, $sp, 32\n"
"	bl	my_direct_func\n"
"	ld.d	$a0, $sp, 0\n"
"	ld.d	$a1, $sp, 8\n"
"	ld.d	$a2, $sp, 16\n"
"	ld.d	$t0, $sp, 24\n"
"	ld.d	$ra, $sp, 32\n"
"	addi.d	$sp, $sp, 48\n"
"	jr	$t0\n"
"	.size		my_tramp, .-my_tramp\n"
"	.popsection\n"
);

#endif /* CONFIG_LOONGARCH */

#ifdef CONFIG_PPC
#include <asm/ppc_asm.h>

#ifdef CONFIG_PPC64
#define STACK_FRAME_SIZE 64
#define STACK_FRAME_ARG1 32
#define STACK_FRAME_ARG2 40
#define STACK_FRAME_ARG3 48
#define STACK_FRAME_ARG4 56
#else
#define STACK_FRAME_SIZE 32
#define STACK_FRAME_ARG1 16
#define STACK_FRAME_ARG2 20
#define STACK_FRAME_ARG3 24
#define STACK_FRAME_ARG4 28
#endif

#if defined(CONFIG_PPC64_ELF_ABI_V2) && !defined(CONFIG_PPC_KERNEL_PCREL)
#define PPC64_TOC_SAVE_AND_UPDATE			\
"	std		2, 24(1)\n"			\
"	bcl		20, 31, 1f\n"			\
"   1:	mflr		12\n"				\
"	ld		2, (99f - 1b)(12)\n"
#define PPC64_TOC_RESTORE				\
"	ld		2, 24(1)\n"
#define PPC64_TOC					\
"   99:	.quad		.TOC.@tocbase\n"
#else
#define PPC64_TOC_SAVE_AND_UPDATE ""
#define PPC64_TOC_RESTORE ""
#define PPC64_TOC ""
#endif

#ifdef CONFIG_PPC_FTRACE_OUT_OF_LINE
#define PPC_FTRACE_RESTORE_LR				\
	PPC_LL"		0, "__stringify(PPC_LR_STKOFF)"(1)\n"	\
"	mtlr		0\n"
#define PPC_FTRACE_RET					\
"	blr\n"
#else
#define PPC_FTRACE_RESTORE_LR				\
	PPC_LL"		0, "__stringify(PPC_LR_STKOFF)"(1)\n"	\
"	mtctr		0\n"
#define PPC_FTRACE_RET					\
"	mtlr		0\n"				\
"	bctr\n"
#endif

asm (
"	.pushsection	.text, \"ax\", @progbits\n"
"	.type		my_tramp, @function\n"
"	.globl		my_tramp\n"
"   my_tramp:\n"
	PPC_STL"	0, "__stringify(PPC_LR_STKOFF)"(1)\n"
	PPC_STLU"	1, -"__stringify(STACK_FRAME_MIN_SIZE)"(1)\n"
"	mflr		0\n"
	PPC_STL"	0, "__stringify(PPC_LR_STKOFF)"(1)\n"
	PPC_STLU"	1, -"__stringify(STACK_FRAME_SIZE)"(1)\n"
	PPC64_TOC_SAVE_AND_UPDATE
	PPC_STL"	3, "__stringify(STACK_FRAME_ARG1)"(1)\n"
	PPC_STL"	4, "__stringify(STACK_FRAME_ARG2)"(1)\n"
	PPC_STL"	5, "__stringify(STACK_FRAME_ARG3)"(1)\n"
	PPC_STL"	6, "__stringify(STACK_FRAME_ARG4)"(1)\n"
"	bl		my_direct_func\n"
	PPC_LL"		6, "__stringify(STACK_FRAME_ARG4)"(1)\n"
	PPC_LL"		5, "__stringify(STACK_FRAME_ARG3)"(1)\n"
	PPC_LL"		4, "__stringify(STACK_FRAME_ARG2)"(1)\n"
	PPC_LL"		3, "__stringify(STACK_FRAME_ARG1)"(1)\n"
	PPC64_TOC_RESTORE
"	addi		1, 1, "__stringify(STACK_FRAME_SIZE)"\n"
	PPC_FTRACE_RESTORE_LR
"	addi		1, 1, "__stringify(STACK_FRAME_MIN_SIZE)"\n"
	PPC_LL"		0, "__stringify(PPC_LR_STKOFF)"(1)\n"
	PPC_FTRACE_RET
	PPC64_TOC
"	.size		my_tramp, .-my_tramp\n"
"	.popsection\n"
);

