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cb8a2ef084
The kernel CONFIG_UNWINDER_ORC option enables the ORC unwinder, which is similar in concept to a DWARF unwinder. The difference is that the format of the ORC data is much simpler than DWARF, which in turn allows the ORC unwinder to be much simpler and faster. The ORC data consists of unwind tables which are generated by objtool. After analyzing all the code paths of a .o file, it determines information about the stack state at each instruction address in the file and outputs that information to the .orc_unwind and .orc_unwind_ip sections. The per-object ORC sections are combined at link time and are sorted and post-processed at boot time. The unwinder uses the resulting data to correlate instruction addresses with their stack states at run time. Most of the logic are similar with x86, in order to get ra info before ra is saved into stack, add ra_reg and ra_offset into orc_entry. At the same time, modify some arch-specific code to silence the objtool warnings. Co-developed-by: Jinyang He <hejinyang@loongson.cn> Signed-off-by: Jinyang He <hejinyang@loongson.cn> Co-developed-by: Youling Tang <tangyouling@loongson.cn> Signed-off-by: Youling Tang <tangyouling@loongson.cn> Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
167 lines
4.2 KiB
ArmAsm
167 lines
4.2 KiB
ArmAsm
/* SPDX-License-Identifier: GPL-2.0 */
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/*
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* Copyright (C) 2022 Loongson Technology Corporation Limited
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*/
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#include <asm/ftrace.h>
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#include <asm/regdef.h>
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#include <asm/stackframe.h>
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.text
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/*
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* Due to -fpatchable-function-entry=2: the compiler inserted 2 NOPs before the
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* regular C function prologue. When PC arrived here, the last 2 instructions
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* are as follows:
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* move t0, ra
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* bl callsite (for modules, callsite is a tramplione)
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*
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* modules trampoline is as follows:
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* lu12i.w t1, callsite[31:12]
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* lu32i.d t1, callsite[51:32]
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* lu52i.d t1, t1, callsite[63:52]
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* jirl zero, t1, callsite[11:0] >> 2
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*
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* See arch/loongarch/kernel/ftrace_dyn.c for details. Here, pay attention to
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* that the T series regs are available and safe because each C functions
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* follows the LoongArch's psABI as well.
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*/
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.macro ftrace_regs_entry allregs=0
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PTR_ADDI sp, sp, -PT_SIZE
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PTR_S t0, sp, PT_R1 /* Save parent ra at PT_R1(RA) */
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PTR_S a0, sp, PT_R4
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PTR_S a1, sp, PT_R5
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PTR_S a2, sp, PT_R6
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PTR_S a3, sp, PT_R7
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PTR_S a4, sp, PT_R8
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PTR_S a5, sp, PT_R9
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PTR_S a6, sp, PT_R10
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PTR_S a7, sp, PT_R11
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PTR_S fp, sp, PT_R22
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.if \allregs
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PTR_S tp, sp, PT_R2
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PTR_S t0, sp, PT_R12
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PTR_S t2, sp, PT_R14
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PTR_S t3, sp, PT_R15
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PTR_S t4, sp, PT_R16
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PTR_S t5, sp, PT_R17
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PTR_S t6, sp, PT_R18
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PTR_S t7, sp, PT_R19
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PTR_S t8, sp, PT_R20
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PTR_S u0, sp, PT_R21
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PTR_S s0, sp, PT_R23
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PTR_S s1, sp, PT_R24
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PTR_S s2, sp, PT_R25
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PTR_S s3, sp, PT_R26
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PTR_S s4, sp, PT_R27
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PTR_S s5, sp, PT_R28
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PTR_S s6, sp, PT_R29
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PTR_S s7, sp, PT_R30
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PTR_S s8, sp, PT_R31
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/* Clear it for later use as a flag sometimes. */
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PTR_S zero, sp, PT_R0
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.endif
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PTR_S ra, sp, PT_ERA /* Save trace function ra at PT_ERA */
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move t1, zero
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PTR_S t1, sp, PT_R13
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PTR_ADDI t8, sp, PT_SIZE
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PTR_S t8, sp, PT_R3
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.endm
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SYM_FUNC_START(ftrace_stub)
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jr ra
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SYM_FUNC_END(ftrace_stub)
