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 static int copy_sc_from_user_skas(struct pt_regs *regs,
  24                                  struct sigcontext *from)
  25 {
  26        int err = 0;
  27
  28 #define GETREG(regs, regno, sc, regname) \
  29        __get_user((regs)->regs.skas.regs[(regno) / sizeof(unsigned long)], \
  30                   &(sc)->regname)
  31
  32        err |= GETREG(regs, R8, from, r8);
  33        err |= GETREG(regs, R9, from, r9);
  34        err |= GETREG(regs, R10, from, r10);
  35        err |= GETREG(regs, R11, from, r11);
  36        err |= GETREG(regs, R12, from, r12);
  37        err |= GETREG(regs, R13, from, r13);
  38        err |= GETREG(regs, R14, from, r14);
  39        err |= GETREG(regs, R15, from, r15);
  40        err |= GETREG(regs, RDI, from, rdi);
  41        err |= GETREG(regs, RSI, from, rsi);
  42        err |= GETREG(regs, RBP, from, rbp);
  43        err |= GETREG(regs, RBX, from, rbx);
  44        err |= GETREG(regs, RDX, from, rdx);
  45        err |= GETREG(regs, RAX, from, rax);
  46        err |= GETREG(regs, RCX, from, rcx);
  47        err |= GETREG(regs, RSP, from, rsp);
  48        err |= GETREG(regs, RIP, from, rip);
  49        err |= GETREG(regs, EFLAGS, from, eflags);
  50        err |= GETREG(regs, CS, from, cs);
  51
  52 #undef GETREG
  53
  54        return(err);
  55 }
  56
  57 int copy_sc_to_user_skas(struct sigcontext *to, struct _fpstate *to_fp,
  58                         struct pt_regs *regs, unsigned long mask)
  59 {
  60         struct faultinfo * fi = &current->thread.arch.faultinfo;
  61         int err = 0;
  62
  63         err |= __put_user(0, &to->gs);
  64         err |= __put_user(0, &to->fs);
  65
  66 #define PUTREG(regs, regno, sc, regname) \
  67        __put_user((regs)->regs.skas.regs[(regno) / sizeof(unsigned long)], \
  68                   &(sc)->regname)
  69
  70         err |= PUTREG(regs, RDI, to, rdi);
  71         err |= PUTREG(regs, RSI, to, rsi);
  72         err |= PUTREG(regs, RBP, to, rbp);
  73         err |= PUTREG(regs, RSP, to, rsp);
  74         err |= PUTREG(regs, RBX, to, rbx);
  75         err |= PUTREG(regs, RDX, to, rdx);
  76         err |= PUTREG(regs, RCX, to, rcx);
  77         err |= PUTREG(regs, RAX, to, rax);
  78         err |= PUTREG(regs, R8, to, r8);
  79         err |= PUTREG(regs, R9, to, r9);
  80         err |= PUTREG(regs, R10, to, r10);
  81         err |= PUTREG(regs, R11, to, r11);
  82         err |= PUTREG(regs, R12, to, r12);
  83         err |= PUTREG(regs, R13, to, r13);
  84         err |= PUTREG(regs, R14, to, r14);
  85         err |= PUTREG(regs, R15, to, r15);
  86         err |= PUTREG(regs, CS, to, cs); /* XXX x86_64 doesn't do this */
  87
  88         err |= __put_user(fi->cr2, &to->cr2);
  89         err |= __put_user(fi->error_code, &to->err);
  90         err |= __put_user(fi->trap_no, &to->trapno);
  91
  92         err |= PUTREG(regs, RIP, to, rip);
  93         err |= PUTREG(regs, EFLAGS, to, eflags);
  94 #undef PUTREG
  95
  96         err |= __put_user(mask, &to->oldmask);
  97
  98         return(err);
  99 }
 100
 101 #endif
 102
 103 #ifdef CONFIG_MODE_TT
 104 int copy_sc_from_user_tt(struct sigcontext *to, struct sigcontext *from,
 105                         int fpsize)
 106 {
 107         struct _fpstate *to_fp, *from_fp;
 108         unsigned long sigs;
 109         int err;
 110
 111         to_fp = to->fpstate;
 112         sigs = to->oldmask;
 113         err = copy_from_user(to, from, sizeof(*to));
 114         from_fp = to->fpstate;
 115         to->fpstate = to_fp;
 116         to->oldmask = sigs;
 117         if(to_fp != NULL)
 118                 err |= copy_from_user(to_fp, from_fp, fpsize);
 119         return(err);
 120 }
 121
 122 int copy_sc_to_user_tt(struct sigcontext *to, struct _fpstate *fp,
 123                       struct sigcontext *from, int fpsize)
 124 {
 125         struct _fpstate *to_fp, *from_fp;
 126         int err;
 127
 128         to_fp = (fp ? fp : (struct _fpstate *) (to + 1));
 129         from_fp = from->fpstate;
 130         err = copy_to_user(to, from, sizeof(*to));
 131         if(from_fp != NULL){
 132                 err |= copy_to_user(&to->fpstate, &to_fp, sizeof(to->fpstate));
 133                 err |= copy_to_user(to_fp, from_fp, fpsize);
 134         }
 135         return(err);
 136 }
 137
 138 #endif
 139
 140 static int copy_sc_from_user(struct pt_regs *to, void __user *from)
 141 {
 142        int ret;
 143
 144        ret = CHOOSE_MODE(copy_sc_from_user_tt(UPT_SC(&to->regs), from,
 145                                               sizeof(struct _fpstate)),
 146                          copy_sc_from_user_skas(to, from));
 147        return(ret);
 148 }
 149
 150 static int copy_sc_to_user(struct sigcontext *to, struct _fpstate *fp,
 151                           struct pt_regs *from, unsigned long mask)
 152 {
 153        return(CHOOSE_MODE(copy_sc_to_user_tt(to, fp, UPT_SC(&from->regs),
 154                                              sizeof(*fp)),
 155                           copy_sc_to_user_skas(to, fp, from, mask)));