#endif /* CONFIG_PPC */

static struct ftrace_ops direct;

static int __init ftrace_direct_init(void)
{
	ftrace_set_filter_ip(&direct, (unsigned long) handle_mm_fault, 0, 0);

	return register_ftrace_direct(&direct, (unsigned long) my_tramp);
}

static void __exit ftrace_direct_exit(void)
{
	unregister_ftrace_direct(&direct, (unsigned long)my_tramp, true);
}

module_init(ftrace_direct_init);
module_exit(ftrace_direct_exit);

MODULE_AUTHOR("Steven Rostedt");
MODULE_DESCRIPTION("Another example use case of using register_ftrace_direct()");
MODULE_LICENSE("GPL");
Commit	Line	Data
	1	// SPDX-License-Identifier: GPL-2.0-only
	2	#include <linux/module.h>
	3
	4	#include <linux/mm.h> /* for handle_mm_fault() */
	5	#include <linux/ftrace.h>
	6	#if !defined(CONFIG_ARM64) && !defined(CONFIG_PPC32)
	7	#include <asm/asm-offsets.h>
	8	#endif
	9
	10	extern void my_direct_func(struct vm_area_struct *vma, unsigned long address,
	11	unsigned int flags, struct pt_regs *regs);
	12
	13	void my_direct_func(struct vm_area_struct *vma, unsigned long address,
	14	unsigned int flags, struct pt_regs *regs)
	15	{
	16	trace_printk("handle mm fault vma=%p address=%lx flags=%x regs=%p\n",
	17	vma, address, flags, regs);
	18	}
	19
	20	extern void my_tramp(void *);
	21
	22	#ifdef CONFIG_RISCV
	23	#include <asm/asm.h>
	24
	25	asm (
	26	" .pushsection .text, \"ax\", @progbits\n"
	27	" .type my_tramp, @function\n"
	28	" .globl my_tramp\n"
	29	" my_tramp:\n"
	30	" addi sp,sp,-5*"SZREG"\n"
	31	" "REG_S" a0,0*"SZREG"(sp)\n"
	32	" "REG_S" a1,1*"SZREG"(sp)\n"
	33	" "REG_S" a2,2*"SZREG"(sp)\n"
	34	" "REG_S" t0,3*"SZREG"(sp)\n"
	35	" "REG_S" ra,4*"SZREG"(sp)\n"
	36	" call my_direct_func\n"
	37	" "REG_L" a0,0*"SZREG"(sp)\n"
	38	" "REG_L" a1,1*"SZREG"(sp)\n"
	39	" "REG_L" a2,2*"SZREG"(sp)\n"
	40	" "REG_L" t0,3*"SZREG"(sp)\n"
	41	" "REG_L" ra,4*"SZREG"(sp)\n"
	42	" addi sp,sp,5*"SZREG"\n"
	43	" jr t0\n"
	44	" .size my_tramp, .-my_tramp\n"
	45	" .popsection\n"
	46	);
	47
	48	#endif /* CONFIG_RISCV */
	49
	50	#ifdef CONFIG_X86_64
	51
	52	#include <asm/ibt.h>
	53	#include <asm/nospec-branch.h>
	54
	55	asm (
	56	" .pushsection .text, \"ax\", @progbits\n"
	57	" .type my_tramp, @function\n"
	58	" .globl my_tramp\n"
	59	" my_tramp:"
	60	ASM_ENDBR
	61	" pushq %rbp\n"
	62	" movq %rsp, %rbp\n"
	63	CALL_DEPTH_ACCOUNT
	64	" pushq %rdi\n"
	65	" pushq %rsi\n"
	66	" pushq %rdx\n"
	67	" pushq %rcx\n"
	68	" call my_direct_func\n"
	69	" popq %rcx\n"
	70	" popq %rdx\n"
	71	" popq %rsi\n"
	72	" popq %rdi\n"
	73	" leave\n"
	74	ASM_RET
	75	" .size my_tramp, .-my_tramp\n"
	76	" .popsection\n"
	77	);
	78
