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