292 lines
		
	
	
		
			8.0 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			292 lines
		
	
	
		
			8.0 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
 | |
|  * Copyright (C) 2003 PathScale, Inc.
 | |
|  * Copyright (C) 2003 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
 | |
|  * Licensed under the GPL
 | |
|  */
 | |
| 
 | |
| #include <linux/personality.h>
 | |
| #include <linux/ptrace.h>
 | |
| #include <asm/unistd.h>
 | |
| #include <asm/uaccess.h>
 | |
| #include <asm/ucontext.h>
 | |
| #include "frame_kern.h"
 | |
| #include "skas.h"
 | |
| 
 | |
| void copy_sc(struct uml_pt_regs *regs, void *from)
 | |
| {
 | |
| 	struct sigcontext *sc = from;
 | |
| 
 | |
| #define GETREG(regs, regno, sc, regname)				\
 | |
| 	(regs)->gp[(regno) / sizeof(unsigned long)] = (sc)->regname
 | |
| 
 | |
| 	GETREG(regs, R8, sc, r8);
 | |
| 	GETREG(regs, R9, sc, r9);
 | |
| 	GETREG(regs, R10, sc, r10);
 | |
| 	GETREG(regs, R11, sc, r11);
 | |
| 	GETREG(regs, R12, sc, r12);
 | |
| 	GETREG(regs, R13, sc, r13);
 | |
| 	GETREG(regs, R14, sc, r14);
 | |
| 	GETREG(regs, R15, sc, r15);
 | |
| 	GETREG(regs, RDI, sc, di);
 | |
| 	GETREG(regs, RSI, sc, si);
 | |
| 	GETREG(regs, RBP, sc, bp);
 | |
| 	GETREG(regs, RBX, sc, bx);
 | |
| 	GETREG(regs, RDX, sc, dx);
 | |
| 	GETREG(regs, RAX, sc, ax);
 | |
| 	GETREG(regs, RCX, sc, cx);
 | |
| 	GETREG(regs, RSP, sc, sp);
 | |
| 	GETREG(regs, RIP, sc, ip);
 | |
| 	GETREG(regs, EFLAGS, sc, flags);
 | |
| 	GETREG(regs, CS, sc, cs);
 | |
| 
 | |
| #undef GETREG
 | |
| }
 | |
| 
 | |
| static int copy_sc_from_user(struct pt_regs *regs,
 | |
| 			     struct sigcontext __user *from,
 | |
| 			     struct _fpstate __user *fpp)
 | |
| {
 | |
| 	struct user_i387_struct fp;
 | |
| 	int err = 0;
 | |
| 
 | |
| #define GETREG(regs, regno, sc, regname)				\
 | |
| 	__get_user((regs)->regs.gp[(regno) / sizeof(unsigned long)],	\
 | |
| 		   &(sc)->regname)
 | |
| 
 | |
| 	err |= GETREG(regs, R8, from, r8);
 | |
| 	err |= GETREG(regs, R9, from, r9);
 | |
| 	err |= GETREG(regs, R10, from, r10);
 | |
| 	err |= GETREG(regs, R11, from, r11);
 | |
| 	err |= GETREG(regs, R12, from, r12);
 | |
| 	err |= GETREG(regs, R13, from, r13);
 | |
| 	err |= GETREG(regs, R14, from, r14);
 | |
| 	err |= GETREG(regs, R15, from, r15);
 | |
| 	err |= GETREG(regs, RDI, from, di);
 | |
| 	err |= GETREG(regs, RSI, from, si);
 | |
| 	err |= GETREG(regs, RBP, from, bp);
 | |
| 	err |= GETREG(regs, RBX, from, bx);
 | |
| 	err |= GETREG(regs, RDX, from, dx);
 | |
| 	err |= GETREG(regs, RAX, from, ax);
 | |
| 	err |= GETREG(regs, RCX, from, cx);
 | |
| 	err |= GETREG(regs, RSP, from, sp);
 | |
| 	err |= GETREG(regs, RIP, from, ip);
 | |
| 	err |= GETREG(regs, EFLAGS, from, flags);
 | |
| 	err |= GETREG(regs, CS, from, cs);
 | |
| 	if (err)
 | |
| 		return 1;
 | |
| 
 | |
| #undef GETREG
 | |
| 
 | |
| 	err = copy_from_user(&fp, fpp, sizeof(struct user_i387_struct));
 | |
| 	if (err)
 | |
| 		return 1;
 | |
| 
 | |
| 	err = restore_fp_registers(userspace_pid[current_thread_info()->cpu],
 | |
| 				   (unsigned long *) &fp);
 | |
| 	if (err < 0) {
 | |
| 		printk(KERN_ERR "copy_sc_from_user - "
 | |
| 		       "restore_fp_registers failed, errno = %d\n",
 | |
| 		       -err);
 | |
| 		return 1;
 | |
| 	}
 | |
| 
 | |
| 	return 0;
 | |
| }
 | |
| 
 | |
| static int copy_sc_to_user(struct sigcontext __user *to,
 | |
| 			   struct _fpstate __user *to_fp, struct pt_regs *regs,
 | |
| 			   unsigned long mask, unsigned long sp)
 | |
| {
 | |
| 	struct faultinfo * fi = ¤t->thread.arch.faultinfo;
 | |
| 	struct user_i387_struct fp;
 | |
| 	int err = 0;
 | |
| 
 | |
| 	err |= __put_user(0, &to->gs);
 | |
| 	err |= __put_user(0, &to->fs);
 | |
| 
 | |
| #define PUTREG(regs, regno, sc, regname)				\
 | |
| 	__put_user((regs)->regs.gp[(regno) / sizeof(unsigned long)],	\
 | |
| 		   &(sc)->regname)
 | |
| 
 | |
| 	err |= PUTREG(regs, RDI, to, di);
 | |
| 	err |= PUTREG(regs, RSI, to, si);
 | |
| 	err |= PUTREG(regs, RBP, to, bp);
 | |
| 	/*
 | |
| 	 * Must use original RSP, which is passed in, rather than what's in
 | |
| 	 * the pt_regs, because that's already been updated to point at the
 | |
| 	 * signal frame.
