Thomas Gleixner | d2912cb | 2019-06-04 10:11:33 +0200 | [diff] [blame^] | 1 | // SPDX-License-Identifier: GPL-2.0-only |
Vineet Gupta | c358103 | 2013-01-18 15:12:19 +0530 | [diff] [blame] | 2 | /* |
| 3 | * Signal Handling for ARC |
| 4 | * |
| 5 | * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com) |
| 6 | * |
Vineet Gupta | c358103 | 2013-01-18 15:12:19 +0530 | [diff] [blame] | 7 | * vineetg: Jan 2010 (Restarting of timer related syscalls) |
| 8 | * |
| 9 | * vineetg: Nov 2009 (Everything needed for TIF_RESTORE_SIGMASK) |
| 10 | * -do_signal() supports TIF_RESTORE_SIGMASK |
| 11 | * -do_signal() no loner needs oldset, required by OLD sys_sigsuspend |
| 12 | * -sys_rt_sigsuspend() now comes from generic code, so discard arch implemen |
| 13 | * -sys_sigsuspend() no longer needs to fudge ptregs, hence that arg removed |
| 14 | * -sys_sigsuspend() no longer loops for do_signal(), sets TIF_xxx and leaves |
| 15 | * the job to do_signal() |
| 16 | * |
| 17 | * vineetg: July 2009 |
| 18 | * -Modified Code to support the uClibc provided userland sigreturn stub |
| 19 | * to avoid kernel synthesing it on user stack at runtime, costing TLB |
| 20 | * probes and Cache line flushes. |
| 21 | * |
| 22 | * vineetg: July 2009 |
| 23 | * -In stash_usr_regs( ) and restore_usr_regs( ), save/restore of user regs |
| 24 | * in done in block copy rather than one word at a time. |
| 25 | * This saves around 2K of code and improves LMBench lat_sig <catch> |
| 26 | * |
| 27 | * rajeshwarr: Feb 2009 |
| 28 | * - Support for Realtime Signals |
| 29 | * |
| 30 | * vineetg: Aug 11th 2008: Bug #94183 |
| 31 | * -ViXS were still seeing crashes when using insmod to load drivers. |
| 32 | * It turned out that the code to change Execute permssions for TLB entries |
| 33 | * of user was not guarded for interrupts (mod_tlb_permission) |
Andrea Gelmini | 2547476 | 2016-05-21 13:45:35 +0200 | [diff] [blame] | 34 | * This was causing TLB entries to be overwritten on unrelated indexes |
Vineet Gupta | c358103 | 2013-01-18 15:12:19 +0530 | [diff] [blame] | 35 | * |
| 36 | * Vineetg: July 15th 2008: Bug #94183 |
| 37 | * -Exception happens in Delay slot of a JMP, and before user space resumes, |
| 38 | * Signal is delivered (Ctrl + C) = >SIGINT. |
| 39 | * setup_frame( ) sets up PC,SP,BLINK to enable user space signal handler |
| 40 | * to run, but doesn't clear the Delay slot bit from status32. As a result, |
| 41 | * on resuming user mode, signal handler branches off to BTA of orig JMP |
| 42 | * -FIX: clear the DE bit from status32 in setup_frame( ) |
| 43 | * |
| 44 | * Rahul Trivedi, Kanika Nema: Codito Technologies 2004 |
| 45 | */ |
| 46 | |
| 47 | #include <linux/signal.h> |
| 48 | #include <linux/ptrace.h> |
| 49 | #include <linux/personality.h> |
| 50 | #include <linux/uaccess.h> |
| 51 | #include <linux/syscalls.h> |
| 52 | #include <linux/tracehook.h> |
