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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 | /* SPDX-License-Identifier: GPL-2.0-or-later */ /* * Code to prepare detour buffer for optprobes in Kernel. * * Copyright 2017, Anju T, IBM Corp. */ #include <asm/ppc_asm.h> #include <asm/ptrace.h> #include <asm/asm-offsets.h> #ifdef CONFIG_PPC64 #define SAVE_30GPRS(base) SAVE_GPRS(2, 31, base) #define REST_30GPRS(base) REST_GPRS(2, 31, base) #define TEMPLATE_FOR_IMM_LOAD_INSNS nop; nop; nop; nop; nop #else #define SAVE_30GPRS(base) stmw r2, GPR2(base) #define REST_30GPRS(base) lmw r2, GPR2(base) #define TEMPLATE_FOR_IMM_LOAD_INSNS nop; nop; nop #endif #define OPT_SLOT_SIZE 65536 .balign 4 /* * Reserve an area to allocate slots for detour buffer. * This is part of .text section (rather than vmalloc area) * as this needs to be within 32MB of the probed address. */ .global optinsn_slot optinsn_slot: .space OPT_SLOT_SIZE /* * Optprobe template: * This template gets copied into one of the slots in optinsn_slot * and gets fixed up with real optprobe structures et al. */ .global optprobe_template_entry optprobe_template_entry: /* Create an in-memory pt_regs */ PPC_STLU r1,-INT_FRAME_SIZE(r1) SAVE_GPR(0,r1) /* Save the previous SP into stack */ addi r0,r1,INT_FRAME_SIZE PPC_STL r0,GPR1(r1) SAVE_30GPRS(r1) /* Save SPRS */ mfmsr r5 PPC_STL r5,_MSR(r1) li r5,0x700 PPC_STL r5,_TRAP(r1) li r5,0 PPC_STL r5,ORIG_GPR3(r1) PPC_STL r5,RESULT(r1) mfctr r5 PPC_STL r5,_CTR(r1) mflr r5 PPC_STL r5,_LINK(r1) mfspr r5,SPRN_XER PPC_STL r5,_XER(r1) mfcr r5 PPC_STL r5,_CCR(r1) #ifdef CONFIG_PPC64 lbz r5,PACAIRQSOFTMASK(r13) std r5,SOFTE(r1) #endif /* * We may get here from a module, so load the kernel TOC in r2. * The original TOC gets restored when pt_regs is restored * further below. */ #ifdef CONFIG_PPC64 LOAD_PACA_TOC() #endif .global optprobe_template_op_address optprobe_template_op_address: /* * Parameters to optimized_callback(): * 1. optimized_kprobe structure in r3 */ TEMPLATE_FOR_IMM_LOAD_INSNS /* 2. pt_regs pointer in r4 */ addi r4,r1,STACK_INT_FRAME_REGS .global optprobe_template_call_handler optprobe_template_call_handler: /* Branch to optimized_callback() */ nop /* * Parameters for instruction emulation: * 1. Pass SP in register r3. */ addi r3,r1,STACK_INT_FRAME_REGS .global optprobe_template_insn optprobe_template_insn: /* 2, Pass instruction to be emulated in r4 */ TEMPLATE_FOR_IMM_LOAD_INSNS .global optprobe_template_call_emulate optprobe_template_call_emulate: /* Branch to emulate_step() */ nop /* * All done. * Now, restore the registers... */ PPC_LL r5,_MSR(r1) mtmsr r5 PPC_LL r5,_CTR(r1) mtctr r5 PPC_LL r5,_LINK(r1) mtlr r5 PPC_LL r5,_XER(r1) mtxer r5 PPC_LL r5,_CCR(r1) mtcr r5 REST_GPR(0,r1) REST_30GPRS(r1) /* Restore the previous SP */ addi r1,r1,INT_FRAME_SIZE .global optprobe_template_ret optprobe_template_ret: /* ... and jump back from trampoline */ nop .global optprobe_template_end optprobe_template_end: |