arch/um/sys-x86_64/signal.c

   1 /*
   2  * Copyright (C) 2003 PathScale, Inc.
   3  * Licensed under the GPL
   4  */
   5
   6 #include "linux/stddef.h"
   7 #include "linux/errno.h"
   8 #include "linux/personality.h"
   9 #include "linux/ptrace.h"
  10 #include "asm/current.h"
  11 #include "asm/uaccess.h"
  12 #include "asm/sigcontext.h"
  13 #include "asm/ptrace.h"
  14 #include "asm/arch/ucontext.h"
  15 #include "choose-mode.h"
  16 #include "sysdep/ptrace.h"
  17 #include "frame_kern.h"
  18
  19 #ifdef CONFIG_MODE_SKAS
  20
  21 #include "skas.h"
  22
  23 void copy_sc(union uml_pt_regs *regs, void *from)
  24 {
  25         struct sigcontext *sc = from;
  26
  27 #define GETREG(regs, regno, sc, regname) \
  28        (regs)->skas.regs[(regno) / sizeof(unsigned long)] = (sc)->regname
  29
  30        GETREG(regs, R8, sc, r8);
  31        GETREG(regs, R9, sc, r9);
  32        GETREG(regs, R10, sc, r10);
  33        GETREG(regs, R11, sc, r11);
  34        GETREG(regs, R12, sc, r12);
  35        GETREG(regs, R13, sc, r13);
  36        GETREG(regs, R14, sc, r14);
  37        GETREG(regs, R15, sc, r15);
  38        GETREG(regs, RDI, sc, rdi);
  39        GETREG(regs, RSI, sc, rsi);
  40        GETREG(regs, RBP, sc, rbp);
  41        GETREG(regs, RBX, sc, rbx);
  42        GETREG(regs, RDX, sc, rdx);
  43        GETREG(regs, RAX, sc, rax);
  44        GETREG(regs, RCX, sc, rcx);
  45        GETREG(regs, RSP, sc, rsp);
  46        GETREG(regs, RIP, sc, rip);
  47        GETREG(regs, EFLAGS, sc, eflags);
  48        GETREG(regs, CS, sc, cs);
  49
  50 #undef GETREG
  51 }
  52
  53 static int copy_sc_from_user_skas(struct pt_regs *regs,
  54                                  struct sigcontext __user *from)
  55 {
  56        int err = 0;
  57
  58 #define GETREG(regs, regno, sc, regname) \
  59        __get_user((regs)->regs.skas.regs[(regno) / sizeof(unsigned long)], \
  60                   &(sc)->regname)
  61
  62        err |= GETREG(regs, R8, from, r8);
  63        err |= GETREG(regs, R9, from, r9);
  64        err |= GETREG(regs, R10, from, r10);
  65        err |= GETREG(regs, R11, from, r11);
  66        err |= GETREG(regs, R12, from, r12);
  67        err |= GETREG(regs, R13, from, r13);
  68        err |= GETREG(regs, R14, from, r14);
  69        err |= GETREG(regs, R15, from, r15);
  70        err |= GETREG(regs, RDI, from, rdi);
  71        err |= GETREG(regs, RSI, from, rsi);
  72        err |= GETREG(regs, RBP, from, rbp);
  73        err |= GETREG(regs, RBX, from, rbx);
  74        err |= GETREG(regs, RDX, from, rdx);
  75        err |= GETREG(regs, RAX, from, rax);
  76        err |= GETREG(regs, RCX, from, rcx);
  77        err |= GETREG(regs, RSP, from, rsp);
  78        err |= GETREG(regs, RIP, from, rip);
  79        err |= GETREG(regs, EFLAGS, from, eflags);
  80        err |= GETREG(regs, CS, from, cs);
  81
  82 #undef GETREG
  83
  84        return err;
  85 }
  86
  87 int copy_sc_to_user_skas(struct sigcontext __user *to,
  88                          struct _fpstate __user *to_fp,
  89                          struct pt_regs *regs, unsigned long mask,
  90                          unsigned long sp)
  91 {
  92         struct faultinfo * fi = &current->thread.arch.faultinfo;
  93         int err = 0;
  94
  95         err |= __put_user(0, &to->gs);
  96         err |= __put_user(0, &to->fs);
  97
  98 #define PUTREG(regs, regno, sc, regname) \
  99        __put_user((regs)->regs.skas.regs[(regno) / sizeof(unsigned long)], \
 100                   &(sc)->regname)
 101
 102         err |= PUTREG(regs, RDI, to, rdi);
 103         err |= PUTREG(regs, RSI, to, rsi);
 104         err |= PUTREG(regs, RBP, to, rbp);
 105         /* Must use orignal RSP, which is passed in, rather than what's in
 106          * the pt_regs, because that's already been updated to point at the
 107          * signal frame.
