2019-11-08 23:27:45 +03:00
// SPDX-License-Identifier: GPL-2.0-only
# include <linux/module.h>
# include <linux/mm.h> /* for handle_mm_fault() */
# include <linux/ftrace.h>
2021-10-12 16:38:02 +03:00
# include <asm/asm-offsets.h>
2019-11-08 23:27:45 +03:00
2021-12-19 16:53:17 +03:00
extern void my_direct_func ( struct vm_area_struct * vma ,
unsigned long address , unsigned int flags ) ;
2019-11-08 23:27:45 +03:00
void my_direct_func ( struct vm_area_struct * vma ,
unsigned long address , unsigned int flags )
{
trace_printk ( " handle mm fault vma=%p address=%lx flags=%x \n " ,
vma , address , flags ) ;
}
extern void my_tramp ( void * ) ;
2021-10-12 16:38:02 +03:00
# ifdef CONFIG_X86_64
2022-03-08 18:30:34 +03:00
# include <asm/ibt.h>
2023-01-30 11:59:54 +03:00
# include <asm/nospec-branch.h>
2022-03-08 18:30:34 +03:00
2019-11-08 23:27:45 +03:00
asm (
" .pushsection .text, \" ax \" , @progbits \n "
2020-04-24 23:40:43 +03:00
" .type my_tramp, @function \n "
2020-11-13 21:34:14 +03:00
" .globl my_tramp \n "
2019-11-08 23:27:45 +03:00
" my_tramp: "
2022-03-08 18:30:34 +03:00
ASM_ENDBR
2019-11-08 23:27:45 +03:00
" pushq %rbp \n "
" movq %rsp, %rbp \n "
2022-09-15 14:11:37 +03:00
CALL_DEPTH_ACCOUNT
2019-11-08 23:27:45 +03:00
" pushq %rdi \n "
" pushq %rsi \n "
" pushq %rdx \n "
" call my_direct_func \n "
" popq %rdx \n "
" popq %rsi \n "
" popq %rdi \n "
" leave \n "
2021-12-04 16:43:41 +03:00
ASM_RET
2020-04-24 23:40:43 +03:00
" .size my_tramp, .-my_tramp \n "
2019-11-08 23:27:45 +03:00
" .popsection \n "
) ;
2021-10-12 16:38:02 +03:00
# 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 */
2019-11-08 23:27:45 +03:00
2023-05-01 12:19:53 +03:00
# 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 */
2023-03-21 17:04:19 +03:00
static struct ftrace_ops direct ;
2019-11-08 23:27:45 +03:00
static int __init ftrace_direct_init ( void )
{
2023-03-21 17:04:19 +03:00
ftrace_set_filter_ip ( & direct , ( unsigned long ) handle_mm_fault , 0 , 0 ) ;
2023-03-21 17:04:21 +03:00
return register_ftrace_direct ( & direct , ( unsigned long ) my_tramp ) ;
2019-11-08 23:27:45 +03:00
}
static void __exit ftrace_direct_exit ( void )
{
2023-03-21 17:04:21 +03:00
unregister_ftrace_direct ( & direct , ( unsigned long ) my_tramp , true ) ;
2019-11-08 23:27:45 +03:00
}
module_init ( ftrace_direct_init ) ;
module_exit ( ftrace_direct_exit ) ;
MODULE_AUTHOR ( " Steven Rostedt " ) ;
2023-03-21 17:04:21 +03:00
MODULE_DESCRIPTION ( " Another example use case of using register_ftrace_direct() " ) ;
2019-11-08 23:27:45 +03:00
MODULE_LICENSE ( " GPL " ) ;