1/* 2 * Copyright (C) 2003 PathScale, Inc. 3 * Copyright (C) 2003 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com) 4 * Licensed under the GPL 5 */ 6 7#include <linux/personality.h> 8#include <linux/ptrace.h> 9#include <linux/kernel.h> 10#include <asm/unistd.h> 11#include <asm/uaccess.h> 12#include <asm/ucontext.h> 13#include "frame_kern.h" 14#include "skas.h" 15 16void copy_sc(struct uml_pt_regs *regs, void *from) 17{ 18 struct sigcontext *sc = from; 19 20#define GETREG(regs, regno, sc, regname) \ 21 (regs)->gp[(regno) / sizeof(unsigned long)] = (sc)->regname 22 23 GETREG(regs, R8, sc, r8); 24 GETREG(regs, R9, sc, r9); 25 GETREG(regs, R10, sc, r10); 26 GETREG(regs, R11, sc, r11); 27 GETREG(regs, R12, sc, r12); 28 GETREG(regs, R13, sc, r13); 29 GETREG(regs, R14, sc, r14); 30 GETREG(regs, R15, sc, r15); 31 GETREG(regs, RDI, sc, di); 32 GETREG(regs, RSI, sc, si); 33 GETREG(regs, RBP, sc, bp); 34 GETREG(regs, RBX, sc, bx); 35 GETREG(regs, RDX, sc, dx); 36 GETREG(regs, RAX, sc, ax); 37 GETREG(regs, RCX, sc, cx); 38 GETREG(regs, RSP, sc, sp); 39 GETREG(regs, RIP, sc, ip); 40 GETREG(regs, EFLAGS, sc, flags); 41 GETREG(regs, CS, sc, cs); 42 43#undef GETREG 44} 45 46static int copy_sc_from_user(struct pt_regs *regs, 47 struct sigcontext __user *from, 48 struct _fpstate __user *fpp) 49{ 50 struct user_i387_struct fp; 51 int err = 0; 52 53#define GETREG(regs, regno, sc, regname) \ 54 __get_user((regs)->regs.gp[(regno) / sizeof(unsigned long)], \ 55 &(sc)->regname) 56 57 err |= GETREG(regs, R8, from, r8); 58 err |= GETREG(regs, R9, from, r9); 59 err |= GETREG(regs, R10, from, r10); 60 err |= GETREG(regs, R11, from, r11); 61 err |= GETREG(regs, R12, from, r12); 62 err |= GETREG(regs, R13, from, r13); 63 err |= GETREG(regs, R14, from, r14); 64 err |= GETREG(regs, R15, from, r15); 65 err |= GETREG(regs, RDI, from, di); 66 err |= GETREG(regs, RSI, from, si); 67 err |= GETREG(regs, RBP, from, bp); 68 err |= GETREG(regs, RBX, from, bx); 69 err |= GETREG(regs, RDX, from, dx); 70 err |= GETREG(regs, RAX, from, ax); 71 err |= GETREG(regs, RCX, from, cx); 72 err |= GETREG(regs, RSP, from, sp); 73 err |= GETREG(regs, RIP, from, ip); 74 err |= GETREG(regs, EFLAGS, from, flags); 75 err |= GETREG(regs, CS, from, cs); 76 if (err) 77 return 1; 78 79#undef GETREG 80 81 err = copy_from_user(&fp, fpp, sizeof(struct user_i387_struct)); 82 if (err) 83 return 1; 84 85 err = restore_fp_registers(userspace_pid[current_thread_info()->cpu], 86 (unsigned long *) &fp); 87 if (err < 0) { 88 printk(KERN_ERR "copy_sc_from_user - " 89 "restore_fp_registers failed, errno = %d\n", 90 -err); 91 return 1; 92 } 93 94 return 0; 95} 96 97static int copy_sc_to_user(struct sigcontext __user *to, 98 struct _fpstate __user *to_fp, struct pt_regs *regs, 99 unsigned long mask, unsigned long sp) 100{ 101 struct faultinfo * fi = ¤t->thread.arch.faultinfo; 102 struct user_i387_struct fp; 103 int