 | |
| 	 */
 | |
| 	err |= __put_user(sp, &to->sp);
 | |
| 	err |= PUTREG(regs, RBX, to, bx);
 | |
| 	err |= PUTREG(regs, RDX, to, dx);
 | |
| 	err |= PUTREG(regs, RCX, to, cx);
 | |
| 	err |= PUTREG(regs, RAX, to, ax);
 | |
| 	err |= PUTREG(regs, R8, to, r8);
 | |
| 	err |= PUTREG(regs, R9, to, r9);
 | |
| 	err |= PUTREG(regs, R10, to, r10);
 | |
| 	err |= PUTREG(regs, R11, to, r11);
 | |
| 	err |= PUTREG(regs, R12, to, r12);
 | |
| 	err |= PUTREG(regs, R13, to, r13);
 | |
| 	err |= PUTREG(regs, R14, to, r14);
 | |
| 	err |= PUTREG(regs, R15, to, r15);
 | |
| 	err |= PUTREG(regs, CS, to, cs); /* XXX x86_64 doesn't do this */
 | |
| 
 | |
| 	err |= __put_user(fi->cr2, &to->cr2);
 | |
| 	err |= __put_user(fi->error_code, &to->err);
 | |
| 	err |= __put_user(fi->trap_no, &to->trapno);
 | |
| 
 | |
| 	err |= PUTREG(regs, RIP, to, ip);
 | |
| 	err |= PUTREG(regs, EFLAGS, to, flags);
 | |
| #undef PUTREG
 | |
| 
 | |
| 	err |= __put_user(mask, &to->oldmask);
 | |
| 	if (err)
 | |
| 		return 1;
 | |
| 
 | |
| 	err = save_fp_registers(userspace_pid[current_thread_info()->cpu],
 | |
| 				(unsigned long *) &fp);
 | |
| 	if (err < 0) {
 | |
| 		printk(KERN_ERR "copy_sc_from_user - restore_fp_registers "
 | |
| 		       "failed, errno = %d\n", -err);
 | |
| 		return 1;
 | |
| 	}
 | |
| 
 | |
| 	if (copy_to_user(to_fp, &fp, sizeof(struct user_i387_struct)))
 | |
| 		return 1;
 | |
| 
 | |
| 	return err;
 | |
| }
 | |
| 
 | |
| struct rt_sigframe
 | |
| {
 | |
| 	char __user *pretcode;
 | |
| 	struct ucontext uc;
 | |
| 	struct siginfo info;
 | |
| 	struct _fpstate fpstate;
 | |
| };
 | |
| 
 | |
| #define round_down(m, n) (((m) / (n)) * (n))
 | |
| 
 | |
| int setup_signal_stack_si(unsigned long stack_top, int sig,
 | |
| 			  struct k_sigaction *ka, struct pt_regs * regs,
 | |
| 			  siginfo_t *info, sigset_t *set)
 | |
| {
 | |
| 	struct rt_sigframe __user *frame;
 | |
| 	unsigned long save_sp = PT_REGS_RSP(regs);
 | |
| 	int err = 0;
 | |
| 	struct task_struct *me = current;
 | |
| 
 | |
| 	frame = (struct rt_sigframe __user *)
 | |
| 		round_down(stack_top - sizeof(struct rt_sigframe), 16);
 | |
| 	/* Subtract 128 for a red zone and 8 for proper alignment */
 | |
| 	frame = (struct rt_sigframe __user *) ((unsigned long) frame - 128 - 8);
 | |
| 
 | |
| 	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
 | |
| 		goto out;
 | |
| 
 | |
| 	if (ka->sa.sa_flags & SA_SIGINFO) {
 | |
| 		err |= copy_siginfo_to_user(&frame->info, info);
 | |
| 		if (err)
 | |
| 			goto out;
 | |
| 	}
 | |
| 
 | |
| 	/*
 | |
| 	 * Update SP now because the page fault handler refuses to extend
 | |
| 	 * the stack if the faulting address is too far below the current
 | |
| 	 * SP, which frame now certainly is.  If there's an error, the original
 | |
| 	 * value is restored on the way out.
