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