	79	#endif /* CONFIG_X86_64 */
	80
	81	#ifdef CONFIG_S390
	82
	83	asm (
	84	" .pushsection .text, \"ax\", @progbits\n"
	85	" .type my_tramp, @function\n"
	86	" .globl my_tramp\n"
	87	" my_tramp:"
	88	" lgr %r1,%r15\n"
	89	" stmg %r0,%r5,"__stringify(__SF_GPRS)"(%r15)\n"
	90	" stg %r14,"__stringify(__SF_GPRS+8*8)"(%r15)\n"
	91	" aghi %r15,"__stringify(-STACK_FRAME_OVERHEAD)"\n"
	92	" stg %r1,"__stringify(__SF_BACKCHAIN)"(%r15)\n"
	93	" brasl %r14,my_direct_func\n"
	94	" aghi %r15,"__stringify(STACK_FRAME_OVERHEAD)"\n"
	95	" lmg %r0,%r5,"__stringify(__SF_GPRS)"(%r15)\n"
	96	" lg %r14,"__stringify(__SF_GPRS+8*8)"(%r15)\n"
	97	" lgr %r1,%r0\n"
	98	" br %r1\n"
	99	" .size my_tramp, .-my_tramp\n"
	100	" .popsection\n"
	101	);
	102
	103	#endif /* CONFIG_S390 */
	104
	105	#ifdef CONFIG_ARM64
	106
	107	asm (
	108	" .pushsection .text, \"ax\", @progbits\n"
	109	" .type my_tramp, @function\n"
	110	" .globl my_tramp\n"
	111	" my_tramp:"
	112	" hint 34\n" // bti c
	113	" sub sp, sp, #48\n"
	114	" stp x9, x30, [sp]\n"
	115	" stp x0, x1, [sp, #16]\n"
	116	" stp x2, x3, [sp, #32]\n"
	117	" bl my_direct_func\n"
	118	" ldp x30, x9, [sp]\n"
	119	" ldp x0, x1, [sp, #16]\n"
	120	" ldp x2, x3, [sp, #32]\n"
	121	" add sp, sp, #48\n"
	122	" ret x9\n"
	123	" .size my_tramp, .-my_tramp\n"
	124	" .popsection\n"
	125	);
	126
	127	#endif /* CONFIG_ARM64 */
	128
	129	#ifdef CONFIG_LOONGARCH
	130
	131	asm (
	132	" .pushsection .text, \"ax\", @progbits\n"
	133	" .type my_tramp, @function\n"
	134	" .globl my_tramp\n"
	135	" my_tramp:\n"
	136	" addi.d $sp, $sp, -48\n"
	137	" st.d $a0, $sp, 0\n"
	138	" st.d $a1, $sp, 8\n"
	139	" st.d $a2, $sp, 16\n"
	140	" st.d $t0, $sp, 24\n"
	141	" st.d $ra, $sp, 32\n"
	142	" bl my_direct_func\n"
	143	" ld.d $a0, $sp, 0\n"
	144	" ld.d $a1, $sp, 8\n"
	145	" ld.d $a2, $sp, 16\n"
	146	" ld.d $t0, $sp, 24\n"
	147	" ld.d $ra, $sp, 32\n"
	148	" addi.d $sp, $sp, 48\n"
	149	" jr $t0\n"
	150	" .size my_tramp, .-my_tramp\n"
	151	" .popsection\n"
	152	);
	153
	154	#endif /* CONFIG_LOONGARCH */
	155
	156	#ifdef CONFIG_PPC
	157	#include <asm/ppc_asm.h>
	158
	159	#ifdef CONFIG_PPC64
	160	#define STACK_FRAME_SIZE 64
	161	#define STACK_FRAME_ARG1 32
	162	#define STACK_FRAME_ARG2 40
	163	#define STACK_FRAME_ARG3 48
	164	#define STACK_FRAME_ARG4 56
	165	#else
	166	#define STACK_FRAME_SIZE 32
	167	#define STACK_FRAME_ARG1 16
	168	#define STACK_FRAME_ARG2 20
	169	#define STACK_FRAME_ARG3 24
	170	#define STACK_FRAME_ARG4 28
	171	#endif
	172
	173	#if defined(CONFIG_PPC64_ELF_ABI_V2) && !defined(CONFIG_PPC_KERNEL_PCREL)
	174	#define PPC64_TOC_SAVE_AND_UPDATE \
	175	" std 2, 24(1)\n" \