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SYM_CODE_START(ftrace_common)
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UNWIND_HINT_UNDEFINED
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PTR_ADDI a0, ra, -8 /* arg0: ip */
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move a1, t0 /* arg1: parent_ip */
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la.pcrel t1, function_trace_op
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PTR_L a2, t1, 0 /* arg2: op */
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move a3, sp /* arg3: regs */
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SYM_INNER_LABEL(ftrace_call, SYM_L_GLOBAL)
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bl ftrace_stub
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#ifdef CONFIG_FUNCTION_GRAPH_TRACER
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SYM_INNER_LABEL(ftrace_graph_call, SYM_L_GLOBAL)
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nop /* b ftrace_graph_caller */
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#endif
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/*
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* As we didn't use S series regs in this assmembly code and all calls
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* are C function which will save S series regs by themselves, there is
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* no need to restore S series regs. The T series is available and safe
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* at the callsite, so there is no need to restore the T series regs.
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*/
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ftrace_common_return:
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PTR_L ra, sp, PT_R1
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PTR_L a0, sp, PT_R4
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PTR_L a1, sp, PT_R5
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PTR_L a2, sp, PT_R6
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PTR_L a3, sp, PT_R7
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PTR_L a4, sp, PT_R8
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PTR_L a5, sp, PT_R9
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PTR_L a6, sp, PT_R10
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PTR_L a7, sp, PT_R11
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PTR_L fp, sp, PT_R22
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PTR_L t0, sp, PT_ERA
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PTR_L t1, sp, PT_R13
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PTR_ADDI sp, sp, PT_SIZE
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bnez t1, .Ldirect
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jr t0
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.Ldirect:
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jr t1
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SYM_CODE_END(ftrace_common)
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SYM_CODE_START(ftrace_caller)
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UNWIND_HINT_UNDEFINED
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ftrace_regs_entry allregs=0
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b ftrace_common
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SYM_CODE_END(ftrace_caller)
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#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
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SYM_CODE_START(ftrace_regs_caller)
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UNWIND_HINT_UNDEFINED
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ftrace_regs_entry allregs=1
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b ftrace_common
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SYM_CODE_END(ftrace_regs_caller)
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#endif
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#ifdef CONFIG_FUNCTION_GRAPH_TRACER
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SYM_CODE_START(ftrace_graph_caller)
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UNWIND_HINT_UNDEFINED
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PTR_L a0, sp, PT_ERA
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PTR_ADDI a0, a0, -8 /* arg0: self_addr */
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PTR_ADDI a1, sp, PT_R1 /* arg1: parent */
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bl prepare_ftrace_return
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b ftrace_common_return
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SYM_CODE_END(ftrace_graph_caller)
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SYM_CODE_START(return_to_handler)
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UNWIND_HINT_UNDEFINED
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/* Save return value regs */
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PTR_ADDI sp, sp, -FGRET_REGS_SIZE
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PTR_S a0, sp, FGRET_REGS_A0
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PTR_S a1, sp, FGRET_REGS_A1
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PTR_S zero, sp, FGRET_REGS_FP
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move a0, sp
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bl ftrace_return_to_handler
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move ra, a0
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/* Restore return value regs */
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PTR_L a0, sp, FGRET_REGS_A0
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PTR_L a1, sp, FGRET_REGS_A1
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PTR_ADDI sp, sp, FGRET_REGS_SIZE
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jr ra
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SYM_CODE_END(return_to_handler)
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#endif
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#ifdef CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS
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SYM_CODE_START(ftrace_stub_direct_tramp)
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UNWIND_HINT_UNDEFINED
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jr t0
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SYM_CODE_END(ftrace_stub_direct_tramp)
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#endif /* CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS */
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