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 <generated/compile.h> 22 23 #include <linux/kernel.h> 24 #include <linux/sched.h> 25 #include <linux/sched/task_stack.h> 26 #include <linux/mm.h> 27 #include <linux/smp.h> 28 #include <linux/errno.h> 29 #include <linux/ptrace.h> 30 #include <linux/regset.h> 31 #include <linux/user.h> 32 #include <linux/elf.h> 33 34 #include <asm/user.h> 35 36 #if arch_has_single_step() 37 /* Both called from ptrace_resume */ 38 void user_enable_single_step(struct task_struct *child) 39 { 40 pt_set_singlestep(task_pt_regs(child)); 41 set_tsk_thread_flag(child, TIF_SINGLESTEP); 42 } 43 44 void user_disable_single_step(struct task_struct *child) 45 { 46 pt_clr_singlestep(task_pt_regs(child)); 47 clear_tsk_thread_flag(child, TIF_SINGLESTEP); 48 } 49 #endif 50 51 static int genregs_get(struct task_struct *target, 52 const struct user_regset *regset, 53 unsigned int pos, unsigned int count, 54 void *kbuf, void __user *ubuf) 55 { 56 int ret; 57 unsigned int dummy; 58 struct pt_regs *regs = task_pt_regs(target); 59 60 61 if (!regs) 62 return -EIO; 63 64 /* The general idea here is that the copyout must happen in 65 * exactly the same order in which the userspace expects these 66 * regs. Now, the sequence in userspace does not match the 67 * sequence in the kernel, so everything past the 32 gprs 68 * happens one at a time. 69 */ 70 ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, 71 ®s->r00, 0, 32*sizeof(unsigned long)); 72 73 #define ONEXT(KPT_REG, USR_REG) \ 74 if (!ret) \ 75 ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, \ 76 KPT_REG, offsetof(struct user_regs_struct, USR_REG), \ 77 offsetof(struct user_regs_struct, USR_REG) + \ 78 sizeof(unsigned long)); 79 80 /* Must be exactly same sequence as struct user_regs_struct */ 81 ONEXT(®s->sa0, sa0); 82 ONEXT(®s->lc0, lc0); 83 ONEXT(®s->sa1, sa1); 84 ONEXT(®s->lc1, lc1); 85 ONEXT(®s->m0, m0); 86 ONEXT(®s->m1, m1); 87 ONEXT(®s->usr, usr); 88 ONEXT(®s->preds, p3_0); 89 ONEXT(®s->gp, gp); 90 ONEXT(®s->ugp, ugp); 91 ONEXT(&pt_elr(regs), pc); 92 dummy = pt_cause(regs); 93 ONEXT(&dummy, cause); 94 ONEXT(&pt_badva(regs), badva); 95 #if CONFIG_HEXAGON_ARCH_VERSION >=4 96 ONEXT(®s->cs0, cs0); 97 ONEXT(®s->cs1, cs1); 98 #endif 99 100 /* Pad the rest with zeros, if needed */ 101 if (!ret) 102 ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf, 103 offsetof(struct user_regs_struct, pad1), -1); 104 return ret; 105 } 106 107 static int genregs_set(struct task_struct *target, 108 const struct user_regset *regset, 109 unsigned int pos, unsigned int count, 110 const void *kbuf, const void __user *ubuf) 111 { 112 int ret; 113 unsigned long bucket; 114 struct pt_regs *regs = task_pt_regs(target); 115 116 if (!regs) 117 return -EIO; 118 119 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, 120 ®s->r00, 0, 32*sizeof(unsigned long)); 121 122 #define INEXT(KPT_REG, USR_REG) \ 123 if (!ret) \ 124 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, \ 125 KPT_REG, offsetof(struct user_regs_struct, USR_REG), \ 126 offsetof(struct user_regs_struct, USR_REG) + \ 127 sizeof(unsigned long)); 128 129 /* Must be exactly same sequence as struct user_regs_struct */ 130 INEXT(®s->sa0, sa0); 131 INEXT(®s->lc0, lc0); 132 INEXT(®s->sa1, sa1); 133 INEXT(®s->lc1, lc1); 134 INEXT(®s->m0, m0); 135 INEXT(®s->m1, m1); 136 INEXT(®s->usr, usr); 137 INEXT(®s->preds, p3_0); 138 INEXT(®s->gp, gp); 139 INEXT(®s->ugp, ugp); 140 INEXT(&pt_elr(regs), pc); 141 142 /* CAUSE and BADVA aren't writeable. */ 143 INEXT(&bucket, cause); 144 INEXT(&bucket, badva); 145 146 #if CONFIG_HEXAGON_ARCH_VERSION >=4 147 INEXT(®s->cs0, cs0); 148 INEXT(®s->cs1, cs1); 149 #endif 150 151 /* Ignore the rest, if needed */ 152 if (!ret) 153 ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf, 154 offsetof(struct user_regs_struct, pad1), -1); 155 156 if (ret) 157 return ret; 158 159 /* 160 * This is special; SP is actually restored by the VM via the 161 * special event record which is set by the special trap. 162 */ 163 regs->hvmer.vmpsp = regs->r29; 164 return 0; 165 } 166 167 enum hexagon_regset { 168 REGSET_GENERAL, 169 }; 170 171 static const struct user_regset hexagon_regsets[] = { 172 [REGSET_GENERAL] = { 173 .core_note_type = NT_PRSTATUS, 174 .n = ELF_NGREG, 175 .size = sizeof(unsigned long), 176 .align = sizeof(unsigned long), 177 .get = genregs_get, 178 .set = genregs_set, 179 }, 180 }; 181 182 static const struct user_regset_view hexagon_user_view = { 183 .name = UTS_MACHINE, 184 .e_machine = ELF_ARCH, 185 .ei_osabi = ELF_OSABI, 186 .regsets = hexagon_regsets, 187 .e_flags = ELF_CORE_EFLAGS, 188 .n = ARRAY_SIZE(hexagon_regsets) 189 }; 190 191 const struct user_regset_view *task_user_regset_view(struct task_struct *task) 192 { 193 return &hexagon_user_view; 194 } 195 196 void ptrace_disable(struct task_struct *child) 197 { 198 /* Boilerplate - resolves to null inline if no HW single-step */ 199 user_disable_single_step(child); 200 } 201 202 long arch_ptrace(struct task_struct *child, long request, 203 unsigned long addr, unsigned long data) 204 { 205 return ptrace_request(child, request, addr, data); 206 } 207