Ingo Molnar | 68db0cf | 2017-02-08 18:51:37 +0100 | [diff] [blame] | 53 | #include <linux/sched/task_stack.h> |
| 54 | |
Vineet Gupta | c358103 | 2013-01-18 15:12:19 +0530 | [diff] [blame] | 55 | #include <asm/ucontext.h> |
| 56 | |
| 57 | struct rt_sigframe { |
| 58 | struct siginfo info; |
| 59 | struct ucontext uc; |
| 60 | #define MAGIC_SIGALTSTK 0x07302004 |
| 61 | unsigned int sigret_magic; |
| 62 | }; |
| 63 | |
| 64 | static int |
| 65 | stash_usr_regs(struct rt_sigframe __user *sf, struct pt_regs *regs, |
| 66 | sigset_t *set) |
| 67 | { |
| 68 | int err; |
Vineet Gupta | 6ffb9c8 | 2014-05-14 19:35:15 +0530 | [diff] [blame] | 69 | struct user_regs_struct uregs; |
| 70 | |
| 71 | uregs.scratch.bta = regs->bta; |
| 72 | uregs.scratch.lp_start = regs->lp_start; |
| 73 | uregs.scratch.lp_end = regs->lp_end; |
| 74 | uregs.scratch.lp_count = regs->lp_count; |
| 75 | uregs.scratch.status32 = regs->status32; |
| 76 | uregs.scratch.ret = regs->ret; |
| 77 | uregs.scratch.blink = regs->blink; |
| 78 | uregs.scratch.fp = regs->fp; |
| 79 | uregs.scratch.gp = regs->r26; |
| 80 | uregs.scratch.r12 = regs->r12; |
| 81 | uregs.scratch.r11 = regs->r11; |
| 82 | uregs.scratch.r10 = regs->r10; |
| 83 | uregs.scratch.r9 = regs->r9; |
| 84 | uregs.scratch.r8 = regs->r8; |
| 85 | uregs.scratch.r7 = regs->r7; |
| 86 | uregs.scratch.r6 = regs->r6; |
| 87 | uregs.scratch.r5 = regs->r5; |
| 88 | uregs.scratch.r4 = regs->r4; |
| 89 | uregs.scratch.r3 = regs->r3; |
| 90 | uregs.scratch.r2 = regs->r2; |
| 91 | uregs.scratch.r1 = regs->r1; |
| 92 | uregs.scratch.r0 = regs->r0; |
| 93 | uregs.scratch.sp = regs->sp; |
| 94 | |
| 95 | err = __copy_to_user(&(sf->uc.uc_mcontext.regs.scratch), &uregs.scratch, |
Vineet Gupta | c358103 | 2013-01-18 15:12:19 +0530 | [diff] [blame] | 96 | sizeof(sf->uc.uc_mcontext.regs.scratch)); |
| 97 | err |= __copy_to_user(&sf->uc.uc_sigmask, set, sizeof(sigset_t)); |
| 98 | |
| 99 | return err; |
| 100 | } |
| 101 | |
| 102 | static int restore_usr_regs(struct pt_regs *regs, struct rt_sigframe __user *sf) |
| 103 | { |
| 104 | sigset_t set; |
| 105 | int err; |
Vineet Gupta | 6ffb9c8 | 2014-05-14 19:35:15 +0530 | [diff] [blame] | 106 | struct user_regs_struct uregs; |
Vineet Gupta | c358103 | 2013-01-18 15:12:19 +0530 | [diff] [blame] | 107 | |
| 108 | err = __copy_from_user(&set, &sf->uc.uc_sigmask, sizeof(set)); |
Vineet Gupta | 6ffb9c8 | 2014-05-14 19:35:15 +0530 | [diff] [blame] | 109 | err |= __copy_from_user(&uregs.scratch, |
| 110 | &(sf->uc.uc_mcontext.regs.scratch), |
Vineet Gupta | c358103 | 2013-01-18 15:12:19 +0530 | [diff] [blame] | 111 | sizeof(sf->uc.uc_mcontext.regs.scratch)); |
Al Viro | 7798bf2 | 2016-09-10 16:31:04 -0400 | [diff] [blame] | 112 | if (err) |
| 113 | return err; |
Vineet Gupta | c358103 | 2013-01-18 15:12:19 +0530 | [diff] [blame] | 114 | |
Al Viro | 7798bf2 | 2016-09-10 16:31:04 -0400 | [diff] [blame] | 115 | set_current_blocked(&set); |