 108          */
 109         err |= __put_user(sp, &to->rsp);
 110         err |= PUTREG(regs, RBX, to, rbx);
 111         err |= PUTREG(regs, RDX, to, rdx);
 112         err |= PUTREG(regs, RCX, to, rcx);
 113         err |= PUTREG(regs, RAX, to, rax);
 114         err |= PUTREG(regs, R8, to, r8);
 115         err |= PUTREG(regs, R9, to, r9);
 116         err |= PUTREG(regs, R10, to, r10);
 117         err |= PUTREG(regs, R11, to, r11);
 118         err |= PUTREG(regs, R12, to, r12);
 119         err |= PUTREG(regs, R13, to, r13);
 120         err |= PUTREG(regs, R14, to, r14);
 121         err |= PUTREG(regs, R15, to, r15);
 122         err |= PUTREG(regs, CS, to, cs); /* XXX x86_64 doesn't do this */
 123
 124         err |= __put_user(fi->cr2, &to->cr2);
 125         err |= __put_user(fi->error_code, &to->err);
 126         err |= __put_user(fi->trap_no, &to->trapno);
 127
 128         err |= PUTREG(regs, RIP, to, rip);
 129         err |= PUTREG(regs, EFLAGS, to, eflags);
 130 #undef PUTREG
 131
 132         err |= __put_user(mask, &to->oldmask);
 133
 134         return(err);
 135 }
 136
 137 #endif
 138
 139 #ifdef CONFIG_MODE_TT
 140 int copy_sc_from_user_tt(struct sigcontext *to, struct sigcontext __user *from,
 141                          int fpsize)
 142 {
 143         struct _fpstate *to_fp;
 144         struct _fpstate __user *from_fp;
 145         unsigned long sigs;
 146         int err;
 147
 148         to_fp = to->fpstate;
 149         sigs = to->oldmask;
 150         err = copy_from_user(to, from, sizeof(*to));
 151         from_fp = to->fpstate;
 152         to->fpstate = to_fp;
 153         to->oldmask = sigs;
 154         if(to_fp != NULL)
 155                 err |= copy_from_user(to_fp, from_fp, fpsize);
 156         return(err);
 157 }
 158
 159 int copy_sc_to_user_tt(struct sigcontext __user *to, struct _fpstate __user *fp,
 160                        struct sigcontext *from, int fpsize, unsigned long sp)
 161 {
 162         struct _fpstate __user *to_fp;
 163         struct _fpstate *from_fp;
 164         int err;
 165
 166         to_fp = (fp ? fp : (struct _fpstate __user *) (to + 1));
 167         from_fp = from->fpstate;
 168         err = copy_to_user(to, from, sizeof(*to));
 169         /* The SP in the sigcontext is the updated one for the signal
 170          * delivery.  The sp passed in is the original, and this needs
 171          * to be restored, so we stick it in separately.
 172          */
 173         err |= copy_to_user(&SC_SP(to), &sp, sizeof(sp));
 174
 175         if(from_fp != NULL){
 176                 err |= copy_to_user(&to->fpstate, &to_fp, sizeof(to->fpstate));
 177                 err |= copy_to_user(to_fp, from_fp, fpsize);
 178         }
 179         return err;
 180 }
 181
 182 #endif
 183
 184 static int copy_sc_from_user(struct pt_regs *to, void __user *from)
 185 {
 186        int ret;
 187
 188        ret = CHOOSE_MODE(copy_sc_from_user_tt(UPT_SC(&to->regs), from,
 189                                               sizeof(struct _fpstate)),
 190                          copy_sc_from_user_skas(to, from));
 191        return(ret);
 192 }
 193
 194 static int copy_sc_to_user(struct sigcontext __user *to,
 195                            struct _fpstate __user *fp,
 196                            struct pt_regs *from, unsigned long mask,
 197                            unsigned long sp)
 198 {
 199        return(CHOOSE_MODE(copy_sc_to_user_tt(to, fp, UPT_SC(&from->regs),
 200                                              sizeof(*fp), sp),
 201                           copy_sc_to_user_skas(to, fp, from, mask, sp)));
 202 }
 203
 204 struct rt_sigframe
 205 {
 206        char __user *pretcode;
 207        struct ucontext uc;
 208        struct siginfo info;
 209 };
 210
 211 #define round_down(m, n) (((m) / (n)) * (n))
 212
 213 int setup_signal_stack_si(unsigned long stack_top, int sig,
 214                           struct k_sigaction *ka, struct pt_regs * regs,
 215                           siginfo_t *info, sigset_t *set)
 216 {
 217         struct rt_sigframe __user *frame;
 218         struct _fpstate __user *fp = NULL;
 219         unsigned long save_sp = PT_REGS_RSP(regs);
 220         int err = 0;
 221         struct task_struct *me = current;
 222
 223         frame = (struct rt_sigframe __user *)
 224                 round_down(stack_top - sizeof(struct rt_sigframe), 16);
 225         /* Subtract 128 for a red zone and 8 for proper alignment */
 226         frame = (struct rt_sigframe __user *) ((unsigned long) frame - 128 - 8);
 227
 228         if (!access_ok(VERIFY_WRITE, fp, sizeof(struct _fpstate)))
 229                 goto out;
 230
 231 #if 0 /* XXX */
 232         if (save_i387(fp) < 0)
 233                 err |= -1;
 234 #endif
 235         if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
 236                 goto out;
 237
 238         if (ka->sa.sa_flags & SA_SIGINFO) {
 239                 err |= copy_siginfo_to_user(&frame->info, info);
 240                 if (err)
 241                         goto out;
 242         }
 243
 244         /* Update SP now because the page fault handler refuses to extend
 245          * the stack if the faulting address is too far below the current
 246          * SP, which frame now certainly is.  If there's an error, the original
 247          * value is restored on the way out.
