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 struct membuf to) 39 { 40 struct pt_regs *regs = task_pt_regs(target); 41 42 /* The general idea here is that the copyout must happen in 43 * exactly the same order in which the userspace expects these 44 * regs. Now, the sequence in userspace does not match the 45 * sequence in the kernel, so everything past the 32 gprs 46 * happens one at a time. 47 */ 48 membuf_write(&to, ®s->r00, 32*sizeof(unsigned long)); 49 /* Must be exactly same sequence as struct user_regs_struct */ 50 membuf_store(&to, regs->sa0); 51 membuf_store(&to, regs->lc0); 52 membuf_store(&to, regs->sa1); 53 membuf_store(&to, regs->lc1); 54 membuf_store(&to, regs->m0); 55 membuf_store(&to, regs->m1); 56 membuf_store(&to, regs->usr); 57 membuf_store(&to, regs->preds); 58 membuf_store(&to, regs->gp); 59 membuf_store(&to, regs->ugp); 60 membuf_store(&to, pt_elr(regs)); // pc 61 membuf_store(&to, (unsigned long)pt_cause(regs)); // cause 62 membuf_store(&to, pt_badva(regs)); // badva 63 #if CONFIG_HEXAGON_ARCH_VERSION >=4 64 membuf_store(&to, regs->cs0); 65 membuf_store(&to, regs->cs1); 66 return membuf_zero(&to, sizeof(unsigned long)); 67 #else 68 return membuf_zero(&to, 3 * sizeof(unsigned long)); 69 #endif 70 } 71 72 static int genregs_set(struct task_struct *target, 73 const struct user_regset *regset, 74 unsigned int pos, unsigned int count, 75 const void *kbuf, const void __user *ubuf) 76 { 77 int ret; 78 unsigned long bucket; 79 struct pt_regs *regs = task_pt_regs(target); 80 81 if (!regs) 82 return -EIO; 83 84 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, 85 ®s->r00, 0, 32*sizeof(unsigned long)); 86 87 #define INEXT(KPT_REG, USR_REG) \ 88 if (!ret) \ 89 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, \ 90 KPT_REG, offsetof(struct user_regs_struct, USR_REG), \ 91 offsetof(struct user_regs_struct, USR_REG) + \ 92 sizeof(unsigned long)); 93 94 /* Must be exactly same sequence as struct user_regs_struct */ 95 INEXT(®s->sa0, sa0); 96 INEXT(®s->lc0, lc0); 97 INEXT(®s->sa1, sa1); 98 INEXT(®s->lc1, lc1); 99 INEXT(®s->m0, m0); 100 INEXT(®s->m1, m1); 101 INEXT(®s->usr, usr); 102 INEXT(®s->preds, p3_0); 103 INEXT(®s->gp, gp); 104 INEXT(®s->ugp, ugp); 105 INEXT(&pt_elr(regs), pc); 106 107 /* CAUSE and BADVA aren't writeable. */ 108 INEXT(&bucket, cause); 109 INEXT(&bucket, badva); 110 111 #if CONFIG_HEXAGON_ARCH_VERSION >=4 112 INEXT(®s->cs0, cs0); 113 INEXT(®s->cs1, cs1); 114 #endif 115 116 /* Ignore the rest, if needed */ 117 if (!ret) 118 user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf, 119 offsetof(struct user_regs_struct, pad1), -1); 120 else 121 return ret; 122 123 /* 124 * This is special; SP is actually restored by the VM via the 125 * special event record which is set by the special trap. 126 */ 127 regs->hvmer.vmpsp = regs->r29; 128 return 0; 129 } 130 131 enum hexagon_regset { 132 REGSET_GENERAL, 133 }; 134 135 static const struct user_regset hexagon_regsets[] = { 136 [REGSET_GENERAL] = { 137 .core_note_type = NT_PRSTATUS, 138 .n = ELF_NGREG, 139 .size = sizeof(unsigned long), 140 .align = sizeof(unsigned long), 141 .regset_get = genregs_get, 142 .set = genregs_set, 143 }, 144 }; 145 146 static const struct user_regset_view hexagon_user_view = { 147 .name = "hexagon", 148 .e_machine = ELF_ARCH, 149 .ei_osabi = ELF_OSABI, 150 .regsets = hexagon_regsets, 151 .e_flags = ELF_CORE_EFLAGS, 152 .n = ARRAY_SIZE(hexagon_regsets) 153 }; 154 155 const struct user_regset_view *task_user_regset_view(struct task_struct *task) 156 { 157 return &hexagon_user_view; 158 } 159 160 void ptrace_disable(struct task_struct *child) 161 { 162 /* Boilerplate - resolves to null inline if no HW single-step */ 163 user_disable_single_step(child); 164 } 165 166 long arch_ptrace(struct task_struct *child, long request, 167 unsigned long addr, unsigned long data) 168 { 169 return ptrace_request(child, request, addr, data); 170 } 171