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#include <linux/sched/stat.h> 7#ifndef CONFIG_ARM64 8#include <asm/asm-offsets.h> 9#endif 10 11extern void my_direct_func(unsigned long ip); 12 13void my_direct_func(unsigned long ip) 14{ 15 trace_printk("ip %lx\n", ip); 16} 17 18extern void my_tramp(void *); 19 20#ifdef CONFIG_RISCV 21#include <asm/asm.h> 22 23asm ( 24" .pushsection .text, \"ax\", @progbits\n" 25" .type my_tramp, @function\n" 26" .globl my_tramp\n" 27" my_tramp:\n" 28" addi sp,sp,-3*"SZREG"\n" 29" "REG_S" a0,0*"SZREG"(sp)\n" 30" "REG_S" t0,1*"SZREG"(sp)\n" 31" "REG_S" ra,2*"SZREG"(sp)\n" 32" mv a0,t0\n" 33" call my_direct_func\n" 34" "REG_L" a0,0*"SZREG"(sp)\n" 35" "REG_L" t0,1*"SZREG"(sp)\n" 36" "REG_L" ra,2*"SZREG"(sp)\n" 37" addi sp,sp,3*"SZREG"\n" 38" jr t0\n" 39" .size my_tramp, .-my_tramp\n" 40" .popsection\n" 41); 42 43#endif /* CONFIG_RISCV */ 44 45#ifdef CONFIG_X86_64 46 47#include <asm/ibt.h> 48#include <asm/nospec-branch.h> 49 50asm ( 51" .pushsection .text, \"ax\", @progbits\n" 52" .type my_tramp, @function\n" 53" .globl my_tramp\n" 54" my_tramp:" 55 ASM_ENDBR 56" pushq %rbp\n" 57" movq %rsp, %rbp\n" 58 CALL_DEPTH_ACCOUNT 59" pushq %rdi\n" 60" movq 8(%rbp), %rdi\n" 61" call my_direct_func\n" 62" popq %rdi\n" 63" leave\n" 64 ASM_RET 65" .size my_tramp, .-my_tramp\n" 66" .popsection\n" 67); 68 69#endif /* CONFIG_X86_64 */ 70 71#ifdef CONFIG_S390 72 73asm ( 74" .pushsection .text, \"ax\", @progbits\n" 75" .type my_tramp, @function\n" 76" .globl my_tramp\n" 77" my_tramp:" 78" lgr %r1,%r15\n" 79" stmg %r0,%r5,"__stringify(__SF_GPRS)"(%r15)\n" 80" stg %r14,"__stringify(__SF_GPRS+8*8)"(%r15)\n" 81" aghi %r15,"__stringify(-STACK_FRAME_OVERHEAD)"\n" 82" stg %r1,"__stringify(__SF_BACKCHAIN)"(%r15)\n" 83" lgr %r2,%r0\n" 84" brasl %r14,my_direct_func\n" 85" aghi %r15,"__stringify(STACK_FRAME_OVERHEAD)"\n" 86" lmg %r0,%r5,"__stringify(__SF_GPRS)"(%r15)\n" 87" lg %r14,"__stringify(__SF_GPRS+8*8)"(%r15)\n" 88" lgr %r1,%r0\n" 89" br %r1\n" 90" .size my_tramp, .-my_tramp\n" 91" .popsection\n" 92); 93 94#endif /* CONFIG_S390 */ 95 96#ifdef CONFIG_ARM64 97 98asm ( 99" .pushsection .text, \"ax\", @progbits\n" 100" .type my_tramp, @function\n" 101" .globl my_tramp\n" 102" my_tramp:" 103" hint 34\n" // bti c 104" sub sp, sp, #32\n" 105" stp x9, x30, [sp]\n" 106" str x0, [sp, #16]\n" 107" mov x0, x30\n" 108" bl my_direct_func\n" 109" ldp x30, x9, [sp]\n" 110" ldr x0, [sp, #16]\n" 111" add sp, sp, #32\n" 112" ret x9\n" 113" .size my_tramp, .-my_tramp\n" 114" .popsection\n" 115); 116 117#endif /* CONFIG_ARM64 */ 118 119#ifdef CONFIG_LOONGARCH 120 121#include <asm/asm.h> 122asm ( 123" .pushsection .text, \"ax\", @progbits\n" 124" .type my_tramp, @function\n" 125" .globl my_tramp\n" 126" my_tramp:\n" 127" addi.d $sp, $sp, -32\n" 128" st.d $a0, $sp, 0\n" 129" st.d $t0, $sp, 8\n" 130" st.d $ra, $sp, 16\n" 131" move $a0, $t0\n" 132" bl my_direct_func\n" 133" ld.d $a0, $sp, 0\n" 134" ld.d $t0, $sp, 8\n" 135" ld.d $ra, $sp, 16\n" 136" addi.d $sp, $sp, 32\n" 137" jr $t0\n" 138" .size my_tramp, .-my_tramp\n" 139" .popsection\n" 140); 141 142#endif /* CONFIG_LOONGARCH */ 143 144static struct ftrace_ops direct; 145 146static int __init ftrace_direct_multi_init(void) 147{ 148 ftrace_set_filter_ip(&direct, (unsigned long) wake_up_process, 0, 0); 149 ftrace_set_filter_ip(&direct, (unsigned long) schedule, 0, 0); 150 151 return register_ftrace_direct(&direct, (unsigned long) my_tramp); 152} 153 154static void __exit ftrace_direct_multi_exit(void) 155{ 156 unregister_ftrace_direct(&direct, (unsigned long) my_tramp, true); 157} 158 159module_init(ftrace_direct_multi_init); 160module_exit(ftrace_direct_multi_exit); 161 162MODULE_AUTHOR("Jiri Olsa"); 163MODULE_DESCRIPTION("Example use case of using register_ftrace_direct_multi()"); 164MODULE_LICENSE("GPL"); 165