 156 }
 157
 158 struct rt_sigframe
 159 {
 160        char *pretcode;
 161        struct ucontext uc;
 162        struct siginfo info;
 163 };
 164
 165 #define round_down(m, n) (((m) / (n)) * (n))
 166
 167 int setup_signal_stack_si(unsigned long stack_top, int sig,
 168                           struct k_sigaction *ka, struct pt_regs * regs,
 169                           siginfo_t *info, sigset_t *set)
 170 {
 171         struct rt_sigframe __user *frame;
 172         struct _fpstate __user *fp = NULL;
 173         int err = 0;
 174         struct task_struct *me = current;
 175
 176         frame = (struct rt_sigframe __user *)
 177                 round_down(stack_top - sizeof(struct rt_sigframe), 16) - 8;
 178         frame = (struct rt_sigframe *) ((unsigned long) frame - 128);
 179
 180         if (!access_ok(VERIFY_WRITE, fp, sizeof(struct _fpstate)))
 181                 goto out;
 182
 183 #if 0 /* XXX */
 184         if (save_i387(fp) < 0)
 185                 err |= -1;
 186 #endif
 187         if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
 188                 goto out;
 189
 190         if (ka->sa.sa_flags & SA_SIGINFO) {
 191                 err |= copy_siginfo_to_user(&frame->info, info);
 192                 if (err)
 193                         goto out;
 194         }
 195
 196         /* Create the ucontext.  */
 197         err |= __put_user(0, &frame->uc.uc_flags);
 198         err |= __put_user(0, &frame->uc.uc_link);
 199         err |= __put_user(me->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
 200         err |= __put_user(sas_ss_flags(PT_REGS_SP(regs)),
 201                           &frame->uc.uc_stack.ss_flags);
 202         err |= __put_user(me->sas_ss_size, &frame->uc.uc_stack.ss_size);
 203         err |= copy_sc_to_user(&frame->uc.uc_mcontext, fp, regs, set->sig[0]);
 204         err |= __put_user(fp, &frame->uc.uc_mcontext.fpstate);
 205         if (sizeof(*set) == 16) {
 206                 __put_user(set->sig[0], &frame->uc.uc_sigmask.sig[0]);
 207                 __put_user(set->sig[1], &frame->uc.uc_sigmask.sig[1]);
 208         }
 209         else
 210                 err |= __copy_to_user(&frame->uc.uc_sigmask, set,
 211                                       sizeof(*set));
 212
 213         /* Set up to return from userspace.  If provided, use a stub
 214            already in userspace.  */
 215         /* x86-64 should always use SA_RESTORER. */
 216         if (ka->sa.sa_flags & SA_RESTORER)
 217                 err |= __put_user(ka->sa.sa_restorer, &frame->pretcode);
 218         else
 219                 /* could use a vstub here */
 220                 goto out;
 221
 222         if (err)
 223                 goto out;
 224
 225         /* Set up registers for signal handler */
 226         {
 227                 struct exec_domain *ed = current_thread_info()->exec_domain;
 228                 if (unlikely(ed && ed->signal_invmap && sig < 32))
 229                         sig = ed->signal_invmap[sig];
 230         }
 231
 232         PT_REGS_RDI(regs) = sig;
 233         /* In case the signal handler was declared without prototypes */
 234         PT_REGS_RAX(regs) = 0;
 235
 236         /* This also works for non SA_SIGINFO handlers because they expect the
 237            next argument after the signal number on the stack. */
 238         PT_REGS_RSI(regs) = (unsigned long) &frame->info;
 239         PT_REGS_RDX(regs) = (unsigned long) &frame->uc;
 240         PT_REGS_RIP(regs) = (unsigned long) ka->sa.sa_handler;
 241
 242         PT_REGS_RSP(regs) = (unsigned long) frame;
 243  out:
 244         return(err);
 245 }
 246
 247 long sys_rt_sigreturn(struct pt_regs *regs)
 248 {
 249         unsigned long sp = PT_REGS_SP(&current->thread.regs);
 250         struct rt_sigframe __user *frame =
 251                 (struct rt_sigframe __user *)(sp - 8);
 252         struct ucontext __user *uc = &frame->uc;
 253         sigset_t set;
 254
 255         if(copy_from_user(&set, &uc->uc_sigmask, sizeof(set)))
 256                 goto segfault;
 257
 258         sigdelsetmask(&set, ~_BLOCKABLE);
 259
 260         spin_lock_irq(&current->sighand->siglock);
 261         current->blocked = set;
 262         recalc_sigpending();
 263         spin_unlock_irq(&current->sighand->siglock);
 264
 265         if(copy_sc_from_user(&current->thread.regs, &uc->uc_mcontext))
 266                 goto segfault;
 267
 268         /* Avoid ERESTART handling */
 269         PT_REGS_SYSCALL_NR(&current->thread.regs) = -1;
 270         return(PT_REGS_SYSCALL_RET(&current->thread.regs));
 271
 272  segfault:
 273         force_sig(SIGSEGV, current);
 274         return 0;
 275 }
 276 /*
 277  * Overrides for Emacs so that we follow Linus's tabbing style.
 278  * Emacs will notice this stuff at the end of the file and automatically
 279  * adjust the settings for this buffer only.  This must remain at the end
 280  * of the file.
 281  * ---------------------------------------------------------------------------
 282  * Local variables:
 283  * c-file-style: "linux"
 284  * End:
 285  */