Greentime Hu | 7ecbac7 | 2017-10-25 11:23:21 +0800 | [diff] [blame] | 1 | // SPDX-License-Identifier: GPL-2.0 |
| 2 | // Copyright (C) 2005-2017 Andes Technology Corporation |
| 3 | |
| 4 | #include <linux/errno.h> |
| 5 | #include <linux/signal.h> |
| 6 | #include <linux/ptrace.h> |
| 7 | #include <linux/personality.h> |
| 8 | #include <linux/freezer.h> |
| 9 | #include <linux/tracehook.h> |
| 10 | #include <linux/uaccess.h> |
| 11 | |
| 12 | #include <asm/cacheflush.h> |
| 13 | #include <asm/ucontext.h> |
| 14 | #include <asm/unistd.h> |
| 15 | |
| 16 | #include <asm/ptrace.h> |
| 17 | #include <asm/vdso.h> |
| 18 | |
| 19 | struct rt_sigframe { |
| 20 | struct siginfo info; |
| 21 | struct ucontext uc; |
| 22 | }; |
| 23 | |
| 24 | static int restore_sigframe(struct pt_regs *regs, |
| 25 | struct rt_sigframe __user * sf) |
| 26 | { |
| 27 | sigset_t set; |
| 28 | int err; |
| 29 | |
| 30 | err = __copy_from_user(&set, &sf->uc.uc_sigmask, sizeof(set)); |
| 31 | if (err == 0) { |
| 32 | set_current_blocked(&set); |
| 33 | } |
| 34 | |
| 35 | __get_user_error(regs->uregs[0], &sf->uc.uc_mcontext.nds32_r0, err); |
| 36 | __get_user_error(regs->uregs[1], &sf->uc.uc_mcontext.nds32_r1, err); |
| 37 | __get_user_error(regs->uregs[2], &sf->uc.uc_mcontext.nds32_r2, err); |
| 38 | __get_user_error(regs->uregs[3], &sf->uc.uc_mcontext.nds32_r3, err); |
| 39 | __get_user_error(regs->uregs[4], &sf->uc.uc_mcontext.nds32_r4, err); |
| 40 | __get_user_error(regs->uregs[5], &sf->uc.uc_mcontext.nds32_r5, err); |
| 41 | __get_user_error(regs->uregs[6], &sf->uc.uc_mcontext.nds32_r6, err); |
| 42 | __get_user_error(regs->uregs[7], &sf->uc.uc_mcontext.nds32_r7, err); |
| 43 | __get_user_error(regs->uregs[8], &sf->uc.uc_mcontext.nds32_r8, err); |
| 44 | __get_user_error(regs->uregs[9], &sf->uc.uc_mcontext.nds32_r9, err); |
| 45 | __get_user_error(regs->uregs[10], &sf->uc.uc_mcontext.nds32_r10, err); |
| 46 | __get_user_error(regs->uregs[11], &sf->uc.uc_mcontext.nds32_r11, err); |
| 47 | __get_user_error(regs->uregs[12], &sf->uc.uc_mcontext.nds32_r12, err); |
| 48 | __get_user_error(regs->uregs[13], &sf->uc.uc_mcontext.nds32_r13, err); |
| 49 | __get_user_error(regs->uregs[14], &sf->uc.uc_mcontext.nds32_r14, err); |
| 50 | __get_user_error(regs->uregs[15], &sf->uc.uc_mcontext.nds32_r15, err); |
| 51 | __get_user_error(regs->uregs[16], &sf->uc.uc_mcontext.nds32_r16, err); |
| 52 | __get_user_error(regs->uregs[17], &sf->uc.uc_mcontext.nds32_r17, err); |
| 53 | __get_user_error(regs->uregs[18], &sf->uc.uc_mcontext.nds32_r18, err); |
| 54 | __get_user_error(regs->uregs[19], &sf->uc.uc_mcontext.nds32_r19, err); |
| 55 | __get_user_error(regs->uregs[20], &sf->uc.uc_mcontext.nds32_r20, err); |
| 56 | __get_user_error(regs->uregs[21], &sf->uc.uc_mcontext.nds32_r21, err); |
| 57 | __get_user_error(regs->uregs[22], &sf->uc.uc_mcontext.nds32_r22, err); |
| 58 | __get_user_error(regs->uregs[23], &sf->uc.uc_mcontext.nds32_r23, err); |
| 59 | __get_user_error(regs->uregs[24], &sf->uc.uc_mcontext.nds32_r24, err); |
| 60 | __get_user_error(regs->uregs[25], &sf->uc.uc_mcontext.nds32_r25, err); |
| 61 | |
| 62 | __get_user_error(regs->fp, &sf->uc.uc_mcontext.nds32_fp, err); |
| 63 | __get_user_error(regs->gp, &sf->uc.uc_mcontext.nds32_gp, err); |
| 64 | __get_user_error(regs->lp, &sf->uc.uc_mcontext.nds32_lp, err); |