Vineet Gupta | 6ffb9c8 | 2014-05-14 19:35:15 +0530 | [diff] [blame] | 116 | regs->bta = uregs.scratch.bta; |
| 117 | regs->lp_start = uregs.scratch.lp_start; |
| 118 | regs->lp_end = uregs.scratch.lp_end; |
| 119 | regs->lp_count = uregs.scratch.lp_count; |
| 120 | regs->status32 = uregs.scratch.status32; |
| 121 | regs->ret = uregs.scratch.ret; |
| 122 | regs->blink = uregs.scratch.blink; |
| 123 | regs->fp = uregs.scratch.fp; |
| 124 | regs->r26 = uregs.scratch.gp; |
| 125 | regs->r12 = uregs.scratch.r12; |
| 126 | regs->r11 = uregs.scratch.r11; |
| 127 | regs->r10 = uregs.scratch.r10; |
| 128 | regs->r9 = uregs.scratch.r9; |
| 129 | regs->r8 = uregs.scratch.r8; |
| 130 | regs->r7 = uregs.scratch.r7; |
| 131 | regs->r6 = uregs.scratch.r6; |
| 132 | regs->r5 = uregs.scratch.r5; |
| 133 | regs->r4 = uregs.scratch.r4; |
| 134 | regs->r3 = uregs.scratch.r3; |
| 135 | regs->r2 = uregs.scratch.r2; |
| 136 | regs->r1 = uregs.scratch.r1; |
| 137 | regs->r0 = uregs.scratch.r0; |
| 138 | regs->sp = uregs.scratch.sp; |
| 139 | |
Al Viro | 7798bf2 | 2016-09-10 16:31:04 -0400 | [diff] [blame] | 140 | return 0; |
Vineet Gupta | c358103 | 2013-01-18 15:12:19 +0530 | [diff] [blame] | 141 | } |
| 142 | |
| 143 | static inline int is_do_ss_needed(unsigned int magic) |
| 144 | { |
| 145 | if (MAGIC_SIGALTSTK == magic) |
| 146 | return 1; |
| 147 | else |
| 148 | return 0; |
| 149 | } |
| 150 | |
| 151 | SYSCALL_DEFINE0(rt_sigreturn) |
| 152 | { |
| 153 | struct rt_sigframe __user *sf; |
| 154 | unsigned int magic; |
Vineet Gupta | c358103 | 2013-01-18 15:12:19 +0530 | [diff] [blame] | 155 | struct pt_regs *regs = current_pt_regs(); |
| 156 | |
| 157 | /* Always make any pending restarted system calls return -EINTR */ |
Andy Lutomirski | f56141e | 2015-02-12 15:01:14 -0800 | [diff] [blame] | 158 | current->restart_block.fn = do_no_restart_syscall; |
Vineet Gupta | c358103 | 2013-01-18 15:12:19 +0530 | [diff] [blame] | 159 | |
| 160 | /* Since we stacked the signal on a word boundary, |
| 161 | * then 'sp' should be word aligned here. If it's |
| 162 | * not, then the user is trying to mess with us. |
| 163 | */ |
| 164 | if (regs->sp & 3) |
| 165 | goto badframe; |
| 166 | |
| 167 | sf = (struct rt_sigframe __force __user *)(regs->sp); |
| 168 | |
Linus Torvalds | 96d4f26 | 2019-01-03 18:57:57 -0800 | [diff] [blame] | 169 | if (!access_ok(sf, sizeof(*sf))) |
Vineet Gupta | c358103 | 2013-01-18 15:12:19 +0530 | [diff] [blame] | 170 | goto badframe; |
| 171 | |
Christian Ruppert | 1046935 | 2013-10-02 11:13:38 +0200 | [diff] [blame] | 172 | if (__get_user(magic, &sf->sigret_magic)) |
Vineet Gupta | c358103 | 2013-01-18 15:12:19 +0530 | [diff] [blame] | 173 | goto badframe; |
| 174 | |
| 175 | if (unlikely(is_do_ss_needed(magic))) |
| 176 | if (restore_altstack(&sf->uc.uc_stack)) |
| 177 | goto badframe; |
| 178 | |