 248          * When writing the sigcontext to the stack, we have to write the
 249          * original value, so that's passed to copy_sc_to_user, which does
 250          * the right thing with it.
 251          */
 252         PT_REGS_RSP(regs) = (unsigned long) frame;
 253
 254         /* Create the ucontext.  */
 255         err |= __put_user(0, &frame->uc.uc_flags);
 256         err |= __put_user(0, &frame->uc.uc_link);
 257         err |= __put_user(me->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
 258         err |= __put_user(sas_ss_flags(save_sp),
 259                           &frame->uc.uc_stack.ss_flags);
 260         err |= __put_user(me->sas_ss_size, &frame->uc.uc_stack.ss_size);
 261         err |= copy_sc_to_user(&frame->uc.uc_mcontext, fp, regs, set->sig[0],
 262                 save_sp);
 263         err |= __put_user(fp, &frame->uc.uc_mcontext.fpstate);
 264         if (sizeof(*set) == 16) {
 265                 __put_user(set->sig[0], &frame->uc.uc_sigmask.sig[0]);
 266                 __put_user(set->sig[1], &frame->uc.uc_sigmask.sig[1]);
 267         }
 268         else
 269                 err |= __copy_to_user(&frame->uc.uc_sigmask, set,
 270                                       sizeof(*set));
 271
 272         /* Set up to return from userspace.  If provided, use a stub
 273            already in userspace.  */
 274         /* x86-64 should always use SA_RESTORER. */
 275         if (ka->sa.sa_flags & SA_RESTORER)
 276                 err |= __put_user(ka->sa.sa_restorer, &frame->pretcode);
 277         else
 278                 /* could use a vstub here */
 279                 goto restore_sp;
 280
 281         if (err)
 282                 goto restore_sp;
 283
 284         /* Set up registers for signal handler */
 285         {
 286                 struct exec_domain *ed = current_thread_info()->exec_domain;
 287                 if (unlikely(ed && ed->signal_invmap && sig < 32))
 288                         sig = ed->signal_invmap[sig];
 289         }
 290
 291         PT_REGS_RDI(regs) = sig;
 292         /* In case the signal handler was declared without prototypes */
 293         PT_REGS_RAX(regs) = 0;
 294
 295         /* This also works for non SA_SIGINFO handlers because they expect the
 296            next argument after the signal number on the stack. */
 297         PT_REGS_RSI(regs) = (unsigned long) &frame->info;
 298         PT_REGS_RDX(regs) = (unsigned long) &frame->uc;
 299         PT_REGS_RIP(regs) = (unsigned long) ka->sa.sa_handler;
 300  out:
 301         return err;
 302
 303 restore_sp:
 304         PT_REGS_RSP(regs) = save_sp;
 305         return err;
 306 }
 307
 308 long sys_rt_sigreturn(struct pt_regs *regs)
 309 {
 310         unsigned long sp = PT_REGS_SP(&current->thread.regs);
 311         struct rt_sigframe __user *frame =
 312                 (struct rt_sigframe __user *)(sp - 8);
 313         struct ucontext __user *uc = &frame->uc;
 314         sigset_t set;
 315
 316         if(copy_from_user(&set, &uc->uc_sigmask, sizeof(set)))
 317                 goto segfault;
 318
 319         sigdelsetmask(&set, ~_BLOCKABLE);
 320
 321         spin_lock_irq(&current->sighand->siglock);
 322         current->blocked = set;
 323         recalc_sigpending();
 324         spin_unlock_irq(&current->sighand->siglock);
 325
 326         if(copy_sc_from_user(&current->thread.regs, &uc->uc_mcontext))
 327                 goto segfault;
 328
 329         /* Avoid ERESTART handling */
 330         PT_REGS_SYSCALL_NR(&current->thread.regs) = -1;
 331         return(PT_REGS_SYSCALL_RET(&current->thread.regs));
 332
 333  segfault:
 334         force_sig(SIGSEGV, current);
 335         return 0;
 336 }
 337 /*
 338  * Overrides for Emacs so that we follow Linus's tabbing style.
 339  * Emacs will notice this stuff at the end of the file and automatically
 340  * adjust the settings for this buffer only.  This must remain at the end
 341  * of the file.
 342  * ---------------------------------------------------------------------------
 343  * Local variables:
 344  * c-file-style: "linux"
 345  * End:
 346  */