| 65 | __get_user_error(regs->sp, &sf->uc.uc_mcontext.nds32_sp, err); |
| 66 | __get_user_error(regs->ipc, &sf->uc.uc_mcontext.nds32_ipc, err); |
| 67 | #if defined(CONFIG_HWZOL) |
| 68 | __get_user_error(regs->lc, &sf->uc.uc_mcontext.zol.nds32_lc, err); |
| 69 | __get_user_error(regs->le, &sf->uc.uc_mcontext.zol.nds32_le, err); |
| 70 | __get_user_error(regs->lb, &sf->uc.uc_mcontext.zol.nds32_lb, err); |
| 71 | #endif |
| 72 | |
| 73 | /* |
| 74 | * Avoid sys_rt_sigreturn() restarting. |
| 75 | */ |
| 76 | forget_syscall(regs); |
| 77 | return err; |
| 78 | } |
| 79 | |
| 80 | asmlinkage long sys_rt_sigreturn(struct pt_regs *regs) |
| 81 | { |
| 82 | struct rt_sigframe __user *frame; |
| 83 | |
| 84 | /* Always make any pending restarted system calls return -EINTR */ |
| 85 | current->restart_block.fn = do_no_restart_syscall; |
| 86 | |
| 87 | /* |
| 88 | * Since we stacked the signal on a 64-bit boundary, |
| 89 | * then 'sp' should be two-word aligned here. If it's |
| 90 | * not, then the user is trying to mess with us. |
| 91 | */ |
| 92 | if (regs->sp & 7) |
| 93 | goto badframe; |
| 94 | |
| 95 | frame = (struct rt_sigframe __user *)regs->sp; |
| 96 | |
| 97 | if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) |
| 98 | goto badframe; |
| 99 | |
| 100 | if (restore_sigframe(regs, frame)) |
| 101 | goto badframe; |
| 102 | |
| 103 | if (restore_altstack(&frame->uc.uc_stack)) |
| 104 | goto badframe; |
| 105 | |
| 106 | return regs->uregs[0]; |
| 107 | |
| 108 | badframe: |
| 109 | force_sig(SIGSEGV, current); |
| 110 | return 0; |
| 111 | } |
| 112 | |
| 113 | static int |
| 114 | setup_sigframe(struct rt_sigframe __user * sf, struct pt_regs *regs, |
| 115 | sigset_t * set) |
| 116 | { |
| 117 | int err = 0; |
| 118 | |
| 119 | __put_user_error(regs->uregs[0], &sf->uc.uc_mcontext.nds32_r0, err); |
| 120 | __put_user_error(regs->uregs[1], &sf->uc.uc_mcontext.nds32_r1, err); |
| 121 | __put_user_error(regs->uregs[2], &sf->uc.uc_mcontext.nds32_r2, err); |
| 122 | __put_user_error(regs->uregs[3], &sf->uc.uc_mcontext.nds32_r3, err); |
| 123 | __put_user_error(regs->uregs[4], &sf->uc.uc_mcontext.nds32_r4, err); |
| 124 | __put_user_error(regs->uregs[5], &sf->uc.uc_mcontext.nds32_r5, err); |
| 125 | __put_user_error(regs->uregs[6], &sf->uc.uc_mcontext.nds32_r6, err); |
| 126 | __put_user_error(regs->uregs[7], &sf->uc.uc_mcontext.nds32_r7, err); |
| 127 | __put_user_error(regs->uregs[8], &sf->uc.uc_mcontext.nds32_r8, err); |
| 128 | __put_user_error(regs->uregs[9], &sf->uc.uc_mcontext.nds32_r9, err); |
| 129 | __put_user_error(regs->uregs[10], &sf->uc.uc_mcontext.nds32_r10, err); |
| 130 | __put_user_error(regs->uregs[11], &sf->uc.uc_mcontext.nds32_r11, err); |
| 131 | __put_user_error(regs->uregs[12], &sf->uc.uc_mcontext.nds32_r12, err); |
| 132 | __put_user_error(regs->uregs[13], &sf->uc.uc_mcontext.nds32_r13, err); |
| 133 | __put_user_error(regs->uregs[14], &sf->uc.uc_mcontext.nds32_r14, err); |
| 134 | __put_user_error(regs->uregs[15], &sf->uc.uc_mcontext.nds32_r15, err); |
| 135 | __put_user_error(regs->uregs[16], &sf->uc.uc_mcontext.nds32_r16, err); |
| 136 | __put_user_error(regs->uregs[17], &sf->uc.uc_mcontext.nds32_r17, err); |
| 137 | __put_user_error(regs->uregs[18], &sf->uc.uc_mcontext.nds32_r18, err); |
| 138 | __put_user_error(regs->uregs[19], &sf->uc.uc_mcontext.nds32_r19, err); |
