1 /* 2 * Ptrace support for Hexagon 3 * 4 * Copyright (c) 2010-2013, The Linux Foundation. All rights reserved. 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License version 2 and 8 * only version 2 as published by the Free Software Foundation. 9 * 10 * This program is distributed in the hope that it will be useful, 11 * but WITHOUT ANY WARRANTY; without even the implied warranty of 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 * GNU General Public License for more details. 14 * 15 * You should have received a copy of the GNU General Public License 16 * along with this program; if not, write to the Free Software 17 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 18 * 02110-1301, USA. 19 */ 20 21 #include <linux/kernel.h> 22 #include <linux/sched.h> 23 #include <linux/sched/task_stack.h> 24 #include <linux/mm.h> 25 #include <linux/smp.h> 26 #include <linux/errno.h> 27 #include <linux/ptrace.h> 28 #include <linux/regset.h> 29 #include <linux/user.h> 30 #include <linux/elf.h> 31 32 #include <asm/user.h> 33 34 #if arch_has_single_step() 35 /* Both called from ptrace_resume */ 36 void user_enable_single_step(struct task_struct *child) 37 { 38 pt_set_singlestep(task_pt_regs(child)); 39 set_tsk_thread_flag(child, TIF_SINGLESTEP); 40 } 41 42 void user_disable_single_step(struct task_struct *child) 43 { 44 pt_clr_singlestep(task_pt_regs(child)); 45 clear_tsk_thread_flag(child, TIF_SINGLESTEP); 46 } 47 #endif 48 49 static int genregs_get(struct task_struct *target, 50 const struct user_regset *regset, 51 unsigned int pos, unsigned int count, 52 void *kbuf, void __user *ubuf) 53 { 54 int ret; 55 unsigned int dummy; 56 struct pt_regs *regs = task_pt_regs(target); 57 58 59 if (!regs) 60 return -EIO; 61 62 /* The general idea here is that the copyout must happen in 63 * exactly the same order in which the userspace expects these 64 * regs. Now, the sequence in userspace does not match the 65 * sequence in the kernel, so everything past the 32 gprs 66 * happens one at a time. 67 */ 68 ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, 69 ®s->r00, 0, 32*sizeof(unsigned long)); 70 71 #define ONEXT(KPT_REG, USR_REG) \ 72 if (!ret) \ 73 ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, \ 74 KPT_REG, offsetof(struct user_regs_struct, USR_REG), \ 75 offsetof(struct user_regs_struct, USR_REG) + \ 76 sizeof(unsigned long)); 77 78 /* Must be exactly same sequence as struct user_regs_struct */ 79 ONEXT(®s->sa0, sa0); 80 ONEXT(®s->lc0, lc0); 81 ONEXT(®s->sa1, sa1); 82 ONEXT(®s->lc1, lc1); 83 ONEXT(®s->m0, m0); 84 ONEXT(®s->m1, m1); 85 ONEXT(®s->usr, usr); 86 ONEXT(®s->preds, p3_0); 87 ONEXT(®s->gp, gp); 88 ONEXT(®s->ugp, ugp); 89 ONEXT(&pt_elr(regs), pc); 90 dummy = pt_cause(regs); 91 ONEXT(&dummy, cause); 92 ONEXT(&pt_badva(regs), badva); 93 #if CONFIG_HEXAGON_ARCH_VERSION >=4 94 ONEXT(®s->cs0, cs0); 95 ONEXT(®s->cs1, cs1); 96 #endif 97 98 /* Pad the rest with zeros, if needed */ 99 if (!ret) 100 ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf, 101 offsetof(struct user_regs_struct, pad1), -1); 102 return ret; 103 } 104 105 static int genregs_set(struct task_struct *target, 106 const struct user_regset *regset, 107 unsigned int pos, unsigned int count, 108 const void *kbuf, const void __user *ubuf) 109 { 110 int ret; 111 unsigned long bucket; 112 struct pt_regs *regs = task_pt_regs(target); 113 114 if (!regs) 115 return -EIO; 116 117 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, 118 ®s->r00, 0, 32*sizeof(unsigned long)); 119 120 #define INEXT(KPT_REG, USR_REG) \ 121 if (!ret) \ 122 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, \ 123 KPT_REG, offsetof(struct user_regs_struct, USR_REG), \ 124 offsetof(struct user_regs_struct, USR_REG) + \ 125 sizeof(unsigned long)); 126 127 /* Must be exactly same sequence as struct user_regs_struct */ 128 INEXT(®s->sa0, sa0); 129 INEXT(®s->lc0, lc0); 130 INEXT(®s->sa1, sa1); 131 INEXT(®s->lc1, lc1); 132 INEXT(®s->m0, m0); 133 INEXT(®s->m1, m1); 134 INEXT(®s->usr, usr); 135 INEXT(®s->preds, p3_0); 136 INEXT(®s->gp, gp); 137 INEXT(®s->ugp, ugp); 138 INEXT(&pt_elr(regs), pc); 139 140 /* CAUSE and BADVA aren't writeable. */ 141 INEXT(&bucket, cause); 142 INEXT(&bucket, badva); 143 144 #if CONFIG_HEXAGON_ARCH_VERSION >=4 145 INEXT(®s->cs0, cs0); 146 INEXT(®s->cs1, cs1); 147 #endif 148 149 /* Ignore the rest, if needed */ 150 if (!ret) 151 ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf, 152 offsetof(struct user_regs_struct, pad1), -1); 153 154 if (ret) 155 return ret; 156 157 /* 158 * This is special; SP is actually restored by the VM via the 159 * special event record which is set by the special trap. 160 */ 161 regs->hvmer.vmpsp = regs->r29; 162 return 0; 163 } 164 165 enum hexagon_regset { 166 REGSET_GENERAL, 167 }; 168 169 static const struct user_regset hexagon_regsets[] = { 170 [REGSET_GENERAL] = { 171 .core_note_type = NT_PRSTATUS, 172 .n = ELF_NGREG, 173 .size = sizeof(unsigned long), 174 .align = sizeof(unsigned long), 175 .get = genregs_get, 176 .set = genregs_set, 177 }, 178 }; 179 180 static const struct user_regset_view hexagon_user_view = { 181 .name = "hexagon", 182 .e_machine = ELF_ARCH, 183 .ei_osabi = ELF_OSABI, 184 .regsets = hexagon_regsets, 185 .e_flags = ELF_CORE_EFLAGS, 186 .n = ARRAY_SIZE(hexagon_regsets) 187 }; 188 189 const struct user_regset_view *task_user_regset_view(struct task_struct *task) 190 { 191 return &hexagon_user_view; 192 } 193 194 void ptrace_disable(struct task_struct *child) 195 { 196 /* Boilerplate - resolves to null inline if no HW single-step */ 197 user_disable_single_step(child); 198 } 199 200 long arch_ptrace(struct task_struct *child, long request, 201 unsigned long addr, unsigned long data) 202 { 203 return ptrace_request(child, request, addr, data); 204 } 205