Christian Ruppert | 1046935 | 2013-10-02 11:13:38 +0200 | [diff] [blame] | 179 | if (restore_usr_regs(regs, sf)) |
| 180 | goto badframe; |
| 181 | |
Vineet Gupta | 55bb948 | 2013-01-18 15:12:19 +0530 | [diff] [blame] | 182 | /* Don't restart from sigreturn */ |
| 183 | syscall_wont_restart(regs); |
| 184 | |
Vineet Gupta | e414081 | 2015-03-26 11:14:41 +0530 | [diff] [blame] | 185 | /* |
| 186 | * Ensure that sigreturn always returns to user mode (in case the |
| 187 | * regs saved on user stack got fudged between save and sigreturn) |
| 188 | * Otherwise it is easy to panic the kernel with a custom |
| 189 | * signal handler and/or restorer which clobberes the status32/ret |
| 190 | * to return to a bogus location in kernel mode. |
| 191 | */ |
| 192 | regs->status32 |= STATUS_U_MASK; |
| 193 | |
Vineet Gupta | c358103 | 2013-01-18 15:12:19 +0530 | [diff] [blame] | 194 | return regs->r0; |
| 195 | |
| 196 | badframe: |
| 197 | force_sig(SIGSEGV, current); |
| 198 | return 0; |
| 199 | } |
| 200 | |
| 201 | /* |
| 202 | * Determine which stack to use.. |
| 203 | */ |
Richard Weinberger | 5290dd7 | 2014-03-05 13:26:26 +0100 | [diff] [blame] | 204 | static inline void __user *get_sigframe(struct ksignal *ksig, |
Vineet Gupta | c358103 | 2013-01-18 15:12:19 +0530 | [diff] [blame] | 205 | struct pt_regs *regs, |
| 206 | unsigned long framesize) |
| 207 | { |
Richard Weinberger | 5290dd7 | 2014-03-05 13:26:26 +0100 | [diff] [blame] | 208 | unsigned long sp = sigsp(regs->sp, ksig); |
Vineet Gupta | c358103 | 2013-01-18 15:12:19 +0530 | [diff] [blame] | 209 | void __user *frame; |
| 210 | |
Vineet Gupta | c358103 | 2013-01-18 15:12:19 +0530 | [diff] [blame] | 211 | /* No matter what happens, 'sp' must be word |
| 212 | * aligned otherwise nasty things could happen |
| 213 | */ |
| 214 | |
| 215 | /* ATPCS B01 mandates 8-byte alignment */ |
| 216 | frame = (void __user *)((sp - framesize) & ~7); |
| 217 | |
| 218 | /* Check that we can actually write to the signal frame */ |
Linus Torvalds | 96d4f26 | 2019-01-03 18:57:57 -0800 | [diff] [blame] | 219 | if (!access_ok(frame, framesize)) |
Vineet Gupta | c358103 | 2013-01-18 15:12:19 +0530 | [diff] [blame] | 220 | frame = NULL; |
| 221 | |
| 222 | return frame; |
| 223 | } |
| 224 | |
Vineet Gupta | c358103 | 2013-01-18 15:12:19 +0530 | [diff] [blame] | 225 | static int |
Richard Weinberger | f6dd2a3 | 2013-10-06 22:42:38 +0200 | [diff] [blame] | 226 | setup_rt_frame(struct ksignal *ksig, sigset_t *set, struct pt_regs *regs) |
Vineet Gupta | c358103 | 2013-01-18 15:12:19 +0530 | [diff] [blame] | 227 | { |
| 228 | struct rt_sigframe __user *sf; |
| 229 | unsigned int magic = 0; |
| 230 | int err = 0; |
| 231 | |
Richard Weinberger | 5290dd7 | 2014-03-05 13:26:26 +0100 | [diff] [blame] | 232 | sf = get_sigframe(ksig, regs, sizeof(struct rt_sigframe)); |
Vineet Gupta | c358103 | 2013-01-18 15:12:19 +0530 | [diff] [blame] | 233 | if (!sf) |