| 139 | __put_user_error(regs->uregs[20], &sf->uc.uc_mcontext.nds32_r20, err); |
| 140 | |
| 141 | __put_user_error(regs->uregs[21], &sf->uc.uc_mcontext.nds32_r21, err); |
| 142 | __put_user_error(regs->uregs[22], &sf->uc.uc_mcontext.nds32_r22, err); |
| 143 | __put_user_error(regs->uregs[23], &sf->uc.uc_mcontext.nds32_r23, err); |
| 144 | __put_user_error(regs->uregs[24], &sf->uc.uc_mcontext.nds32_r24, err); |
| 145 | __put_user_error(regs->uregs[25], &sf->uc.uc_mcontext.nds32_r25, err); |
| 146 | __put_user_error(regs->fp, &sf->uc.uc_mcontext.nds32_fp, err); |
| 147 | __put_user_error(regs->gp, &sf->uc.uc_mcontext.nds32_gp, err); |
| 148 | __put_user_error(regs->lp, &sf->uc.uc_mcontext.nds32_lp, err); |
| 149 | __put_user_error(regs->sp, &sf->uc.uc_mcontext.nds32_sp, err); |
| 150 | __put_user_error(regs->ipc, &sf->uc.uc_mcontext.nds32_ipc, err); |
| 151 | #if defined(CONFIG_HWZOL) |
| 152 | __put_user_error(regs->lc, &sf->uc.uc_mcontext.zol.nds32_lc, err); |
| 153 | __put_user_error(regs->le, &sf->uc.uc_mcontext.zol.nds32_le, err); |
| 154 | __put_user_error(regs->lb, &sf->uc.uc_mcontext.zol.nds32_lb, err); |
| 155 | #endif |
| 156 | |
| 157 | __put_user_error(current->thread.trap_no, &sf->uc.uc_mcontext.trap_no, |
| 158 | err); |
| 159 | __put_user_error(current->thread.error_code, |
| 160 | &sf->uc.uc_mcontext.error_code, err); |
| 161 | __put_user_error(current->thread.address, |
| 162 | &sf->uc.uc_mcontext.fault_address, err); |
| 163 | __put_user_error(set->sig[0], &sf->uc.uc_mcontext.oldmask, err); |
| 164 | |
| 165 | err |= __copy_to_user(&sf->uc.uc_sigmask, set, sizeof(*set)); |
| 166 | |
| 167 | return err; |
| 168 | } |
| 169 | |
| 170 | static inline void __user *get_sigframe(struct ksignal *ksig, |
| 171 | struct pt_regs *regs, int framesize) |
| 172 | { |
| 173 | unsigned long sp; |
| 174 | |
| 175 | /* Default to using normal stack */ |
| 176 | sp = regs->sp; |
| 177 | |
| 178 | /* |
| 179 | * If we are on the alternate signal stack and would overflow it, don't. |
| 180 | * Return an always-bogus address instead so we will die with SIGSEGV. |
| 181 | */ |
| 182 | if (on_sig_stack(sp) && !likely(on_sig_stack(sp - framesize))) |
| 183 | return (void __user __force *)(-1UL); |
| 184 | |
| 185 | /* This is the X/Open sanctioned signal stack switching. */ |
| 186 | sp = (sigsp(sp, ksig) - framesize); |
| 187 | |
| 188 | /* |
| 189 | * nds32 mandates 8-byte alignment |
| 190 | */ |
| 191 | sp &= ~0x7UL; |
| 192 | |
| 193 | return (void __user *)sp; |
| 194 | } |
| 195 | |
| 196 | static int |
| 197 | setup_return(struct pt_regs *regs, struct ksignal *ksig, void __user * frame) |
| 198 | { |
| 199 | unsigned long handler = (unsigned long)ksig->ka.sa.sa_handler; |
| 200 | unsigned long retcode; |
| 201 | |
| 202 | retcode = VDSO_SYMBOL(current->mm->context.vdso, rt_sigtramp); |
| 203 | regs->uregs[0] = ksig->sig; |
| 204 | regs->sp = (unsigned long)frame; |
| 205 | regs->lp = retcode; |
| 206 | regs->ipc = handler; |
| 207 | |
| 208 | return 0; |
| 209 | } |
| 210 | |
| 211 | static int |
| 212 | setup_rt_frame(struct ksignal *ksig, sigset_t * set, struct pt_regs *regs) |
| 213 | { |
| 214 | struct rt_sigframe __user *frame = |
| 215 | get_sigframe(ksig, regs, sizeof(*frame)); |
| 216 | int err = 0; |
| 217 | |
| 218 | if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) |
| 219 | return -EFAULT; |
| 220 | |
