mirror of
https://github.com/torvalds/linux.git
synced 2024-12-05 10:32:35 +00:00
8778ba2c8a
This patch implements CONFIG_DYNAMIC_FTRACE_WITH_REGS on LoongArch, which allows a traced function's arguments (and some other registers) to be captured into a struct pt_regs, allowing these to be inspected and modified. Co-developed-by: Jinyang He <hejinyang@loongson.cn> Signed-off-by: Jinyang He <hejinyang@loongson.cn> Signed-off-by: Qing Zhang <zhangqing@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
150 lines
3.7 KiB
ArmAsm
150 lines
3.7 KiB
ArmAsm
/* SPDX-License-Identifier: GPL-2.0 */
|
|
/*
|
|
* Copyright (C) 2022 Loongson Technology Corporation Limited
|
|
*/
|
|
|
|
#include <asm/export.h>
|
|
#include <asm/ftrace.h>
|
|
#include <asm/regdef.h>
|
|
#include <asm/stackframe.h>
|
|
|
|
.text
|
|
/*
|
|
* Due to -fpatchable-function-entry=2: the compiler inserted 2 NOPs before the
|
|
* regular C function prologue. When PC arrived here, the last 2 instructions
|
|
* are as follows:
|
|
* move t0, ra
|
|
* bl callsite (for modules, callsite is a tramplione)
|
|
*
|
|
* modules trampoline is as follows:
|
|
* lu12i.w t1, callsite[31:12]
|
|
* lu32i.d t1, callsite[51:32]
|
|
* lu52i.d t1, t1, callsite[63:52]
|
|
* jirl zero, t1, callsite[11:0] >> 2
|
|
*
|
|
* See arch/loongarch/kernel/ftrace_dyn.c for details. Here, pay attention to
|
|
* that the T series regs are available and safe because each C functions
|
|
* follows the LoongArch's psABI as well.
|
|
*/
|
|
|
|
.macro ftrace_regs_entry allregs=0
|
|
PTR_ADDI sp, sp, -PT_SIZE
|
|
PTR_S t0, sp, PT_R1 /* Save parent ra at PT_R1(RA) */
|
|
PTR_S a0, sp, PT_R4
|
|
PTR_S a1, sp, PT_R5
|
|
PTR_S a2, sp, PT_R6
|
|
PTR_S a3, sp, PT_R7
|
|
PTR_S a4, sp, PT_R8
|
|
PTR_S a5, sp, PT_R9
|
|
PTR_S a6, sp, PT_R10
|
|
PTR_S a7, sp, PT_R11
|
|
PTR_S fp, sp, PT_R22
|
|
.if \allregs
|
|
PTR_S tp, sp, PT_R2
|
|
PTR_S t0, sp, PT_R12
|
|
PTR_S t1, sp, PT_R13
|
|
PTR_S t2, sp, PT_R14
|
|
PTR_S t3, sp, PT_R15
|
|
PTR_S t4, sp, PT_R16
|
|
PTR_S t5, sp, PT_R17
|
|
PTR_S t6, sp, PT_R18
|
|
PTR_S t7, sp, PT_R19
|
|
PTR_S t8, sp, PT_R20
|
|
PTR_S u0, sp, PT_R21
|
|
PTR_S s0, sp, PT_R23
|
|
PTR_S s1, sp, PT_R24
|
|
PTR_S s2, sp, PT_R25
|
|
PTR_S s3, sp, PT_R26
|
|
PTR_S s4, sp, PT_R27
|
|
PTR_S s5, sp, PT_R28
|
|
PTR_S s6, sp, PT_R29
|
|
PTR_S s7, sp, PT_R30
|
|
PTR_S s8, sp, PT_R31
|
|
/* Clear it for later use as a flag sometimes. */
|
|
PTR_S zero, sp, PT_R0
|
|
.endif
|
|
PTR_S ra, sp, PT_ERA /* Save trace function ra at PT_ERA */
|
|
PTR_ADDI t8, sp, PT_SIZE
|
|
PTR_S t8, sp, PT_R3
|
|
.endm
|
|
|
|
SYM_FUNC_START(ftrace_stub)
|
|
jr ra
|
|
SYM_FUNC_END(ftrace_stub)
|
|
|
|
SYM_CODE_START(ftrace_common)
|
|
PTR_ADDI a0, ra, -8 /* arg0: ip */
|
|
move a1, t0 /* arg1: parent_ip */
|
|
la.pcrel t1, function_trace_op
|
|
PTR_L a2, t1, 0 /* arg2: op */
|
|
move a3, sp /* arg3: regs */
|
|
|
|
SYM_INNER_LABEL(ftrace_call, SYM_L_GLOBAL)
|
|
bl ftrace_stub
|
|
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
|
|
SYM_INNER_LABEL(ftrace_graph_call, SYM_L_GLOBAL)
|
|
nop /* b ftrace_graph_caller */
|
|
#endif
|
|
|
|
/*
|
|
* As we didn't use S series regs in this assmembly code and all calls
|
|
* are C function which will save S series regs by themselves, there is
|
|
* no need to restore S series regs. The T series is available and safe
|
|
* at the callsite, so there is no need to restore the T series regs.
|
|
*/
|
|
ftrace_common_return:
|
|
PTR_L ra, sp, PT_R1
|
|
PTR_L a0, sp, PT_R4
|
|
PTR_L a1, sp, PT_R5
|
|
PTR_L a2, sp, PT_R6
|
|
PTR_L a3, sp, PT_R7
|
|
PTR_L a4, sp, PT_R8
|
|
PTR_L a5, sp, PT_R9
|
|
PTR_L a6, sp, PT_R10
|
|
PTR_L a7, sp, PT_R11
|
|
PTR_L fp, sp, PT_R22
|
|
PTR_L t0, sp, PT_ERA
|
|
PTR_ADDI sp, sp, PT_SIZE
|
|
jr t0
|
|
SYM_CODE_END(ftrace_common)
|
|
|
|
SYM_CODE_START(ftrace_caller)
|
|
ftrace_regs_entry allregs=0
|
|
b ftrace_common
|
|
SYM_CODE_END(ftrace_caller)
|
|
|
|
#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
|
|
SYM_CODE_START(ftrace_regs_caller)
|
|
ftrace_regs_entry allregs=1
|
|
b ftrace_common
|
|
SYM_CODE_END(ftrace_regs_caller)
|
|
#endif
|
|
|
|
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
|
|
SYM_CODE_START(ftrace_graph_caller)
|
|
PTR_L a0, sp, PT_ERA
|
|
PTR_ADDI a0, a0, -8 /* arg0: self_addr */
|
|
PTR_ADDI a1, sp, PT_R1 /* arg1: parent */
|
|
bl prepare_ftrace_return
|
|
b ftrace_common_return
|
|
SYM_CODE_END(ftrace_graph_caller)
|
|
|
|
SYM_CODE_START(return_to_handler)
|
|
/* Save return value regs */
|
|
PTR_ADDI sp, sp, -2 * SZREG
|
|
PTR_S a0, sp, 0
|
|
PTR_S a1, sp, SZREG
|
|
|
|
move a0, zero
|
|
bl ftrace_return_to_handler
|
|
move ra, a0
|
|
|
|
/* Restore return value regs */
|
|
PTR_L a0, sp, 0
|
|
PTR_L a1, sp, SZREG
|
|
PTR_ADDI sp, sp, 2 * SZREG
|
|
|
|
jr ra
|
|
SYM_CODE_END(return_to_handler)
|
|
#endif
|