| 234 | return 1; |
| 235 | |
| 236 | /* |
Christian Ruppert | 1046935 | 2013-10-02 11:13:38 +0200 | [diff] [blame] | 237 | * w/o SA_SIGINFO, struct ucontext is partially populated (only |
| 238 | * uc_mcontext/uc_sigmask) for kernel's normal user state preservation |
| 239 | * during signal handler execution. This works for SA_SIGINFO as well |
| 240 | * although the semantics are now overloaded (the same reg state can be |
| 241 | * inspected by userland: but are they allowed to fiddle with it ? |
| 242 | */ |
| 243 | err |= stash_usr_regs(sf, regs, set); |
| 244 | |
| 245 | /* |
Vineet Gupta | c358103 | 2013-01-18 15:12:19 +0530 | [diff] [blame] | 246 | * SA_SIGINFO requires 3 args to signal handler: |
| 247 | * #1: sig-no (common to any handler) |
| 248 | * #2: struct siginfo |
| 249 | * #3: struct ucontext (completely populated) |
| 250 | */ |
Richard Weinberger | f6dd2a3 | 2013-10-06 22:42:38 +0200 | [diff] [blame] | 251 | if (unlikely(ksig->ka.sa.sa_flags & SA_SIGINFO)) { |
| 252 | err |= copy_siginfo_to_user(&sf->info, &ksig->info); |
Vineet Gupta | c358103 | 2013-01-18 15:12:19 +0530 | [diff] [blame] | 253 | err |= __put_user(0, &sf->uc.uc_flags); |
| 254 | err |= __put_user(NULL, &sf->uc.uc_link); |
| 255 | err |= __save_altstack(&sf->uc.uc_stack, regs->sp); |
| 256 | |
| 257 | /* setup args 2 and 3 for user mode handler */ |
| 258 | regs->r1 = (unsigned long)&sf->info; |
| 259 | regs->r2 = (unsigned long)&sf->uc; |
| 260 | |
| 261 | /* |
| 262 | * small optim to avoid unconditonally calling do_sigaltstack |
| 263 | * in sigreturn path, now that we only have rt_sigreturn |
| 264 | */ |
| 265 | magic = MAGIC_SIGALTSTK; |
| 266 | } |
| 267 | |
Vineet Gupta | c358103 | 2013-01-18 15:12:19 +0530 | [diff] [blame] | 268 | err |= __put_user(magic, &sf->sigret_magic); |
| 269 | if (err) |
| 270 | return err; |
| 271 | |
| 272 | /* #1 arg to the user Signal handler */ |
Richard Weinberger | e6de3ca | 2015-03-27 09:55:52 +0100 | [diff] [blame] | 273 | regs->r0 = ksig->sig; |
Vineet Gupta | c358103 | 2013-01-18 15:12:19 +0530 | [diff] [blame] | 274 | |
| 275 | /* setup PC of user space signal handler */ |
Richard Weinberger | f6dd2a3 | 2013-10-06 22:42:38 +0200 | [diff] [blame] | 276 | regs->ret = (unsigned long)ksig->ka.sa.sa_handler; |
Vineet Gupta | c358103 | 2013-01-18 15:12:19 +0530 | [diff] [blame] | 277 | |
| 278 | /* |
| 279 | * handler returns using sigreturn stub provided already by userpsace |
Vineet Gupta | e414081 | 2015-03-26 11:14:41 +0530 | [diff] [blame] | 280 | * If not, nuke the process right away |
Vineet Gupta | c358103 | 2013-01-18 15:12:19 +0530 | [diff] [blame] | 281 | */ |
Vineet Gupta | e414081 | 2015-03-26 11:14:41 +0530 | [diff] [blame] | 282 | if(!(ksig->ka.sa.sa_flags & SA_RESTORER)) |
| 283 | return 1; |
| 284 | |