err = 0; 104 105 err |= __put_user(0, &to->gs); 106 err |= __put_user(0, &to->fs); 107 108#define PUTREG(regs, regno, sc, regname) \ 109 __put_user((regs)->regs.gp[(regno) / sizeof(unsigned long)], \ 110 &(sc)->regname) 111 112 err |= PUTREG(regs, RDI, to, di); 113 err |= PUTREG(regs, RSI, to, si); 114 err |= PUTREG(regs, RBP, to, bp); 115 /* 116 * Must use original RSP, which is passed in, rather than what's in 117 * the pt_regs, because that's already been updated to point at the 118 * signal frame. 119 */ 120 err |= __put_user(sp, &to->sp); 121 err |= PUTREG(regs, RBX, to, bx); 122 err |= PUTREG(regs, RDX, to, dx); 123 err |= PUTREG(regs, RCX, to, cx); 124 err |= PUTREG(regs, RAX, to, ax); 125 err |= PUTREG(regs, R8, to, r8); 126 err |= PUTREG(regs, R9, to, r9); 127 err |= PUTREG(regs, R10, to, r10); 128 err |= PUTREG(regs, R11, to, r11); 129 err |= PUTREG(regs, R12, to, r12); 130 err |= PUTREG(regs, R13, to, r13); 131 err |= PUTREG(regs, R14, to, r14); 132 err |= PUTREG(regs, R15, to, r15); 133 err |= PUTREG(regs, CS, to, cs); 134 135 err |= __put_user(fi->cr2, &to->cr2); 136 err |= __put_user(fi->error_code, &to->err); 137 err |= __put_user(fi->trap_no, &to->trapno); 138 139 err |= PUTREG(regs, RIP, to, ip); 140 err |= PUTREG(regs, EFLAGS, to, flags); 141#undef PUTREG 142 143 err |= __put_user(mask, &to->oldmask); 144 if (err) 145 return 1; 146 147 err = save_fp_registers(userspace_pid[current_thread_info()->cpu], 148 (unsigned long *) &fp); 149 if (err < 0) { 150 printk(KERN_ERR "copy_sc_from_user - restore_fp_registers " 151 "failed, errno = %d\n", -err); 152 return 1; 153 } 154 155 if (copy_to_user(to_fp, &fp, sizeof(struct user_i387_struct))) 156 return 1; 157 158 return err; 159} 160 161struct rt_sigframe 162{ 163 char __user *pretcode; 164 struct ucontext uc; 165 struct siginfo info; 166 struct _fpstate fpstate; 167}; 168 169int setup_signal_stack_si(unsigned long stack_top, int sig, 170 struct k_sigaction *ka, struct pt_regs * regs, 171 siginfo_t *info, sigset_t *set) 172{ 173 struct rt_sigframe __user *frame; 174 unsigned long save_sp = PT_REGS_RSP(regs); 175 int err = 0; 176 struct task_struct *me = current; 177 178 frame = (struct rt_sigframe __user *) 179 round_down(stack_top - sizeof(struct rt_sigframe), 16); 180 /* Subtract 128 for a red zone and 8 for proper alignment */ 181 frame = (struct rt_sigframe __user *) ((unsigned long) frame - 128 - 8); 182 183 if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) 184 goto out; 185 186 if (ka->sa.sa_flags & SA_SIGINFO) { 187 err |= copy_siginfo_to_user(&frame->info, info); 188 if (err) 189 goto out; 190 } 191 192 /* 193 * Update SP now because the page fault handler refuses to extend 194 * the stack if the faulting address is too far below the current 195 * SP, which frame now certainly is. If there's an error, the original 196 * value is restored on the way out. 197 * When writing the