projects / linux-2.6-block.git / blame
| Commit | Line | Data |
|---|---|---|
| 51c9c084 A |
1 | /* |
| 2 | * Code to prepare detour buffer for optprobes in Kernel. | |
| 3 | * | |
| 4 | * Copyright 2017, Anju T, IBM Corp. | |
| 5 | * | |
| 6 | * This program is free software; you can redistribute it and/or | |
| 7 | * modify it under the terms of the GNU General Public License | |
| 8 | * as published by the Free Software Foundation; either version | |
| 9 | * 2 of the License, or (at your option) any later version. | |
| 10 | */ | |
| 11 | ||
| 12 | #include <asm/ppc_asm.h> | |
| 13 | #include <asm/ptrace.h> | |
| 14 | #include <asm/asm-offsets.h> | |
| 15 | ||
| 16 | #define OPT_SLOT_SIZE 65536 | |
| 17 | ||
| 18 | .balign 4 | |
| 19 | ||
| 20 | /* | |
| 21 | * Reserve an area to allocate slots for detour buffer. | |
| 22 | * This is part of .text section (rather than vmalloc area) | |
| 23 | * as this needs to be within 32MB of the probed address. | |
| 24 | */ | |
| 25 | .global optinsn_slot | |
| 26 | optinsn_slot: | |
| 27 | .space OPT_SLOT_SIZE | |
| 28 | ||
| 29 | /* | |
| 30 | * Optprobe template: | |
| 31 | * This template gets copied into one of the slots in optinsn_slot | |
| 32 | * and gets fixed up with real optprobe structures et al. | |
| 33 | */ | |
| 34 | .global optprobe_template_entry | |
| 35 | optprobe_template_entry: | |
| 36 | /* Create an in-memory pt_regs */ | |
| 37 | stdu r1,-INT_FRAME_SIZE(r1) | |
| 38 | SAVE_GPR(0,r1) | |
| 39 | /* Save the previous SP into stack */ | |
| 40 | addi r0,r1,INT_FRAME_SIZE | |
| 41 | std r0,GPR1(r1) | |
| 42 | SAVE_10GPRS(2,r1) | |
| 43 | SAVE_10GPRS(12,r1) | |
| 44 | SAVE_10GPRS(22,r1) | |
| 45 | /* Save SPRS */ | |
| 46 | mfmsr r5 | |
| 47 | std r5,_MSR(r1) | |
| 48 | li r5,0x700 | |
| 49 | std r5,_TRAP(r1) | |
| 50 | li r5,0 | |
| 51 | std r5,ORIG_GPR3(r1) | |
| 52 | std r5,RESULT(r1) | |
| 53 | mfctr r5 | |
| 54 | std r5,_CTR(r1) | |
| 55 | mflr r5 | |
| 56 | std r5,_LINK(r1) | |
| 57 | mfspr r5,SPRN_XER | |
| 58 | std r5,_XER(r1) | |
| 59 | mfcr r5 | |
| 60 | std r5,_CCR(r1) | |
| 4e26bc4a | 61 | lbz r5,PACAIRQSOFTMASK(r13) |
| 51c9c084 | 62 | std r5,SOFTE(r1) |
| 51c9c084 | 63 | |
| f558b37b NR |
64 | /* |
| 65 | * We may get here from a module, so load the kernel TOC in r2. | |
| 66 | * The original TOC gets restored when pt_regs is restored | |
| 67 | * further below. | |
| 68 | */ | |
| 69 | ld r2,PACATOC(r13) | |
| 70 | ||
| 51c9c084 A |
71 | .global optprobe_template_op_address |
| 72 | optprobe_template_op_address: | |
| 73 | /* | |
| 74 | * Parameters to optimized_callback(): | |
| 75 | * 1. optimized_kprobe structure in r3 | |
| 76 | */ | |
| 77 | nop | |
| 78 | nop | |
| 79 | nop | |
| 80 | nop | |
| 81 | nop | |
| 82 | /* 2. pt_regs pointer in r4 */ | |
| 83 | addi r4,r1,STACK_FRAME_OVERHEAD | |
| 84 | ||
| 85 | .global optprobe_template_call_handler | |
| 86 | optprobe_template_call_handler: | |
| 87 | /* Branch to optimized_callback() */ | |
| 88 | nop | |
| 89 | ||
| 90 | /* | |
| 91 | * Parameters for instruction emulation: | |
| 92 | * 1. Pass SP in register r3. | |
| 93 | */ | |
| 94 | addi r3,r1,STACK_FRAME_OVERHEAD | |
| 95 | ||
| 96 | .global optprobe_template_insn | |
| 97 | optprobe_template_insn: | |
| 98 | /* 2, Pass instruction to be emulated in r4 */ | |
| 99 | nop | |
| 100 | nop | |
| 101 | ||
| 102 | .global optprobe_template_call_emulate | |
| 103 | optprobe_template_call_emulate: | |
| 104 | /* Branch to emulate_step() */ | |
| 105 | nop | |
| 106 | ||
| 107 | /* | |
| 108 | * All done. | |
| 109 | * Now, restore the registers... | |
| 110 | */ | |
| 111 | ld r5,_MSR(r1) | |
| 112 | mtmsr r5 | |
| 113 | ld r5,_CTR(r1) | |
| 114 | mtctr r5 | |
| 115 | ld r5,_LINK(r1) | |
| 116 | mtlr r5 | |
| 117 | ld r5,_XER(r1) | |
| 118 | mtxer r5 | |
| 119 | ld r5,_CCR(r1) | |
| 120 | mtcr r5 | |
| 51c9c084 A |
121 | REST_GPR(0,r1) |
| 122 | REST_10GPRS(2,r1) | |
| 123 | REST_10GPRS(12,r1) | |
| 124 | REST_10GPRS(22,r1) | |
| 125 | /* Restore the previous SP */ | |
| 126 | addi r1,r1,INT_FRAME_SIZE | |
| 127 | ||
| 128 | .global optprobe_template_ret | |
| 129 | optprobe_template_ret: | |
| 130 | /* ... and jump back from trampoline */ | |
| 131 | nop | |
| 132 | ||
| 133 | .global optprobe_template_end | |
| 134 | optprobe_template_end: |