Richard Weinberger | f6dd2a3 | 2013-10-06 22:42:38 +0200 | [diff] [blame] | 285 | regs->blink = (unsigned long)ksig->ka.sa.sa_restorer; |
Vineet Gupta | c358103 | 2013-01-18 15:12:19 +0530 | [diff] [blame] | 286 | |
| 287 | /* User Stack for signal handler will be above the frame just carved */ |
| 288 | regs->sp = (unsigned long)sf; |
| 289 | |
| 290 | /* |
| 291 | * Bug 94183, Clear the DE bit, so that when signal handler |
| 292 | * starts to run, it doesn't use BTA |
| 293 | */ |
| 294 | regs->status32 &= ~STATUS_DE_MASK; |
| 295 | regs->status32 |= STATUS_L_MASK; |
| 296 | |
| 297 | return err; |
| 298 | } |
| 299 | |
| 300 | static void arc_restart_syscall(struct k_sigaction *ka, struct pt_regs *regs) |
| 301 | { |
| 302 | switch (regs->r0) { |
| 303 | case -ERESTART_RESTARTBLOCK: |
| 304 | case -ERESTARTNOHAND: |
| 305 | /* |
| 306 | * ERESTARTNOHAND means that the syscall should |
| 307 | * only be restarted if there was no handler for |
| 308 | * the signal, and since we only get here if there |
| 309 | * is a handler, we don't restart |
| 310 | */ |
| 311 | regs->r0 = -EINTR; /* ERESTART_xxx is internal */ |
| 312 | break; |
| 313 | |
| 314 | case -ERESTARTSYS: |
| 315 | /* |
| 316 | * ERESTARTSYS means to restart the syscall if |
| 317 | * there is no handler or the handler was |
| 318 | * registered with SA_RESTART |
| 319 | */ |
| 320 | if (!(ka->sa.sa_flags & SA_RESTART)) { |
| 321 | regs->r0 = -EINTR; |
| 322 | break; |
| 323 | } |
| 324 | /* fallthrough */ |
| 325 | |
| 326 | case -ERESTARTNOINTR: |
| 327 | /* |
| 328 | * ERESTARTNOINTR means that the syscall should |
| 329 | * be called again after the signal handler returns. |
| 330 | * Setup reg state just as it was before doing the trap |
| 331 | * r0 has been clobbered with sys call ret code thus it |
| 332 | * needs to be reloaded with orig first arg to syscall |
| 333 | * in orig_r0. Rest of relevant reg-file: |
| 334 | * r8 (syscall num) and (r1 - r7) will be reset to |
| 335 | * their orig user space value when we ret from kernel |
| 336 | */ |
| 337 | regs->r0 = regs->orig_r0; |
Vineet Gupta | 1f6ccff | 2013-05-13 18:30:41 +0530 | [diff] [blame] | 338 | regs->ret -= is_isa_arcv2() ? 2 : 4; |
Vineet Gupta | c358103 | 2013-01-18 15:12:19 +0530 | [diff] [blame] | 339 | break; |
| 340 | } |
| 341 | } |
| 342 | |
| 343 | /* |
| 344 | * OK, we're invoking a handler |
| 345 | */ |
| 346 | static void |
Richard Weinberger | f6dd2a3 | 2013-10-06 22:42:38 +0200 | [diff] [blame] | 347 | handle_signal(struct ksignal *ksig, struct pt_regs *regs) |
Vineet Gupta | c358103 | 2013-01-18 15:12:19 +0530 | [diff] [blame] | 348 | { |
| 349 | sigset_t *oldset = sigmask_to_save(); |
Vineet Gupta | e414081 | 2015-03-26 11:14:41 +0530 | [diff] [blame] | 350 | int failed; |
Vineet Gupta | c358103 | 2013-01-18 15:12:19 +0530 | [diff] [blame] | 351 | |
| 352 | /* Set up the stack frame */ |
Vineet Gupta | e414081 | 2015-03-26 11:14:41 +0530 | [diff] [blame] | 353 | failed = setup_rt_frame(ksig, oldset, regs); |