| 221 | __put_user_error(0, &frame->uc.uc_flags, err); |
| 222 | __put_user_error(NULL, &frame->uc.uc_link, err); |
| 223 | |
| 224 | err |= __save_altstack(&frame->uc.uc_stack, regs->sp); |
| 225 | err |= setup_sigframe(frame, regs, set); |
| 226 | if (err == 0) { |
| 227 | setup_return(regs, ksig, frame); |
| 228 | if (ksig->ka.sa.sa_flags & SA_SIGINFO) { |
| 229 | err |= copy_siginfo_to_user(&frame->info, &ksig->info); |
| 230 | regs->uregs[1] = (unsigned long)&frame->info; |
| 231 | regs->uregs[2] = (unsigned long)&frame->uc; |
| 232 | } |
| 233 | } |
| 234 | return err; |
| 235 | } |
| 236 | |
| 237 | /* |
| 238 | * OK, we're invoking a handler |
| 239 | */ |
| 240 | static void handle_signal(struct ksignal *ksig, struct pt_regs *regs) |
| 241 | { |
| 242 | int ret; |
| 243 | sigset_t *oldset = sigmask_to_save(); |
| 244 | |
| 245 | if (in_syscall(regs)) { |
| 246 | /* Avoid additional syscall restarting via ret_slow_syscall. */ |
| 247 | forget_syscall(regs); |
| 248 | |
| 249 | switch (regs->uregs[0]) { |
| 250 | case -ERESTART_RESTARTBLOCK: |
| 251 | case -ERESTARTNOHAND: |
| 252 | regs->uregs[0] = -EINTR; |
| 253 | break; |
| 254 | case -ERESTARTSYS: |
| 255 | if (!(ksig->ka.sa.sa_flags & SA_RESTART)) { |
| 256 | regs->uregs[0] = -EINTR; |
| 257 | break; |
| 258 | } |
| 259 | case -ERESTARTNOINTR: |
| 260 | regs->uregs[0] = regs->orig_r0; |
| 261 | regs->ipc -= 4; |
| 262 | break; |
| 263 | } |
| 264 | } |
| 265 | /* |
| 266 | * Set up the stack frame |
| 267 | */ |
| 268 | ret = setup_rt_frame(ksig, oldset, regs); |
| 269 | |
| 270 | signal_setup_done(ret, ksig, 0); |
| 271 | } |
| 272 | |
| 273 | /* |
| 274 | * Note that 'init' is a special process: it doesn't get signals it doesn't |
| 275 | * want to handle. Thus you cannot kill init even with a SIGKILL even by |
| 276 | * mistake. |
| 277 | * |
| 278 | * Note that we go through the signals twice: once to check the signals that |
| 279 | * the kernel can handle, and then we build all the user-level signal handling |
| 280 | * stack-frames in one go after that. |
| 281 | */ |
| 282 | static void do_signal(struct pt_regs *regs) |
| 283 | { |
| 284 | struct ksignal ksig; |
| 285 | |
| 286 | if (get_signal(&ksig)) { |
| 287 | handle_signal(&ksig, regs); |
| 288 | return; |
| 289 | } |
| 290 | |
| 291 | /* |
| 292 | * If we were from a system call, check for system call restarting... |
| 293 | */ |
| 294 | if (in_syscall(regs)) { |
| 295 | /* Restart the system call - no handlers present */ |
| 296 | |
| 297 | /* Avoid additional syscall restarting via ret_slow_syscall. */ |
| 298 | forget_syscall(regs); |
| 299 | |
| 300 | switch (regs->uregs[0]) { |
| 301 | case -ERESTART_RESTARTBLOCK: |
| 302 | regs->uregs[15] = __NR_restart_syscall; |
| 303 | case -ERESTARTNOHAND: |
| 304 | case -ERESTARTSYS: |
| 305 | case -ERESTARTNOINTR: |
| 306 | regs->uregs[0] = regs->orig_r0; |
| 307 | regs->ipc -= 0x4; |
| 308 | break; |
| 309 | } |
| 310 | } |
| 311 | restore_saved_sigmask(); |
| 312 | } |
| 313 | |
| 314 | asmlinkage void |
| 315 | do_notify_resume(struct pt_regs *regs, unsigned int thread_flags) |
| 316 | { |
| 317 | if (thread_flags & _TIF_SIGPENDING) |
| 318 | do_signal(regs); |
| 319 | |
| 320 | if (thread_flags & _TIF_NOTIFY_RESUME) { |
| 321 | clear_thread_flag(TIF_NOTIFY_RESUME); |
| 322 | tracehook_notify_resume(regs); |
| 323 | } |
| 324 | } |