1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Ptrace support for Hexagon 4 * 5 * Copyright (c) 2010-2013, The Linux Foundation. All rights reserved. 6 */ 7 8 #include <linux/kernel.h> 9 #include <linux/sched.h> 10 #include <linux/sched/task_stack.h> 11 #include <linux/mm.h> 12 #include <linux/smp.h> 13 #include <linux/errno.h> 14 #include <linux/ptrace.h> 15 #include <linux/regset.h> 16 #include <linux/user.h> 17 #include <linux/elf.h> 18 19 #include <asm/user.h> 20 21 #if arch_has_single_step() 22 /* Both called from ptrace_resume */ 23 void user_enable_single_step(struct task_struct *child) 24 { 25 pt_set_singlestep(task_pt_regs(child)); 26 set_tsk_thread_flag(child, TIF_SINGLESTEP); 27 } 28 29 void user_disable_single_step(struct task_struct *child) 30 { 31 pt_clr_singlestep(task_pt_regs(child)); 32 clear_tsk_thread_flag(child, TIF_SINGLESTEP); 33 } 34 #endif 35 36 static int genregs_get(struct task_struct *target, 37 const struct user_regset *regset, 38 unsigned int pos, unsigned int count, 39 void *kbuf, void __user *ubuf) 40 { 41 int ret; 42 unsigned int dummy; 43 struct pt_regs *regs = task_pt_regs(target); 44 45 46 if (!regs) 47 return -EIO; 48 49 /* The general idea here is that the copyout must happen in 50 * exactly the same order in which the userspace expects these 51 * regs. Now, the sequence in userspace does not match the 52 * sequence in the kernel, so everything past the 32 gprs 53 * happens one at a time. 54 */ 55 ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, 56 ®s->r00, 0, 32*sizeof(unsigned long)); 57 58 #define ONEXT(KPT_REG, USR_REG) \ 59 if (!ret) \ 60 ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, \ 61 KPT_REG, offsetof(struct user_regs_struct, USR_REG), \ 62 offsetof(struct user_regs_struct, USR_REG) + \ 63 sizeof(unsigned long)); 64 65 /* Must be exactly same sequence as struct user_regs_struct */ 66 ONEXT(®s->sa0, sa0); 67 ONEXT(®s->lc0, lc0); 68 ONEXT(®s->sa1, sa1); 69 ONEXT(®s->lc1, lc1); 70 ONEXT(®s->m0, m0); 71 ONEXT(®s->m1, m1); 72 ONEXT(®s->usr, usr); 73 ONEXT(®s->preds, p3_0); 74 ONEXT(®s->gp, gp); 75 ONEXT(®s->ugp, ugp); 76 ONEXT(&pt_elr(regs), pc); 77 dummy = pt_cause(regs); 78 ONEXT(&dummy, cause); 79 ONEXT(&pt_badva(regs), badva); 80 #if CONFIG_HEXAGON_ARCH_VERSION >=4 81 ONEXT(®s->cs0, cs0); 82 ONEXT(®s->cs1, cs1); 83 #endif 84 85 /* Pad the rest with zeros, if needed */ 86 if (!ret) 87 ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf, 88 offsetof(struct user_regs_struct, pad1), -1); 89 return ret; 90 } 91 92 static int genregs_set(struct task_struct *target, 93 const struct user_regset *regset, 94 unsigned int pos, unsigned int count, 95 const void *kbuf, const void __user *ubuf) 96 { 97 int ret; 98 unsigned long bucket; 99 struct pt_regs *regs = task_pt_regs(target); 100 101 if (!regs) 102 return -EIO; 103 104 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, 105 ®s->r00, 0, 32*sizeof(unsigned long)); 106 107 #define INEXT(KPT_REG, USR_REG) \ 108 if (!ret) \ 109 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, \ 110 KPT_REG, offsetof(struct user_regs_struct, USR_REG), \ 111 offsetof(struct user_regs_struct, USR_REG) + \ 112 sizeof(unsigned long)); 113 114 /* Must be exactly same sequence as struct user_regs_struct */ 115 INEXT(®s->sa0, sa0); 116 INEXT(®s->lc0, lc0); 117 INEXT(®s->sa1, sa1); 118 INEXT(®s->lc1, lc1); 119 INEXT(®s->m0, m0); 120 INEXT(®s->m1, m1); 121 INEXT(®s->usr, usr); 122 INEXT(®s->preds, p3_0); 123 INEXT(®s->gp, gp); 124 INEXT(®s->ugp, ugp); 125 INEXT(&pt_elr(regs), pc); 126 127 /* CAUSE and BADVA aren't writeable. */ 128 INEXT(&bucket, cause); 129 INEXT(&bucket, badva); 130 131 #if CONFIG_HEXAGON_ARCH_VERSION >=4 132 INEXT(®s->cs0, cs0); 133 INEXT(®s->cs1, cs1); 134 #endif 135 136 /* Ignore the rest, if needed */ 137 if (!ret) 138 ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf, 139 offsetof(struct user_regs_struct, pad1), -1); 140 141 if (ret) 142 return ret; 143 144 /* 145 * This is special; SP is actually restored by the VM via the 146 * special event record which is set by the special trap. 147 */ 148 regs->hvmer.vmpsp = regs->r29; 149 return 0; 150 } 151 152 enum hexagon_regset { 153 REGSET_GENERAL, 154 }; 155 156 static const struct user_regset hexagon_regsets[] = { 157 [REGSET_GENERAL] = { 158 .core_note_type = NT_PRSTATUS, 159 .n = ELF_NGREG, 160 .size = sizeof(unsigned long), 161 .align = sizeof(unsigned long), 162 .get = genregs_get, 163 .set = genregs_set, 164 }, 165 }; 166 167 static const struct user_regset_view hexagon_user_view = { 168 .name = "hexagon", 169 .e_machine = ELF_ARCH, 170 .ei_osabi = ELF_OSABI, 171 .regsets = hexagon_regsets, 172 .e_flags = ELF_CORE_EFLAGS, 173 .n = ARRAY_SIZE(hexagon_regsets) 174 }; 175 176 const struct user_regset_view *task_user_regset_view(struct task_struct *task) 177 { 178 return &hexagon_user_view; 179 } 180 181 void ptrace_disable(struct task_struct *child) 182 { 183 /* Boilerplate - resolves to null inline if no HW single-step */ 184 user_disable_single_step(child); 185 } 186 187 long arch_ptrace(struct task_struct *child, long request, 188 unsigned long addr, unsigned long data) 189 { 190 return ptrace_request(child, request, addr, data); 191 } 192