sigcontext to the stack, we have to write the 198 * original value, so that's passed to copy_sc_to_user, which does 199 * the right thing with it. 200 */ 201 PT_REGS_RSP(regs) = (unsigned long) frame; 202 203 /* Create the ucontext. */ 204 err |= __put_user(0, &frame->uc.uc_flags); 205 err |= __put_user(0, &frame->uc.uc_link); 206 err |= __put_user(me->sas_ss_sp, &frame->uc.uc_stack.ss_sp); 207 err |= __put_user(sas_ss_flags(save_sp), 208 &frame->uc.uc_stack.ss_flags); 209 err |= __put_user(me->sas_ss_size, &frame->uc.uc_stack.ss_size); 210 err |= copy_sc_to_user(&frame->uc.uc_mcontext, &frame->fpstate, regs, 211 set->sig[0], save_sp); 212 err |= __put_user(&frame->fpstate, &frame->uc.uc_mcontext.fpstate); 213 if (sizeof(*set) == 16) { 214 __put_user(set->sig[0], &frame->uc.uc_sigmask.sig[0]); 215 __put_user(set->sig[1], &frame->uc.uc_sigmask.sig[1]); 216 } 217 else 218 err |= __copy_to_user(&frame->uc.uc_sigmask, set, 219 sizeof(*set)); 220 221 /* 222 * Set up to return from userspace. If provided, use a stub 223 * already in userspace. 224 */ 225 /* x86-64 should always use SA_RESTORER. */ 226 if (ka->sa.sa_flags & SA_RESTORER) 227 err |= __put_user(ka->sa.sa_restorer, &frame->pretcode); 228 else 229 /* could use a vstub here */ 230 goto restore_sp; 231 232 if (err) 233 goto restore_sp; 234 235 /* Set up registers for signal handler */ 236 { 237 struct exec_domain *ed = current_thread_info()->exec_domain; 238 if (unlikely(ed && ed->signal_invmap && sig < 32)) 239 sig = ed->signal_invmap[sig]; 240 } 241 242 PT_REGS_RDI(regs) = sig; 243 /* In case the signal handler was declared without prototypes */ 244 PT_REGS_RAX(regs) = 0; 245 246 /* 247 * This also works for non SA_SIGINFO handlers because they expect the 248 * next argument after the signal number on the stack. 249 */ 250 PT_REGS_RSI(regs) = (unsigned long) &frame->info; 251 PT_REGS_RDX(regs) = (unsigned long) &frame->uc; 252 PT_REGS_RIP(regs) = (unsigned long) ka->sa.sa_handler; 253 out: 254 return err; 255 256restore_sp: 257 PT_REGS_RSP(regs) = save_sp; 258 return err; 259} 260 261long sys_rt_sigreturn(struct pt_regs *regs) 262{ 263 unsigned long sp = PT_REGS_SP(¤t->thread.regs); 264 struct rt_sigframe __user *frame = 265 (struct rt_sigframe __user *)(sp - 8); 266 struct ucontext __user *uc = &frame->uc; 267 sigset_t set; 268 269 if (copy_from_user(&set, &uc->uc_sigmask, sizeof(set))) 270 goto segfault; 271 272 sigdelsetmask(&set, ~_BLOCKABLE); 273 274 spin_lock_irq(¤t->sighand->siglock); 275 current->blocked = set; 276 recalc_sigpending(); 277 spin_unlock_irq(¤t->sighand->siglock); 278 279 if (copy_sc_from_user(¤t->thread.regs, &uc->uc_mcontext, 280 &frame->fpstate)) 281 goto segfault; 282 283 /* Avoid ERESTART handling */ 284 PT_REGS_SYSCALL_NR(¤t->thread.regs) = -1; 285 return PT_REGS_SYSCALL_RET(¤t->thread.regs); 286 287 segfault: 288 force_sig(SIGSEGV, current); 289 return 0; 290} 291