Vineet Gupta | c358103 | 2013-01-18 15:12:19 +0530 | [diff] [blame] | 354 | |
Vineet Gupta | e414081 | 2015-03-26 11:14:41 +0530 | [diff] [blame] | 355 | signal_setup_done(failed, ksig, 0); |
Vineet Gupta | c358103 | 2013-01-18 15:12:19 +0530 | [diff] [blame] | 356 | } |
| 357 | |
| 358 | void do_signal(struct pt_regs *regs) |
| 359 | { |
Richard Weinberger | f6dd2a3 | 2013-10-06 22:42:38 +0200 | [diff] [blame] | 360 | struct ksignal ksig; |
Vineet Gupta | c358103 | 2013-01-18 15:12:19 +0530 | [diff] [blame] | 361 | int restart_scall; |
| 362 | |
Vineet Gupta | 55bb948 | 2013-01-18 15:12:19 +0530 | [diff] [blame] | 363 | restart_scall = in_syscall(regs) && syscall_restartable(regs); |
Vineet Gupta | c358103 | 2013-01-18 15:12:19 +0530 | [diff] [blame] | 364 | |
Richard Weinberger | f6dd2a3 | 2013-10-06 22:42:38 +0200 | [diff] [blame] | 365 | if (get_signal(&ksig)) { |
Vineet Gupta | 55bb948 | 2013-01-18 15:12:19 +0530 | [diff] [blame] | 366 | if (restart_scall) { |
Richard Weinberger | f6dd2a3 | 2013-10-06 22:42:38 +0200 | [diff] [blame] | 367 | arc_restart_syscall(&ksig.ka, regs); |
Vineet Gupta | 55bb948 | 2013-01-18 15:12:19 +0530 | [diff] [blame] | 368 | syscall_wont_restart(regs); /* No more restarts */ |
| 369 | } |
Richard Weinberger | f6dd2a3 | 2013-10-06 22:42:38 +0200 | [diff] [blame] | 370 | handle_signal(&ksig, regs); |
Vineet Gupta | c358103 | 2013-01-18 15:12:19 +0530 | [diff] [blame] | 371 | return; |
| 372 | } |
| 373 | |
| 374 | if (restart_scall) { |
| 375 | /* No handler for syscall: restart it */ |
| 376 | if (regs->r0 == -ERESTARTNOHAND || |
| 377 | regs->r0 == -ERESTARTSYS || regs->r0 == -ERESTARTNOINTR) { |
| 378 | regs->r0 = regs->orig_r0; |
Vineet Gupta | 1f6ccff | 2013-05-13 18:30:41 +0530 | [diff] [blame] | 379 | regs->ret -= is_isa_arcv2() ? 2 : 4; |
Vineet Gupta | c358103 | 2013-01-18 15:12:19 +0530 | [diff] [blame] | 380 | } else if (regs->r0 == -ERESTART_RESTARTBLOCK) { |
| 381 | regs->r8 = __NR_restart_syscall; |
Vineet Gupta | 1f6ccff | 2013-05-13 18:30:41 +0530 | [diff] [blame] | 382 | regs->ret -= is_isa_arcv2() ? 2 : 4; |
Vineet Gupta | c358103 | 2013-01-18 15:12:19 +0530 | [diff] [blame] | 383 | } |
Vineet Gupta | 55bb948 | 2013-01-18 15:12:19 +0530 | [diff] [blame] | 384 | syscall_wont_restart(regs); /* No more restarts */ |
Vineet Gupta | c358103 | 2013-01-18 15:12:19 +0530 | [diff] [blame] | 385 | } |
| 386 | |
| 387 | /* If there's no signal to deliver, restore the saved sigmask back */ |
| 388 | restore_saved_sigmask(); |
| 389 | } |
| 390 | |
| 391 | void do_notify_resume(struct pt_regs *regs) |
| 392 | { |
| 393 | /* |
| 394 | * ASM glue gaurantees that this is only called when returning to |
| 395 | * user mode |
| 396 | */ |
| 397 | if (test_and_clear_thread_flag(TIF_NOTIFY_RESUME)) |
| 398 | tracehook_notify_resume(regs); |
| 399 | } |