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         unsigned long eflags;
  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         err |= __put_user(current->thread.err, &to->err);
  88         err |= __put_user(current->thread.trap_no, &to->trapno);
  89         err |= PUTREG(regs, RIP, to, rip);
  90         err |= PUTREG(regs, EFLAGS, to, eflags);
  91 #undef PUTREG
  92
  93         err |= __put_user(mask, &to->oldmask);
  94         err |= __put_user(current->thread.cr2, &to->cr2);
  95
  96         return(err);
  97 }
  98
  99 #endif
 100
 101 #ifdef CONFIG_MODE_TT
 102 int copy_sc_from_user_tt(struct sigcontext *to, struct sigcontext *from,
 103                         int fpsize)
 104 {
 105        struct _fpstate *to_fp, *from_fp;
 106        unsigned long sigs;
 107        int err;
 108
 109        to_fp = to->fpstate;
 110        from_fp = from->fpstate;
 111        sigs = to->oldmask;
 112        err = copy_from_user(to, from, sizeof(*to));
 113        to->oldmask = sigs;
 114        return(err);
 115 }
 116
 117 int copy_sc_to_user_tt(struct sigcontext *to, struct _fpstate *fp,
 118                       struct sigcontext *from, int fpsize)
 119 {
 120        struct _fpstate *to_fp, *from_fp;
 121        int err;
 122
 123        to_fp = (fp ? fp : (struct _fpstate *) (to + 1));
 124        from_fp = from->fpstate;
 125        err = copy_to_user(to, from, sizeof(*to));
 126        return(err);
 127 }
 128
 129 #endif
 130
 131 static int copy_sc_from_user(struct pt_regs *to, void __user *from)
 132 {
 133        int ret;
 134
 135        ret = CHOOSE_MODE(copy_sc_from_user_tt(UPT_SC(&to->regs), from,
 136                                               sizeof(struct _fpstate)),
 137                          copy_sc_from_user_skas(to, from));
 138        return(ret);
 139 }
 140
 141 static int copy_sc_to_user(struct sigcontext *to, struct _fpstate *fp,
 142                           struct pt_regs *from, unsigned long mask)
 143 {
 144        return(CHOOSE_MODE(copy_sc_to_user_tt(to, fp, UPT_SC(&from->regs),
 145                                              sizeof(*fp)),
 146                           copy_sc_to_user_skas(to, fp, from, mask)));
 147 }
 148
 149 struct rt_sigframe
 150 {
 151        char *pretcode;
 152        struct ucontext uc;
 153        struct siginfo info;
 154 };
 155
 156 #define round_down(m, n) (((m) / (n)) * (n))
 157
 158 int setup_signal_stack_si(unsigned long stack_top, int sig,
 159                           struct k_sigaction *ka, struct pt_regs * regs,
 160                           siginfo_t *info, sigset_t *set)
 161 {
 162         struct rt_sigframe __user *frame;
 163         struct _fpstate __user *fp = NULL;
 164         int err = 0;
 165         struct task_struct *me = current;
 166
 167         frame = (struct rt_sigframe __user *)
 168                 round_down(stack_top - sizeof(struct rt_sigframe), 16) - 8;
 169         frame -= 128;
 170
 171         if (!access_ok(VERIFY_WRITE, fp, sizeof(struct _fpstate)))
 172                 goto out;
 173
 174 #if 0 /* XXX */
 175         if (save_i387(fp) < 0)
 176                 err |= -1;
 177 #endif
 178         if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
 179                 goto out;
 180
 181         if (ka->sa.sa_flags & SA_SIGINFO) {
 182                 err |= copy_siginfo_to_user(&frame->info, info);
 183                 if (err)
 184                         goto out;
 185         }
 186
 187         /* Create the ucontext.  */
 188         err |= __put_user(0, &frame->uc.uc_flags);
 189         err |= __put_user(0, &frame->uc.uc_link);
