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