 | |
| 	 * When writing the sigcontext to the stack, we have to write the
 | |
| 	 * original value, so that's passed to copy_sc_to_user, which does
 | |
| 	 * the right thing with it.
 | |
| 	 */
 | |
| 	PT_REGS_RSP(regs) = (unsigned long) frame;
 | |
| 
 | |
| 	/* Create the ucontext.  */
 | |
| 	err |= __put_user(0, &frame->uc.uc_flags);
 | |
| 	err |= __put_user(0, &frame->uc.uc_link);
 | |
| 	err |= __put_user(me->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
 | |
| 	err |= __put_user(sas_ss_flags(save_sp),
 | |
| 			  &frame->uc.uc_stack.ss_flags);
 | |
| 	err |= __put_user(me->sas_ss_size, &frame->uc.uc_stack.ss_size);
 | |
| 	err |= copy_sc_to_user(&frame->uc.uc_mcontext, &frame->fpstate, regs,
 | |
| 			       set->sig[0], save_sp);
 | |
| 	err |= __put_user(&frame->fpstate, &frame->uc.uc_mcontext.fpstate);
 | |
| 	if (sizeof(*set) == 16) {
 | |
| 		__put_user(set->sig[0], &frame->uc.uc_sigmask.sig[0]);
 | |
| 		__put_user(set->sig[1], &frame->uc.uc_sigmask.sig[1]);
 | |
| 	}
 | |
| 	else
 | |
| 		err |= __copy_to_user(&frame->uc.uc_sigmask, set,
 | |
| 				      sizeof(*set));
 | |
| 
 | |
| 	/*
 | |
| 	 * Set up to return from userspace.  If provided, use a stub
 | |
| 	 * already in userspace.
 | |
| 	 */
 | |
| 	/* x86-64 should always use SA_RESTORER. */
 | |
| 	if (ka->sa.sa_flags & SA_RESTORER)
 | |
| 		err |= __put_user(ka->sa.sa_restorer, &frame->pretcode);
 | |
| 	else
 | |
| 		/* could use a vstub here */
 | |
| 		goto restore_sp;
 | |
| 
 | |
| 	if (err)
 | |
| 		goto restore_sp;
 | |
| 
 | |
| 	/* Set up registers for signal handler */
 | |
| 	{
 | |
| 		struct exec_domain *ed = current_thread_info()->exec_domain;
 | |
| 		if (unlikely(ed && ed->signal_invmap && sig < 32))
 | |
| 			sig = ed->signal_invmap[sig];
 | |
| 	}
 | |
| 
 | |
| 	PT_REGS_RDI(regs) = sig;
 | |
| 	/* In case the signal handler was declared without prototypes */
 | |
| 	PT_REGS_RAX(regs) = 0;
 | |
| 
 | |
| 	/*
 | |
| 	 * This also works for non SA_SIGINFO handlers because they expect the
 | |
| 	 * next argument after the signal number on the stack.
 | |
| 	 */
 | |
| 	PT_REGS_RSI(regs) = (unsigned long) &frame->info;
 | |
| 	PT_REGS_RDX(regs) = (unsigned long) &frame->uc;
 | |
| 	PT_REGS_RIP(regs) = (unsigned long) ka->sa.sa_handler;
 | |
|  out:
 | |
| 	return err;
 | |
| 
 | |
| restore_sp:
 | |
| 	PT_REGS_RSP(regs) = save_sp;
 | |
| 	return err;
 | |
| }
 | |
| 
 | |
| long sys_rt_sigreturn(struct pt_regs *regs)
 | |
| {
 | |
| 	unsigned long sp = PT_REGS_SP(¤t->thread.regs);
 | |
| 	struct rt_sigframe __user *frame =
 | |
| 		(struct rt_sigframe __user *)(sp - 8);
 | |
| 	struct ucontext __user *uc = &frame->uc;
 | |
| 	sigset_t set;
 | |
| 
 | |
| 	if (copy_from_user(&set, &uc->uc_sigmask, sizeof(set)))
 | |
| 		goto segfault;
 | |
| 
 | |
| 	sigdelsetmask(&set, ~_BLOCKABLE);
 | |
| 
 | |
| 	spin_lock_irq(¤t->sighand->siglock);
 | |
| 	current->blocked = set;
 | |
| 	recalc_sigpending();
 | |
| 	spin_unlock_irq(¤t->sighand->siglock);
 | |
| 
 | |
| 	if (copy_sc_from_user(¤t->thread.regs, &uc->uc_mcontext,
 | |
| 			      &frame->fpstate))
 | |
| 		goto segfault;
 | |
| 
 | |
| 	/* Avoid ERESTART handling */
 | |
| 	PT_REGS_SYSCALL_NR(¤t->thread.regs) = -1;
 | |
| 	return PT_REGS_SYSCALL_RET(¤t->thread.regs);
 | |
| 
 | |
|  segfault:
 | |
| 	force_sig(SIGSEGV, current);
 | |
| 	return 0;
 | |
| }
 |