	176	" bcl 20, 31, 1f\n" \
	177	" 1: mflr 12\n" \
	178	" ld 2, (99f - 1b)(12)\n"
	179	#define PPC64_TOC_RESTORE \
	180	" ld 2, 24(1)\n"
	181	#define PPC64_TOC \
	182	" 99: .quad .TOC.@tocbase\n"
	183	#else
	184	#define PPC64_TOC_SAVE_AND_UPDATE ""
	185	#define PPC64_TOC_RESTORE ""
	186	#define PPC64_TOC ""
	187	#endif
	188
	189	#ifdef CONFIG_PPC_FTRACE_OUT_OF_LINE
	190	#define PPC_FTRACE_RESTORE_LR \
	191	PPC_LL" 0, "__stringify(PPC_LR_STKOFF)"(1)\n" \
	192	" mtlr 0\n"
	193	#define PPC_FTRACE_RET \
	194	" blr\n"
	195	#else
	196	#define PPC_FTRACE_RESTORE_LR \
	197	PPC_LL" 0, "__stringify(PPC_LR_STKOFF)"(1)\n" \
	198	" mtctr 0\n"
	199	#define PPC_FTRACE_RET \
	200	" mtlr 0\n" \
	201	" bctr\n"
	202	#endif
	203
	204	asm (
	205	" .pushsection .text, \"ax\", @progbits\n"
	206	" .type my_tramp, @function\n"
	207	" .globl my_tramp\n"
	208	" my_tramp:\n"
	209	PPC_STL" 0, "__stringify(PPC_LR_STKOFF)"(1)\n"
	210	PPC_STLU" 1, -"__stringify(STACK_FRAME_MIN_SIZE)"(1)\n"
	211	" mflr 0\n"
	212	PPC_STL" 0, "__stringify(PPC_LR_STKOFF)"(1)\n"
	213	PPC_STLU" 1, -"__stringify(STACK_FRAME_SIZE)"(1)\n"
	214	PPC64_TOC_SAVE_AND_UPDATE
	215	PPC_STL" 3, "__stringify(STACK_FRAME_ARG1)"(1)\n"
	216	PPC_STL" 4, "__stringify(STACK_FRAME_ARG2)"(1)\n"
	217	PPC_STL" 5, "__stringify(STACK_FRAME_ARG3)"(1)\n"
	218	PPC_STL" 6, "__stringify(STACK_FRAME_ARG4)"(1)\n"
	219	" bl my_direct_func\n"
	220	PPC_LL" 6, "__stringify(STACK_FRAME_ARG4)"(1)\n"
	221	PPC_LL" 5, "__stringify(STACK_FRAME_ARG3)"(1)\n"
	222	PPC_LL" 4, "__stringify(STACK_FRAME_ARG2)"(1)\n"
	223	PPC_LL" 3, "__stringify(STACK_FRAME_ARG1)"(1)\n"
	224	PPC64_TOC_RESTORE
	225	" addi 1, 1, "__stringify(STACK_FRAME_SIZE)"\n"
	226	PPC_FTRACE_RESTORE_LR
	227	" addi 1, 1, "__stringify(STACK_FRAME_MIN_SIZE)"\n"
	228	PPC_LL" 0, "__stringify(PPC_LR_STKOFF)"(1)\n"
	229	PPC_FTRACE_RET
	230	PPC64_TOC
	231	" .size my_tramp, .-my_tramp\n"
	232	" .popsection\n"
	233	);
	234
	235	#endif /* CONFIG_PPC */
	236
	237	static struct ftrace_ops direct;
	238
	239	static int __init ftrace_direct_init(void)
	240	{
	241	ftrace_set_filter_ip(&direct, (unsigned long) handle_mm_fault, 0, 0);
	242
	243	return register_ftrace_direct(&direct, (unsigned long) my_tramp);
	244	}
	245
	246	static void __exit ftrace_direct_exit(void)
	247	{
	248	unregister_ftrace_direct(&direct, (unsigned long)my_tramp, true);
	249	}
	250
	251	module_init(ftrace_direct_init);
	252	module_exit(ftrace_direct_exit);
	253
	254	MODULE_AUTHOR("Steven Rostedt");
	255	MODULE_DESCRIPTION("Another example use case of using register_ftrace_direct()");
	256	MODULE_LICENSE("GPL");