 190         err |= __put_user(me->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
 191         err |= __put_user(sas_ss_flags(PT_REGS_SP(regs)),
 192                           &frame->uc.uc_stack.ss_flags);
 193         err |= __put_user(me->sas_ss_size, &frame->uc.uc_stack.ss_size);
 194         err |= copy_sc_to_user(&frame->uc.uc_mcontext, fp, regs, set->sig[0]);
 195         err |= __put_user(fp, &frame->uc.uc_mcontext.fpstate);
 196         if (sizeof(*set) == 16) {
 197                 __put_user(set->sig[0], &frame->uc.uc_sigmask.sig[0]);
 198                 __put_user(set->sig[1], &frame->uc.uc_sigmask.sig[1]);
 199         }
 200         else
 201                 err |= __copy_to_user(&frame->uc.uc_sigmask, set,
 202                                       sizeof(*set));
 203
 204         /* Set up to return from userspace.  If provided, use a stub
 205            already in userspace.  */
 206         /* x86-64 should always use SA_RESTORER. */
 207         if (ka->sa.sa_flags & SA_RESTORER)
 208                 err |= __put_user(ka->sa.sa_restorer, &frame->pretcode);
 209         else
 210                 /* could use a vstub here */
 211                 goto out;
 212
 213         if (err)
 214                 goto out;
 215
 216         /* Set up registers for signal handler */
 217         {
 218                 struct exec_domain *ed = current_thread_info()->exec_domain;
 219                 if (unlikely(ed && ed->signal_invmap && sig < 32))
 220                         sig = ed->signal_invmap[sig];
 221         }
 222
 223         PT_REGS_RDI(regs) = sig;
 224         /* In case the signal handler was declared without prototypes */
 225         PT_REGS_RAX(regs) = 0;
 226
 227         /* This also works for non SA_SIGINFO handlers because they expect the
 228            next argument after the signal number on the stack. */
 229         PT_REGS_RSI(regs) = (unsigned long) &frame->info;
 230         PT_REGS_RDX(regs) = (unsigned long) &frame->uc;
 231         PT_REGS_RIP(regs) = (unsigned long) ka->sa.sa_handler;
 232
 233         PT_REGS_RSP(regs) = (unsigned long) frame;
 234  out:
 235         return(err);
 236 }
 237
 238 long sys_rt_sigreturn(struct pt_regs *regs)
 239 {
 240         unsigned long sp = PT_REGS_SP(&current->thread.regs);
 241         struct rt_sigframe __user *frame =
 242                 (struct rt_sigframe __user *)(sp - 8);
 243         struct ucontext __user *uc = &frame->uc;
 244         sigset_t set;
 245
 246         if(copy_from_user(&set, &uc->uc_sigmask, sizeof(set)))
 247                 goto segfault;
 248
 249         sigdelsetmask(&set, ~_BLOCKABLE);
 250
 251         spin_lock_irq(&current->sighand->siglock);
 252         current->blocked = set;
 253         recalc_sigpending();
 254         spin_unlock_irq(&current->sighand->siglock);
 255
 256         if(copy_sc_from_user(&current->thread.regs, &uc->uc_mcontext))
 257                 goto segfault;
 258
 259         /* Avoid ERESTART handling */
 260         PT_REGS_SYSCALL_NR(&current->thread.regs) = -1;
 261         return(PT_REGS_SYSCALL_RET(&current->thread.regs));
 262
 263  segfault:
 264         force_sig(SIGSEGV, current);
 265         return 0;
 266 }
 267 /*
 268  * Overrides for Emacs so that we follow Linus's tabbing style.
 269  * Emacs will notice this stuff at the end of the file and automatically
 270  * adjust the settings for this buffer only.  This must remain at the end
 271  * of the file.
 272  * ---------------------------------------------------------------------------
 273  * Local variables:
 274  * c-file-style: "linux"
 275  * End:
 276  */